On some new and peculiar Mollusca. 153 



XIII. — New an! peculiar Mollusca of the Order Solenoconcliia 

 procured in the ' Valorous^ Expedition. By J. GwYN 

 jEFFREiTS, LL.D., F.R.S. 



SolenoconcMa. 



Genus Dentalium. 

 Dentalium candidum'^, Jeffr. 



Body whitish, with a faint tinge of brown : mantle very 

 thin, forming a collar, which encircles the inside of the upper 

 part of the shell : tentacles very numerous, with pear-shaped 

 tips, issuing between the mantle and tlie shell : foot when at 

 rest conical, having a semicircular lobe or flap on each side, 

 so as to give it a tricusped appearance ; the lobes are fringed 

 or puckered at the edges. The animal from which I took the 

 above description was sluggish and probably half-dead, in 

 consequence of its having been dredged up from a depth of 

 1100 fathoms. 



Shell having the shape of a narrow funnel, tapering, 

 slightly curved, rather thin, opaque, more or less glossy : 

 sculpture, about forty fine and regular rounded longitudinal 

 strise, which disappear towards the front margin ; these striae 

 are crossed by extremely numerous and close-set circular 

 microscopic lines : colour glistening- white : margin at the 

 anterior or broader end jagged, at the posterior or narrower 

 end abruptly truncated ; there is no notch, groove, slit, or 

 channel. L. 1-75. B. 0-3. 



Station 5, 410 fms. ; 6, 1100 fms. ; 8, 1750 fms. ' Porcu- 

 pine' Expedition, 1869, west coast of Ireland, 664-1476 fms.; 

 Bay of Biscay, 2090-2435 fms. 



Allied to I), grande^ of Deshayes, from Japan. The pre- 

 sent species differs from D. striolatum, Stimpson (Z). abys- 

 sorum, M. Sars), in being straighter, less cylindrical, and of a 

 thinner and more delicate texture, and in having twice the 

 number of ribs. 



Dentalium capillosum f, Jeffr. 



Shell tapering to a fine point, slightly curved, rather 

 solid, opaque, and mostly lustreless : sculpture, numerous and 

 sharp (not rounded) longitudinal striae, some of which are 

 intermediate and smaller than the rest ; they disappear towards 

 the posterior or narrow end, which is quite smooth and glossy 



* Glistening-white. 



t Covered with threads or hair-like markings. 



Ann. & Mag, N. Hist. Ser. 4. Vol. xix. 11 



