Diagnosis. Shell large, but slightly curved, nearly straight, solid, slowly tapering; 

 cream-white with whitegray -white ribs. Sculpture : near the apex 1 7 subequal but unequally 

 spaced, narrow, sharply defined riblets very much narrower than the interspaces ; these continue 

 to the aperture, increasing in size ; their number is early increased by the intercalation of some 

 interstitial threads, mainly on the concave side, so that at the aperture there are 25 unequal, 

 unevenly spaced ribs and threads; the whole surface densely and conspicuously striated trans- 

 versely, the striae unequal, like cords scattered among threads, crenulating the riblets. Aperture 

 oblique, subcircular, a trifle wider than long, the peristome jagged from fracture. Apex large, 

 the orifice simply circular, without notch or slit. 

 Length 78,5, diam. at aperture 10, at apex 3,2 mill. (P. & Sh.). 



Distribution. 50 miles off Aden in 678 fms. 



Remark s. A large species apparently without near allies. It is remarkable for the 

 prominence of the growth striae, and the clearly carv^ed ribs of the surface. (P. & Sh.). 



-t t 



Dentaliuin transversostriahim n. sp. PI. I\', fig. 23. 



Stat. 212. 5°54'.5S., 120° 19'. 2 E. oft" Saleyer. 462 Metres. Fine grey mud. 3 Spec. 



Diagnosis. Shell but slightly curved, the greatest bend near the ape.x, solid, of a 

 yellowish tint, lusterless. The sculpture consists of 1 4 — 1 9 strong j^rominent sharp-edged lon- 

 gitudinal ribs, separated by rather wide concave interstices in some of which an interstitial 

 riblet arises. The longitudinal ribs are crossed by a pronounced transverse sculpture, consisting 

 of regular elevated striae, which become almost spinulose on the longitudinal ribs, and can be 

 felt by rubbing one's nail over the shell's surface. Apex simple, or with a long wide slit on 

 the convex side. Anterior aperture circular rather oblique with very thick edges. 

 Length 55, diam. of apert. 7,5 mill. Length of slit 8 mill. 



Remarks. To my regret I had no opportunity of comparing specimens oi D. cardmts 

 Dall '), a species reported from several stations in the West Indian Archipelago. It bears a 

 ver)' great resemblance to iransversostriahnn but as it differs from it in some minor details, 

 it seems advisable to distinguish as yet the Western Atlantic from the Indopacific form. In 

 the East Indian specimens the sculpture remains distinct toward the anterior aperture and the 

 edge of the peristome is very thick, measuring in one specimen 1,2 mill, in another i mill., two 

 qualities which distinguish it from carchins. The number of the ribs of cardtms is not given. 



34. Dentalium nialayanum n. sp. PI. V, figs 4, 5. 



Stat. 133. Anchorage oft" Lirung, Salibabu Island up to 36 Metres. Mud and hard sand. 2 Spec. 

 Stat. 159. 0° 59. 1 S., 1 29° 48'. 8 E. North of Kofian Island. 41 1 Metres. Coarse sand, i Spec, juv.? 

 Stat. 300. io°48'.6S., 123° 23'.! E. Timor Sea. 91S Metres. Fine grey mud. 2 Spec. 



Diagnosis. Shell slightly curv'ed, solid: sculpture of 16 — 17 narrow rounded ribs at 



i) D. carduus Dall. Blake, Rep. Bull. Mus. Comp. Zool. XVIII, (18S9), p. 423, pi. 27, fig. 3. 



