EMARGINULIN^E. 201 



Mai. Cubana p. 228. F. hondurasensis RVE., Concb. Icon. f. 70 

 (=F. siiffusa Rve. /. c., errata). Glyphis cancellata Sowb., DALL, 

 Catal. Mar. Moll. S. E. U. 8., p. 170. 



Sowerby's original figures look more like F. adspersa than like 

 the species universally known as cancellata. The cancellata of all 

 authors is the shell described above, characterized by a large oval 

 orifice, a black hole-callus and blackish-blue around the hole out- 

 side. F. hondurasensis sujfusa is an absolute synonym, said to be 

 from Honduras, the only mainland locality reported. 



Subfamily III. EMARGINULIN^ (Gill) Pilsbry. 



This subfamily is probably equivalent to Dr. Gill's family Emar- 

 ginulidcB (Arrangement of the Families of Mollusks, 1871, p. 13) ; 

 but I do not know whether Gill would have included Glyphis in his 

 family, or restricted it to forms imperforate at the apex. 



All Fitsurellidce having the apex persistent in the adult belong in 

 this subfamily, and also those having the apex removed by the hole 

 or fissure, behind which, inside, there is a septum or deck, or a pos- 

 teriorly truncated hole-callus. 



The EmarginuUncK as a whole differ from FissurellincK in having 

 the rhachidian tooth of the radula broad; the radula bilaterally 

 asymmetrical; the hole-callus, (in forms having a perforation) 

 truncated behind. From Fissurellidince this subfamily differs in hav- 

 ing the hole small, when present, the hole-callus truncated behind, 

 the shell wholly external and capable of containing the entire 

 animal. 



Emarginulince includes the more primitive types of the Fissurellid 

 stock both from the morphological and the palseontological stand- 

 point. 



Beginning with a few doubtful forms in the Carboniferous, the 

 family attains a considerable number of species in the early Tertiary ; 

 but as far as I have seen, no described species older than Pliocene 

 is to be referred to Fissurellina: or Fissurellidince; they are all 

 Emarginulince, of the genera Emarninula (-}- R'unula and Deslong- 

 ehampsia), Pancturella (and its subgenera Fissurisepta, Rostrisepta 

 etc.), and Glyphis. 



The presence of a verge in Cranopsis, Puncturella, etc., and its 

 absence in the more modern and differentiated groups, such as 

 Fissurella, indicates that that organ is a common inheritance of the 

 primitive Rhipidoglossate stock, now lost in the various divergent 



