184 CEPOLIS. 



with a large split inner cusp and a simple or bifid ectocone (pi. 57, 

 figs. 50, 51, C. varians). 



Genital system having a long, slender penis branching into v. d. 

 and a long flagellum, and with a thread-like retractor attached low, 

 and inserted distally on the lung floor. Spermatheca duct free 

 below, but firmly bound to uterus above, with a long spermatheca 

 and a spiral twist in the duct near base of uterus. Dart sack long ; 

 mucus glands two, flat and glandular, inserted at base of dart sack- 

 Eye stalk retracted between branches of genitalia (pi. 52, fig. 14, C. 

 varians Mke.). 



The shell in this section differs but little from that of Coryda and 

 Dialeuca ; and while quite distinct from the typical forms of Pla- 

 gioptycha, there are a number of species so intermediate in character 

 that they may be placed as well in one as in the other group. Ana- 

 tomically there are no differences of more than specific worth 

 between these groups, unless the larger (though still very weak) 

 penis retractor of Hemitrochm be considered such. Many of the 

 species are excessively closely allied. 



There are two groups of species: the Cuban, consisting of com- 

 pact forms of the type of H. cesticulus; the Bahama group varying 

 from globose-conical like H. varians to depressed and rib-striate, H. 

 maynardi. 



Species of Florida and Bahamas. 



C. varians Mke., v, 24. C. gallopavonis Val., v, 27. 



carnicolor Pfr. v. calacaloides Pi Is., v, 28. 



submeris Migh. C. troscheli Pfr., v, 28. 



rhodocheila Binn. tenuicostata Dkr. 



polychroa Binn. v. calacala Weinl., v, 29. 



hcKmastomus Sw. C. multifasciata W. & M., v, 30. 

 C. xanthophaes Pils., viii, 242. f. polytteniata Pils., v, 30. 



C. milleri Pfr., v, 25. C. filicosta Pfr., v, 30. 



C. constantior Weinl., v, 26. C. brownii Pils., v, 29. 



C. caribsea Weinl., v, 26. C. maynardi Pils., viii, 241. 



Cuban Species. 



C. gilva Fer., v, 31. C. fuscolabiata Poey, v, 34. 



corrvgata Pfr. subfusca Poey not Bk. 



v. tephrites Morel., v, 31. v. morbida Morel., v, 35. 



