252 



Records of the Indian Museum. 



[Vol. XIII, 



B. Carapace octagonal ; its antero-lateral border 

 without teeth ; inerus of chehpede without teeth 

 on its upper border ; dactyh of last three legs with 

 a single large tooth near apex 



II. No tooth on side of carapace above base of ist walking 

 legs [no teeth on antero-lateral border of carapace]. 



A. Rostrum trilobate or tridentate ; basal segment of 

 antennular peduncle not visible in dorsal view ; 

 penultimate piece of abdomen of male longer than 

 broad, without tubercle. 



I. Rostrum composed of three very broad lobes ; 

 post-ocular tooth not visible from abo\e ; legs 

 stout, dactyli without teeth 



2. Rostrum composed of three narrow lobes or 

 teeth ; post -ocular tooth visible from above ; 

 legs slender, dactyli with teeth. 



a. Carapace not longer than broad ; rostrum 

 composed of three lobes ; 2nd walking legs 

 not more than 2i times length of carapace. 



i. Postero-lateral border of carapace nor- 

 mal ; dactyli of walking legs very 

 strongl)' curved and with very large 

 teeth ; terminal segment of male abdo- 

 men broader than long 



ii. Side-walls of branchial region of cara- 

 pace reflected upwards, forming a crest 

 outside the true postero-lateral border ; 

 dactyli of walking legs moderately 

 curved, with small teeth ; terminal seg- 

 ment of male abdomen much longer 

 than broad 



b. Carapace much longer than broad, rostrum 

 composed of three long teeth ; 2nd walking- 

 legs more than 3 times length of carapace 

 [dactyli of walking legs moderately curved, 

 with small teeth ; terminal segment of male 

 abdomen as long as broad] 



B. Rostrum composed of a single tooth-like process ; 

 basal segment of antennular peduncle completeK 

 visible in dorsal view ; penultimate piece of abdo- 

 men of male broader than long, with a large tubercle 

 at distal end [no post-ocular tooth ; dactyli of last 

 three legs with a single tooth] 



R. octagonalis, 

 sp. nov. 



R. c/eineloi, 

 sp. no\ 



R. e.xigmis, 



sp. nov, 



A', introverstis, 

 sp. nov. 



A'. inacIioides, 

 Alcock. 



A*, luisolis, 

 sp. nov. 



Rhynchoplax wood-masoni (Alcock). 



igoo. Nymein'ciis ivooif-iiiaso)/!, Alcock, yoin-i/. Asinf. Spc. Bengal, LXIX, 

 p. 388, and (1902) Illiist. Zoo/. Investigntoy,' \A. Ixiv, fig. 4. 



A few particulars regarding the structure of this species, 

 some of which are additions to Alcock's description, are given 

 below in the course of a comparison with the closely allied R. 

 alcocki. 



Stimpson's Rhynchoplax messor from Simoda appears also to 

 be a related form, agreeing in the presence of a series of teeth on 

 the upper aspect of the carpus of the chelipede. In the Japanese 



