8 



Var. a, with the outer perilreme deep red, and the spiral stria? 

 stronger ; of which I have seen but two individuals. 



20. Cyclostoma proxijium. Species like C. fascia, Gray, but the 

 shell is much more coarsely decussated, the transverse lines being 

 stronger and the spiral lines less numerous ; the lip is less expanded 

 and more solid, and the whole shell is thicker and smaller. 



21. Cvclostoma Nkwcombianum. Shell much elongated, conic; very 

 pale orange, elegantly decorated with several spiral series of small 

 brown oblique spots which have white shadows, the spots being in 

 transverse series ; with numerous small but strong transverse whitish 

 raised lines, which are mostly in groups of three to five and at the 

 summits are developed into minute sutural crenulations ; spire with 

 slightly convex outlines; apex truncate with the loss of two or three 

 whorls ; five whorls remaining, with a well impressed suture ; last 

 whorl detached from the penult whorl near the aperture ; aperture pub- 

 orbicular, quite angular above ; inner peritreme slighty produced ; 

 outer peritreme moderately expanding, shining, reflected exactly into 

 the plane of the aperture, rather thick, nearly wanting opposite to the 

 penult whorl, moderately produced above into a sharply angular con- 

 cave wing ; umbilicus very small. 



Mean divergence 37° ; length 52 inch ; greatest breadth .28 inch ; 

 least breadth .22 inch. 



22. Cyclostoma. n:tens. Shell moderately elongated, conic ; shi- 

 ning, brownish white with white spots, and spiral interrupted bands of 

 pale brown, deep orange near the aperture ; very finely decussate with 

 nearly equa! slightly elevated lines, but on the upper whorls the trans- 

 verse lines are more prominent and the spiral lines obsolete ; spire 

 with the outlines slightly convex; apex truncate, with the loss of two 

 or three whorls ; four whorls remaining, witR a well impressed su- 

 ture ; aperture large, ovate orbicular, moderately angulated above; 

 inner peritreme scarcely distinct, reflected upon the outer peritreme^ 

 which is reflected nearly into the plane of the aperture, is moderately 

 spreading, sharp, thickened, narrower and bent back opposite the 

 umbilicus, which is small. 



Mean divergence 40°; length ..56 inch; greatest breadth .30 inch ; 

 least breadUi .20 inch. 



23. Cyclostoma tenuistkiatum. Shell elongate ; deeply colored 

 with greyish and reddish slate color, with an orange lip; with numer- 

 ous distinct spiral striae decussated by excessively minute and numer- 

 our transverse striae and by a few distant fine deep striae ; spire with mod- 

 erately convex outlines ; apex truncate with the loss of two or three 

 whorls ; four and one-hnlf rather convex whorls remaining, with a 



