Mollusca in the Collection of the Zoological Society. 373 



*Harpa gracilis. 

 H. testd oblongd, gracili, costis distantibus, muticis, Imvigatis ; long. 

 It'o, lat. Jq, poll. 

 Hah. 



An unique specimen of this remarkably slender Harp is in Mr. Bland's 

 collection. It is white, varied with pale rose colour, and on the ribs are 

 a few small transverse brown lines. 



Tkichotropis.* 



Testa univalvis, turbinata, carinata, tenuis, apertiird longitudinem 

 spircB superante, basi integrd, columella ad basim oblique trun- 

 catd, labio externo tenuissimo, acuto. Epidermis cornea, super ca- 

 rinas testes erinacea. Operculum corneum, parvum, lamellis el- 

 lipticis confertum, nucleo laterali. 



The shell may be characterized as being turbinated, and carinated ex- 

 ternally ; its aperture is wide, but still longitudinal, and it is rather longer 

 than the spire ; its base is entire, without any notch, although immedi- 

 ately below the obliquely truncated base of the columella there is an 

 mdistinct canal. The whole shell is thin and delicate, its outer lip par- 

 ticularly so. Epidermis horny, forming numerous sharp-pointed bristle- 

 like processes on the edges of the carinas outside the shell ; very strong 

 and by its contraction in drying frequently breaking the edge of the lip. 

 Operculum horny, much smaller than the aperture, composed of ellipti- 

 cal laminae, its apex or nucleus lateral. 



The animal in most particulars resembles a Buccinum as to its exter- 

 nal form and characters, differing from it principally in having only a very 

 small fold of the mantle to line the nearly obsolete canal of the shell. 



This and some other inequalities on the edge of the mantle corres- 

 ponding in position to the keels on the outside of the shell, constitute 

 the whole of the differences observable between the soft parts of the 

 animals. 



It may not be improper to add a short explanation of the characters 

 by which the present genus may be distinguished from others with which 

 it has either been confoimded or to which it may be related. These are 



* GjOtS seta, rpo-iriq carina. 



