Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/177

 of the shell ; area moderately wide, marked with perpendicular parallel lines, and with two deep circular pits (elevations on the cast), one on each side of the centre, divided by a small flattened space ; the saucer-shaped muscular scars are large, and, in the shell, divided by a median ridge.

Mr. Vicary found this single specimen associated with R. ovalis. The peculiar shape of its area and accompanying pits seems to distinguish it from other known forms of the genus, although it is impossible to offer a complete description of its characters.

33. Streptorhynchus crenistria, Phil. Pl. V. fig. 26. Spirifer crenistria, Phil. Geol. of Yorkshire, vol. ii. p. 216, pl. 9. fig. 6 ; Streptorhynchus crenistria, Dav. Dev. Mon. p. 81, pl. xviii. fig. 7.

Of this species, only a fragment of the exterior of one valve has been found. It seems to agree entirely with similar portions of S. crenistria, with which we have compared it. The shell has been fully described in my monograph. It was found along with Spirifera Verneuilii, Rhynchonella inaurita, and Productus Vicaryi, and is consequently a Devonian species.

34. Productus Vicaryi, Salter, sp. Pl. VI. fig. 14. Leptoena Vicaryi, Salter, Quart. Journ. Geol. Soc. vol. xx. p. 296, pl. xvii. figs. 16-17.

Well described and figured by Mr. Salter, but incorrectly identified as a Leptoena, while all its external and internal characters show it to be a Productus ; in addition to the cardinal spines, we find the large cardinal or divaricator muscular impressions of the genus Productus. These finely striated scars were correctly drawn by Mr. Salter in 1864. In his description he states, "I know no Silurian species, except the small L. quadrata of Russia, and L. tenuicincta of Britain, which resemble this form ; both are much smaller and less gibbous." But these last belong to the genus Leptoena, and are quite different both as to shape and character, while the so-called Leptoena Vicaryi is a well- characterized Productus. P. Vicaryi is not very rare at Budleigh-Salterton, and is found associated with Spirifera Verneuilii, Rhynchonella inaurita, and Streptorhynchus crenistria, all well-known Devonian species.

35. Chonetes, sp. Pl. VI. fig. 13.

Of this small species of Chonetes several specimens have been met with by Messrs. Edgell and Vicary in one or two pebbles ; and as it was associated with Rhynchonella inaurita, it is no doubt of Devonian age ; but as the exterior has not been discovered, we cannot refer it with certainty to any of the described species. The casts are marginally semicircular ; hinge-line straight, with acute, slightly projecting cardinal angles ; ventral valve evenly convex. Length 3, width 4 lines. In external shape it resembles some Devonian casts of C. hardrensis, but is a smaller shell.

Besides the species above enumerated, Mr. Vicary has found in-