264 
THE VOYAGE OF H.M.S. CHALLENGER. 
Brachynotus, de Haan. 
Brachynotus, de Haan, Crust, in v. Siebold, Fauna Japonica, decas ii. p. 34, 1835. 
„ Hilgendorf, Sitz. Gesellsch. Freunde zu Berlin, p. 68, 1882. 
Heterograpsus, Lucas, Anim. articules in Explor. Sci. de l’Algerie, vol. i. p. 18, 1849. 
„ Milne Edwards, Ann. d. Sci. Nat., ser. 3, Zool., vol. xx. p. 192, 1853. 
„ Kingsley, Proc. Acad. Nat. Sci. Pliilad., p. 207, 1880, et synonyma. 
This genus is very nearly allied to Pseudograpsus, but may be distinguished by the 
form of the exterior maxillipedes, whose merus-joint is not produced at its antero- 
external angle as in that genus ; the exognath also is much narrower. As in Pseudograpsus , 
there are normally two teeth behind the orbital angle. From Platygrapsus, it is dis- 
tinguished by the shorter merus-joint and the form of the ischium of the exterior 
maxillipedes, which is squarely, not obliquely truncated, at the distal extremity ; Cyrto- 
grapsus, Dana, has a differently shaped carapace, with normally three teeth behind the 
exterior orbital angle, a narrower front, and widely gaping maxillipedes . 1 
The species, which are enumerated by Kingsley, are distributed throughout the 
Indo-Pacific region, and one, Brachynotus sexdentatus occurs in the Mediterranean. To 
those he mentions, the following is to be added : — 
Brachynotus longitarsis (Miers). Japanese and Corean Seas. 
The Oriental forms (true Heterograpsi) may perhaps be still regarded as subgenerically 
distinct from the Mediterranean type of the genus Brachynotus, on account of their 
broader, more depressed carapace, which has a median dorsal H -shaped impression (which 
does not exist in Brachynotus sexdentatus, Eisso), by the less prominent and less 
accentuated lateral marginal teeth, and by the more prominent front . 2 
Brachynotus ( Heterograpsus ) penicillatus (de Haan). 
Eriocheir penicillatus, de Haan, Crust, in v. Siebold, Fauna Japonica, pp. 32, 60, pi. xi. fig. 6, 
1835. 
Heterograpsus penicillatus, Stimpson, Proc. Acad. Nat. Sci. Philad., p. 104, 1858. 
„ „ Kingsley, tom. cit., p. 209, 1880. 
Japan, Oosima, from pools (three adult males). 
Adult $ . Lines. Millims. 
Length of carapace, nearly . . . . . .9 18'5 
Breadth of carapace, . . . . . . .10 21 
1 The species with three antero-lateral marginal teeth, constituting Kingsley’s Section B of the genus Heterograpsus, 
would perhaps be better referred to Cyrtograpsus. 
2 Dr. Hilgendorf (tom. cit., p. 70) has proposed the name Brachynotus edwardsii for Heterograpsus sexdentatus, Milne 
Edwards, not Risso. 
