CEPOLIS. 185 



O. lucipeta Poey, v, 32. C. maculifera Gut., v, 35. 



picturata Poey not Ad. C. sauvallei Arango, v, 37. 



lepida Poey. C. comta Gundl., v, 34. 



bellula Poey. C. araplecta Gundl., v, 35. 



penicillata Poey not Gld. C. rufoapicataPoey, v, 36. 



newcombiana Poey. C. graminicola C. B. Ad., v, 36. 

 v. velasqueziana Poey, v, 32. 

 v. cesticulus Gundl., v, 33. 



Section Plagioptycha Pfr., 1 856. 



Plagioptycha PFR., Mai. BL, 1856, p. 135 (for indistincta, albers- 

 iana, duclosiana, bahamensis, strumosa, loxodon, monodonta). 

 MART, in Alb. Die Hel., p. 145 (type H. loxodon}. W. G. BINNEY, 

 Ann. N. Y. Acad. Sci., iii, p. 95, jaws and dentition of loxodon, 

 albersiana, monodonta, duclosiana, diaphana, macroglossa. 



Shell umbilicate or imperforate, thin, depressed-globose or de- 

 pressed, the last whorl deflexed in front. Aperture transversely 

 oblong or lunate ; outer lip expanded or simple ; and either on the 

 Jloor of the whorl within the mouth, or on the columellar lip, there is 

 an oblique nodule or fold of callus, sometimes reduced to a slight 

 trace only. Type C. loxodon Pfr. (See pi. 56, figs. 8, 9, C. duclos- 

 iana). 



Animal light colored, externally similar to Hemitrochus. 



Jaw high arched, with a median projection (pi. 57, fig. 42, C. sal- 

 vatoris). 



Kadula (pi. 57, fig. 47, C. sahatoris) similar to that of Hemitro- 

 chus, but with the cusps rather more acute. 



Genital system as described for Hemitrochus (pi. 52, fig. 15, C. 

 salvatoris). 



Plagioptycha is probably nearest to the ancestral forms whence 

 the modern sections of this genus arose. Its habits are terrestrial 

 and the dentition is somewhat less abnormal than in Coryda and 

 typical Hemitrochus. Moreover, characteristic forms of Plagiopty- 

 cha are found in the Miocene Silex Beds of Tampa, Florida, (jET. 

 latebrosa Dall, instrumosa Dall), with other species (JET. crusta and 

 H. diespiter of Dall) which would probably be classed in the mod- 

 ern section Eurycampta, although it is obvious that these latter 

 Miocene forms are more intermediate between Eurycampta, Jean- 

 neretia and Plagioptycha than any living species. In the Miocene 



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