6b 



Canadian Arctic Expedition, 1913-18 



Mysis relicta Lov^n. 

 G. O. Sars, Mon. Norges Mysider, III, 73, pi. XXXXI, 1879. 



Station 42 



Bernard harbour, Northwest Territories, October 10, 1915. 



From stomach of Cristivomer namaycush W., caught in lake 



inland. 

 49. 



26, 



Neomysis andersoni n. sp. 



This apparently new species of Neomysis was collected by Mr. Frits Johansen 

 of the Southern Party of the Canadian Arctic Expedition at Grantley harbour. 

 Port Clarence, Alaska, August 3-4, 1913. (Stations 20 a, f, surface, 1 d', length 

 20 mm., 3 9, 20 + juv.). Catalogue, Nos. 1251 and 1252, Victoria Memorial 

 Museum, Ottawa, Canada. 



Though considerably smaller, it is similar to Neomysis rayi. It differs, 

 however, from this arid all other related species on the west coast in the arma- 

 ture of the telson. This consists of comparatively large spines, between which 

 are intercalated groups of smaller ones rather regularly arranged, except for 

 the interspace adjacent to the large terminal spines of the telson, which contains 

 three of the smaller spines; the interspaces of the distal third of the telson have 

 four, five, or six spines between each of two larger ones; proximally there seem 

 to be only two small spines to each interspace; terminally there are two large 

 spines with two small ones between. The telson is deeply sulcate above and 

 about one-fourth as long as the rest of the abdomen; the inner branch of the 

 uropods is about as long as the telson, while the outer exceeds the telson by a 

 little more than one-third its length. 



M^ a 



Fig. 1. — Nromysis andersoni, 9, X about 15. a, dorsal view of anteniial region; h, of tail fan. 



From Mynisl costata Holmes (see Hansen, University (California Pub. Zool., 

 11, 177, pi. 9, figs, 2 a-d), which has a telson somewhat similarly armed laterally 

 it is at once distinguished by the fact that the two large terminal spines are not 

 juxtaposed, but are separated by two smaller ones. 



The frontal plate is proportioned like i that Jof N. franciscana Holmes 

 (Hansen, I. c, 178, pi. 9, figs. 3 a-b, 1913), and is subtruncate, and somewhat 

 sinuous, forming on the frontal margin^three very slight lobes, one at each 



