194 

 CYRTOCERAS SYPHAX. (N. sp.) 



Fig. 178. 



Description. Shell only slightly curved ; section nearly circular, the 

 dorso-ventral diameter being a little greater than the lateral ; chamber of 

 habitation gently contracted from the middle to the aperture ; siphuncle 

 small, in contact with the shell on the ventral side ; septa, eleven in seven 

 and a half lines. 



Several specimens of this species have been ^collected, the best pre- 

 served of which has the following dimensions : Length 16 lines ; lateral 

 diameter of the aperture 7J- lines ; lateral diameter at the smaller 

 extremity 5 lines ; depth of chamber of habitation 8J lines. The 

 siphuncle is about a line in diameter, and its section is nearly semi- 

 circular, being much flattened on the side next the shell. 



Locality and Formation. Point LeVis ; limestone of the Quebec 

 group. 



Collectors. J. Richardson, R. Bell. 



CYRTOCERINA MERCURIUS. (N. sp.) 



Fig. 179. 



Description. Shell short, abruptly tapering, rather strongly curved ; 

 section elliptical, the dorso-ventral diameter being, as nearly as can be 

 ascertained, one-third or one-fourth greater than the lateral. The septa, 

 measured on the surface on the ventral side near the chamber of habita- 

 tion, are about half a line distant, but on the dorsal side near the apex 

 they must be much closer together. 



Associated with the two specimens represented by fig. 179, in the 

 same rock, were found- two other fragments. One of these fragments 

 shows a section of the siphuncle, and that its position is in contact with 

 the shell on the dorsal side, while its dorso-ventral diameter is about 

 three-fourths the lateral diameter of the shell. In a polished longitudinal 

 section through this fragment, there are ten septa in the length of two 

 lines. This would be double the number shown by the other in the same 

 space, but in this latter the measurement gives the distance on the surface 

 where they (the septa) come out obliquely, and are consequently not 

 so approximated. 



This species must be very closely allied to 0. typica. The septa, as 

 shown by one of the fragments of the former, are the same in number, in 

 the same length as the grooves on the inside of the siphuncle of the latter. 



