from North Cormcall. 157 



border of the aperture. The latter does not appear to have been 

 constricted as in the genus Phragmoceras, but widely open. The 

 fossil appears to bear slight traces of the ornaments of the test. 

 These are most conspicuous on the body-chamber, and consist of 

 several faint parallel longitudinal ridges from 5 to 12 mm. on the 

 outer, convex, or ventral surface ; they extend on to the septate 

 part of the shell, where, however, most of them are much less 

 distinct owing to the roughness of the surface of the specimen, 

 but the innermost ridge, which is at about 30 mm. from the outer 

 boundary of the specimen, is very pronounced and somewhat 

 irregular, as though the test here might have been roughly nodose. 

 On the body-chamber these ridges are connected by transverse, 

 fairly closely-set, but slightly irregular lines crossing the interspaces- 

 between the ridges in curves which are forwardly-concave. There 

 are also some rather coarser and more irregular wavy lines near tha 

 base of the inner or dorsal portion of the body-chamber, but these 

 may not be traces of any surface ornaments. On the inner or dorsal 

 side of the body-chamber a strongly incised line starts from the 

 last septum at about 12 mm. from the inner edge of the fossil '^ 

 passing forwards and curving over towards the dorsal side, it 

 reaches the boundary of the fossil at a point about 12-5 mm. in 

 advance of the last septum. Judging from observations in other 

 fossils the writer believes this to indicate the boundai'y of one of 

 the shell-muscles, this being, in fact, the impression of one of the 

 muscle-scars as it was preserved on the inside of the test, the latter 

 having subsequently disappeared. When received the dorsal 

 portion of the specimen was entirely obscured by matrix, and the 

 fossil looked very much like a portion of a Phragmoceras, but the 

 removal of the matrix from the dorsal surface revealed the incised 

 line just referred to, and this suggests to the writer that the fossil is 

 referable to a widely-apertnred shell rather than to a form with 

 a contracted aperture such as Phragmoceras. 



In general appearance the fossil presents some resemblance to the 

 specimen figured by D' Arch lac & De Verneuil as Phragmoceratites^ 

 subventricosiis ^ from the Middle Devonian of the Eifel, but that 

 species seems to lack the characteristic sculpture of the present 

 specimen. 



The fossil appears to be referable to Hyatt's genus Cophinoceras,'^ 

 a genus confined to the Middle Devonian, and including both 

 cyrtoceracones or slightly curved forms and gyroceracones or 

 loosely coiled forms. Tlie genotype is Cyrtoceratites ornatits, 

 D'Archiac & De Verneuil (Trans. Geol. Soc, ser. ii, vol. vi, pt. 2, 

 1842, p. 349, pi. xxvii, fig. 5), originally described from the 



1 Trans. Geol. Soc. London, ser. ii, vol. vi, pt. 2 (1842), p. 3r)l, pi. xxx, figs. 1, la. 

 Referred to Cyrtoceras (Ooceras) Jlexuosum, Schlotheim, sp., by A. H. Foord : Cat. 

 Foss. Ceph. Brit. Mus., pt. i (1888), p. 316. 



2 Proc. Boston Soc. Xat. Hist., vol. xxii (1883), p. 285. See also E. Holzapfel: 

 Abhandl. d. k. Preuss. geolog. Landesanst., Neue Folge, Heft 16 (1895), pp. 123 

 et seq. Hyatt originally spelt the name Kophinoceras, a spelKng adopted by 

 Holzapfel ; but in Eastman's translation of Zittel's Textbook of Paleontology (1900) 

 Hyatt spells the name Cophinoceras (p. 522). 



