330 PROCEEDINGS OF THE ACADEMY OF [1896. 



Cerion iostomum Arangoi Pilsbry &, Vanatta. PI. XI, fig. 12. 



Shell similar to the type in form, but smaller. Latter iwo 

 whorls only of equal diameter, those above forming a rather long 

 cone. Whorls 8? to 9. Surface closely and regularbj ribbed through- 

 out (except the smooth uepionic whorls), the ribs mainly white, 

 interstices purplish-brown, mottled with white. Sutures without 

 noticeably exserted marginatiou. Aperture deep, rich purple 

 within. 



Alt. 235, diam. IO5 ; alt. of aperture 9 mm. 



Alt. 181, diam. 9 ; alt. of aperture 8 mm. 



Alt. 24, diam. lOt ; alt. of aperture 9f mm. 



Cienfuegos, Cuba (R. Arango). 



Strikingly different from iostomum at first sight, but we believe it 

 to be closely allied and probably a subspecies thereof. 



Cerion hyperlissum Pilsbry & Vanatta. PI. XI, tig. 10. 



Shell moderately strong, much elongated, cylindrical, the latter 

 four whorls of about equal diameter, those earlier gradually taper- 

 ing, forming an obtuse cone with slightly convex outlines. Pinkish- 

 brown (with more or less white maculation), the riblets white. 

 Whorls 11 J, weakly convex, those of the cone smooth, the rest 

 sculptured with rather fine riblets narrower than the intervals, 

 about 86 in number on each of the several later whorls. Umbilicus 

 a short rimation, compressed. 



Aperture ovate, decidedly higher than wide, the throat flesh-tinted. 

 Peristome white, well reflexed and revolute, thickened ; parietal 

 callus light, its edge hardly thickened ; parietal fold median, very 

 long, one-fourth to one-third of a whorl in length. 



Alt. 32}, diam. 10 ; alt. of aperture 12 mm. 



Alt. 29?, diam. 10; alt. of aperture 11 mm. 



Cuba. 



This species has the unusually long parietal tooth of the Cayman 

 Island Cerions. For the rest, it does not differ remarkably from 

 such Cuban forms as C. maritimum. The whorls of the cone are 

 ribless. 



A form also referable to this species is much striped and maculated 

 with fleshy-brown and white, the riblets being finer. 



Cerion regina Pilsbry & Vanatta. PI. XI, figs. 2.3, 24. 



Shell thick, subcylindrical, gradually tapering above, the long 

 terminal cone passing gradually into cylindrical portion ; lower 3 



