GRAMMOCERAS LOTHARINGICUM. 199 



and exhibiting the ventral projection to the mouth-border. The lateral part of the 

 mouth-border has not been preserved. 



Grammocbgas LOTHARINGICUM {Branco). Plate XXX, figs. 8, 9, 10. 



1879. Haepoceeas lothaeingictjm, Branco. Untere Dogger ; Abhandl. z. G-eol. 



Spez.-Kartev.Elsass-Lothringen, 

 Bd. ii, pi. ii, fig. 6. 

 1885. — — Haug. Beitr. Monogr. Harpoceras; Neues 



Jahrbuch fiir Mineralogie, &c , 

 Beil.-Band iii, p. 668. 



Discoidal, compressed, carinate. Whorls flat, ornamented with small, but 

 well-marked subsigmoidal radii which, on the air-chambers, join together, two and 

 two, at the inner edge, and which are strongly projected on the ventral area. 

 This area is undefined, and slopes sharply to form a distinct, solid carina. Inner 

 margin distinct and subconcave. Inclusion about one-half. 



I have so little material belonging to this species that I do not feel confident 

 concerning the identification. Branco says (p. 80), " Die Seiten der Schaale sind 

 flach und fallen nach dem Nabel zu in Gestalt einer niedrigen, aber ziemlich 

 steilen Nahtfliiche ab, bilden jedoch keine Nabelkante." My specimen differs from 

 this description because it shows a distinct inner margin ; but I believe that this is 

 practically the only matter in which it does not coincide with Branco's figure and 

 description. 



From Gramm. aalense, of which it is probably a mutation, this species differs in 

 its more regular, smaller ribbing, which is rather more strongly bent on the 

 lateral area. The species also increases in diameter more quickly. 



This species occurs in the OpaUmmi-zone at North Nibley, Gloucestershire. It 

 is very scarce. 



PI. XXX, figs. 8, 9, show two views of a specimen in my collection. Fig. 10 

 exhibits a young form with larger umbilicus, possibly a variety of this species, 

 with which it was found. 



