SUBCLYMENIA. 26 



2. GoNiATiTES, sp. Plate IV, figs. 1, 1 a. 



Bescrijption. — Shell very small, globose. Umbilicus minute, deep. Sides of the 

 whorls rising from the margin of umbilicus for a short distance in a gentle curve, 

 and then arching round still more gently to form a broad, regular, and very mode- 

 rately convex back. Suture-lines unseen. Sulci three (two only being distinctly 

 visible) straight, crossing the whorls perpendicularly. 



Size. — Diameters 10 mm. and 9 mm. ; width 6 mm. 



Locality. — Two small specimens from Barnstaple are in the "Woodwardian 

 Museum. 



Remarks. — These specimens, which from the nature of their matrix evidently 

 come from the Pilton beds, show little beyond the general form of the species, the 

 chief feature of which is the convexity of the sides as they rise from the umbilicus. 

 The shell is very closely coiled, the backs of succeeding whorls having little 

 room between them, so that the shape of the shell-cavity must have been highly 

 lunate, and the whorls numerous. 



Affinities. — Goniatites micromjjJialus, F. A. Romer,' of the Wissenbach slates, 

 differs in having the margin of the umbilicus higher and more angular. 



Mr. Crick and I compared the specimens with Carboniferous examples of 

 G. crenistria (the name these specimens had borne in the Museum), and came to 

 the conclusion that it was in no way connected with that shell. With G. linearis, 

 Miinster, as given by Phillips, it may have more in common, but I am not certain 

 whether the rounding-in of the shell round the umbilicus occurs in that species. 



Sub-Oedee— NAUTILOIDEA, cVOrUgny, 1826. 



I. Family— NKGIllADM, Owen, 1836. 

 1. Gemfs— SUBCLYMENIA, d'Orbigmj, 1849. 



" This genus differs from Discitoceras (Discites) in the sutures and position of 

 the siphon. The sutures have a deep V-shaped ventral and acute linguiform first 

 pair of saddles, first pair of lateral lobes narrow, a second pair of small lateral saddles 

 near the umbilical shoulders, and dorsal saddles divided by shallow annular lobes 

 with a minute median saddle. The abdomens are hollow, and the dorsal region 

 gibbous, as in the adults of Aphelseceras. The siphon is near the venter, but the 



1 1850, F. A. Eomer, ' Beitr. Harzgeb.,' pt. 1, p. 19, pi. iii, figs. 30 a, h. 



D 



