CONCHIFERA, 457 
CorBIs, Cuvier 
Etymology, corbis, a basket. 
Type, C. elegans. Pl. XIX., Fig. 8. 
Synonyms, Fimbria, Muhl. not Bohadsch. ‘‘ Idotzea,”’ Schum. 
Shell oval, ventricose, sub-equilateral, concentrically sculp- 
tured ; margins denticulated within; hinge-teeth 2, laterals 2, 
in each valve; palliallinesimple ; umbonal area with an oblique 
furrow, 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, 5 species. India, China, North Australia, Pacific. 
Fossil, 80 species (including sub-genera). Lias —. United 
States, Europe. 
In C. dubia (Semi-corbis) Desh., from the Mocene, Paris, the 
lateral teeth are obsolete. 
Sub-genera. Sphera (corrugata), Shy. 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 Sphera, 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. Jossil, 40 species? Tiias 
— Portlandian. Europe. 
P TANCREDIA, Lycett, 1850- 
Dedicated to Sir Thomas Tancred, Bart., founder of the 
Cotteswold Naturalists’ Club. 
Example, T. extensa, L. Pl. XXI., Fig. 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 yalye; ligament external; muscular impressions oval ; 
pallial line simple. 
Fossil, 12 species. Lias — Bath Oolite. Britain, France. 
