MUSEUM OF COMPARATIVE ZOOLOGY. 373 



compared to the stem of the pear bent over, are extremely narrow and long and 

 symmetrically serrate on each side with 4-6 serrations. The major uncinus is 

 stout and has a large four-toothed ovate cusp; there are about twenty more 

 slender' uncini with scythe-like cusps serrate on the outer edge; outside of 

 these are two or three of a flat form, like a section of a palm-leaf fan from 

 handle to margin with four riblets, and the distal edge with three or more 

 indentations. Under jjressure these uncini have a tendency to split up length- 

 wise, beginning at the indentations. They are flat and «mooth, thinner toward 

 the distal end, and have no distinct shaft. 



Habitat. Off Havana, at Station 101, in 174 fins., Sigsbee. 



This interesting species looks at the first glance as if the excavated space be- 

 tween the peripheral cinguli was fasciolar, like that of Eucasta, but a more 

 careful inspection shows that there is no sign of a notch or sulcus in the lines 

 of growth. The dentition forms a combination so far not recorded among the 

 Trochidse, but which will perhaps seem less singular when more species have 

 been examined. The radula is quite minute and difficult to examine; when 

 only the cusps of the central and lateral teeth were in the field of the micro- 

 scope, they were so slender and elongated as to suggest little tails, and the 

 symmetrical notching gave them almost a jointed appearance. The shell is 

 very pretty, and recalls Bas'dissa in its general appearance. 



Calliostoma (Dentistyla) asperrimum Dall. 

 Margarita asperrima Dall, Bull. M. C. Z., IX. p. 40, 1881. 



Habitat. Station 12, in 177 fms.; Barbados, in 100 fms.; Station 20, in 220 

 fms.; Station 206, off Martinique, in 170 fms., sand, bottom temperature 49°.0; 

 Stations 273 and 299, off Barbados, in 103-140 fms., coral, bottom tempera- 

 tures 56° to 59°. F. U. S. Fish Commission Station 2602, off North Caro- 

 lina, in 124 fms., sand. 



Variety deniiferum Dall, Plate XXIII. Figs. 7, 8. 



Sculpture more strongly and exclusively nodulous; a strong blunt tooth on 

 the columella just within the aperture and above the base. Outer lip Urate 

 within. Alt. 7.5, lat. 6.0 mm. Habitat, Station 299. 



Calliostoma (Dentistyla) sericifilum n. s. 



Plate XXIV. Figs. 1, la. 



Shell delicately but sharply reticulate all over; two peripheral spirals mi- 

 nutely spinose at the intersections; columellar tooth present but not strong. 

 Shell thinner and more nacreous than the typical form, and with the radiating 

 and spiral sculpture not differing so much in strength. Alt. 4.5, lat. 4.1 mm. 



Habitat. Station 262, off Grenada, in 92 fms., sand, bottom temperature 

 62°.0 F. 



