174 PROCEEDINGS OF THE HAXACOLOGICAX SOCIETY. 



ON THE ANATOMY OF BULIMIXUS L.JURDJURENSIS, ANCEY, 

 FROM THE DJURDJURA MOUNTAINS, KABYLIA. 



Bv R. Murdoch. 



Redd Uth January, 1901. 



The following description is founded ou the investigation of a number 

 of examples, extracted from the shells and preserved in alcohol, which 

 were received from Monsieur C. F. Aneey himself. 



External Features. — Animal blackish in colour, upper surface 

 with small irregular granulations, on the sides and tail the granules 

 are smaller and less dark ; a somewhat larger row surrounding the 

 foot-margin and giving it a slightly tessellated appearance. 



Foot rounded in front, gradually narrowing to the tail, the latter 

 pointed and rounded above. Foot-sole whitish in the centre, with 

 a narrow, darker band around the sides. Mantle with an even margin, 

 and a small narrow lappet on the right under side. 



Tentacles apparently of medium length, black, and very finely 

 granulated. Labial tentacles large, somewhat hatchet-shaped. 



Genital pore posterior to, and a little below, the right tentacle. 



Internal Anatomy. — Jaw (Fig. I) thin and delicate, with a slight 

 median projection, finely striated, and the low T er margin minutely 

 denticulated. When highly magnified the striations appear as some- 

 what irregular riblets, numerous longitudinal strengthening lines also 

 become visible. 



Dentition (Fig. II) has a formula varying from 32 : 1 : 32 to 

 35 : 1 : 35, in numerous transverse rows. Central tooth smaller 

 than the adjoining laterals, with a single cusp, the cutting-point not 

 quite extending to the basal margin. First eight (in some examples 

 nine) laterals have the apex of the cusp slightly projecting on to the 

 adjoining row of teeth; basal plates somewhat oblique, and produced 

 on the outer sides. The succeeding two or three teeth are transitional, 

 and develop a small ectocone. Marginals with the basal plates much 

 shorter, the cutting-points of the cusp largely developed and slightly 

 variable in outline ; the apex in some teeth irregularly rounded, 

 and in others obtusely pointed. Proceeding outwards, the ectocone 



