CONCHIFERA. 485 



separate, orifices cirrated, branchial cirri dendritic ; foot com- 

 pressed, broadly lanceolate ; gills large, unequal ; palpi small. 



Suh-genus. Anapa, Gray. A. Smithii, PI. XXI., Fig. 17. 

 Umbones anterior, sipbonal inflection obsolete. 



Ceronia^ Gray. Lateral teeth marked with coarse oblique 

 etriae. 



? Davila^ Gray. Laterals unequal ; anterior teeth small and 

 erect. 



Distribution, 31 species. "West Indies, Mediterranean, Crimea, 

 India, New Zealand, Chili ; sands at low water. 



Fossil, 7 species. Neocomian — . United States, Europe. 

 {DonaciUa, D'Orbigny.) 



Ervilia, Turton. Lentil- shell. 



Etymology, ervilia, diminutive of ervum, the bitter- vetch. 



Tyjoe, E. nitens, PL XXL, Fig. 18. 



Shell minute, oval, close ; cartilage in a central pit ; right 

 valve with a single prominent tooth in front and an obscure 

 tooth behind ; left valve with 2 obscure teeth ; no lateral teeth ; 

 pallial sinus deep. 



Distribution, 2 species. West Indies, Britain, Canaries, 

 Mediterranean, Eed Sea. — 50 fathoms. 



DoNAX, L. Wedge-shell. 



Example, D. denticulatus, PI. XXL, Fig. 19. 



Etymology, clonax, a sea-fish. (Pliny.) 



Synonyms, Chione, Scop. Cuneus, Da Costa. Capisterium, 

 Meuschen.* Latona and Hecuba, Schum. Egeria, Lea (not 

 Koissy). 



Shell trigonal, wedge-like, closed ; front produced, rounded ; 

 posterior side short, straight ; margins usually crenulated ; 

 hinge-teeth 2.2 ; laterals 1 — 1 in each valve ; ligament external, 

 prominent ; pallial sinus deep, horizontal. 



Animal with the mantle fringed; siphons short and thick, 

 diverging, anal orifice denticulated, branchial with pinnate 

 cirri ; foot very large, pointed, sharp-edged, projected quite in 

 front ; gills ample, recumbent, outer shortest ; palpi small, 

 pointed. 



Distribution, 68 species. Norway, Baltic, — Black Sea, all 

 tropical seas. In sands near low-water mark ( — 8 fathoms) 

 buried an inch or two beneath the surface. 



Fossil, 45 species. Carb. — . United States, Europe. 



* Meuschen was a Dutch auctioneer; the names occur in his "sale latalr^ea * 

 Idiots imposuere nomina alsurda. LinDsii:^. 



