196 CALIFORNIA ACADEMY OF SCIENCES. 



chelipeds filiform; carpus seven-jointed; hand small and narrow. Pos- 

 terior legs of subeqnal length; carpus produced distally over the propodus;. 

 propodi and dactyls spinulous below. Telson tapering and armed above 

 with several pairs of spines. Branchiae five. 



Type. — H.palpator (Owen). 



Beside the characters mentioned in the diagnosis of 

 the genus, all of the species I have seen agree in pos- 

 sessing the following features: There is a spine at the 

 antero-external angle of the oblong first joint of the- 

 antennular peduncle and another spine on the lower 

 margin of the inner side a short distance behind the- 

 distal end; the second joint of the peduncle has a spine 

 on the outer side, and the third joint has a spine above 

 the articulation of the thick flagellum, and there is- 

 generally a small spine above and internal to the articu- 

 lation of the slender one. On the second joint of the 

 antenna there is a blunt tooth above and a sharp spine 

 below the outer edge of the scale. The tips of the 

 external maxillipeds are armed with a circle of spines. 

 The carpus of the anterior chelipeds has a short, trans- 

 verse groove behind the inner distal margin. 



Heptacarpus palpator (Oiuen). 



Hippolyte palpator Owen, Zool. Beechy's Voyage, 1839, p. 89, PI. XXVIII, 

 fig. 3. Brandt in MiddendorfiTs Siberische Keise, Bd. II, Th. 1, 1851, 

 p. 117. Stimpson, Proc.'Cal. Acad. Sci., Vol. I, 1856, p. 89; Journ. 

 Bost. Soc. Nat. Hist., Vol. VI, 1857, p. ^99. Kingsley, Bull. Essex 

 Inst., Vol. X, 1878, p. 62. Lockington, Ihid., Vol. X, 1878, p. 160. 



? Hippolyte Hemphillii Lockington, Proc. Gal. Acad. Sci., Vol. VII, 1877, 

 p. 35; Bull. Essex Inst., Vol. X, 1878, p. 160. Kingsley, Ibid., VoU 

 X. 1878, p. 63. 



Rostrum slender, horizontal, considerably shorter than the carapace and 

 armed above with six teeth, the last two (or three) of which are on the cara- 

 pace; the lower margin may be devoid of teeth, or there may be a small 

 tooth near the tip. The outer basal spine of the antennules reaches 

 nearly to the tip of the second joint of the peduncle; the upper distal 

 margin of the first basal joint is armed with four spines, the spine at the 



