CONCHIFERA. 429 
(Dr. Mighels.) ossil, Phocene—. (Crag and Glacial deposits. ) 
England, Belgium. 
Fig. 220. Yoldia imatula (after Barrett). 
SOLENELLA, Sowerby. 
Type, 8. Norrisii, Pl. XVII., Fig. 22. 8S. ornata, Fig. 23. 
Synonyms, Malletia, Desm. Ctenoconcha, Gray. Neilo, 
Adams. 
Shell oval, or ark-shaped, compressed, smooth or concentri- 
_ cally furrowed, epidermis olive; ligament external, elongated, 
prominent: hinge with an anterior and posterior series of fine 
sharp teeth; interior sub-nacreous; pallial sinus large and 
deep; anterior adductor giving off a long oblique pedal line. 
Animal like Yoldia; mantle-margins slightly fringed and 
furnished with ventral lobes; siphonal tubes united, long, and 
slender, completely retractile ; palpi appendiculated, convoluted, 
as long as the shell; gills narrow, posterior ; foot deeply cleft ; 
forming an oyal disk, even-margined and striated across. 
Distribution, 2 species. Valparaiso, New Zealand (shell like 
S. ornata). 
Fossil, 1 species. Miocene. Point Desire, Patagonia. 
? SoLEMYA, Lamarck. 
. Type, 8. togata, Pl. XXIT., Fig. 17. 
Synonym, Solenomya, Menke. 
Shell elongated, cylindrical, gaping at each end; epidermis 
dark, horny, extending beyond the margins ; umbones poste- 
rior; hinge edentulous; ligament concealed; pallial line 
obscure. Outer layer of long prismatic cells, nearly parallel 
with the surface, and mingled with dark cells, as in Pinna ; 
inner layer also cellular. 
Animal with the mantle lobes united behind, with a single 
siphonal orifice, hour-glass shape, and cirrated ; foot probos- 
cidiform, truncated and fringed at the end; gills forming a 
single plume on each side, with the lamin free to the base; 
palpi long and narrow, nearly free. 
