55 



2. Carpus of second pair of thoracic legs subdivided into 2 or 

 many segments : — 



i. First pair of thoracic legs very robustly chelate, of 



unequal size ... ... ... ... Alpheid.e. 



ii. First pair of legs robust, subchelate ... ... Glyphocrangonim:. 



iii. First pair of legs slender, appa7-ently mono- 



dactylous ... ... ... ... Pandalid,*:. 



II. The thoracic legs, or at least the first four pairs, have exopodites : 

 carpus of the second pair unsegmented, simple : — 



1. The thoracic legs are slender, and of enormous length, the 



first four pairs have small exopodites ... ... Nematocarcinim:. 



2. The thoracic legs are of no extraordinary length, all five pairs 



have large exopodites : — 



i. The exopodites of the 2nd maxillipeds are large ... Hoplo thorite. 

 ii. The exopodites of the 2nd maxillipeds are rudimen- 

 tary or absent ... ... ... Pasiph^id*. 



The following table is meant to illustrate my own views as to the natural 

 inter-relations of the Cari(lea of the Indian Necton and Benthos. 



Alliance I. Pasiph^oida. Mandibles with a simple serrated edge, Avith or 

 without palp. Exopodites of 1st maxillipeds with a broad foliaceous flagellum. 

 The last segment of the 2nd maxillipeds is a typical dactylus articulating end-on 

 with the propodite, as in P< j «r»*. All the thoracic legs have large exopodites, 

 but the exopodites of the 2nd maxillipeds are rudimentary or absent. The first 

 two pairs of thoracic legs are the longest and stoutest and end in elongate well- 

 formed chelae, the 2nd pair having a simple carpus. 



This alliance includes the genera that constitute the single family 

 Pasiptheeidse. Of these genera the only one that might perhaps be separated to 

 form a distinct family within the alliance is Psathyrocaris. 



Alliance II. Hoplophoroida, including the single family Hoplophovidsa. 

 Mandibles with incisor and molar processes distinct but almost confluent; with 

 a stout incurved palp. The last segment of the 2nd maxillipeds may (Ephyrina) 

 be an almost typical dactylus, but usually it lies obliquely along the distal part 

 of the inner border of the propodite as if it were a complemental piece of that 

 joint. The exopodites of the 1st maxillipeds have the form of a simple falcate 

 leaf without a flagellum. All eight pairs of thoracic appendages have well 

 developed exopodites. The first two pairs of thoracic legs end in slender well 

 formed chelfe, the 2nd pair having a simple carpus. 



In this alliance Ephyrina marks the point of connexion with the Pasiphasidse. 



Alliance III. Pandaloida, including the two families Paudalidas and 

 Nematocarcinidse. Mandibles deeply cleft into two well formed well calcined 

 branches — an incisor and a molar — and having a stout incurved palp. The 



