198 Marsh — Cyclopidoe and Calanidw of Wisconsin, 



This species, which is abundant in the G-reat Lakes, I found 

 as a common pelagic species in Green Lake in the summers of 

 1890 and 1891, In a large number of collections made in 1892, 

 however, I did not find a single individual. This seems par- 

 ticularly strange, as the collections in 1892 were made at 

 about the same seasons as in the preceding years. 



The G-reen Lake specimens differ slightly from Forbes's type. 

 They are somewhat smaller, the males averaging .9 mm., and 

 the females 1.08 mm. The inner rami of the male fifth feet are 

 not evidently two-jointed. 



DlAPTOMUS ASHLANDI Sp. 110V. 



Plate III. Figs. 11-13. 



A small pelagic species closely resembling D. sicilis Forbes. 

 In form it is slender, hardly to be distinguished from D. sicilis 

 and D. minutus. 



The first joint of the abdomen in the female is longer than 

 the remaining part of the abdomen, is dilated at the sides, and 

 bears two minute lateral spines. The second and third joints 

 are so closely united that the abdomen appears two-jointed. 

 The furcal joints are about twice as long as broad.' 



The antennae reach just beyond the furca. The right antenna 

 of the male is much swollen anterior to the geniculating joint, 

 and bears on the antepenultimate joint an appendage slightly 

 exceeding in length the penultimate joint. This appendage 

 may be blunt pointed or slightly enlarged at the extremity. 



The fifth feet of the female are rather slender; the outer 

 ramus is two-jointed. The third joint is represented by two 

 short spines. The inner ramus is one-jointed, a little longer 

 than the first joint of the outer ramus, armed at tip with two 

 rather long spines. 



The fifth feet of the male are slender. The basal joint of 

 the right foot is about twice as long as that of the left. The 

 first joint of the outer ramus is a little wider than long. The 

 second joint is wider at the inner than at the outer end; the 



