Indian Deep-sea Dredging. 275 



The last epipodite (xii.) is simple and unbranclied, and 

 there is no vestige of an anterior arthrobranchia in the thir- 

 teentli somite. 



Length, from rip of rostrum to tip of telson, 113 to 129 

 millim. ; length of carapace 25'5 to 29"5 millim. ; of rostrum 

 21'5 to 24 millim. ; of antennulary flagella 23 to 26 millim. 



The three preceding species, in common with other infra- 

 littoral allies of littoral forms, seem to be in many respects in 

 a more primitive phase of evolution than their littoral allies. 

 Their primitive characters are (1) that the last abdominal 

 segment is elongate, (2) that the caudal svvimmeret is more 

 natatory, as evidenced by its being prolonged far beyond 

 the level of the marginal spine of the exopodite, and (3) that 

 the telson is trifurcate and spinulose at the sides. 



In the first two of these characters they recall many of the 

 true deep-sea Penasida?, many of the Schizopoda (e. g. Gnatho- 

 phausia)^ and the final larval stages of their own kind ; while 

 the lateral prongs and spines of their telson are to be inter- 

 preted as the modified vestiges of the larval caudal fork, 

 which, it may be remarked, persists throughout life almost 

 nnchanged in at least one Pena3id, viz. Sicyonia furcata. 



Subfamily Solenocerina. 

 SOLENOCEEA, Lucas. 



8. Solenocera Hextii, W.-J\I. 



Solenocera Hextii, Wood-Mason, Ann. & Mag. Nat. Hist. (6) vii. 1891, 

 p. 188, 6 $ . 



Nine males and six females from Station 119, 95 fathoms, 

 including a full-grown pair, which prove that the rostrum of 

 the fully adult female is shorter, broader, and mpre ascendant 

 than in'the juvenile stages, and that that of the male, while 

 retaining the length and breadth it has in youth, is deflexed 

 with the line of the teeth decidedly convex ; length of the 

 large female about 75 millim., of the male about 67 millim. 



Also a mutilated male from Station 120, 240 to 276 fathoms. 



This species has a distinct supra-orbital angle, which is 

 not, however, spinose, a post-orbital spine, a small hepatic 

 spine, and a third spine smaller than this on the edge of the 

 gastro-hepatic crest, but no branchiostegal spine. 



The telson is trifurcate. 



The common Indian littoral form (? P. crassicoryiis^ M.- 



