imperfectly -defined Species of Jurassic &c. Nautili. 405 



and distorted, and nothing is seen in them of the septa or 

 siphuncle ; nevertheless the ornaments of the test are suffi- 

 cient to distinguish the species from others which it may 

 resemble. The general form of N. libanoticus suggests that 

 of N. eleyans, J. Sowerby, but the character of the ornaments 

 in the latter differs from that of the former, the ribs being at 

 once broader and closer together in Sowerby's species than 



Ffc. 6. 



Nautilus libanoticus. — a, peripheral view of a distorted specimen (no. 

 C. 542) ; b, portion of the test of another specimen (no. C. 542 a) ; c, 

 beak from specimen no. 83G63 ; d, beak from no. C. 2918. Drawn 

 from specimens in the British Museum, a rather exceeding one 

 half natural size ; b natural size ; c and d one and a half times natural 

 size. 



they are in the present one ; and this distinction is main- 

 tained even in casts. Fortunately one of our specimens has 

 a portion of the test preserved, and it is here figured (fig. 6, b). 

 The beaks are exposed to view on the ventral surface of the 

 body-chambers of several of the specimens (fig. 6, c, d). 



Horizon. Upper Cretaceous. 



Locality. Sahil Alma, Lebanon, Syria. 



10. Nautilus Bayfieldi } sp. no v. 



Sp. char. Shell somewhat compressed upon the sides and 

 a little flattened upon the periphery, the thickest part of the 

 whorls being in the umbilical region. The umbilicus is rather 

 small, with steeply sloping sides and rounded borders ; the 

 inner whorls partly exposed. The whorls present a sub- 

 tiiangular outline in section, owing to the flattening of the 

 sides and the superior width of the dorsal as compared with 



