443 



Nucleus wanting, remaining whorls nearly 7, convex, separated by a deep, undulated suture. 

 Sculpture consisting of remote, rounded, axial ribs, more conspicuous on upper whorls, nearly 

 disappearing on last one, iS in number on penultimate whorl and conspicuous growth-lines on 

 ribs and interstices; the whole shell is crossed by unequal spirals, of which about 5 on penult- 

 imate one are more prominent. Aperture subquadrangularly oval, with a blunt angle above and 

 a short, wide canal below ; peristome moderately thin, undulated, with a shallow sinus just below 

 suture, angular at the entrance of canal ; columellar margin nearly straight in its lower part. 

 Interior of aperture light brownish, with a bluish tint in the depth. 



Alt. ió 1 /,, lat. 6 1 /,; apert. alt. 7 1 /., lat. 2 s / 4 Mill. 



Allied to D. albibalteata Reeve (Conch. Ie. Pleurotoma, hg. 84), but the new species is 

 much more slender, the whorls are less convex, more elongated, the ribs, especially on last 

 whorl, are much fainter and I see no tracé of the white belt in the new species. 



9. Daphanclla perfragilis n. sp. PI. XXIX, fig. 12. 



Stat. 76. 4°22'.i S., iiS°i6'.9E. Makassar-strait. 2029 M. Fine grey mud. 1 Spec. 

 Stat. 178. 2°4o'S., I28°37'.5E. Ceram-sea. S35 M. Blue mud. 1 Spec. 



Shell fusiform, with moderately long canal, very thin, fragile, hyaline, white. Whorls 8, 

 of which about 2 l /, 2 form the nucleus, with convex whorls and criss-cross sculpture. Post-nuclear 

 whorls convex, separated by a deep, linear suture, the upper ones are strongly angular at the 

 shoulder, the angle however is fainter on lower whorls and nearly disappears on last one ; a 

 seconcl prominent liration is visible on upper whorls, but becomes likewise fainter, moreover 

 the shell is crossed by numerous, fine, raised, spiral striae and finer axial ones, producino- a 

 fine cancellation ; on the canal the spirals are stronger. Aperture oval, angular above, with a 

 rather short, moderately wide canal below; peristome broken, according to growth-lines with a 

 shallow sinus above, roundedly-angular at the entrance of canal. Columellar margin convex at 

 the body whorl, then nearly straight, slightly curved to the left, with a thin layer of enamel. 



Alt. 18 1 /,, lat. 7 1 /,; apert. alt. g 3 / é , lat. about 3 Mill. 



Allied to D. dea Melv. (Proc. Mal. Soc. Lond. Vol. VI, p. 167, PI. 10, fig. 24), but 

 the new shell is much larger, the canal is longer and I see nothing of the angularity of whorls, 

 neither in the description nor in the figure ; the specimen from Stat. 76 is a younger, worn 

 shell, but still conspicuously angular. 



Pleurotomella Verrill. 



Under this name I have united some shells, which agree in having a dark nucleus, 

 sculptured with criss-cross lines, strongly contrasting with the rest of the shell ; this group has 

 been united as a section of Mangilia and of Daphnella by Dall and by Tryon. Dall, in 

 1908 gives generic rank to Pleurotomella, but unites Gymnobela as a subgenus, for species with 

 short spire, smaller than the average Pleurotomella and erects a new group Pliymorliyuchus 

 on characters of the animal. As the Siboga-specimens contain no soft parts, I am unable 

 to state if the animals are blind, as Pleurotomella ought to be, nor if they have the shape of 



79 



