GONIATITES. 73 



is remarkable for its extremely elongate shape, the spiral formed by its whorls 

 being of an elhptic and not circular character. This seems a constant character, 

 as it exists in a greater or less degree in every specimen I have examined. Hence 

 the measurements of the shell vary much according to the position on the ellipse 

 which the mouth happened to have reached at the time of the animal's death. In 

 the largest specimen known it is upon the longest diameter, but in a specimen in 

 the Jermyn Street Museum, which nearly equals it in size, it is upon the shortest. 

 The mouth seems slightly expanded laterally, and its margins appear to form a 

 simple and gently advancing curve, so that it rather overhangs the aperture. 



Unfortunately, in common with most of the "Wolborough fossils, the surface of 

 the specimens is decayed, and the suture-line is obliterated except in a few obscure 

 examples. The former would appear, however, in all likelihood to have been 

 smooth. 



I formerly supposed that this was the G. linearis of Miinster^ and Phillips,^ 

 chiefly because Mr, Vicary's specimen had been so labelled by Salter. When, 

 however, Mr. Roberts and I examined them carefully, he convinced me that it 

 could not belong to their shell or shells. It is not globular, its mouth is larger, 

 and the curvature of the suture-line is quite different. In fact, on referring to 

 Mlinster's ' Beitrage ' (in the 2nd edition of which his earlier paper is incor- 

 porated), Phillips's description becomes obscure, the more so as his references 

 are inaccurate and interchanged, and all we can say is that Miinster's pi. v a, 

 fig. 1, seems to correspond with his larger figure (229 a) and that the latter 

 certainly does not resemble our Wolborough shell, the identity of which must 

 therefore be sought elsewhere. 



Affinities. — Its constant elliptic form distinguishes it from all the other species 

 given by Miinster except G. hyhridus,^ which has a very zigzagged suture-line ; 

 G. suhhilobahis*, in which the central saddle is angulated and the lateral lobe acute ; 

 and G. Bronnii^ which has two lateral lobes. G. ovatus, Miinst.,^ is slightly elliptic, 

 but it is flatter, and the suture-line is almost like G. linearis, having very narrow 

 side lobes and a very elongate central lobe. In G. suhlcevis, Miinst.,'^ G. undulosus,^ 

 Miinst., and G. suhUnearis, Miinst.,® the side lobe of the suture-line is also sharp 

 and narrow. In G. subsulcatus, Miinst.,^" the mouth is smaller and the front view 

 more squared. 



1 1832, Miinst., ' tJher Clym. und G-on. Ficlitelgeb.,' p. 22, pi. v a, fig. 1. 



3 1841, Phil., ' Pal. Foss.,' p. 120, pi. xlix, figs. 229, a—d. 



3 1832, Munst., ' tJber Clym. und Gon. Fichtelgeb.,' p. 19, pi. iv a, fig, 6. 



4 1839, ibid., ' Beitriige,' pt. 1, p. 21, pi. xvii, fig. 1. 



5 1840, ibid., pt. 3, p. 108, pi. xvi, fig. 9. 



6 1832, ibid., ' tJber Clym. und Gon. Fichtelgeb.,' p. 18, pi. ivA, fig. 1. 



7 Ibid., p. 20, pi. iv A, fig. 2. ^ Ibid., p. 20, pi. iv a, fig. 3. 

 9 Ibid., p. 22, pi. iv a, fig. 5, lo Ibid., p. 23, pi. v a, fig. 2. 



