REPORT ON THE BRACHY O’ RA. 
255 
margins have a fissure or notch, near the exterior orbital tooth ; the epistoma is 
transverse and rather large ; the buccal cavity small, and the ridges of the endostome or 
palate distinctly defined. The post-abdomen (in the male) is distinctly seven-jointed, 
and its basal segments cover the whole width of the sternum between the bases of the 
fifth ambulatory legs. The eye-peduncles are robust and short ; the antennules are 
transversely plicated in very narrow fossetts. The basal antennal joint is very short 
and is produced at its antero-external angle ; it lies wdthin the interior orbital hiatus, 
between the front and the interior subocular lobe of the orbit, which is dentiform and 
acute ; the flagellum is short. The exterior maxillipedes have a rhomboidal gape, and 
their endognathi are narrow (the ischium-joints are not in contact at the base); the merus- 
joints are truncated or slightly concave at the distal extremity, the carpi are articulated 
at the distal extremity of the merus-joints near the antero-external angle. 
The chelipedes (in the adult male) are robust and rather short ; merus-joints trigonous, 
with the anterior margins clentated ; carpus with a strong lobe or tooth on the inner 
margin ; palm short, granulated above ; clactyli denticulated on the inner margin and 
excavated at the distal extremity. Ambulatory legs large and robust, with the merus- 
joints dilated and compressed ; dactyli strongly spinulose. 
There are probably but two distinct species of this long-known genus, to one or other 
of which many of the forms briefly characterised by M. H. Milne Edwards and other 
authors are to be referred as synonymous, or at most, as varieties. 
Grapsus maculatus (Catesby). Common on all the warmer temperate and 
tropical coasts and islands both of the Indo-Pacific and Atlantic regions. 
Grapsus trigosus (Herbst). Common on the shores and islands of the Indo- 
Pacific region . 1 
Grapsus maculatus (Catesby). 
Pagurus maculatus, Catesby, Nat. Hist, of the Carolinas, vol. ii. p. 36, pi. xxxvi. fig. 1, 1743 
and 1771. 
Cancer grapsus , Linne, Syst. Nat., ed. xii., p. 1048, 1766. 
Grapsus pidus, Latreille, Hist. Nat. Crust, et Ins., vol. vi. p. 69, pi. xlvii. fig. 2, 1803-1804. 
„ ,, Milne Edwards, Hist. Nat. Crust., vol. ii. p. 86, 1837; Crust, in Cuvier, Regne 
Animal, ed. 3, pi. xxii. fig. 1. 
„ maculatus, Milne Edwards, Ann. d. Sei. Nat., ser. 3, Zool., vol. xx. p. 167, pi. vi. fig. 1 , 
1853. 
„ „ Kingsley, Proc. Acad. Nat. Sci. Philad., p. 192, 1880, et synonyma (?). 
,, pidus, var. ocellatus, Studer, Abhandl. d. k. Akad. d. Wiss. Berlin, Abh. ii., p. 14, 
1882. 
Of this common and widely distributed species, specimens are in the collection from 
the following localities : — Bermuda, an adult male (in spirits), and an adult male and 
1 Grapsus gracilipes, Milne Edwards, is retained as distinct by Kingsley, but is regarded by M. de Man as a variety 
of Grapsus maculatus. Grapsus simplex, Herklots, referred to by de Man, may be a distinct species. 
