384 



ZOOLOGY. 



of concentrated salt water on railroad bridges in New En- 

 gland. Artemia fertilis Verrill abounds in Great Salt Lake. 



Fig. 2i5.^77uimnocepkalus plaiyurui, male, natural size, eide and front view, a^ 

 head of the female ; d, end of the body of the female, showing the ovisac. 



They may often be seen swimming about in pairs, as in 

 Fig. 248. This species has a Xauplius young like that of 



Fig. 2ii.—Branchineeies ColorademU Pack. 



the brine-shrimp of Europe (Fig. 244 I). It is a signifi- 

 cant fact, bearing on the question of the origin of species, 

 that, according to Schmankiewirsch, Artemia mar change its 



