Dr. H. Woodward—Prosopon in the Clypeus- Grit. 79 
V.—On a new Bracnyvrovus Crustacran From THE ‘‘ Crypzus-Grir”’ 
(Inventor Oo1rrn) OF THE Correswotp Hurts. 
By Henry Woopwarp, LL.D., F.R.S., F.G.S., 
late Keeper of Geology, British Museum (Natural History). 
aa November last Mr. L. Richardson, of Cheltenham, very kindly 
sent me (with other fossils for inspection and determination) the 
carapace of a small Crustacean from the ‘ Clypeus-Grit”’ of the 
Cotteswolds, which had been picked up and given him by Mr. C. L. 
Walton. As Mr. Richardson anticipated, the species proves to be new 
to this country, and I readily obtained his permission to describe 
the same. 
Forty years ago (in November, 1866) I communicated to the 
Geological Society of London an account of the then oldest known 
British crab, Paleinachus longipes, from the Forest Marble of Malmes- 
bury, Wilts (see Quart. Journ. Geol. Soc., vol. xxii (1866), pp. 493-494, 
pl. xxiv, fig. 1), obtained by the late Wm. Buy, of Christian Malford, 
the well-known collector of Oxford Clay and Oolitic fossils. This 
form (which has the limbs preserved and still attached to the carapace) 
agrees closely with the living ‘Spider-crabs’ of the genus Jnachus, 
and differs generically from the newly-discovered fossil. Two years 
later, in 1868, I described an Oolitic crab from the ‘‘ Stonesfield Slate,” 
of which three specimens (two of them very imperfect and one 
a nearly perfect carapace) are known. It was named by me Prosopon 
mammillatum (see Grou. Mac., 1868, p. 1, Pl. I, Figs. 2, 2a). This 
erab carried the Brachyurous Decapods considerably further back, 
chronologically, than the Forest Marble example, which in its turn 
has now been surpassed in age by the newly-discovered specimen from 
the ‘‘ Clypeus-Grit”’ of the Inferior Oolite. The Stonesfield crab, 
Prosopon mamnullatum, although near generically to the new crab, is 
twice its size, and differs in several important details from it— 
especially in the frontal region of the carapace—but the absence of 
limbs and other ventral and oral structures renders strict determination 
rather unsatisfactory. 
Fortunately Professors Reuss' and Herman von Meyer’ have described 
and figured three genera and twenty-nine species of small crab 
carapaces, some fifteen of which have been refigured by me in Salter & 
Woodward’s Chart of Fossil Crustacea. These are from the Upper 
White Jura of Oerlinger Thal and other localities in Germany, also 
one from the Lower Oolite, three from the Coral Rag, and one from 
the Neocomian. In my paper in 1868 (Gror. Mac., January, pp. 3-4), 
I endeavoured to separate von Meyer’s Oolitic species of the genus 
Prosopon, and referred eleven of them with some hesitation to Bell’s 
genus Plagiophthalmus (op. cit., p. 4). Of the remaining species— 
still retained by me in the genus Prosopon—those most nearly related 
to the new species from the ‘‘ Clypeus-Grit’”? are P. marginatum, 
P. grande, P. excisum, and P. lingulatum. To these also most probably 
belong P. elongatum and P. subleve. 
1 Sitzungsb. k.k. Akad. d. Wiss. in Wien, xxxi, 1858. 
2 Mon. Prosoponide : Paleontographica, 1859-61, Bd. vii, p. 183, t. xxiii (Cassel). 
3 Catalogue and Chart Fossil Crustacea, 1865, figs. 1-15. 
