REPORT ON THE BRACHYURA. 
279 
An adult male measures as follows : — 
Adult $. 
Lines. 
Millims. 
Length of carapace, .... 
13-5 
Breadth of carapace, .... 
H 
11-5 
This species nearly resembles the following, but may always be distinguished by the 
smooth, not granulated, dorsal surface of the carapace. 
Myctiris plcitycheles, Milne Edwards. 
Myctiris platycheles, Milne Edwards, Ann. d. Sci. Nat., tom. cit., p. 154, 1852. 
„ ,, Targioni-Tozzetti, Crostacei del Yiaggio della Magenta, p. 186, pi. xi. 
tig. 6, a-e, 1877. 
„ ,, Haswell, tom. cit., p. 117, 1882 ( Mycteris ). 
„ subverrucatus, White, List Crust. Brit. Mus. p. 34, 1847; descript, nulla. 
„ ,, Kinahan, Journ. Roy. Dublin Soc., vol. i. p. 123, 1858. 
New South Wales, Botany Bay (beach). A good series of specimens. 
Adult $ . Lines. Millims. 
Length of carapace, . . . . . . 8 17 
Breadth of carapace, nearly . . . . . 7 14 
Subfamily 3. Hymenosomiisle. 
Hymenosoma, Leach. 
Hymenosoma, Leach ( ined . 1), Desmarest, Consid. sur les Crust., p. 163, 1825. 
„ Milne Edwards, Hist. Nat. Crust., vol. ii. p. 35, 1837; Ann. d. Sci. Nat., ser. 3, 
Zool., vol. xx. p. 222, 1853. 
Carapace dorsally flattened, and rounded on the posterior and lateral margins, which 
are defined by a granulated line or ridge, which is not dentated, as in Halicarcinus; 
beneath this line the carapace usually slopes outwards obliquely to the bases of the 
ambulatory legs. The front is simple, triangulate, and nearly horizontal ; the hepatic 
region is tuberculated. There is a distinct postocular spine or tooth. Scarcely any 
trace exists of an epistoma, or of longitudinal ridges on the endostome. The post- 
abdomen of the male is very narrow, and is six-jointed, and its base barely occupies the 
whole width of the sternum between the last ambulatory legs ; the sternum is large and 
circular. The eye-peduncles are short ; the antennulary fossettes are not separated from 
the orbits ; the antennae are somewhat elongated, and their basal joint is very short. 
The exterior maxillipedes are not arcuated, and have the ischium and merus-joints well 
developed, the merus usually obliquely truncated, and bearing the following joint near 
its antero-external angle, at the distal extremity. The chelipedes in the adult male are 
