3/6 MR. H.ADAMS ON SHELLS FROM CENTRAL AFRICA. [Jlllie 26, 



4. Lanistes, sp. ? 



Too immature for the species to be determined. 



5. Btthynia badiella, Parr. 



6. Melania tuberculata, Mull. 



7. Corbicula radiata, Phil. 



8. Corbicula pusilla, Phil. 



9. Unio ^gyptiacus, Caill. 



10. Unio caillaudi, Fer. 



11. Unio bakeri, H. Ad. 



U. testa transversa, ovata, tenui, subinjlata, incequilaterali, antice 

 rotundata, postice dilatata, subangulata, valde undulato-pli- 

 cata, epidermide olivacea induta ; umbonibus subprominenti- 

 bus, ad apices nodosis ; dentibus cardinalibus parvis, sulcatis, 

 lateralibus subrectis, in valva sinistra duplicibus ; margarita 

 argentea et iridescente. 



Long. 30, alt. 21, lat. 14 mill. 



From the Albert N'yanza. 



This species bears much resemblance to U. aferula, Lea, from the 

 Victoria N'yanza, but is less inaequilateral, thinner, and more corru- 

 gated. I have much pleasure in dedicating it to Mr. Baker. 



12. Unio acuminatus, H. Ad. 



U. testa ovali-elongata, valde inceqnilaterali, antice rotunda, 

 postice subrostrata, ad umbones undulato-plicata costaque 

 umbonali instructa, epidermide fulvo-viridi induta ; umboni- 

 bus parvis ; dentibus cardinalibus crassis, sulcatis, lateralibus 

 subrectis; margaritacea et iridescente. 

 Long. 29, alt. 15, lat. 10 mill. 

 From the Albert N'yanza. 



This is an elongate species partaking of the form of U. cail- 

 laudi, but the ventral margin is convex and not incurved as in that 

 species, and the surface of the valves towards the umboes is cor- 

 rugated. 



With the exception of the last two species, viz. U. bakeri and U. 

 acuminatus, which are new to science, the shells in the preceding 

 list are not of peculiar interest. The other species of Unio and the 

 Corbicula are well known Nile shells ; the Limicolaria is found at 

 Ibu and in Guinea ; and the remainder are also met with in Asia and 

 in Northern Africa. 



