THE FAIRY SHRIMPS (PHYLLOPODA) 



66f 



4 (3) Male frontal appendage wanting; male clasping antenna triramose. 



Polyartemiella judayi Daday 1909. 



The copulatory appendages of this form are thick, spiny, and shaped like 

 a fish-hook; the female has a long median finger-like appendage on the 

 dorsal surface above the egg sac. 



Pribyloff Islands and Alaska. The genus to which this species belongs is 

 entirely arctic in its distribution. 



Fig. 1016. PolyarlemieUa judayi. Dorsal view of head of male. X 5. (After Daday.) 



5 (2) Eleven pairs of pregenital ambulatory limbs 6 



6 (33) Clasping antenna of male biarticulate. 7 



7(16) Head of male unarmed in front, basal segment of clasping antenna with- 

 out a laminar appendage. , Family Branchinectidae . . 8 



Post-genital region 9-segmented, apical article of male clasping antenna 

 triangular and falciform. . . Branchinecta . . 9 



Basal segment of male clasping antenna serrate on inner margin. 



Branchinecta paludosa (O. F. Miiller) 1788. 



The egg sac of the female is very long and slender. The copulatory 

 appendage of the male is thick and arcuate. 



This is an arctic species and occurs in northern Europe as well as in 

 Greenland, Labrador, and Alaska, in North America. See also Fig. 10 1 1 . 



Fig. 1017. Branchinecta paludosa. Head of male, dorsal view. X S. 

 (After Daday.) 



10 (9) Basal segment of male clasping anteima not serrate on inner margin. 1 1 



11 (14) Basal segment of male clasping antenna with a spiny area on 



inner margin 12 



12 (13) Inner margin of basal segment of male clasping antenna with a 



rounded tubercle near base and a swollen spiny area 

 just proximal to middle. 



Branchinecta coloradensis Packard 1874. 



The segmentation and early development take place under the ice in 

 Alpine Lakes. The eggs of this species are much larger than those of 

 others in the genus. This fact may account for the ability to develop 

 so early. 



Reported from Colorado where it occurs at an altitude of 11,000 ft. 



The larvae appear as soon as the ice melts in the spring. 



Fig. 1018. Branchinecta coloradensis. Head of male, front view. 

 (After Shantz.) 



X7. 



13 (12) Basal segment of male clasping antenna armed with a large spiny 

 process, one third as long as the segment, which arises just 

 distal to the middle of the inner margin and projects proxi- 

 mally, a prominent finger-like process with a tuberculated 

 tip near inner proximal angle. 



Branchinecta packardi Pearse 1913. 



The five pregenital segments of female produced laterally into strong 

 spinous processes; these grow larger posteriorly. Collected at La Junta, 

 Colorado. 



Fig. 1019. Branchinecta packardi. Basal segment of second antenna of male. 



