REPORT ON THE BRACHYURA. 
283 
Subfamily 1. Calappijsle. 
Calappinse, Dana, tom. cit., p. 390, 1852. 
The eight posterior legs are gressorial, not natatorial, i.e., the dactyli not dilated 
and expanded. 
The genera referred to this subfamily are : — Camara, de Haan ; Calappa, Fabricius 
( = Lophos , de Haan, subgenus; Gallus, de Haan, subgenus); Paracyclois, n. gen.; 
Mursia, Desmarest ( = Thealia, Lucas) ; Cryptosoma, Brulle ( = Cycloes, de Haan) ; 
Platymera, Milne Edwards ; Acanthocarpus, Stimpson. 
Subfamily 2. Opithyesle. 
Oritliyinse, Dana, torn, cit., p. 391, 1852. 
The eight posterior legs are natatorial, i.e., with the dactyli more or less dilated and 
compressed, those of the fifth pair lanceolate, ovate. 
Genus: — Orithyia, Fabricius. 
This subfamily is not represented in the Challenger collection. 
Calappa, Fabricius. 
Calappa, Fabricius, Entom. Syst. Suppl., p. 345, 1798. 
„ Milne Edwards, Hist. Nat. Crust., vol. ii. p. 102, 1837. 
Lophos, de Haan, subgenus, Crust, in v. Siebold, Fauna Japonica, decas iii. p. 69, 1837. 
Gallus, de Haan, subgenus, tom. cit., p. 70, 1837. 
Carapace very convex and tuberculated, rounded in front, with the antero-lateral 
margins regularly arcuated and granulated or toothed ; and the postero-lateral margins 
prolonged into two large rounded wings or clypeiform expansions, which partly cover the 
ambulatory legs, but are not developed to so great a degree as in Camara, de Haan, and 
are dentatecl on the margins, not entire, as in that genus. The front is very small, 
triangulate or concave in the median line. Orbits very small, circular. The post- 
abdomen (in the male) covers the sternum at the base, between the bases of the fifth 
ambulatory legs, and is usually five-jointed. Eye-peduncles short, robust. Antennules- 
nearly vertically plicated. Antennse with the basal joint usually more or less dilated, 
and occupying the wide inferior hiatus of the orbit ; flagellum short. The exterior 
maxillipedes do not entirely cover the buccal cavity (which is narrowed and prolonged in 
its anterior part, and divided by a median septum) ; their ischium-joint is not produced at 
its antero-internal angle ; the merus is subacute or distally truncated, and emarginate at 
the antero-internal angle, where the next joint is articulated. The chelipedes are equal 
and very large, and can be closely applied to the body ; merus and carpus trigonous, palm 
vertically very deep, and laterally compressed, and armed above with a strongly dentated 
crest ; the fingers of the right and left chelipedes are usually somewhat dissimilar, and 
are acute at the distal extremity. Ambulatory legs slender and of moderate length, 
with the dactyli styliform. 
