494 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 23, 



In the swollen form of the branchial regions, and the well- 

 marked nuchal furrow, it resembles the genus Inachus, with which 

 it also agrees in the form and proportion of its limbs ; but the bifid 

 and diverging rostral tubercles more nearly agree with the Maiadce, 

 thus offering a connecting link for these divisions of Milne-Edwards's 

 Triangulares. The Triangular Crabs are certainly one of the 

 earliest families of Brachyura; and notwithstanding their dull 

 habits, they make up by their exceeding fecundity* for want of 

 strength and cunning, and have thus been enabled to maintain their 

 ground even to the present day. 



Pal^inachus longipes, H. W. pi. XXIY. fig. 1. 



Carapace suborbicular, broadest behind; branchial regions large 

 and rounded, their surfaces covered with extremely minute rounded 

 tubercles; the gastric region well defined by a somewhat deep 

 furrow ; the frontal and hepatic regions more than half the length 

 of the entire carapace, tumid and ornamented with two subcentral 

 tubercles and a semicircle of five other tubercles ; margin irregularly 

 swollen and depressed, and contracting towards the rostrum, which 

 is represented by two prominent widely diverging and rounded 

 horns, at th*e exterior bases of which, in the recent Leptopodidoi, 

 the eyes are placed; these, however, cannot be detected in the 

 fossil. 



The abdomen is imperfect, but indicates a female ; the lateral mar- 

 gins of the most perfect segment are somewhat angular, deeply grooved 

 across, and also between the central portion and the epimera. 



The arm, wrist, and hand have respectively five, three, and two 

 tubercles on their upper angle ; the hand is didactyle, and resembles 

 the recent Stenorhynchus in form. 



The walking legs are of about three times the length of the 

 carapace, very slender, and have a row of minute tubercles upon 

 their upper surface. 



Breadth of carapace across the branchial region 8 lines, length from 

 attachment of abdomen to base of rostral spines 9 Knes ; rostral 

 spines 2^ lines in length ; arm about 5 lines ; wrist 2| lines ; hand 

 5| lines ; longest limb 28 lines. 



EXPLANATION OF PLATE XXIV. fig. 1. 



Fig. 1. PalcBinachus longijpes, H. Woodw. Forest Marble, Malmesbury, Wilts. 

 Natural size. 



3. Nottes on the Species of the Genus Eryon, Desm., from the 

 Lias and Oolite of Efglan^d and Bavakia. By Henry Wood- 

 ward, Esq., E.G.S., F.Z.S. (of the British Museum). 

 [Plates XXIV. figs. 2-4, & XXV. figs. 1-3.] 

 The genus Eryon was established by Desmarest (in Brongniart 

 and Desmarest's ' Natural History of Eossil Crustacea :' Paris, 1822) 



* The female Maia squinado bears at one time upwards of seventy-six 

 thousand eggs (Couch). 



