168 Messrs. J. Wood-lMason and A. Alcock on 



Smith's description of that of P. suhatifrons ; but the inner 

 fiagellum of these organs is only about one half the lengtli 

 of the carajiace measured from the apex of the rostrum to the 

 middle of the hinder margin in a straight line, and less than 

 one third the length of the outer flagellum ; this is much 

 stouter than the inner and expanded at the base in the usual 

 manner. 



The thoracic limbs differ in the relative proportions of their 

 parts and in armature from those of P. suhatifrons to an 

 extent and in a manner which will be best appreciated by 

 comparison of the figures of the two species. 



Length, from apex of rostrum to end of caudal appendages, 

 49 millin). ; of carapace, from apex of rostrum to middle of 

 hinder margin, 19*5 millim.; of outer flagellum of antennules 

 34 "5 millim., of inner 9*5 millim.; of antennal scale 7*25 

 millim. ; length of abdomen from base to end of telson 27*5 

 millim., of its sixth somite bb millim., of telson (tip wanting) 

 Q)b millim, 



A single female was taken on Jan. 15th, 1888, off Cinque 

 Island, Andaman Sea, in 650 fathoms. 



PSATHYROCARIS, gen. nov. 



rsathyrocaris, Wood-Mason, Admin, Rep. Marine Survey of India, 

 1890-91, p. 19, 



Integument thin and delicate; all appendages and processes 



of extraordinary fragility. 



Body moderately com])ressed. 



Carapace shortly rostrate, longitudinally carinate for a 



longer or shorter distance in backward continuation of the 



• • • 1 



dorsal crest of the rostrum ; its anterior margin unarmed — • 



antennal and branchiostegal spines being absent, — at first 



broadly arched, then narrowly emarginate between the blunt 



triangular extraorbital angle and the antero-lateral angle on 



each side ; its sides distinctly ridged, the ridging varying with 



the species ; the efferent portion of the branchial chamber 



relatively spacious. 



Antennules and antenna? broken off in all the specimens 

 near the base. 



Eye-peduncles and corneaj depressed, the latter hemi- 

 spherical, occupying the whole width of the extremities of the 

 former, on which they are set quite square. The usual papilla 

 is present close to the edge of the corner on each side. 



Mandibles (PI. XI, tig, 1) of typical Pasiphaidean form, 

 with a very large two-jointed palp. 



First maxillaj (PI. XI, tig. 2) with the inn'r lacinia [ex) 



