io4 



shape of the suborbital ridge, characters of the chelae being largely dependent on 

 sexual differences, and consequently only of secondary importance. 



Key to the Indo-Pacific species 1 ): 

 i. Two teeth behind external orbital angle, large, generally 



depressed and acute 2 



Three teeth behind external orbital angle, small, conical 9 



2. ( >uter surface of palm with tour prominent longitudinal 



crests B. pallipes (H. Milne-Edwards) s ) 



Outer surface of palm with a single crest or smooth . 3 



3. Suborbital ridge s ) with a few (2 — 6) tubercles, at least in cf 4 

 Suborbital ridge finely or coarsely serrulate or striate . 6 



4. Outer margins of ext. orbital angles diverging backward 5 

 < hiter margins of ext. orbital angles converging backward; 



epig - astric ridges sharp; ant. margin of front notched 

 in the middle ; epibranchial teeth very acute, narrow, 

 not flattened: suborbital ridge four-lobed in cf, regu- 

 larly granular in Q. Ischium of ext. maxilliped with a 

 fine longitudinal sulcus immediately near inner margin; 

 merus nearly quadrate, with outer margin straight. . B. Jiarpax Hilgendori *) 



5. Suborbital ridge notched beneath cornea of the eye, and 



thickened at either end of this notch; a third tubercle 

 placed farther back. Palm of cheliped in cf thickly 

 clothed with hairs at inner surface and between bases 



of fingers B. penicillatns (de Haan) 5 ) 



Suborbital ridge with 4 lovv tubercles, directed forward. 

 Palm of cheliped of cf with a sharply circumscribed patch 

 of hairs at inner surface, no hairs between bases of fingers B. oregonensis (Dana) 6 ) 



1) I am unable to include B. longitarsis {Hetcrograpsus l. Miers, Proc. Zool. Soc. London, 1879, p. 37, pi- 2, f. 3; Ortma.nn, 

 Zool. Jahrb., Syst., Bd 7, 1894, p. 715) here, as the infra-orbital ridge is not described. The species is recorded from Japanese and 

 Corean waters. 



2) 1'seudograpsus pallipes H. Milne-Edwards, Hist. nat. Crust., t. 2, 1837, p. 82; Hetcrograpsus pallipes H. Milne-Edwards, 

 Ann. Sc. Nat. (3) t. 20, 1853, p. 194; Haswei.l, Cat. Austral. Crust., 1882, p. 100. Hab. Anstralia. The character of the chela here noted 

 is also observed in the § of B. sexdentatus from the Mediterranean. 



3) This ridge is apparently used in the same way as in Macrophthaliiius and Mctapla.\\ according to Koelbel (Wiss. Erg. 

 Reise Széchenyi in Ost-Asien 1877 — 1880, Bd 2, 1898, p. 571), the ridge produces a stridulating sound when being rubbed against a 

 horny crest on the inner surface of the arm of the cheliped. 



4) Sitzungsber. Gesellsch. naturforsch. Freunde Berlin, 1892, n° 4, p. 38; DE Man, Zool. Jahrb., Syst., Bd 9, 1S95, p. 124, 

 Bd 10, 1S9S, pi. 29, f. 26; Nobili, Ann. Sc. Nat. (9) t. 4, 1906, p. 320; Pesta, Denkschr. Ak. Wiss. Wien, Bd 88, 1912, p. 62, 

 textfig. 5. Hab. Red Sea, Atjeh and Upolu (Samoah). 



5) Crapsus (Eriocheir) penicillatns de Haan, Faun. Japon., 1835, p. 60, pi. II, f. 6; Hetcrograpsus p. Stimpson, Proc. Ac. 

 Nat. Sc. Philadelphia, 1858, p. 104; DE Man, Notes Leiden Mus., v. I, 1S79, P- 7' i Kingsley, Proc. Ac. Nat. Sc. Philadelphia, 1880, 

 p. 209; Brachynotus (Heterograpsus) p. Miers, Rep. "Challenger", Brachyura, 1886. p. 264; Hetcrograpsus p. Ortmann. Zool. Jahrb, 

 Syst., Bd 7, 1894, p. 714; Brachynotus p. Koelbel, Wiss. Erg. Reise Széchenyi 1877 — 1880, Bd. 2, 1898, p. 570, pi. 1, f. 5 — 6; 

 STIMPSON, Smithson. Inst., Miscell. Coll., v. 49, 1907, p. 126. Hab. Japan and Hongkong. 



6) 1'seudograpsus oregonensis Dana, Proc. Ac. Nat. Sc. Philadelphia, 1851, p. 248; Dana, U. S. Expl. Exp., Crust., 1852, p. 334, 

 pi. 20, f. 6; Hetcrograpsus o. Stimpson, Proc. Ac. Nat. Sc. Philadelphia, 1S5S, p. 104; Kingsley, Proc. Ac. Nat. Sc. Philadelphia, 1880^ 

 p. 209: Stimpson, Smithson. Inst., Miscell. Coll., v. 49, 1907, p. 126. Hab. west coast of North America. 



104 



