20 
DEVONIAN PAUNA. 
They have been usually referred to Gardium aliforme, Sowerby, but it 
will be seen that the name which they should rightfully bear is probably G. 
clathratum. 
G. aliforme, Sowerby,^ was first described in the ' Min. Conch.,' from Queen's 
County, Ireland, and, as seen both from that description, and from the original and 
other specimens in the British Museum, it is distinctly different from the present 
form. It is a larger and much less angulated shell ; the ribs on the median region 
are much more numerous and more distant; the anterior slope is distinctly 
concave ; and the ribs on the posterior wing are much larger. De Koninck points 
out its distinctness, and says that the following have been wrongfully identified 
with it : — Bucardites hystericus, Schlotheim,^ G. inversum, Honinghaus,^ Fl. 
aliformis, Phillips, Liclias antiquus, Steininger,* Gardium elongatum, Bronn/ 
C. elongatum, Groldfuss,^ and G. aliforme, Goldfuss, and d'Archiac and de Verneuil. 
Under the name of Sowerby's shell, Goldfuss'^ described as varieties several 
distinct Carboniferous and Devonian forms. Of these, his two figures, pi. cxlii, 
figs, a and g, alone appear to represent the present species. 
Phillips, in the 'Pal. Foss.,' divides his Devonshire specimens into two species, 
G. aliforme and G. minax, Phillips.^ The two figures which he refers to the 
former clearly belong to the present form, and the original of one of them I find 
among the specimens in the Museum of Practical Geology. His so-called Devonian 
G. minax is distinguished by its smaller and distinctly concave cordiform slope, its 
broader median region, which contains many more ribs, and the large size of the 
ribs on the conical aliform protuberance. The defective shell figured as G. aliforme 
by Sowerby,^ from Stonehouse Hill, Devon, appears to agree with this latter species, 
and shows similar distinctions, though a crushed Lummaton example of our 
present shell, which is in my Collection, mimics its general shape. 
D'Archiac and de Verneuil give as G. aldeforme, var. clathratum, Goldfuss 
(referring to his fig. 1 ^/), a shell which differs from ours only in having the median 
ridge rather more pronounced, and which therefore, in all probability, belongs to 
this present species. 
F. A. Romer gives an indistinct figure of PI. alceformis, Sow., which, from his 
1 1827, Sowerby, ' Min. Conch.,' vol. vi, p. 100, pi. dlii, fig. 2. 
2 1820-2, Schlotheim, ' Petrefack.,' vol. i, p. 207 ; vol. ii, p. 63, pi. sx, figs. 1 a—c. 
3 1830, Honinghaus, ' Jahrb. f. Min.,' p. 236. 
* 1853, Steininger, ' Bull. Soc. Geol. Fr.,' vol. viii, p. 231, figs. 
5 1837, Bronn, ' Lethsea,' p. 92, pi. iii, fig. 9. 
6 1834-40, Goldfuss, ' Petref. Germ.,' vol. v, p. 213, pi. cxlii, fig. 2. 
7 Ibid., p. 214, pi. cxlii, figs. 1 a — m. 
8 1836, Phillips, ' Geol. Torks.,' vol. ii, p. 210, pi. v, fig. 27 ; and 1841, Phillips, ' Pal. Poss.,' 
p. 33, pi. xvii, figs. 50 a, h. 
9 1840, Sowerby, ' Geol. Trans.,' ser. 2, vol. v, pt. 3, pi. Ivi, fig. 2. 
