FREE INSTITUTE OF SCIENCE 



TERTIARY FAUNA OF FLORIDA 



91. 



Subfamily DAVILIN^. 



Pallial line simple. 



Genus DAVILA Gray. 

 Davila Gray, Ann. Mag. N. Hist., 1S53, p. 44. 

 Type D. polita Gray (MS. ?) =: D. plana Hanley, Philippines. 



Shell compressed, rounded, smooth, with a thin epidermis and simple 

 pallial line; laterals as in Donacilla ; left cardinal very large and prominent, 

 right cardinal obsolete; ligament small, nearly marginal; cartilage narrow, 

 elongated. 



There are three or four species, all Indo-Pacific. They are all small and 

 much alike. D. crassida Desh. [Alesodcsma iniindiiiii Gld.) has color markings 

 near the umbones. 



Genus ANAPELLA Dall. 



Anapella Dall, Proc. Mai. Soc. LoncL, i, p. 213, 1895. 



Atiapa Gray, 1853 ; not Gray, 1847. (The latter was based upon Lascea rubra, other- 

 wise Erycina Pefiiiana Reckiz.) 

 Type Anapa Sniit/iii Gxs.y, = A. triqiictra Hanley, Tasmania. 



Shell subtrigonal, solid, inflated, concentrically sculptured; dorsal areas 

 obscure; beaks moderate, adjacent, somewhat anterior; valves close fitting; 

 pallial sinus absent, the pallial line presenting a projecting angle below the 

 posterior adductor ; ligament short, partly external between the beaks, partly 

 sunken and attached in a short sinus over the chondrophore, not set off from 

 the resilium by any shelly ridge; chondrophore somewhat below the level of 

 the hinge-plate, strong, its ventral margin somewhat projecting, directed back- 

 ward; left cardinal strong, narrow, grooved at the apex, with a small obscure 

 accessory lamella ; laterals strong, rather irregular and distant ; right cardinal 

 small, rude, its posterior arm walling the pit, its anterior arm short, more 

 prominent, coalescent above; laminae rude, normal, the ventrals most promi- 

 nent ; resilium strong, with its anterior face calcareous. 



A few species range from Tasmania to the Philippine Islands. They 

 resemble Atactodea except in the absence of a pallial sinus and in having a 

 ruder hinge. 



Subfamily ERVILIIN.ffi;. 



Shells small, thin, equilateral, concentrically sculptured or smooth; liga- 

 ment marginal, obsolete, or absent ; resilium small; hinge much concentrated; 

 laterals small, dorsal anterior lamina absent, the ventral more or less coales- 



