420 BULLETIN OF THE 



Habitat. Station 128, near Santa Cruz, in 180 fms. ooze, temperature 60°.0 ; 

 Station 143, off Saba Bank, a fragment, in 150 fms. ; Station 167, off Guade- 

 lupe, in 175 fms., sand, temperature 55° ; Station 220, oflf Santa Lucia, in 116 

 fms., hard bottom, temperature 58°.5 ; Station 262, off Grenada, in 92 fms., 

 sand, temperature 62°. Also at U. S. Fish Commission Stations 2314, off 

 South Carolina, in 159 fms., sand, and 2400, in the Gulf of Mexico, in 169 fms., 

 mud, temperature 57°.5 F. 



This elegant species has also been received from the coast of Honduras and 

 from Samana Bay, St. Domingo. 



Its nearest relative is D. ruhescens Deshayes, which is less curved in front 

 and more curved near the tip, is smaller, deeper colored, and has a very long 

 narrow posterior slit, when perfect, quite different from that of callipeplum. 



The specimen figured is young ; better specimens, from which the descrip- 

 tion was drawn up, were dredged by the Fish Commission. The striation on 

 the tip is so faint as to be very difficult to see, while the surface is so brilliant as 

 not easily to be scrutinized. 



DentaHum matara n. s. 



Shell slender, salmon-colored, whiter toward the aperture, glistening, the 

 lines of growth hardly perceptible in fresh specimens, other sculpture none; 

 very slightly arched ; aperture circular, very little oblique ; anal orifice higher 

 than wide, slightly notched below and above, with a short wide notch, but on 

 the convex side this is prolonged by a rather wide slit, about 1,0 mm. long. 

 Anterior diameter, 2.75 ; posterior diameter, 0.6 ; length of shell, 41.0 ; height 

 of arch above the chord, 3.75 mm. 



Habitat. U. S. Fish Commission Stations 2608 and 2611, off Cape Lookout, 

 N. C, in 22 to 31 fms., sand, temperature 74° to 79°, and Stations 2402 and 

 2409, in the Gulf of Mexico, in 26 and 111 fms., sand and mud. Also at 

 Samana Bay, Santo Domingo, in 16 fms. mud, Couthouy, in 1854. 



This shell is colored like D. ruhescens^ but has a shorter and very different 

 notch, is slimmer, straighter, and has a proportionally larger posterior end 

 when perfect. It is less conical, less arched, and smaller than D. callipeplum, 

 which it resembles in brilliancy. It entirely wants the fine posterior striation 

 of D. Upturn, Bush, which is still more slender. 



The tube or sheath, which is often seen protruding from the posterior end of 

 Dentalia, is a pathological production, due to the truncation of the tip, which 

 is partially repaired to protect the anal extreme of the animal by the formation 

 of this thin tube. It may occur in any species, but is more marked in thick 

 shells. It has been made the basis of a genus or subgenus, but I doubt if the 

 formation is ever normal and regular in any species; it certainly is not in any 

 specimen I have been able to examine. It is probably confined to such species 

 as do not normally possess a slit or notch in any part of the circumference of 

 the anal aperture. 



