252 



Records of the Indian Museum. 



[Vol. XIII, 



B. Carapace octagonal ; its antero-lateral border 

 without teeth ; merus of chelipede 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 abo\e 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 above ; 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 verv 

 strongly 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 J 



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

 basal segment of antennular peduncle completely 

 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. demeloi, 



sp. no\', 



R. exiguus, 



sp. nov. 



R. iiitroversits, 

 sp. nov. 



R. inachoides, 

 Alcock. 



A", nasalis. 

 sp. no\- 



Rhynchoplax wood-masoni (Alcock). 



1900. Hymeiiicits ivood-inasoiii, .Alcock, JoHvn. Asiai. Soc. Bengal, LXIX, 

 p. 388, and (1Q02) Illiist. Zool. 'Investigator,' pi. 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 



