CALLIOSTOMA. 



377 



Thi.s somewhat resembles a Calliostoma aiinulatum in miniature, 

 with the characters exaggerated and minus the coloration. It 

 appears to have a dextral nucleus. (Dall.) 



C. circumcinctum Dall, Bull. M. C. Z. ix, p. 44, 1881 ; ' Blake ' 

 Gasterop., p. 364, t. 22, f. 3, 3a. 



C. ECHixATUM Dall. PI. 49, figs. 40, 41. 



Shell small, white, acute-conical, in general resembling C. sapidum, 

 but less stout and solid and with wholly different sculpture ; whorls 

 six, somewhat appressed toward the apex; nucleus smooth, semi- 

 transparent, inflated, shining, sinistral, subimmersed ; remainder of 

 shell opaque white with the following sculpture ; on the upper whorls, 

 four revolving ribs with smaller inconspicuous ones between them, 

 crossed by faint plications (more evident on the smaller whorls), 

 producing nodosities which on the four principal ribs, and especially 

 on the third one, counting from the suture toward the base, rise to 

 acutely pointed projections separated by an incurved scallop of about 

 twice the width of the projections ; toward the aperture the ribs and 

 nodosities become more equal in size ; base flattened, impervious, 

 sculptured with some fifteen close-set flattened revolving ribs crossed 

 by impressed radiating lines of growth ; aperture nearly rectangular; 

 pillar straight, stout, not projecting, without a callous ; margin thin 

 a little crenulated by the sculpture. Alt. 5t, diani. 4| mill. 



Off Havana, 8(> fms. 



a echinatum Dall, Bull. M. C. Z. ix, p. 47, 1881; 'Blake' 

 Gasterop., p. 364, t. 21, f 2a, 5. 



C. STiROPHORUM Watson. PI. 17, fig. 19. 



Shell small, conical, scalar, inflated on the base ; whorls angu- 

 lated, with three strong carinse near the periphery, white over 

 nacre. Sculpture: spirals — at the periphery is a sharp flange-like 

 carina ; above this, about one-third of the distance to the suture, is 

 a second, almost equally strong and prominent, which forms a 

 shoulder to the whorls. The space between this and the sutui'e is 

 divided pretty equally by two threads, the lower of which is feeble. 

 On the up])er whorls all of these are closely beaded, on the last 

 whorl only the two highest are so. Below the carina is another 

 remote strong thread, which meets the outer lip ; within it is 

 another, not quite so strong nor so distant, and occupying the S2iace 

 from this to the middle are five flat close-set threads, followed by 

 three rather more separated and roughly beaded threads, tiie inner- 



