NO. 1199. CB USTA CEANS OF WEST AFRICA— R A THB UN. 277 



Genus GECARCINUS Leach. 

 GECARCINUS LAGOSTOMA Milne-Edwards. 



Gecarcinus lagostoma Milne-Edwards, Hist. Nat. Crust., II, 1837, ji. 27. 

 Range. — Australasia (Milne-Edwards, Miers); Soiitb. and West 

 Africa; Bermuda? (Miers). 



African localities. — West Africa (Miers); St. Thomas and Eolas 

 (Greeft", as ruricola; Osorio, as r«>■^co/fl); Beuguellaj Angola (Osorio/; 

 Cape of Good Hope (Miers); Ascension Island (Drew, Miers, Benedict, 

 Ortmann). 



Genus CARDISOMA Latreille. 



CARDISOMA ARMATUM Herklots. 



Cardisoma armatum Herklots, Addit. Fauna Afr. Occ, 1851, j). 7, pi. i, figs. 4, 5. 

 West African localities. — St. Jago, Cape Yerde Islands (Stimpson, 

 as C.guanhumi), Cat. Xo. 2037, U.S.I^.M. ; Porto Praya, St. Jago, Cape 

 Verde Islands (Miers); Eufisque, Senegal (Hilgeudorf); Dakar, Senegal 

 (O. F. Cook) ; St. George del Mina, and near Boutry, Guinea (Herklots) ; 

 Lagos (Ortmann, as C. guanhimii) , Bibundi, Kamerun (Aurivillius); St. 

 Tbomas aud Eolas (Greeft", as G. guanhumi); Eibeira Peixe, St. Thomas 

 (Osorio); Ogove (Thallwitz); Benguella, i^ovo Eedondo, Lobito, and 

 Koroka Eiver (Osorio). 



Family GEAPSID^. 



KEY TO THE WEST AFRICAN GENERA AND SUBGENERA OF THE FAMILY GRAPSID^. 



A. Autenna} covered by the front. 



B. External maxillipeds without a piliferous ridge. 

 C. Autennte excluded from the orbit. 



D. Merus of maxillipeds as long as ischium Goniopsis. 



D' . Merus of maxillipeds shorter than ischium Metopoarapsxis. 



C . Antenn;e entering the orbit. 



D. Merus of maxillipeds longer than broad Cirapsus. 



D'. Merus of maxillipeds as broad as long. 

 E. Outer surface of palm of large chela quite flat, and prolonged proximally 



beyond the wrist Platydiirograpsus. 



E'. Outer surface of palm not flattened and prolonged. 



F. Carapace longer than broad Planes. 



F' . Carapace transverse Pachygrapsus. 



B'. External maxillipeds with a piliferous ridge Sesarma. 



C. Sides arcuate Subgenus Sarmatium. 



C . Sides straight. 

 D. Sides with a tooth behind orbital tooth. Manus with jjectinated ridges 



above Subgenus Perisesarma. 



D'. Sides entire. 



E. Manus without pectinated ridges above Subgenus Holometopus. 



E'. Manus with pectinated ridges above Subgenus Parasesarma. 



A'. Antennae visible from above. 



B. Merus of maxillipeds large, as broad as ischium Plagtisia. 



B'. Merus of maxillipeds small, much narrower than ischium Percnon. 



