215 



volutions. Another immature specimen (fig. 2c), whose apex is not 

 quite perfect, and which measures twenty-nine mm. (or an inch and a 

 quarter) in length and eight mm. at the larger end, has eleven volutions 

 preserved. The entire number of volutions was probably about twenty. 

 This species belongs to the sub-genus Nerinella of Sharpe. 



CERITHIUM SKIDEGATENSE. (N. Sp.) 

 Plate 27, figs. 3 and 3a. 



Shell small, not much exceeding half an inch in length, pupiform, 

 turreted but not much elongated, the length being about twice the 

 greatest breadth : whorls six or seven, the earlier ones obliquely com- 

 pressed, the later ones more cylindrical : spire not much longer than 

 the last whorl preserved, and possibly not any longer than the body 

 whorl, which is more or less broken in all the specimens collected : 

 suture angularly but not very deeply impressed. Surface marked by 

 rows of beaded or tuberculated spiral raised lines. On the two last 

 volutions but one there are four rows of nearly equidistant, prominent 

 and regularly rounded tubercles. On the upper or posterior half of 

 the last volution preserved there are also four rows of bead-like 

 tubercles, and on the lower or anterior half of the same volution there 

 are three or four spiral raised lines, the uppermost of which is 

 indistinctly tuberculated. 



Length of the most perfect specimen (in which part of the body 

 whorl is broken off,) eight millimetres ; breadth rather more than 

 three and a-half mm. ; length of the last whorl (which is imperfect) 

 nearly four mm. 



East end of Maud Island, opposite Leading Island : five or six well 

 preserved but imperfect specimens. 



VANIKORO PULCHELLA. (Nona, prov.) 



Plate 27, figs. 4 and 4a. 

 Possibly a variety of Lyosoma Powelli, White. 



Comp. Nerit'ma ? f Powelli, White. 1876. Powell's Report on a Geological 



Survey of the Uinta. Mountains, p. 110. 



" Lyosoma Powelli, White. 1880. U. S. Geol. Survey, Contributions 



to Paleontology, Nos. 2-8, p. 153, pi. 30, 

 figs. 6, 6a, 66, 6c, and 6d. 



Shell obliquely subovate, its length and breadth being nearly equal : 



