10 G Canadian Arctic Expedition, 1913-1918 



Suborder Anostraca. 

 FAMILY POLYARTEMIIDAE Simon. 

 Genus Polyartetniella Daday de Dees. 

 Polyartemiella hazeni (Murdoch). 



Polyartemia hazeni Murdoch, 1884, p. 522; 1885, p. 150, pi. II; Ekman, 1902, p. 



5, figs. 1-5. 

 Polyartemiella hanseni Daday de Dees., 1910, p. 106, fig. 2; Pearse, 1913, p. 2; 



1918, p. 666. 

 Polyartemiella hazeni Johansen, 1921 p. 25. ("Can. Field-Nat.") 



This species was first described and named by the collector, John Murdoch. 

 Ekman and Daday de Dees later amplified Murdoch's description, giving some 

 far better figures of both sexes but Daday apparently misread the specific name 

 as hanseni, a mistake later followed by Pearse. 



While the southern party of the Canadian Arctic Expedition stayed at 

 Teller (Port Clarence), near IBering strait, Alaska, in 1913, I found specimens 

 of both sexes of this species in two different tundra-ponds here.^ 



Two males were secured in the brackish pond, between the large lagoon 

 lake and Port Clarence baj', on August 3, 1913. 



I give here (text figure 2) an outline of the head and tail-ends (dorsal and 

 ventral views) of one of these males. The total length (from tip of A2 to end 

 of cercopods) is 12 mm., A2 being 3 mm. and tail 2 mm. long including the, short 

 (f mm.) cercopods. Murdoch states, that with his specimens the body (probably 

 exclusive of A2) is double the length of the abdomen (tail) ; but from an examin- 

 ation of my specimens this applies more to the female (see below) than to the male 

 where its body length is three or four times that of the abdomen. The colour 

 of the living animal is, according to ^lurdoch, a pale iridescent green; in addition 

 to this I find, however, that the accessory claspers (see below), the mouth 

 parts and the protruding genitalia are more brownish (cuticula) , and the contents 

 of the intestine dark green, as also the paired eyes have a brilliant purplish- 

 black colour, bordered with red. The number of foliaceous legs are 18, while 

 the females from August 6, 1913, have only 17 pairs, a sexual difference alreadj' 

 noted by Murdoch. 



As seen on text figure '2c the front-end of the head runs out anteriorly into 

 a broad, coniform and thorny "lamellar process" ^ behind which the small, 

 black nauplius-eye is situated. The first pair of antennae are more obscure, 

 being more or less hidden by the enormously developed second pair of antennae 

 (A2). The latter are, with my two males much swollen and antler-like, being 

 divided into three branches, of which the lower one is the longest (and biggest) 

 with three joints; the next shorter and with two joints; and the terminal one a 

 stubby, single joint. The whole of the inner (under) side of these claspers (A2), 

 from their base to the tips of the branches is covered with small spines, particu- 

 larly extensive on the middle part of the clasper. At the base of each clasper is 

 inserted, ventrallij, a much shorter, truncate appendage tapering off at the free 

 end, and also with small spine-hooks on the inner side, from the base to the 

 terminal point. I propose to call these the "accessory claspers." They are only 

 about one-third the lengths of the large claspers ( A2), but distinctly set off from 



' A comparison of the description and figures of P. hizfni, from Teller, Alaska, given in this, report, 

 with Murdoch's and Ekman's (the latter copied by Daday, 1910) descriptions and figures, shows certain 

 differences in the male claspers and in the genital region of both se.'tes. Prof. A. S. Pearse, of Madison, 

 Wisconsin, however prononnces the specimens from Teller, se-it to him for examination, to be P. hanseni, 

 (P. hizmi) Murdoch. 



Daday's "appendage." 



