194 CALIFORNIA ACADEMY OF SCIENCES. 



the rostrum, which probably varies in different individuals of the same 

 species (although the number was constant as above quoted in three 

 specimens of each species which was preserved), Hip. Layi has a longer 

 and narrower rostrum, extending to the extremity of the superior anten- 

 nae; the inferior seta of these antennge is also proportionately longer. Hip. 

 affinis has a spine above the eye, at the root of the rostrum, which is want- 

 ing in the Hip. Layi; whilst this species has the fifth and sixth abdominal 

 segments unispinous inferiorly on each side, Hip. affinis having the sixth 

 segment only so armed. 



" From the Alpheus Polaris of Sabine (Zool. Appendix to Parry's Voyage, 

 p. 238, PI. II, fig. 5) which is a Hippolyte of Leach, and from the species 

 characterized by the latter author in the Malacostraca Podoph. Brit., the 

 above species differ in the forms and proportions, as well as in the serra- 

 tions of the rostrum." 



Monterey (Owen); Vancouver's Island (Bate); Alaska 

 (Lockington). 



It is impossible to determine from Owen's description 

 and figure in what genus this species belongs. It is 

 certainly not a Hippolyte; it may be a Heptacarpus, but 

 until more is known concerning it, it is best, I think, 

 to leave its name unchanged. 



Hippolyte affinis Oiven. 



Hippolyte affinis Owen, Zool. Beechy's Voyage, 1839, p. 90, PL XXVII, 

 fig. 4. Brandt, in Middendorff's Siberische Keise, Bd. II, Th. 1, 

 1851, p. 117. Stimpson, Journ. Bost. Soc. Nat. Hist., Vol. VI, 1857, 

 498. KiNGSLEY, Bull. Essex Inst., Vol. X, 1878, p. 62. 



Owen's short description of this species is as follows: 



" Hip. rostro antennis superioribus breviore, supra multi-serrato, ante 

 medium subtus sex-serrato. Long. corp. 1|. Color ruber." 



Rostrum shorter than the antennules, multi-serrate above, and armed 

 below with six teeth in front of the middle. Length of the body IJ inch. 

 Color red. 



Monterey (Owen). 



There are several species of Hippolyte reported from 

 Vancouver's Island by Professor Smith: viz., H. Gai- 

 mardii Milne-Edw. ; H. Groenlandica, under which are 



