1G8 Mossrs. .1. \Vo()(l-Ma-?on ami A. Alcock on 



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

 flajxelluin of those orii^aiis is only about one lialf the Ien!i;th 

 of the carapace measured from the ajiex of the rostrum to the 

 middle of the hinder mar/^in in a strai^lit 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. sulcatifrons 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 

 liinder margin, 19*5 millim.; of outer flagellum of aiitennules 

 3-4 "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 b'b millim., of telson (tip wanting) 

 6 5 millim. 



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

 Island, Andaman Sea, in 650 fathoms. 



PSATHYROCARIS, gen. nov. 



rmthi/rncarix, Wood-Mason, Admin. Rep. Marine Survey of India, 

 J. -90-91, p. 19. 



Integument thin and delicate ; all appendages and processes 

 of extraordinary fragility. 



Body moderately compressed. 



Carapace shortly rostrate, longitudinally carinate for a 

 longer or shorter distance in backward continuation of the 

 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 si)ecies ; the effei'ent portion of the branchial chamber 

 relatively spacious. 



Antennules and antenna3 broken off in all the specimens 

 near the base. 



Eye-peduncles and cornea? 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 corneaj on eacii side. 



Mandibles (PI. XI. fig. 1) of ty|)ical Pasiphaidean form, 

 with a very large two-jointed jjalp. 



First maxillai (PI. XI. fig, 2) with the inivr lacinia {ex) 



