98 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 



tions particularly that it was found ofteuer at night than during the 

 day. In America a similar species was described from near Paducah, 

 Ky., under the name (7. tenuissimus; but the possibility of identity 

 with the Scandinavian species seemed excluded by the habitat. A 

 gathering taken at night from one of the lakes near Minneapolis con- 

 tained a few specimens of similar characters, and there no longer 

 seems to be a doubt of the identity or very close relation between 

 these forms. 



"The antennae are longer than described for C. tenuissimus, nearly 

 equalling the thorax. The last joint of the antennae is short, but the 

 toothed character was not noted. The fifth feet are small, the spines 

 are very long and slender. The margins of the abdominal segments 

 are irregularly toothed. The species will be confused with no other. 

 It is marked with blue in spots. Length 0.5 to 1.0 mm." 



Cyclops scourfieldi Brady. 

 Brady '91. 



It is very difficult to determine whether we have in this species 

 a variety of C. leiicJcarti or a distinct species. Brady identifies it with 

 Sirs' C. leucJcarti, which is regarded as distinct from Claus' G. leuckarti. 

 Schmeil has decided, after examination of Sars' specimens, that they 

 belong to G. leuckarti Claus, and are the same as G. simplex of other 

 authors. Under these circumstances there would seem to be no rea- 

 son for hesitating in referring G. scourjieldi to G. leucJcarti were it not 

 that the figure of the fourth foot given by Brady differs in armature 

 from that of Schmeil, and Brady fails to remark the striking armature 

 of the last joint of the antenna. If Schmeil is correct in saying that 

 the pearling or crenulation of the posterior margin of the maxilliped 

 is diagnostic of G. leacJcarti, the matter would be settled at once, for 

 Brady clearly figures it. On the whole, we incline to believe that 

 Brady's figure incorrectly shows a seta where there should be a spine 

 at the apex of the outer ramus of the fourth foot and that he has over- 

 looked the hyaline plate on the antenna. He says, however, "the 

 character which, so far as I know, distinguishes at once G. scourjieldi 

 from all other species is the presence, on the second joint of the pos- 

 terior maxilliped, of a series of short marginal spines.'' Length 1.4 

 mm. It may be added, that, in a figure of what is considered a va- 

 riety of G. scourfieldi, the armature of the outer ramus is figured as it 

 occurs in G. leucJcarti, while that of the inner ramus is obviously inac- 

 curate. 



* Cyclops oitlionoicles Sars. 



Very slender, thorax twice as long as wide, abdomen narrow, length 

 compared to that of the thorax as 9:13. Stylets about twice as long as 

 wide, strongly divergent, with short sette; the lateral seta near the 



