ERYCINID"^. 2 it 



lous, with a simple insinuation or a slight notch ; ligamental fur- 

 row snbinternal ; lunule not excavated ; muscular impressions 

 ovate, marginal. 



PsATHURA, Deshayes, 1860. 



Etym. — ipaOppdi^ friable. 



Type, Erycina fragilis, Lamk. (cxx, *76, 78). Eocene; Paris 

 Basin. 



Shell oval, inequilateral, thin, transparent, fragile ; hinge-teeth, 

 in the right valve, two equal and deeply bifid ; left valve, two 

 unequal, entire ; ligament external ; anterior adductor scar nar- 

 row, claviform ; posterior subquadrangular ; pallial line simple, 

 thus differing from Clementia,to which it is related by the hinge- 

 characters. 



ScACCHiA, Philippi, 1844. 



Distr. — 2 sp. Mediterranean. Fossil, 1 sp. Pliocene; Sicily. 

 S. eMiptica, Phil, (cxix, 75). 



Shell minute, ovate, posterior side shortest ; hinge-teeth 1 or 

 2, laterals obsolete; ligament minute; cartilage internal, in an 

 oblong pit. 



Animal with mantle widely open ; siphonal orifice single ; foot 

 compressed, lingniform ; palpi moderate, oblong. 



Family ERYCINIDJE. 



Shells very small, thin, fragile, usually transparent, and some- 

 times gaping, rounded or transverse, laterally depressed ; hinge 

 narrow, with one or two cardinal teeth, the laterals more or less 

 elongated, compressed, sometimes wanting; muscular impres- 

 sions small, not well-marked ; pallial line simple. 



Erycina, Lam., 1804. 



Distr. — 12 sp. Fossil, 50 sp. Cret. — Eocene — ; K. Am., 

 Paris Basin. E. Geoffroyi^ Payr. (cxx, 25-27). 



Shell equivalve, subinequilatei'al, usually transversely oval ; 

 one, or two unequal, diverging cardinal teeth, separated by a 

 pit; lateral teeth oblong, compressed, short ; ligament external 

 and internal ; muscular impressions rounded, pallial line simple. 



Erycinella, Conrad, 1845. 



Distr. — E. ovalis, Conr. Miocene ; Virginia (cxx, 62) ; and 

 Crag; England (cxx, 79, 80). 



Shell subtrigonal, inequilateral, thick ; two cardinal teeth, 

 separated by a pit in each valve ; lateral teeth rudimentary ; 

 ligament internal ; pallial line simple. 



Spaniodon, Reuss, 1867. 

 Type, S. nitidus, Reuss (cxx, 83, 84). Miocene ; Galicia. 

 15 



