8 
DEVONIAN FAUNA. 
least presumptively, as synonyms, especially as in one of Hall's figures, the minor 
transverse strias mentioned by Phillips are visible. 
Hall unites Gypricardites inflata, Conrad, with G. indenta. 
The English specimens and Sandberger's, Bilhngs', and Hall's figures all vary 
much more in themselves than tbev difier from each other, and a continuous chain 
might be formed by intermixing them. The German form has the shortest hinge- 
line, the Canadian and Bohemian the longest. The Canadian is the largest shell, 
the Grerman the next, and the Bohemian the smallest ; but English specimens may 
be found as small as any. 
Affinities. — Modiola squamifera, Phillips,^ is evidently a kindred form, but 
differs in so many particulars that I agree with Clarke in separating it. It is 
much larger and more transverse, and has no central constriction, a longer hinge- 
line, and much smaller umbones. 
Gypricardia glabrata, Phillips,'^ also seems very similar in general shape, but 
Phillips's figure and description are too slight for comparison. 
Gervillia squamosa, Phillips,^ appears to belong to the same genus, but his 
figure is insufficient for specific comparison. 
Gypricardia semisulcata, Phillips,* is at once distinguishable by the divarication 
of its ridges and their posterior effacement. 
G. impressa, Sowerby (?), as given by Phillips,^ is much broader in front, and 
has the ribs of uniform size. 
Isocardia Humholdti, Honinghaus,® as given by P. A. E-omer,^ is a small 
variable shell, not very dissimilar, but differing in having a smaller umbo and a 
more produced anterior side, and in being decidedly less produced. Sandberger,* 
without giving a reason, changes its name to Isocardia coelata, and his figure is 
very different from Romer's version of it, as well as from the present shell, from 
which he distinguishes it. It shows transverse divaricating growth-lines which 
suggest its identity with Gypricardia semisulcata, Phillips. 
In Myacites striatulus, F. Romer,^ the umbo is so much more central that there 
is no doubt that it is distinct. 
Gypricardinia squamifera, F. A. Romer, as given by Maurer, has much finer 
ribs, and varies much in shape, so that I doubt its identity. 
1 1836, Phillips, ' Geol. Torks.,' vol. ii, p. 209, pi. v, fig. 22. 
2 Ibid., p. 209, pi. V, fig. 25. 3 jbid., p. 212, pi. vi, fig. 9. 
* 1841, Phillips, ' Pal. Foss.,' p. 36, pi. xvii, figs. 57 a—c. 
5 Ibid., p. 36, pi. xvii, fig. 58. 
6 1828. Honinghaus, ' Isis,' p. 96, pi. i, fig. 1 ; and 1834-40, Goldfuss, ' Petref. Germ.,' vol. ii, 
207, pi. cxl, fig. 2. 
7 1850, F. A. Eomer, ' Beitr.,' pt. 1, p. 14, pi. iii, figs. 10a— c. 
8 1853, Saudberger, ' Verst. Rhein. Nassau,' p. 260, pi. xxvii, figs. 11, 11 a, 11 b. 
9 1844, F. Eomer, ' Ehein. Uebergangsgeb.,' p. 79, pi. ii, figs. 5 a, b. 
