DECAPODS 87 



Typical form. -In the typical S. gaimardii (Milne Edwards), of which 

 Hippolyte gibba Kroyer is probably the male form, there is in the female 

 no lobe on the third abdominal segment (in a side view), although the 

 segment is somewhat compressed ; the rostrum is distinctly shorter than 

 the antennal scale, scarcely if at all longer than the carapace, and is 

 armed with fewer spines. In both sexes the scale is longer and wider 

 in the typical form, being about four fifths as long as the carapace. 



Distribution. S. gaimardii belcheri is found from the Arctic coast of 

 Alaska and Siberia southward to Sitka, taking the place of typical 

 S. gaimardii; it occurs also in Kara Sea (Dijmphna Exped.), Nova 

 Zembla (Birula), and at Nakvak, Labrador (L. M. Turner). 



Lat. 700 i5'io"N., long. 1620 55' oo" W., 16 fathoms; lat. 71002' 

 oo" N., long. 1570 46' oo" W., 19 fathoms ; and off Point Hope, Alaska, 

 25 fathoms (U. S. R. S. Corwiri). 



Ten miles west of Point Franklin, 13^ fathoms (Point Barrow Exped.). 



Bering Strait and Bering Sea in lat. 66 12' oo" N., long. 168 54' 

 oo" W., 30 fathoms; lat. 640 12' oo" N., long. 1620 52' oo" W., 17 

 fathoms; lat. 62 15' oo" N., long. 167 48' oo" W., 20^ fathoms 

 (Lieutenant George M. Stoney, U. S. N.). 



Plover Bay, Siberia, 10 to 25 fathoms; Cape Lisburne; off Cape Sa- 

 bine, 13 fathoms; Bering Strait, 13 fathoms; Sitka Harbor, 15 fathoms 

 (W. H. Dall). 



Off mouth of Yukon, 3^ fathoms (E. W. Nelson). 



Off St. Matthew Island, 37 fathoms, station 3519 ; off Pribilof Islands, 

 50 to 52 fathoms (Albatross stations 3527 and 3611). 



That the belcheri form cannot be considered a species is shown by the 

 existence of specimens which unite the characters with those of S. gai- 

 mardii. In three females from Henley Harbor, Labrador, the abdomen is 

 without a lobe, but the rostrum is longer than the rest of the carapace, 

 and just as long as the acicle ; the acicle is long as in typical S. gai- 

 mardii. 



SPIRONTOCARIS TOWNSENDI Rathbun. 



Spirontocaris gaimardii RATHBUN, The Fur Seals and Fur-Seal Islands of 



the North Pacific Ocean, Pt. Ill, 556, 1899 (part). 

 Spirontocaris townsendi RATHBUN, Proc. U. S. Nat. Mus., xxiv, 897, 1902. 



On the Pacific coast there is a large group of species of the gaimardii 

 type, which can be distinguished only by the closest observation. Of 

 these species, S. townsendi resembles S. gaimardii and S. gaimardii belcheri 

 in having the outer maxilliped provided with an exopod and epipod, and 

 the first two feet also with epipods. S. townsendi continues the range of 



