JURASSIC AND TRIASS1C BRACHIOPODA. 221 



If we examine Quenstedt's figures of both forms in pi. 26 of the ' Handbuch,' and pi. 

 17 of 'Der Jura/ we find that almost all oar British examples agree entirely in shape 

 and character with Quenstedt's figures of T. calcicosta ; and indeed they seem as if 

 drawn from some of our Churchdown or Stonehouse specimens. Rh. plicatissima, 

 Quenstedt, as its name implies and Quenstedt's figures show, is a shell with many more 

 and smaller ribs. I have two German specimens of the last-named form, sent me by 

 Dr. Oppel, from Giniind and Ofterdingen, which show a larger number of smaller ribs 

 than is seen in the English and Scotch examples of R. calcicosta. Indeed, I do not 

 positively know any British specimens that could be correctly identified with the German 

 Rh. plicatissima, and therefore think it will be more correct to refer the shells under 

 description to Rh. calcicosta. 



I cannot agree with Prof. Tate or Dr. Brauns in uniting several species with smooth 

 umbonal regions, such as Rh. gryphitica, Rh. oxynoti, and others, with the essentially 

 ribbed Rh. calcicosta. Dr. D. Brauns states in his ' Nordwestlicher Deutschland ' that 

 Rh. curviceps (Quenstedt), 'Jura,' pi. 17, figs. 13 — 15, and Rh. tetrahedra rufimontana, 

 pi. 37, figs. 1, 2, 3, 1870, are synonyms of the species under description ; but, as I 

 have not seen authentic German types, I will not venture upon any opinion on that 

 subject. 



Localities. — Specimens of Rh. calcicosta have been found by the Rev. P. Smithe, 

 Prof. Tate, and others in the zone of Am. margaritatus, at Huntcliff in Yorkshire, — in the 

 top bed of the Am. Bucklandi zone, of the Lower Lias, of Churchdown, Gloucestershire, — 

 at Stonehouse and Badgsworth near Cheltenham, and also at Applecross in the West of 

 Scotland, &c. The shell is exceedingly abundant in some of our Lower Lias localities. 



230. Rhynchonella Glevensis, Smithe, MS. Dav., Sup., PI. XXVIII, fig. 22. 



Shell somewhat triangular, longer than wide, broad anteriorly, corners rounded, 

 straight in front, tapering posteriorly into an acute, incurved beak ; valves almost equally 

 convex or deep. Dorsal valve divided into three lobes, of which the central one forms a 

 moderately raised and broad mesial fold, a shallow sinus corresponding to it in the 

 ventral valve. Surface of each valve ornamented with about sixteen simple, angular, 

 radiating ribs, of which about four occupy the fold, and three the sinus. 

 Length 6, width 5^, depth 4 lines. 



Obs. — This small species is distinguishable from Rh. plicatissima by its greater 

 length as compared with its width. Several specimens of this shell were discovered by 

 the Rev. P. Smithe in the Am. angulatus zone, and are especially interesting as occur- 

 ring so early in the Lias, — the only Hettangian species, according to the Rev. F. Smithe, 

 taking that word to comprise the Am.planorbis and Am. angulatus beds. Indeed, scarcely 



