JOURNAL 



OF THE 



ASIATIC SOCIETY OF BENGAL. 



Vol. LXVIll. Part II. — NATURAL SCIENCE. 

 No. III. — 1899. 



Materials for a Carcinological Fauna of India. No-. 5. The Brachyitra 

 Primigenia, or Dromiacea. By A. Alcock, M.B., C.M.Z.S., Superin- 

 tendent of the Indian Museum. 



[Received let September ; Read 1st November, 1899.] 



The opinions adopted in this paper are those of Boas, that the 

 Dromiacea are Brachyura ; and of BouTiER, that they connect tiie higher 

 Brachyura with the Homarid family of Macruva. 



I have endeavoured to show that the Dromiacea, or Brachyura 

 Primigenia^ include two natuial groups — Dromiidea and HomoUdea — 

 each of wliicli is a collection of families equivalent to the collections of 

 families recognized as Catometopa, Cyclometopa, etc. ; but, as is only to 

 be expected in dealing with primitive groups, the families are small. 



After raising a family to the rank of a tribe, and splitting it up 

 into several independent families, it may seem inconsistent to unite the 

 recognized genera of other autliors, as is done in this paper with tlie 

 genera Dromia, Dromidia, Cryptodrcnnia, and Petalomera, all of which 

 are treated as sub-genera of Dromia. But the reason for this treatment 

 is that these are all linked together by intermediate forms. 



The Indian species of Dromiacea Bumber 28 and belong to the 

 following genera and families : — 



/ Homolodromidse : — Araehnodromia {? = Homolodromia). 

 Dromiidea j Dynomenidse : — Dynomene, Acanthodromia. 



\ Dromiidse : — Dromia (Bromidia, Cryptodroinia ^ Petalomera), 

 Psetidodromia^ Conclwecetes, Sfhaerodrmnia. 

 J. II. 16 



