148 TWELFTH ANNUAL REPORT. 



longer, external setae very short. Terminal joint of outer rami 

 with three spines externally and four setae internally. Length 1.3- 

 mm. I know nothing of this species save the description of Sars,. 

 a part of which is quoted above. 



Sp. O. Cyclops parens, Henick. 



(Plate R. Fig. 22.) 

 Cyclops parcus, herrick, Crustacea of Minnesota, p. 229 ; Plate VI., Figs. 12—15. 



In form and general appearance greatly resembling Cyclops 

 thomasi, which it nearly equals in size. The chief differences are- 

 found in the length of the caudal stylets and antennge and in the 

 form of the fifth foot. The antennae are shorter than, or about as 

 long as, the first thoracic segment. The formula expressing the 

 length of the joints corresponds with that for C. thomasi. The 

 antennules are shortish. The labrum is rather narrow, projecting 

 below into obtuse angles, the middle of the lower face being occu- 

 pied with nine rather small teeth. The terminal joint of the larger 

 branch of the maxilliped bears four hairs. The second joint has a 

 moderately large dactyl, the movable finger of which is small and 

 sparsely spiny, the immovable finger is ornamented by an oblique 

 series of blunt prominences and a small seta at its base. The first 

 pair of feet has two terminal and two interior set« and two exter- 

 nal spines on the ultimate joint of the outer ramus, while the cor- 

 responding joint of the inner ramus bears one inner seta and large 

 spine and three outer setee. The fourth foot has, in the first case, 

 two outer spines, a terminal spine and seta and three internal setas, 

 and, in the second, one external seta, two subequal terminal spiaes 

 and two internal setae. The fifth foot is two-jointed, bearing on 

 the short basal joint a moderate seta and on the larger second joint 

 a considerable seta and a small oval spine on its side. The caudal 

 stylets are short and the lateral seta is near the end (about 1-5). 

 The outer seta is but three- fourths the length of the inner. The 

 inner of the median setas is considerably longer than the outer. 

 The shape of the operculum of the female is very characteristic, it 

 being nearly oval. The last two joints of the thorax are acute. 

 The entire length is about 1.5 mm. 



Sp. lO. Cyclops brevisplnosiis. (Sp. e.) 



(Plate S. Figs. 7— 11.) 

 The form for which this name is proposed takes the place of the 



