imperfectly -defined Species of Jurassic dbc. Nautili. 397 



The locality of the specimen figured is unknown, but it 

 agrees in all essential points with the German specimens 

 in the Collection, and adds to our knowledge of the species 

 the characters of the body-chamber and of the test. The 

 latter is smooth, being ornamented only with delicate lines 

 of growth. The last two septa are exposed by the removal 

 of the test. A heavy ridge is developed near the base 

 of the body-chamber, its indented outline corresponding 

 roughly with that of the last suture. Part of the anterior 

 boundary of the shell-muscle is seen on the cast of the body- 

 chamber (see fig. 2). The aperture is deeply emarginate. 



In an excellent figure of this species given by v. Amnion 

 (loc. cit.} the anterior border of the shell-muscle is repre- 

 sented upon the cast of the body-chamber. 



Horizon. Tithonian. 



Localities. Normandy, Escragnolles (Var), France ; Ran- 

 den, near Schaffhausen, Switzerland ; Einsingen, Wiirtem- 

 berg. 



4. Nautilus (Hercoglossa) portlandicus, sp. no v. 

 Fiff. 3. 



Nautilus portlandicus. — a, lateral view, showing two of the septa and the 

 siphuncle, which projects a little ; b, peripheral view. Drawn from 

 a specimen in the British Museum (no. 62165). About one sixth 

 natural size. 



Sp. char. Shell subglobose, narrowly rounded on the peri- 

 phery, gently rounded on the sides, widest immediately above 

 the umbilicus ; the latter probably closed, or, if open, exceed- 



