PACKARD. J PHYLLOPODS OF NOETH AMEEICA. 335 



This genus stands in simplicity of structure next above Artemia^ being- 

 related to it by its short cercopoda or caudal appendages, and the simple 

 male claspers, with the knob-like projection at the base of each. It is 

 less complicated than in Braneliipus, and in his valuable paper on this 

 group I hardly understand why Professor Verrill should have interposed 

 BranckijniSyliis JEuhrancMpus, iStreptocephalus, and Chirocephalus between 

 Artemia and the present genus, as the genera in the order we place them 

 in this essay present successive degrees of complexity from Arteinia to 

 Chirocephalus and Thamnocephahis. The Southern European BrancJii- 

 pus spinosus Nordman, from a salt lake at Odessa, appears to us, on ex- 

 amination of a number of specimens received from Professor Siebold, to 

 belong to this genus, contrary to Verrill's opinion, who referred it to his 

 genus JEuhranchipus. In this species the knob-like processes of the 

 male claspers are present; the male claspers also are much as in B. 

 coloradensis, but much slenderer ; the caudal ai)pendages are short and 

 small, as in our American species of Branchinecta, but the ovisacs are 

 rather shorter than in any American and Arctic species, though still 

 longer than in Branchipus. The genus is certainly a good one, and easily 

 distinguishable. It is especially interesting to indicate the close aftin- 

 ities of this genus to Artemia, for it is Branchinecta ferox (Fischer sp.) 

 which Schmankevitch found to transform by artificial means into Arte- 

 mia, and the characters ot Branchinecta are such as we might believe a 

 well-fed Artemia subjected also to water of suitable temperature and 

 freshness might suddenly acquire. The fact, however, that the two 

 genera may be artificially produced does not militate against the natural- 

 ness of the two genera, Artemia and Branchinectes, since we can i)oint 

 to three American and Arctic species of Branchinecta which preserve 

 their generic identity. 



As suggested by Verrill, Milne-Edwards' Branchipus ferox (Edwaidn^ 

 Crustaces, iii, 369), from fresh water near Odessa, most x>robably belongs 

 to this genus. Milne-Edwards thus characterizes it: " Cornes cepha- 

 liques sans appendice pres du cote interne de leur base, pointues an 

 bout et sans dent sur le bord externe. Abdomen lisse, nageoires can- 

 dales longues et etroites." It has been rediscovered in 1872 in salt 

 pools near Odessa by Schmankevitch. Verrill also states that Bran- 

 chipus midclendorffiana Fischer, of Siberia and Lapland, may be a Bran- 

 chinecta, and, judging by Fischer's figures of the male clasper, the ovisac, 

 and the cercopoda, it is without much doubt a genuine Branchinecta. By 

 Grube and Dybowski it is regarded as a synonym of B. paludosa. It 

 inhabits Siberia, having been collected by Middendorf near the rivers 

 Taimyr and Boganida, as also in Lapland near Tri-Ostrowa, while it was 

 also collected by the Ural Expedition. Hence the species of the genus 

 Branchinecta range from the Arctic regions to Southern Eussia in Eu- 

 rope, and to the higher portions of the Eocky Mountain plateau of Colo- 

 rado in North America, as well as the plains of Kansas, the genus, with 

 the exception of the two species living at Odessa, and B. UndahU, of 

 Kansas, being inhabitants of Arctic and Alpine regions. 



Synopsis of the species. 



Male claspers pointed, not turned in, serrated inside of 2d joint; no 

 knob B. paludosa. 



Male claspers large, end broad and bent in, with no teeth; knob 

 present „ B. coloradensis. 



Male claspers short; caudal appendages very long B. lindaliU. 



