﻿DUMORTIERIA. 231 



species in the Cotteswolds. The specimen from which the outlines (figs. 9, 10) 

 were taken came from Penn Wood, near Stroud ; and fragments have been 

 collected at Cam Down, North Nibley, and Wootton-under-Edge. 



From the Dispansum-heds of White Lackington, near Ilminster, I obtained a 

 poor fragment. 



PI. XXXVIII, fig. 9, is the outline of the side view of a very inferior 

 specimen of this species ; fig. 10 is its aperture ; and fig. 11 its suture-line. It 

 came from Penn Wood, near Stroud. Fig. 12 shows the aperture of a fragment 

 from Cam Down, near Dursley. This aperture differs somewhat in shape from 

 fig. 10, but then the specimen is much smaller. 



Family — Polymorphic, Haug. 

 Genus — Dumortieria, Haug. 



{Type — Dumobtieeia Levesqttei, cTOrbigny sp.) 



1885. Dumobtiebia, Haug. Beitr. Monogr. Harpoceras ; Neues Jahrbuch fur 



Mineral., Ac, Beil.-Bd. iii, p. 666. 



1887. — — " Polymorphidaj;" Neues Jahrbuch fur Mineral., Ac, 



Bd. ii, p. 147. 



Discoidal, compressed, fairly evolute. Whorls ornamented with ribs, straight 

 or nearly straight on the lateral area, 1 slightly projected forwards on the ventral 

 area. Ventral area more or less carinate. Mouth furnished with a long lateral 

 process and a slight pointed ventral projection. Suture-line fairly ornate, lobes 

 rather long and saddles rather deep. The inner part of the suture-line, including 

 the rather small inferior lateral lobe, somewhat dependent — that is, the lobes 

 pointing across the whorl towards the carina. 



The species of Ammonites which compose the genus Dumortieria appear to me 

 to possess unusual interest ; and yet they have attracted but little attention in this 

 country. I attribute this want of notice, first, to their generally inferior preserva- 

 tion, as well as comparative scarcity ; and secondly, to their having probably 

 passed as belonging to other species of Ammonites — species now separated into 

 the genus Grammoceras. 



1 These ribs will be described as direct (= straight) or subdirect (= nearly straight) ribs, 

 ventrally inclined — that is, with a short ventral projection, not a long ventral projection (= ventrally 

 projected) as in Grammoceras. 



