160 DEVONIAN FAUNA. 
ally. This portion of the shell is, unfortunately, very obscure, and it does not 
seem to lie quite symmetrically, which, however, may possibly be due to crushing. 
Affinities. —Discina anomala, Kayser,’ is somewhat similar in shape, but is 
larger and ornamented with fine rays. 
Il. Family.—Cranupm, d@ Orbigny, 1847. 
1. Genus.—Crania, Retziws, 1781. 
1. Cranta proavia, Goldfuss ?. Pl. XVIII, fig. 1. 
1840. Cranrta PRoavia, Goldfuss. Petref. Germ., vol. ii, p. 298, pl. clxiii, figs. 
NOkaanOs 
1854. _ — Schnur. Paleontographica, vol. ili, p. 230, pl. xliii, 
figs. 9a, b. 
Ise, — — ? Kayser. Zeitsch. Deutsch. Geol. Gesell., vol. xxiii, 
p- 641, pl. xiv, fig. 6. 
Locality.—A single small specimen attached toa shell of Pentamerus brevirostris 
from Lummaton is in my Collection. 
Remarks.—This little fossil is clearly a Crania, but it is too imperfect for me 
to say more than that it accurately corresponds with Goldfuss’s species as far as its 
characters are seen, except in size. It is less than 4 mm. in diameter, slightly 
wider than long, subquadrate in shape, and flatly conical in contour, being much 
steeper behind. ‘The shell is removed from the central parts of the upper or free 
valve, exposing two adjacent kidney-shaped impressions of the anterior adductors, 
which are situate at about the posterior third of the longitudinal diameter and 
immediately in front of the apex. ‘lhe surface of the cast is minutely granulose, 
and seems bounded by one or two strong marginal furrows. The shell-structure 
is rather thick for the size of the shell, and appears to have borne a lamellose 
concentric ornament. 
1 1892, Kayser, ‘ Jahrbuch Konigl. Preuss. Geol. Landes,’ p. 97, pl. x, figs. 1—3. 
