182 INFERIOR OOLITE AMMONITES. 



and Wotton-under-Edge in Gloucestershire. Branco quotes his specimens from 

 ' Oberregion d. Sch. m. Trig, navis. Ziemlich hiiufig. Signalberg bei Boevingen." 

 Dr. Haug sent me from Gundershofen a specimen which I identify as this species. 

 Plate XXXI, figs. 5, 6, represent two views of a specimen, from North Nibley, 

 of moderate size and without test. Larger examples have been found. Fig. 7 

 shows the side view of another specimen from the same place with its test ; 

 figs. 8 and 9 illustrate the aperture and the suture-line respectively. In figs. 10, 

 11, 12 are seen the two views, and the suture-line, of a specimen from Haresfield 

 Beacon, with a slightly larger umbilicus. Fig. 13 exhibits a specimen with small 

 umbilicus, also from Haresfield Beacon ; fig. 14 is the suture-line. 



Grammoceras doerntense {DencJcmann). Plate XXIX ; Plate XXXIII, figs. 11, 12. 



1867. Ammonites aalensis, Meneghini (non Zieten). Foss. calc. rouge; Pal. 



Lombarde, 4e serie, pi. xi, figs. 1 — 3. 



1867. — sp. iNDET, Meneghini. Ibid., pi. xi, fig. 4 only. 



1884. Haepoceeas steiatulum, Wright (non Sowerbg). Lias Amm. ; Pal. Soc, 



pi. Ixxxiv, figs. 5, 6 (non fig. 4). 



1887. Ammonites (Haepoceeas) Doeentensis, Benckmann. Fauna Ob. Lias 



Doernten ; Abb. geol Specialkarte von 

 Preussen und den Thuringisehen Staaten, 

 pi. ii, fig. 4 ; pi. viii, figs. 1 — 6 ; pi. x, fig. 9, 

 p. 50 [164]. 



Discoidal, compressed, carinate. Whorls elliptical, ornamented with ventrally 

 projected subarcuate ribs, which are often irregular in the inner whorls, and are 

 then sometimes united towards the inner margin. Ventral area not defined ; 

 carina small and solid. Inner margin not actually defined ; the whorls are almost 

 regularly convex, though the slope towards the preceding whorl is sometimes a 

 little steeper. Inclusion about one-third. Umbilicus open. Sutures simple, on 

 the same pattern as in Gramm. toarcense, but with rather longer lobes. 



This species, which is practically of later date than Gramm. toarcense, is 

 undoubtedly a mutation of the forms with united ribs. It is distinguished from 

 Gramm. toarcense by its broader whorls with more convex sides, its smaller 

 umbilicus, and its rather more acute ventral area. Its ribs are also more numerous, 

 less conspicuous, and are, if anything, rather more curved. Its siphonal and 

 superior lateral lobes are also larger in proportion. 



For the separation of this species we are indebted to Denckmann's recent 



