1900.] A. Alcock — Carcinological Fauna of India, 291 



flattish and not very deep, the regions usually well defined : front 

 variable, but never very broad : antennules with a well developed flagel- 

 lum that folds transversely, interantennular septum very narrow : 

 eyestalks usually elongate: the external maxillipeds do not always meet 

 across the buccal cavern, though the gap between them is never very 

 wide, their exognath is not, or not entirely, concealed and has a flagel- 

 lum : chelipeds usually subequal. No special recess between the bases 

 of any of the legs. 



Family MICTYRID^E, Dana. 



Finnotheriens, Milne Edwards (pt.), Hist. Nat. Crust. IT. 39. 



Myctiroidea, Milne Edwards, Ann. Sci. Nat., Zool., (3) XVIII. 1852, p. 154. 



Mictyridse, Dana, U. S. Expl. Exp., Crust, pfc. I, pp. 309, 389. 



Pinnotheridge-Mycbirinae, Miers (pt.), Challenger Brachyura, p. 275 ; Ortmann 

 (pfc.) in Bronn's Thier Reich, torn. cit. f p. 1179. 



Ocypodidae-Mtjctirinse, Ortmann (pfc.), Zool. Jahrb., Syst. VII. 1893-94', pp. 742, 

 747. 



There can be little question that Milne Edwards was right in 

 reckoning Midyris as a " satellite " of the Ocypodidse, or that Dana's 

 plan of separating them as a distinct family is fully justified. The 

 affinities which several authors find between Mictyris and the Pinnoteridse 

 are by no means easy to recognize. 



Family HYMENOSOMID^E, Ortmann. 



Finnotheriens, Milne Edwards (pfc.), Hist. Nafc. Crust. 11. 39. 

 Hymenosominae, Milne Edwards, Ann. Sci. Nat., Zool. (3) XX. 1853, p. 221. 

 Pinnotheridae-Hymenicinse, Dana, U. S. Expl. Exp,, Crust, pt. I. pp. 379, 384. 

 Pinnotheridx-Hymenosominx, Miers, Challenger Brachyura, p. 275. 

 Majoidea-Htjmenosomidge, Ortmann, in Bronn's Thier Reich, torn, cit., p. 1168. 



Three types seem to be distinguishable in this family : in one (e.g. 

 Hymenosoma) there is no epistome and the external maxillipeds almost 

 encroach on the bases of the antennules, which appendages are not 

 concealed by the front; in the second (e.g. Ealicarcinus) there is an 

 epistome of considerable length, but the antennules are still uncon- 

 cealed by the front; in the third (e.g. Hymenicus) there is along 

 epistome and the antennules are quite concealed by the front. 



Family PTENOPLACID^E. 



This family has no very close connexions with any of the others 

 although it is an undoubted Catometope. 



