According to Professor Robert Farris Thompson,figures having the left arm raised and the right arm pointing downwards are "calling on God". 
Although I have been interested in the study of African art for over thirty years, I only came across figurative carvings made by the Adan people of south eastern Ghana some ten years ago. One London dealer, Owen Hargreaves, began to import and sell such carvings, which he described as "ancestor figures". He also added that the figures were kept in the eaves of houses and that they were brought out once a year to be ceremonially washed and, if appropriate, dusted with white kaolin powder before being returned to the eaves. I must say that I am always a little suspicious when I hear African carvings being described as "ancestor figures",because further research often indicates that such figures are not as previously described. The phrase "ancestor figures" was often used by early collectors as something of a catch-all, even when the figures in question were clearly not representations of the ancestors. There is a saying in Haiti, "When the anthropologist arrives, the gods depart".  But, in truth, some, though not all, Adan figures do have a connection with departed souls, though, as we shall see, in a slightly roundabout way.
The Adan are a small sub-group of the Ewe people and live in south-east Ghana, close to the border with Togo. They are believed to only number about 2,200 people. They are also known under a variety of names, such as Ada, Adangme, Adangbe, Adantomwi, Agotime, Dangbe or Ga, and they believe that they originally came from southern Egypt, leaving there in the 15th century. Adan oral history suggests that they travelled through present day Ethiopia before arriving in Nigeria, where they settled in the towns of Ife and Tado. Once there, the people split into four distinct groups. The first moved group moved to Togo, where they became known as the Ewe, the second group moved to Porto Novo, on the coast of Benin, and became associated with both the Yoruba and the Fon people. The third group settled in the district of Keta, in Ghana, where they became the "Ewe of Ghana", while the fourth group moved to the area around Ada, in south-east Ghana, some 35km from Accra. This fourth group became the present day Adan. Interestingly, the Adan language appears to be related to that of the Igbo people of eastern Nigeria, and thus appears to confirm that the Adan did, at one time, live in Nigeria.  .
Early accounts of Adan Art
Sometime around 1920, Sir Cecil Hamilton Armitage presented four small wooden figure carvings to the British Museum. He had collected them in what was then the Gold Coast, now Ghana, sometime during the period 1895 - 1920 and the Museum catalogued the carvings as being from the Ada people. As explained above, the name Ada is one used for the Adan people who now live in southeast Ghana, close to the border with Togo. These four carvings were probably the first Adan pieces to be brought out of Africa and it is unlikely that they were ever displayed publically by the Museum. In 1958 Ladislas Segy included two illustrations of similar figures in his book African Sculpture. One figure (plate 12) is said to represent Ariza, "the malevolent spirit". It only has one arm. The second figure (plate 13) represents Arbor, the "spirit of water" and the figure's left arm holds something on top of its head. Both figures are said to be from the region of the "Black Volta", although no details are given as to which people carved the figures.
A photograph of a further Adan figure, actually incorrectly attributed as being from the Ewe people of Togo, appeared in a Dutch book that was printed in 1971. This was A. G. Claerhout's Nederlands en belgisch bezif uit openbare verzamelingen. Openbaar Kunstbezif. Nederland & Vlaanderen (Plate 43. A "Water carrier" figure, called Abor.) Finally, in 2002, the Afrika Museum at Berg en Dal in the
Netherlands produced a two volume set of books, Forms of Wonderment. The history and collection of the Afrika Museum, Berg en Dai, which includes two photographs of Adan figures. In both photographs the figures are labelled as being figures made by the Konkomba, a people who live in north-east Ghana (Volume 1, page 258 & Volume 2, page 397). Subsequent enquiries with the Museum confirm that the figures were initially misattributed by the person selling them to the
Museum and it is now agreed that these are Adan carvings. The second photograph is interesting in that it shows four Adan figures, each standing in a small clay pot. The pots have been filed with earth into which the figures have been planted. There may be a connection here with similar pots described and illustrated in the book Geest en Kracht - Vodun uit West-Afrika / Spirit Power - West African Vodun (published by The Afrika museum, Bergen Dai, The Netherlands. 1996. p.113. Dutch and English text).
Types of Adan figurative Art
"Le monde invisible est le maitre du visible" Guérin Montilus 
In her book African Vodun. Art, Psychology, and Power Suzanne Preston Blier talks about the aziza, which she outlines as "miniature forest dwellers (who) are believed to control the hunt and all that pertains to the forest...Descriptions of the aziza vary. While few individuals claim to have ever seen them (indeed, many assert that ordinarily they are invisible), others characterize them as small, humanlike forms with a single leg and a long white hair".  Quoting from a Roberto Pazzi mimeograph of 1976, she adds:
(The aziza is)...a fairy having one leg, one arm, a single hair that covers them entirely and making them invisible. They inhabit the forest and their houses are in large termite mounds. One does not whistle in the woods for fear of attracting their attention. One does not collect a bundle of wood t one finds beside the road because the aziza could have placed it there, to come back to get it later...Aziza know the virtues of leaves and it is they that reveal them to humans. That is why one fears and venerates its mysterious power. 
It would therefore seem that the figure called Ariza, "the malevolent spirit" by Ladislas Segy, is a depiction of aziza.
One of the best sources for Adan iconography is Albert de SurgVs 1988 book La Systeme Religieux des Evhe (Éditjons LHarmattan. Paris.)  de Surgy calls the Ariza/aziza figures Age and defines Age as the god of the spirits of the bush and forest as well as of magic plants. Statuettes, he says, have one arm and leg in reference to trees, which only have one stem. Pazzi confirms the difference between Artza/aziza and Agé by saying that the chief of the aziza is Age, and calls him "the God of the forest". It was, he adds, Age who taught humans the secrets of art, farming and hunting.
Ladislas Segy's second figure, Arbor, the .spirit of water", appears, on the surface, to depict a person
(female?) carrying a water pot on her head. This would, of course, be in keeping with a representation of tt.e .spirit of water". However, de Surgy's second type of Adan figure, which he calls
Adela, is described as carrying a rifle on its shoulder (or, in some cases, Adela may simply be shown as a carving of a rifle.) According to de Surgy, all those who perish by iron (i.e. with hunting, with the war, in car crashes etc.) or in relation to the power of iron (the god Gu), are transformed into Adela, the hunter. I have only seen one Adan carving that depicted a man with a rifle, and in that case the rifle was slung across the man's back.  I therefore suspect that the figures described by de Surgy as carrying a rifle on the shoulder are, in fact, carrying something on their head, which is being supported by an arm.
Occasionally, one finds such figures using both arms to hold the container on the head.
Dr Volkler Schneider, a German ethnographer and photographer, tries to explain the differences between these two types of Adan figures in the following manner.
These special Ade (Adan) figures represent the various Ade hunting divinities of Ewe and also Yoruba people. Those figures are called:
Agevi - a wooden or earthen statuette of a person, male or female, which has one arm, one leg and even one eye. Agevi is a representation of the dwarf spirit Age, used in the Age aspect of the circle of
Adela (deified ancestor killed by a gun or a deified prominent hunter) or Ade divinities. Agevi symbolizes mysticism.
Asisiagbate - a wooden or earthen statuette of a person carrying a load. Asisiagbate is a composte of the Agbewu or Mama circle of Ade divinities, a female counterpart of the hunter, in search of trade or commerce. Asisiagbate symbolizes commerce. 
The chief difference here is that Asisiagbate carries a "load", symbolizing commerce, rather than water.
Things, however, can be further complicated when one sees that some "water carrier/load carrying" figures are also carved with missing limbs.
There is also a third type of Adan figurative carvings, namely of "normal" looking people carved with two arms and two legs. According to de Surgy they are called Avlé and are "for the hearts of the victims of magic practices or the traps of the bush".
The Adan also carve objects that can be placed on to shrines, such as animals - lizards, crocodiles, tortoise and chameleons, for example, and birds, especially hornbills. Of course, this is not unusual. Many African people make carvings of reptiles and birds.  For a number of years it was thought that the Senufo people made large wooden carvings of hornbills (although Timothy F. Garrard points out that the Senufo themselves do not call these carvings "hornbills", but simply "birds" - see Jean Paul Barbier (editor) Art of Cote D'Ivoire from the collections of the Barbier-Mueller Museum (2 volumes), The Barbier-Mueller Museum, Geneva. 1993. Volume 2 p. 31.) Nevertheless, hornbills or not, it is interesting to see what the Senufo, who are scattered throughout the Ivory Coast, Mali and Burkina Faso, have to say about these carvings, which they call sétien. Robert Goldwater, writing in an earlier book about the Senufo, had this to say:
According to Senufo belief, the sétien - along with chameleon, the tortoise, the serpent and the crocodile, also shown frequently - was one of the first five living creatures, and was the first to be killed for food. In its allegoric form, with its long beak touching, or almost touching, it's swollen belly to suggest the male and female components of increase, it is called porpianong or porparga. This means...that it stands for the whole category of the porpia, tribal effigies symbolizing the continuity of the whole community, or "the constituent elements of the collectivity". 
There is, so far as I know, no known direct connection between Adan and Senufo beliefs, but it does seem interesting that both groups carve images of this bird and of various types of reptiles, although there may very well be different reasons behind the Adan carvings.Occasionally, one also sees animals, such as dogs or horses, being depicted.
Other shrine objects include ritual knives. According to Schneider such objects are known as Guyi and are "an indispensable relic of Kpokpo - the divinity of leadership and war". The knife shown below contains cut-out images of a half moon, a star, a stool and a key, while the second knife omits the moon and the stars.
Other knives have blades which are often painted in red and white ochre stripes and handles that are wrapped in knotted twine and cowry shells. Such wrappings are, of course, similar to ones used by both the Ewe and the Fon (who are linguistically related to both the Ewe and the Adan people) and a Fon saying may be relevant here. Greeting to the one who has just unraveled the enigma of the intertwinings. Every time a knot is undone, a god is released.
Other ritual objects include small axes, such as the following which has a characteristically striped handle. The blade is shaped into the symbol of the west African vodun thunder god Hevioso. And his confirms that Adan art, like that of the Fon and Ewe, is steeped in vodun beliefs. As Jan Cocle, a Roman Catholic Priest and authority on vodun says:"Vodun religion is like an African baobab (tree); a single large and thick trunk, and an infinite number of branches, depending on the people, the villages and even the places and centers of worship". .
In Albert de Surgy's book there are two photographs of Adan shrines (plates 13 & 14). The shrines are in Anloga and Avume, two towns on the coast of Ghana, close to the border with Togo, and one photograph shows a number of small stools that are placed on the shrine. Presumably these are to be used by the spirits. (de Surgy calls these stools " petits trônes" and adds that they can have from one to five legs.) The one depicted below has three legs and is about 6 inches in length.
Other Adan shrine stools, like the one shown below, are more akin, in shape, to those carved by the Ashanti of central Ghana. .
Finally, the Adan carve small round objects that are described as "spirit houses". Presumably they are designed as homes for certain "spirits", although I have no idea where such objects would be placed. The "houses" that I have seen have some form of face carved at the top of the "house", sometimes in very rudimentary form.
Although only two columns can be seen between the top and bottom of this .spirit house", there are, in fact, four. There is a simple face, comprising two eyes, a nose and a mouth, on the side of the top disc. The house measures 17.5 cms in height (14).
The "face" of this second "spirit house", which also has four columns, is reduced to a simple mouth. It measures 17 cms in height.
A third "spirit house" is more abstract in design. Both top and bottom are solid and the four columns bend inwards. Again, a rudimentary mouth has been cut into the top of the "house". It measures 14 cms in height.
Robert Ferris Thompson Aesthetic of the Cool. Afro-Atlantic Art and Music Periscope Publishing Ltd., Pittsburg & New York. 2011. p. 43.
The quotation can be found in Maya Deren's excellent study of Voodoo, Divine Horsemen. The Living Gods of Haiti 1953. p. xiv.
For a rare 1950's recording of a group of Adan singers, see the Ohue Sapey Band performing Oblemo on the four CD set Opika pende - Africa at 78rpm Dust to Digital DTD22. Atlanta, 2011. C02, track 15.
Guérin Montilus "L'homme dans la pensée traditionelle Fon" 1979. Cotonou. Mimeograph. Quoted in Suzanne Preston Blier African Vodun. Art, Psychology, and Power The University of Chicago Press. Chicago and London, 1995. p. 171.
Suzanne Preston Blier African Vodun. Art, Psychology, and Power The University of Chicago Press. Chicago and London, 1995. p. 83.
Roberto Pazzi "L'Homme eve, aja, gen, fon et son univers: Dictionnaire." Lome, Togo. 1976. Mimeograph. Quoted In Suzanne Preston Blier African Vodun. Art, Psychology, and Power The University of Chicago Press. Chicago and London, 1995. p. 83.
I am using the spelling Ewe for these people. Both De Surgy and Blier use Evhe, which is closer to the correct pronunciation.
The object was being sold by the American art dealer J. K. Rasmussen of the Dark Shrine Gallery in Washington.
I found these comments on the webpage of a tribal art dealer. The page seems to have now removed from the web.
See, for example, Allen F. Roberts Animals in African Art The Museum for African Art, New York, & Prestel, Munich. 1995.
Robert Goldwater Senufo Sculpture from West Africa The Museum of Primitive Art New York. 1964. p. 28.
Various authors Geest en Kracht — Vodun uit West-Afrika / Spirit Power — West African Vodun The Afrika museum, Bergen Dal, The Netherlands. 1996. p.113. (Dutch and English text).
For a comparison with Ashanti stools, see the set of illustrations in Sandro Bocola (ed) African Seats Prestel, Munich & New York. 1995. pp. 44-45.
Although described to me as "spirit houses" by the English person who sold them to me, I have to say that I have never come across similarly described objects elsewhere in African. However, there is a very similarly shaped image of a stool, 27.2 cms in height, shown in Sandro Bocola (ed) African Seats Prestel, Munich & New York. 1995. pp. 56 & 170. The original is in the collection of The Africa Museum, Tervuren, Belgium.