62 RATHBUN 



but there is some individual variation. The usual number of spines is 

 one on the second and sixth segments and two on each of the other 

 segments. 



Distribution. — Arctic coast of America; Bering Sea to Puget Sound; 

 Kamchatka ; Okhotsk Sea ; Atlantic coast of America from Greenland 

 to Narragansett Bay, Rhode Island, 1-72 fathoms: 



Berg Bay, Glacier Bay, Alaska (Harriman Expedition). 



Dredged by the Albatross from off Cape Menshikof, Bering Sea, to the 

 Aleutian Islands and Portlock Bank, Alaska, in 16 to 72 fathoms; at 

 the unusual depth of 283 fathoms, off Seguam, Aleutians, a lot of 

 large specimens, the largest ? measuring 77 mm., the largest ^ 67 mm. ; 

 Strait of Fuca and Puget Sound, 40-48 fathoms; off Kamchatka, 

 12 and 42 fathoms, stations 3780 and 3781 ; Avacha Bay, Kamchatka, 

 16 fathoms, station 3642 ; Rakovaya Bay, Avacha Bay; off Robben 

 Island, Okhotsk Sea, 10 fathoms, station 3645. 



Various localities from Kadiak westward along the Aleutian Islands, in 

 3-25 fathoms (W. H. Dall). 



Puget Sound (T. Kincaid). 



Avacha Bay and Petropavlovsk, Kamchatka (L. Stejneger). 



Bering Island, among Laminaria, and Solovarennaja Bay, Petropavlovsk, 

 Kamchatka, 10-12 fathoms (N. Grebnitzky). 



Arctic Ocean (Stimpson). 



SPIRONTOCARIS LAMELLICORNIS (Dana). 



Hippolyte lamellicornis'DK^K, Proc. Acad. Nat. Sci. Phila., 1852, 24; Crust. 



U. S. Expl. Exped., I, 567, 1852, pi. xxxvi, fig. 6, 1855. — Stimpson, 



Jour. Boston Soc. Nat. Hist., vi, 498, 1857. — KlNGSLEY, Bull. Essex 



Inst., X, 62, 1878. 

 SpiroTitocaris lamellicornis WALKER, Trans. Liverpool Biol. Soc, XII, 277, 



1898. — Holmes, Occas. Papers Calif. Acad. Sci., vii, 208, 1900. 



This species, though resembling strongly S. spina, is at once separated 

 by the acuteness of the lateral margins of the first to third abdominal 



segments, which in S. spina are broadly 

 rounded. The rostrum is about three 

 fourths as long as the rest of the cara- 

 pace, and does not exceed the antennal 

 scale, although it may exceed the blade 

 Fig. 18. spiroiitocaHs ia,ncUicorms. Side -of the scalc. The spiue of the scale ex- 



of carapace of 9 (X:i). Station 3046. ^^^^^ \,^yoXi^ the blade tO a distaUCC 



equaling or exceeding the distal width of the blade. The dactyli of the 

 last three pairs of feet are longer than in S. spina, those of the last pair 

 being half the length of their propodi ; they are armed with spinules so 

 minute that the segment appears entire in comparison with S. spina. 

 Dimensions. — $ , length 63 mm., carapace 23 mm. 



