CONCHIFEEA. 467 



ObKBis, Cuvier, 



Etymology, corlis, a basket. 



Type, 0. elegans. PL XIX., Fig. 8. 



Synonyms, Fimbria, Mubl. not Bobadscli. " Idotsea," Schutn. 



Shell oval, ventricose, sub-equilateral, concentrically sculp- 

 tured ; margins denticulated witbin ; binge-teetb 2, laterals 2, 

 in eacb valve ; pallial line simple ; umbonal area witb an oblique 

 farrow, muscular impressions round and polished ; pedal scars 

 close to adductors. 



Animal with the mantle open below, doubly fringed; foot 

 long pointed ; siphonal opening single, with a long retractile 

 tubular, valve ; lips narrow ; palpi rudimentary ; gills single on 

 each side, thick, quadrangular, plaited, united behind. 



Distribution, 6 species. India, China, North Australia, Pacific. 



Fossil, 80 species (including sub-genera). Lias — . United 

 States, Europe. 



In 0. dubia (Semi-corbis) Desh., from the Eocene, Paris, the 

 lateral teeth are obsolete. 



Sub-genera. BjplicEra (corrugata), Sby. Shell globular, con- 

 centrically furrowed and obscurely radiated ; ligament promi- 

 nent; margins crenulated; hinge-teeth 2.2, obscure; laterals 

 obsolete. Fossil, Trias — Chalk. Europe. 



Sportella, Deshayes. Like Sphsera, but with 2.1 hinge-teeth. 



? Unicardium, D'Orb. (Mactromya, Ag. part.) = Corbula 

 cardioides, Sby. Shell thin, oval, ventricose, concentrically 

 striated ; ligamental plates elongated ; pallial line simple ; hinge 

 with an obscure tooth, or edentulous. Fossil, 40 species ? Lias 

 — Portlandian. Europe. 



? TAifCEEDiA, Lycett, 1850- 



Dedicated to Sir Thomas Tancred, Bart., founder of the 

 Cotteswold Naturalists' Club. 



Example, T. extensa, L. PI. XXL, Pig. 22. 



Synonym, Hettangia, Turquem. 



Shell trigonal, smooth ; anterior side usually longest ; cardi- 

 nal teeth 2.2, one of them small ; a posterior lateral tooth in 

 each valve ; ligament external ; muscular impressions oval ; 

 pallial line simple. 



Fossil, 12 species. Lias — Bath Oolite. Britain, France. 



