﻿JURASSIC AND TRIASSIC BRACHIOPODA. 



97 



In external shape this species (?) bears much resemblance to Sp. rostrata ; but, while 

 in the last named the fold is obscurely represented, it is generally sharply defined in the 

 form under description. Then again, while the whole surface of Sp. rostrata is stated to 

 be always smooth, the lateral portions of both valves in Sp. pinguis are covered with 

 numerous radiating simple ribs, the fold and sinus alone remaining smooth. From 

 twenty to forty ribs may be counted on the surface of each valve, and while these are 

 scarcely defined in some specimens, they are strongly marked in others. Not much 

 difference seems to exist in the spines which rise from the surface of this and the two 

 preceding species (?); they are very numerous, short, and slender. 



Mr. Deslongchamps informs us moreover that, in addition to the ribs already described, 

 the spiral coils, instead of being almost horizontal, as in Sp. rostrata, form an oblique 

 angle, the conical extremity of each coil lying close to the hinge-line (Sup., PI. XI, fig. 

 8). This form appears to occur both in the Lower and Middle Lias, and in localities 

 where the two preceding species are found. It is abundant in the Middle Lias of 

 France, and occurs, though, I believe, but rarely, in the Marlstone or Middle Lias of 

 England. It must not be confounded with Spirifer pinguis of Sowerby, which is a 

 well-known Carboniferous species, and we should have objected entirely to the name 

 being made use of for this liassic shell, had the two not been generically distinct. 



36. Spiriferina verrucosa, von Buck, sp. Dav., Ool. Mon. (pars), p. 20, Pi. Ill, 



fig. 1; Sup., PI. XI, figs. 9, 10. 



Delthyris verrucosa, von Buck. Petrifications remarq., pi. vii, fig. 2, 1831. 

 Spirifer verrucosus, Zieten. Die Verst. "Wiirtemb., pi. xxxviii, fig. 2, 1838. 

 Delthyris verrucosa, von Such. Classif. et Desc. des Delthyris, Mem. Soc. Geol. 



de France, 1st ser., vol. iv, pi. x, fig. 30, 1840. 

 Spirifer verrucosus, Quenstedt. Das Floegebirge "Wiirtemb., p. 185, 1843. 

 Spiriferina verrucosa, d'Orb. Prod., p. 221, No. 151, 1849. 



Spirifer verrucosus, Quenstedt, Handbuch der Petrefack., p. 482, tab. 38, figs. 35, 



40, 1852. 



— — Oppel. Des Mittlere Lias Scbwabens, pi. iv, fig. 6, 1853. 



— — Oppel. Die Jura-Formation, p. 108, No. 119, 1856. 

 Spiriferina verrucosa, E. Desl. Bulletin Soc. Linn, de Normandie, tab. iii, p. 135, 



1858. 



Spirifer verrucosus l^evigatus, Quenstedt. Der Jura, p. 152, pi. xviii, figs. 6 



and 14, 1858. 



— plicatus, Quenstedt. Der Jura, p. 152, pi. xviii, fig. 15, 1858. 

 Spiriferina verrucosa, E. Desl. Etudes Critiques sur des Brachiopodes neuveaux 



ou peu connus, p. 17, pi. ii, figs. 4 — 6, 1862. 



The shell of this species appears to be always much smaller than that of Sp. rostrata, 



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