14 ART. 20. — M. YOKOYAMA. 



hepatic region witli a rounded elevation ; the hepatico-branchial 

 as well as the hepatico-gastric furrows broad and shallow ; 

 epibranchial lobes hardly divided from the mesobranchial, while 

 both are distinctly separated from the elevated metabranchial 

 lobes as well as from the gastric region by a shallow groove ; 

 the posterior border of the carapace, is broken, but may have 

 been more or less straight : orbits moderate in size, and shown 

 by shallow arched notches with elevated borders. 



Of the genus Xanthilites the only species described is X. 

 Bowerhankii Bell (Monograph of the Fossil Malacostracous 

 Crustacea of Great Britain, part I, p. 17, pi. II, fig. 2) from 

 the Eocene of the Isle of Sheppey, which Bell recognized as 

 most closely allied to the species of Xantho now living in Japan. 

 The difference between the Japanese fossil and all the living 

 species of Xantho as well as from the English form consists 

 in the much broader posterior border. 



The specimen was found at a depth of 484 feet. 



PISCES. 



13. Lamna cf. cuspidata Ag. 



PI. III. Fig. 7. 



We designate under the above name a subulate tooth with 

 the root broken off, about 22 millim. long and 4 millim. broad. 

 It is slightly recurved, flatly inflated, smooth and with sharp 

 edges, and furnished with a slightly acute denticle on each 

 side. The fossil is firmly attached to the stone, but judging 

 from its general appearance, it comes nearest to the Lamna 



