178 CAEROXIFEEOrs CEPHALOPODA OF lEELAXD. 



1S54. Ctoniatites micronotus, J. Morris. Cat. Brit. Foss., 2nd ed., p. 304. 

 1855-57. — — /. KeUy. Joum. Geol. Soc. Dublin, vol. vii, 



p. 7. 

 1880. — — TT. Branco. Palseontographica, vol. sxvii, p. 24, 



pi. iv, fig. iv a — 7. 

 1883. Gltphioceras miceonotum, A. Hyatt. Proc. Boston Soc. Nat. Hist., 



vol. sxii, p. 329. 



1888. GoNiATiTES MICRONOTUS, E. Etlieridge. Brit. Foss., vol. i, Palaeozoic, 



p. 312. 



1889. Gltphioceras micronotom, E. Hohapfel. Pala'ont. Abhandl., Diunes uud 



Kayser, vol. v, i, p. 28, pi. ii, fig. 1. 

 1897. — — A. H. Foord and G. C. CricJc. Cat. Foss. 



Ceph. British Museum, pt. 3, p. 173, 

 fig. 81 (suture-line), also fig. 74 

 (developmental) . 



Des^cnption. — "Shell discoidal, compressed, involute; greatest thickness at the 

 umbilical margin, about one-half of the diameter of the shell ; height of outer whorl 

 a little more than one-half of the diameter of the shell. Whorls (? number) ; 

 inclusion almost complete ; umbilicus narrow, about one-twelfth of tlie diameter 

 of the shell, infuudibuliform, with suliangular margin. "Whorl semi-elliptical 

 in section, a little higher than wide ; indented to three-sevenths of its height 

 by the preceding whorl ; periphery narrowly convex ; sides feebly convex, 

 flattened ; inner area narrow, sloping towards the umbilicus, somewhat flattened. 

 Body-chamber occupying at least two-thirds of the last whorl. Chambers shallow, 

 about nine in the last half-whorl preceding the body-chamber. Test thin, orna- 

 mented with very fine striae, which are slightly waved on the sides and form a 

 deep, broad, backwardly directed sinus on the periphery. Internal casts some- 

 times with four shallow constrictions having the same course as the ornaments, 

 being deepest at the periphery and becoming very feeble near the umbiUcus. 

 Initial chamber ellipsoidal or spindle-shaped, transversely elongate. Shell attaining 

 a diameter of about 33 mm." (' Cat. Foss. Ceph. British Museum,' loc. cit.) 



Affinities. — Holzapfel (loc. cit.) compares the suture-line of the present species 

 with that of Ghjphioceras (Beiji-ichoceras) truncatum, Phil., but the resemblance is 

 not very close. The whorls in the former are more compressed than in the latter 

 species. The ornaments of the test in G. mierouotum would be the best guide for 

 distinguishing the species. 



Bemarls. — The single individual in the " Griffith Collection " bearing the name 

 of G. (B.) micronotum is very small and badly preserved, and is partly covered by 

 the rock in which it is embedded. I have therefore figured a larger and better 

 specimen in the British Museum ; this one is labelled " KUdare, Ireland." 



Localitie.^. — Clane, county of Kildare (exact localit}' in the comity unknown) ; 

 Ballinacourty (Dungarvan), county of Waterford {fdc Griffith). 



