ILLUSTEATIONS OF THE FAUNA OF THE ST. JOHN GROUP. 105 



use it in preference, though Styliola has precedence by three years, having been given in 

 1825. So far as the writer knows Styliola has been applied only to the straight shells, 

 while Creseis has been given to both straight and curved shells. Between these curved 

 shells of the St. John Group and the straight ones, there seems sufhcient différence to 

 found at least a sub-generic distinction, and for the curved shells Rank's name may be 

 retained. 



Creseis minut.\ n. sp. (PI. VII., figs. 11 a—c) 



Oyriotheca minuta. Nat. Hist. Soc. N.B., Bulletin x., p. viii. 



A minute, elongated, arched cone or sheath, acutely pointed at the apex, near which 

 the shell is more rigid than at the larger end. 



Sculpture. The outer surface is smooth, except toward the apex where some examples 

 show longitudinal ridges. Under the microscope the surface is seen to be minutely 

 striulate transversely. 



Size. Length 4 mm. Width about one-fifth of the length. 



Horizon and Locality. Same as the preceding. 



The shell substance of this fossil appears to have been of a horny consistency, or of 

 thick chitenous substance. Many of the sheaths are marked by transverse ridges, 

 which under the microscope appear to be due to cracks in which carbonaceous 

 matter has become segregated. These ridges are often very regularly spaced and may 

 possibly mark the position of diaphragms within the shell, but the spaces are not so 

 regular as they are in nautiloid shells. 



Creseis corrugata n. sp. (PI. VII., figs. 12 a and b.) 



Cyrtoiheca corrugata. Nat. Hist. Soc. Bulletin x., p. viii. 



A sheath more elongated than the preceding ; it is also larger, straighter, and is tra- 

 versed by numerous, closely set undulations of the surface, forming rings that fade out 

 toward the larger end of the shell. 



Size. Length 10 mm., width about one-tenth of the length. 



Horizon and Locality. Same as the preceding, bttt this species is not so abttndant. 

 Among the Pteropods of the Miocene formation of Western Hungary, Ernst Kyttl fiffures 

 a Creseis (C. Fvchsi) of about the size and form of this.' The Hungarian species is straighter 

 in the body of the shell and more abruptly ciirved toward the apex. The annulations (or 

 striations) are also finer, closer, and more regular. 



CEPHALOPODA. 



ORTHOCERAS, Breyn. 



Imperfectly preserved examples of the shells of this genus have been found in 

 calcareous nodules at the Suspension Bridge. 



' Anualen des K.K. Naturhistorischen Hofmuseum. Band, i., No. 2., p. 5, Taf. ii., figs. 1 — 3, Wien., 1886. 



Sec. IV., 1892. 14. 



