BELLEROPHON. 63 



It closely resembles and probably belongs to the Devonian Bellerophon 

 elegans, d'Orbigny, although its ornament seems to be set more closely. In that 

 respect it agrees with the Carboniferous B. clathraUis, d'Orbigny, which its 

 describer distinguishes from the former species by its having only three 

 longitudinal threads on the keel instead of numerous finer lines. These two 

 species de Koninck unites ; but he separates from them B. elegans, d'Archiac 

 and de Yerneuil, on account of its wider and flatter keel. It appears to me 

 that in that particular our fossil agrees with B. elegans, as originally given by 

 d'Orbigny, and comes exactly half-way between d'Archiac and de Verneuil's and 

 de Koninck's versions of it. On the whole it may prove that the species was 

 variable and long-lived. 



Affinities. — From Euphemus Barumensis, the only North Devon species at all 

 resembling it, it is at once distinguished by its open umbilicus and elevated keel. 



B. Vogulicus, Tschernyschew,^ is a narrow, more rapidly-increasing form with 

 a closed umbilicus. 



2. Bellekophon labyrinthodes, n. sp. Plate VIII, figs. 1 — 2 b. 



Description. — Shell small, convex, globose, horizontally symmetrical, probably 

 of rather numerous whorls. Umbilicus rather large, expanding laterally. Whorls 

 nearly evenly convex, bearing a central narrow elevated sinus-band, which is 

 bordered by elevated threads and crossed by minute arching strige. Surface- 

 ornament very minute, so as to be invisible to the naked eye, consisting of close 

 zigzag rows of puncta between sharp ridges, which are scored by the puncta, 

 about four zigzags occupying each side of the shell-surface ; beneath which are 

 sometimes seen indications of larger transverse arching growth-lines and radiating 

 ribs. 



Size. — Height 11 mm., width 8 mm. 



Localities. — In the Barnstaple Athenaeum are several specimens on two slabs 

 from Kingdon's, Shirwell, and one from Top Orchard, all of which are casts 

 except one. In the Museum of Practical Geology is a specimen from Baggy Point. 



Remarks. — This is a very beautiful and highly ornamented species. The orna- 

 ment is microscopical, but it is much in the style of B. Hicksii,^ except that it is 

 much finer and more definitely zigzag. Roughly speaking, the pattern is reticulate, 

 the zigzaging being only visible in some lights. The Baggy specimen is rather 

 more coarsely and definitely marked, and under the superficial ornament it shows 

 signs of transverse ribs like those of B. costatus, and radiations like those of 

 Eu. TJrii. It is possible that the latter are the true ornaments, and that the finer 



1 1893, Tschernyschew, ' Mem. Com. G-eol.,' vol. iv. No. .3, p. 159, pi. iii, figs. 1 a—d. 



2 1891, Whidborne, ' Dev. Faun.,' vol. i, p. 326, pi. 31, figs. 7— 8 a. 



