﻿190 BRITISH FOSSIL CEPHALOPODA. 



The septa have a considerable convexity, i the diameter. The sutures are direct, 

 and the siphuncle \ the diameter from the ventral edge. Length of body-chamber, 

 1 inch ; greatest diameter, 1^ inches. From the Wenlock Limestone of Malvern. 

 In the Museum of Practical Geology. 



General Description. — The section is very often elliptic ; but it is presumed that 

 this is due to compression, as the inequality of the axes is never very great, and the 

 longer one is always in the plane of symmetry. The body-chamber is the only part 

 that has been preserved in any examples. This has always a length rather less 

 than its basal diameter, and contracts uniformly to the aperture, so that its shape is 

 conoidal. Some little differences of aperture are seen in specimens nevertheless 

 included in the species. In many it is like the type. In some the passage and 

 ventral opening are wider, and in one (fig. 4) the circumference (perhaps broken 

 down) is different, and may indicate a distinct species. The shell was thick, and had 

 rough transverse undulations and lines of growth. The septa are very convex, up 

 to -^ of the diameter. The siphuncle is \ of the diameter from the edge, and is 

 bulbous. The type is as large as any that are found. 



Relations. — The peculiar conoidal form of the body-chamber, combined with the 

 great convexity of the septa, mark off this species very clearly. The specimen 

 (fig. 4) very closely resembles Barrande's G. ferum, but in our fossil the apparent 

 aperture is taken to be due to some defect in the preservation. G. decurtatwn and 

 G. microstoma are somewhat similar in shape, but differ in the details of the aperture 

 and the less convexity of the septa. 



Distribution. — In the Woolhope Beds, Littlehope (1) ; in the Wenlock Shale of 

 Malvern (4) ; in the Wenlock Limestone of Malvern (5). 



Gomphoceras ellipticum, M'Coy, PI. XXII. figs. 1, la, 4. 



1838. Gomphoceras pyriforme, Sowerby in Murchison's 'Silurian Syst.' pi. 8, fig. 19 (lower), 



and fig. 20, not upper fig. 19. 



1851. Poterioceras ellipticum, M'Coy, ' Ann. and Mag. of Nat. Hist.' Ser. II. vol. vii. p. 45. 



1852. „ „ M'Coy, ' British Palaeozoic Fossils,' p. 321. 



1854. Phragmoceras pyriforme, Morris, 'Catalogue of British Fossils,' p. 312 (with fig. 19 of 



Sowerby). 



1866. Gomphoceras ovum, Barrande, ' Syst. Sil. de Boheme,' pi. 75, 84, and 105. 



1867. Gomphoceras pyriforme, Dixon, 'Woolhope Nat. Field Club, Fossil Sketches,' No. 1, fig. 4, 



p. 136. 



Type. — The section at the last septum is elliptic, the antero-posterior diameter 

 being 2^ inches, and the transverse diameter 2-^- inches, which is therefore the 

 greater. The general shape of the shell perpendicular to this section is elliptic, 

 the greatest diameter being opposite the last septum. The septal portion begins 

 by being nearly cylindrical. After 1 inch of this from the broken end a sudden 



