676 SYSTEMATIC PALEOXTOLOGY 



Superfamily VENERACEA 



Family VENERIDAE 



Genus DOSINIA Scopoli 



[Introd. ad Hist. Nat. 1777, p. 399] 



Type. Dosinia africana Hanley. 



" Animal with a large arcuate foot and closely united siphons. Com- 

 plete dental formula (the posterior right cardinal, being extremely thin, 



is often broken off, eroded, or obsolete) L ' 0101010.010 The thick 



E. 1010101.101 



middle cardinals are often bifid or excavated. Valves suborbicular, gen- 

 erally compressed, with a long and strong ligament seated in a groove and 

 enfolding a heavy resilium, lunule small, impressed ; escutcheon narrow, 

 nearly linear or absent; hinge plate broad and thick, valve margins 

 smooth ; pallial sinus rather long and usually acute, anterior lateral teeth 

 nearly obsolete and usually simple; sculpture usually of elegantly con- 

 centric grooves and interspaces, sometimes raised into lamella at the 

 borders of the lunule and escutcheon, crossed rarely with weak radial 

 threads; coloration of the recent species rarely disposed in patterns and 

 usually pale, many species being white. The periostracum is usually thin 

 and polished." Ball, 1903. 1 



The genus was initiated in the Cretaceous but not very well represented. 

 The rather large and rotund shells are, however, very much in evidence in 

 the Tertiary and Eecent faunas. The Becent species number about one 

 hundred, and have an almost universal distribution in the temperate and 

 warmer waters. 



DOSINIA OBLIQUATA Conrad 



Dosinia obliguata Conrad, 1860, Jour. Acad. Nat. Sci., Phila., 2d ser., vol. iv, 



p. 278, pi. xlvi, fig. 2. 

 Dosinia oUiquata Meek, 1864, Check List Inv. Fossils N. A., Cret. and Jur., 



p. 13. 



Description. " Lentiform, very oblique ; beaks almost terminal ; 

 minute, concentric, regular, closely arranged, impressed lines on the 

 anterior side." Conrad, 1860. 



Etymology: Dosin, a Sengalese name used by Adanson as a specific name. 

 1 Trans. Wagner Free Inst. Sci., Phila., vol. iii, pt. vi, p. 1227. 



