128 PERMIAN FOSSILS. 
SPIRIFER CRIsSTATUS, Schl. Geinitz, Geea von Sachsen, p. 97, 1843. 
— —_ » Morris, Catalogue, p. 128, 1843. 
== —_ » De Verneuil, Bull. Soc. Géol. de France, 2™° série, t. i, 
p. 28, 1844. 
= —— » Geol. Russ., vol. i, p. 221, 1845. 
— — » Tennant, Brit. Fossils, p. 88, 1847. 
— — » King, Catalogue, p. 8, 1848. 
== — », Howse, Trans. T. N. F. C., vol. 1, p. 254, 1848. 
— — »  Geinitz, Verstemerungen, p. 12, pl. v, fig. 10, 1848. 
(?) ae aS », De Koninck, Bull. Soc. Géol. de France, 2™° série, t. vi, 
Seance June 2, 1849. 
Diagnosis.—Semi-elliptical marginally: with generally eight prominent angular 
ribs. Surface with prominent lines of growth. Punctwres large, giving the valves a 
coarsely granulated appearance. Large valve half as high as it is wide, slightly rounded : 
umbone slightly incurving: area moderately high: jisswre moderately large, and open: 
median plate deep, and extending from the umbonal point to the centre of the valve. 
Small valve slightly elevated, and somewhat flat: median rib twice the size of those 
immediately adjoining. 
Trigonotreta cristata closely resembles one or more so-called species found in the 
Carboniferous and other formations, particularly the 7. ocfoplicata of J. Sowerby. 
Having examined in Mr. J. de C. Sowerby’s collection the originals (from Derbyshire) 
of the figures in the ‘ Mineral Conchology, the only difference I could perceive is, that 
they are wider than any examples which have occurred to me of the present species.! 
Specimens bearmg the name of Spirifera imsculpta, in the Gilbertsonian collection 
of the British Museum, appear to be undistinguishable from Zrigonotreta cristata. 
The Jurassic fossil which Zeiten has identified with the 7. octoplicata, is another 
closely analogous species. 
Its large punctures give this species a remarkable appearance, particularly im 
casts, which are often crowded with short truncated spines standing erect on the 
surfaces to which they adhere; the same being casts of tubular punctures, which 
passed uninterruptedly through the entire thickness of the valves from the inner to 
the outer surface. The punctures, and their casts, are represented, highly magnified, 
in figs. 13, 14, Pl. VIII. 
Trigonotreta cristata was first recorded as a British species by Quenstedt, who 
notices its occurrmg at Humbleton. I have found it at Tunstall Hill, Hylton North 
Farm, and Tynemouth Cliff; but in none of these localities is it a common fossil, 
especially in the last three. Schlotheim, its earliest discoverer, noticed it at Gliicksbrunn ; 
and Geinitz gives the following additional German localities, Konitz, Possneck, Alten- 
stem, Schwaara, and Ropsen. If De Koninck be correct in the identification, it may 
be stated as also occurrmg im Spitzbergen. It does not appear to have been found in 
Russia. 
' Mr. J. de C. Sowerby’s specimens have punctures like those of Trigonotreta cristata. 
