210 INFERIOR OOLITE AMMONITES. 



band and a portion of the infilling of the hollow-carina remaining attached to the 

 ventral area. Fig. 3 is the suture-line. In PI. XXXIV, figs. 8, 9, are exhibited 

 two views of a smaller specimen. 



Geammoceras METALLARiDM {Dumovtier). Plate XXXVI, figs. 1, 2. 



1874. Ammonites metallaeius, Dmnortier. Etudes paleont. Bassin du Ehone, 



4e partie, pi. xvi, figs. 2 — 4. 



Discoidal, compressed, hollow-carinate. Whorls compressed with rather broad 

 sides, ornamented with strongly-marked, veutrallj-projected, subsigmoidal ribs, 

 irregularly fasciated on the inner area and inner margin, producing irregular, 

 elongate tuberosities. Ventral area acute, carrying a large hollow-carina not 

 laterally sulcate. Inner margin fairly steep, but very rugose on account of the 

 fascicled ribs. Inclusion about two-fifths. 



I cannot form any conjecture concerning the parentage of this form, but it is 

 very obviously the parent of Gramm. dispansum. The fasciation of the ribbing 

 upon the inner area distinguishes it from all the previously-described species of 

 hollow-carinate Gramiibocerata, and gives it the appearance of Haugia ; but from the 

 forms of this genus its ventrally-projected ribs at once separate it, and show that 

 its correct place is in the genus Gh^ammoceras. 



Of the previously-described species of hollow-carinate Grammocerata only 

 Gramm. MueUeri shows any indication of fasciated ribbing, and this only so 

 slightly that no stress can be laid thereon. 



So far as I know the example figured is the only specimen which has been found 

 in this country. It has its test preserved. It does not exhibit the suture-line, 

 which must for the present remain unknown, as Dumortier did not figure it. 



The Bispansum-beds of Buckholt Wood have yielded me this rare specimen. 

 It bears evidence of having continued for at least three parts of another whorl. 



PI. XXXVI, figs. 1, 2, exhibit two views of this specimen. The hollow-carina 

 is present upon the greater part of the ventral area. The remains of a further 

 continuation of the whorl are to be seen on the lateral area as depicted. 



