1899.] A. Alcock — Carcinological Fauna of Indid. 95 



Cyclinea and Corystoidea (part)Dana, U, S. Expl. Exp. Crnst. pf. T. pp. 2di and 

 296 : Miers, Challenger Brachyura, pp. 208 and 209. 



Cancrini fexc. Carcinus) and Xanthini {Thiidie only) Ortmann, Zool. Jahrb. 

 Syst. VII. 1893-9+, pp. 421 and 428. 



Carapace moderately convex, either broadly transversely-oval (as 

 in the Gancrinse) or elongate-oval or subcircular or (rarely) somewhafc 

 hexagonal, the regions rarely strongly defined and rarely areolated. 



Front not very broad, commonly cut into 3 teeth, Avhich are some- 

 times prominent : [sometimes ( Thiinae) the front is subentire or bilobed ; 

 in Acanthocycliis it is triangular and pointed.] 



The antennules always fold longitudinally. 



Antennal flagella usually long, coarse, and setaceous [absent in 

 Acanthocycliis, short and slender in Ki-anssia']. 



Epistome usually sunken, always more or less overlapped by the 

 external maxillipeds which are often somewhat elongate. 



Legs gressorial. 



Sternum narrow. 



I propose to divide the Cancridse into the following five subfami- 

 lies : — 



Subfamily I. Gancrinse. Carapace broadly transverse, oval, the 

 antero-lateral borders cut into many teeth or puckers, the regions 

 either not defined or fairly well defined and areolated. Front cut into 

 3 teeth. Buccal orifice about square. Epistome but slightly sunken 

 and slightly overlapped by the external maxillipeds, which completely 

 close the mouth and have the merus not elongate. Basal antenna-joint 

 fixed. 



Constituent genera : — 



1. ^Gancer, Lamk., Leach, A. Milne Edwards Nouv. Archiv. du 

 Mus. L J865, p. 185. 



2. Metacarcinus, A. Milne Edwards, Nouv. Archiv. du Mus. I. 1865, 

 p. 20L 



3. Triclwcarcimis, Miers, P.Z.S. 1879, p. 34 (=TricJiocera, De Haan, 

 Faun. Japon. Crust, p. 16). 



Subfamily XL Pirimellnse. Carapace somewhat hexagonal, not 

 transverse, regions very well defined and areolated, antero-lateral borders 

 cat into 5 teeth. Front cut into 3 teeth. Buccal orifice moderately 

 elongate. Epistome a good deal sunken and much overlapped by the 

 external maxillipeds which completely close the mouth. Basal antenna- 

 joint fixed. 



Includes a single genus, namely 



* Firimela, Leach, Milne Edwards, Hist. Nat. Crust. I. 423. 



