24 G Canadian Arctic Expedition, 1913-1918 



harbour were uniformly pale orange, without any of the blue or purple colours 

 of the other sex. 



Four days later, August 10, 1915, I examined a very large pond or small 

 lake inland at Bernard harbour. It has already been described (p. 8), under 

 Lepidurus arcticus, which also occurred in the same lake, and it has been men- 

 tioned there how much the fairy-shrimps were appreciated as food by the other 

 Phyllopods. The former were particularly found in the sheltered, plant-filled, 

 shallow bights of the lake, where they were swimming briskly around, dodging 

 away with great alertness, when I tried to catch them. Fourteen were secured 

 (11-15 mm.), five of which were males. The former had very big claspers, well- 

 developed genitalia, and were of a uniform pale brown colour, with intestine 

 (food particles) orange, and the head bluish dorsally. Their colours were thus 

 more like the males from August 4, 1915 (see above) than like the males from 

 Martin point (p. 19). The females all had ripe light brown eggs in the ovisac 

 and unripe, white eggs in the ovarium. In colour they had the same brilliant 

 coloration as given above (August 4, 1915); but there was quite a variety 

 in its intensity in the various females. Thus some of them had even the second 

 pair of antennae, the dorsal side of the foliaceous legs and the back between 

 these, besides the dorsal side of the body-trunk violet-brown (thus with similar 

 colours to those of the females from Martin point (p. 19); while other females 

 had the colours of those from August 4, 1915. The variation in colour of these 

 females from August 10, 1915, is mainly given by the different extension and 

 intensity of the purple (violet-brown) and deep blue pigmentation. The decided 

 difference in colour between the males and females of this species has probably 

 something to do with the lesser size, but greater numbers of the latter compared 

 with the former ones; and perhaps also with the fact that the males seem to die 

 off earlier in the fall than the females; and therefore it is of importance to the 

 latter ones to attract the attention of the males in time to get their eggs fertilized. 

 I kept several of these fairy-shrimps from August 10, 1915, alive, but in the 

 course of a week they all died. I kept, however, some of the eggs all during 

 the winter and three of them hatched next June (see p. 22). 



On August 23, 1915, I secured 20 more fairy-shrimps of this species in a 

 shallow pond situated on the north facing slope of a ridge at Bernard harbour, 

 thus a place where the power of the sun to dry up the pond was somewhat 

 curtailed. Five of these were males and had big claspers, and the rest were 

 females with ripe eggs in the ovisac. In all the length was from 12 to 15 mm. 

 I did not observe this species at Bernard harbour later in that year; and as the 

 winter set in early (middle of September) it is possible they did not last long. 

 Nor did I observe them at Bernard harbour in the fall of 1914, and at that time 

 in 1916 we had left the Arctic. 



Other Material 



Rae's specimens from Cape Krusenstern, east of Bernard harbour ^ (see 

 p. 16), recorded by Baird (1852), almost certainly belong to this species, as 

 believed by Packard (1883, p. 337). It is extremely improbable that they could 

 belong to the new species of Artemiopsis, seeing that it is very rare, found only 

 in one pond at Bernard harbour during two years' stay, and does not seem to 

 occur in ponds on the coastal lowland where Rae travelled, but only in certain 

 elevated ponds inland. 



The fairy-shrimps secured by the "Neptune" Expedition (see p. 16), were 

 collected "in freshwater ponds, formed of melted snow, in the barrens at Ful- 

 lerton," on the west side of Hudson bay (about lat. 63° N.). They were 

 identified a,s Branchinecta paludosahy Prof. G. 0. Sars and have been mentioned 

 by Halkett (1905, p. 107). 



Not Cape Krusenstern, Alaska, as given by Murdoch (1885). 



