268 



Messrs. l'ourd and Crick on new and 



the shell than on the periphery ; finer lines are intercalated 

 between these, and the whole are crossed by tine and nume- 

 rous lines of growth, which impart a cancellated appearance 

 to the test, especially in young shells. In addition to the 

 finer ornaments there are a series of obscure folds radiating 

 from the umbilicus, and dying out upon the periphery. 



Remarks. This species resembles Nautilus striatus 7 J. 

 Sowerby *, in its general form and perfectly in its sculpture, 

 but it is distinguished by its completely closed umbilicus. 

 A large but imperfect and crushed example (no. 39850) repre- 

 sents the adult stage in the growth of the shell, while the 

 young is exemplified in an exquisitely preserved specimen 

 (no. 39887). The name simillimus which we have given to 

 this species is intended to express its close resemblance to N. 

 striatus. 



Horizon. Lias. 



Locality. Charmouth, Dorsetshire. 



2. Nautilus Jourdani, Dumortier. 



1874. Nautilus Jourdcmi, Dumortier, Etudes Paleontologiques sin- 

 k's Depots Jurassiques du Bassin du Rhone, pt. iv. (Lias Superieur) 

 p. 44, pi. vii. figs. 1-5. 



1889. Nautilus Jourdani, S. S. Buckman, Quart. Journ. Geol. Soc 

 vol. xlv. p. 4G3 (footnote). 



Fiir. 2. 



Nautilus Jourdani. — a, lateral view, showing the deep umbilicus and the 

 orrjaiuents of the test ; b, peripheral view, showing the form of the 

 sutures. Drawn from a specimen in the British Museum (no. Il>-">s7 ). 

 About one half natural size. 



Sp. char. Shell moderately inflated ; umbilicus not very 

 * Min. Conch, vol. ii. p. 183, pi. clxxxii. 



