466 



MAirtTAI. OF THE MOLLITSCA* 



Ceassatella, Lamarck. 



Synonyms^ Ptycliomya, Ag. Paphia (Lamarck, part) Koissy. 



Type, C. ponderosa, PL XXL, Pig. 4. C. pulchra. Fig. 259. 



Etymology, crassus, thick. 



Shell solid, yentricose, attenuated behind, smooth or con- 

 centrically furrowed ; lunule distinct ; ligament internal ; 

 margin smooth or denticulated ; pallial line simple ; hinge- 

 teeth 1.2, striated, in front of cartilage pit ; lateral teeth — 1, 

 1— ; adductor impressions deexD, rounded ; pedal small, 

 distinct. 



Animal with mantle -lobes united only by the branchial 

 septum ; inhalent margins cirrated ; foot moderate, compressed, 

 triangular grooved; gills smooth, unequal, outer semi-lunar, 

 inner widest in front ; palpi triangular. 



Fig. 259. Crassatella pulchra. Sandj^ Cape, J. E. Jukes. 

 Animal as seen on the removal of right valve, and portion of the ipaantle. 



In Crassatella pulchra the animal is like Astarte ;■ foot lingui- 

 form, slightly grooved; palpi short and broad, few-plaited; 

 outer gill narrower in front. 



Distribution, 34 species. Australia, New Zealand, Philippines, 

 India, West Africa, Canaries, Brazil. 



Fossil, 64 species. Neocomian — . Patagonia, tTnited States, 

 Europe. 



IsocAEDlA, Lamarck. Heart-cockle. 



Etymology, isos, like, cardia, the heart. 

 Type, I. cor. PI. XX., Fig. 3. 



