346 Bulletin American Museum of Natural History [Vol. LIII 
Soleilletia abbadiana Bourauienat, 1885, ‘Moll. Choa,’ p. 34, Pl., figs. 15-18. 
Hauash River, Abyssinia. 
Soleilletia hamyana BourauiGcnat, 1885, ‘Moll. Choa,’ p. 35, Pl., fig. 19. Hauash 
River, Abyssinia. 
Sohertides 
Shell oval, squarish, or subtriangular, of small or minute size, rather thin, porce- 
lanous within, the adductor scars not impressed. Pallial line simple. Hinge curved, 
narrow, with anterior and posterior lateral teeth in both valves; cardinals very small, 
not more than two in each valve; those of the right valve sfiited into an inverted V 
or a straight lamella; those of the left valve wholly separate, the posterior obliquely 
above the anterior (or sometimes wanting); ligament narrowly exposed or more or less 
completely immersed. 
Mantle margins united posteriorly to form siphons. Viviparous and herma- 
phroditic. 
R. J. Gilmore has contributed an interesting paper on the reproduc- 
tion in this family, which also briefly reviews previous observations on 
the subject. These mussels incubate their embryos in a brood pouch. 
At a later stage the young are found in the gills where they may remain 
a long time.! 
They inhabit ponds and small streams as well as the larger rivers 
and lakes; they often occur in ponds which become dry part of the year 
and seem to be well able to withstand drought. They can anchor or 
sometimes suspend themselves by a number of mucous threads attached 
to pebbles, plants, or the surface film of the water. The African Huperz 
are usually found attached to the outer surface or within cavities in the 
shell of the Etheriide. The food consists mainly of diatoms. Owing 
to their small size, the living mussels are readily carried about by ad- 
ventitious means. They have, for instance, been found attached to the 
legs of large water beetles. The family is of world-wide distribution. 
Key to Ethiopian Genera of Spheeriidee 
1. Beaks behind the middle, the almost wholly immersed ligament thus on the 
shorter-end- ol tlre hime, Sayre ao ae he Seed i Pisidium C. Pfeiffer. 
Beaks median or in front of the middle, the partly exposed ligament therefore 
GUthe eng. Penis ae. crete aia ea eh P ete Z: 
2. Beaks decidedly in front of the middle. Valves fragile, with one minute, simple 
cardinal tooth in each valve, or none in the right... ... Eupera Bourguignat. 
Denke Wea or Ce eG ede c cites acer ee cee ea Nee arta rr mes BASEN 3. 
3. Two cardinal teeth in each valve, but those of the right valve united to form a 
broad inverted V. Shell sii or very thin, not rayed....Spherium Scopoli. 
One very weak cardinal in the right valve, two in the left. Shell Corbicula-like, 
Talen alias Payee. oe ee gis oe ee ry ot Pseudocorbicula Dautzenberg. 
1Gilmore, R. J. 1917. ‘Notes on reproduction and growth in certain vivi Is of th 
family Spheertide,’ The Nautilus, XX XI, pp. 16-30, ia fou oer EO Phe 
