BAHAMA MOLLUSKS AND BRACHIOPODS. jt 



Cerion (Maynardia) niteloides n. s. 

 Plate i. — Fig. 2. 



Shell compact solid, grayish white, with a livid brownish 

 lining, ten whorls of which two and and a half are nepionic 

 and smooth, the remainder polished and for the most part 

 faintly sculptured with little raised transverse lines, often obso- 

 lete; on the last half of the last whorl these lines are coarser, 

 irregular and more prominent; the aperture is rounded except 

 where the peristome crosses the body, with a slightly bevelled 

 reflected edge; the parietal tooth is nearly central, short and 

 low, the pillar-tooth also low, is situated about the middle of 

 the pillar and makes a little less than a complete turn around 

 the axis of the shell. Height of the shell 28; maximum 

 diameter 12 mm. 



Habitat. Water Cay, Salt Cay Bank on the north side of 

 Cuba near the western end of the Bahama banks. 



Types in the University and National Museums. 



This species externally much resembles Cerion (Afaynardia) 

 nitela Maynard, which is a species native to the west end of 

 Little Cayman island in the Caribbean Sea on the south side 

 of Cuba. As the species of Cerion are very limited in their 

 distribution the wide separation of the two localities raises a 

 suspicion of distinctness, notwithstanding their superficial like- 

 ness, and this suspicion is measurably confirmed by the fol- 

 lowing differences : C. nitela has a larger axis and a consider- 

 ably larger and perforate umbilicus; its parietal tooth is more 

 elevated and less elongated, the pillar tooth slightly more ele- 

 vated, and its inward prolongation decidedly more feeble, 

 lastly its aperture is narrower, more horse-shoe shaped and 

 less rotund than in C. niteloides. The apex is decidedly more 

 pointed in the specimens of C. nitela before me as well as in 

 Maynard's figures, but this character is variable in some of 

 the species. 



It may be noted here that the use of the shells by hermit 

 crabs tends to wear away the pillar and denticulations, so 

 that persons working over these shells should make sure, 



