CONCHIFEEA. 429 



(Dr. Migliels.) Fossil, Pliocene — . (Crag and Glacial deposits.) 

 England, Belgium. 



Fig. 220. Yoldia limatula (after Barrett). 



SoLEiSTELLA, Sowerby. 



Type^ S. Norrisii, PL XYIL, Pig. 22. S. ornata, Pig. 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 fino 

 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 ; siphonai tubes united, long, and 

 slender, completely retractile ; palpi appendiculated, convoluted, 

 as long as the shell ; gills narrow, posterior ; foot deeply cleft ; 

 forming an oval disk, even-margined and striated across. 



Distribution, 2 species. Yalparaiso, New Zealand (shell like 

 S. ornata). 



Fossil, 1 species. Miocene. Point Desire, Patagonia. 



? SoLEMYA, Lamarck. 



Tijpe, S. togata, PL XXII. , Pig. 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 

 siphonai 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 laminse free to the base ; 

 palpi long and narrow, nearly free. 



