1899.] A. Alcock — Carcinological Fauna of India. 7 



last pair end in a lanceolate dactylus and otherwise do not differ much 

 from the other three pairs. Carapace not at all broad, its antero-lateral 

 borders cut into 4 or 5 teeth. The basal antenna- joint is fixed : it is 

 longer than broad and lies in the longitudinal axis of the carapace. 



Sub-family I. Carcininj:. 



This sub-family comes nearest to the other Cancroid families. Of 

 its constituent genera Garcinus touches the Cancridaa and Xanthidae, 

 Nectocarcinus touches the Xanthidse, and Portumnus touches the Corys- 

 tid^. 



It may be divided into two Alliances : — 



Alliance 1. Portnmnoida. Carapace as long as broad : antennae 

 setaceous : crests of endostome ? For the single genus. 



Portumnus, Leach, Malac. Pod. Brit, text of pi. iv. {=Xawa, 

 Macleay in Smith's 111. Annulosa S. Africa, p. 62). 



Alliance 2. Garcinoida. Carapace broader than long : antennce 

 not setaceous, the basal antenna-joint fixed : the palatal crests defining 

 the efferent branchial channels are either interrupted or completely 

 wanting. Constituent genera : — 



1. *Carcinus, Leach. 



2. * Nectocarcinus. A. Milne Edwards, Ann. Sci. Nat. Zool. (4) 

 XIY. 1860, pp. 220, 228 ; and Archiv. du Mus. X. 1861, p. 404. 



Sub-family II. Portuninji. 



The material at my disposal is not suflBcient to enable me with any 

 confidence to separate the genera of this sub-family into groups, so that 

 the following classification is meant to be merely a suggestion. 



Alliance 1. Portunoida : The last pair of legs are typical swim- 

 ming-paddles : the basal antenna- joint may be either fixed or movable : 

 the palatal crests defining the efferent branchial channels may either be 

 distinct and complete or be wanting. Constituent genera : — 



1. Bathynectes, Stimpson, Bull. Mus. Comp. Zool. II. 1870-71, 

 p. 145 { = ThraniteSy Bovallius, Ofversigt Kongl. Yetensk.-Ak. Forhandl. 

 1876, No. 9, p. 61). 



2. *Benthochascon, Alcock. 



3. ^LiocarcinuSy Stimpson, Bull. Mus. Comp. Zool. II. 1870-71, 

 p. 146 (footnote). 



4. ^Omlipes, M. J. Rathbun, Proc. U. S. Nat. Mus. XXI. 1898, 

 p. 597 (for Platyonyclius as restricted by Miers, Challenger Brachyura, 

 p. 201 ; = Anisopus DeHaan Faun. Japon. Crust, p. 12). 



5. *ParatliraniteSj Miers, Alcock. 



