[9] LAKE SUPERIOR ENTOMOSTRACA. 709 



last segments of the abdomen. The inner terminal bristle three times 

 as long as the outer, three fifths as long as the outer median, and about 

 two fifths the length of the longest. A transverse row of spiuules at 

 the base of the outer seta; the distal end of the last abdominal segment 

 dentate ; and the distal end of the segment preceding with a few teeth 

 at the sides. 



Last thoracic segment minutely dentate on posterior margin. 



This species is allied to coronatus, from which it is distinguished 

 (among other characters) by the absence of the dentations of the anten- 

 nal segments, which gave the latter its name, by the absence of cilia on 

 the inner surfaces of the rami of the furca, and by the much smaller 

 size. 



Described from several specimens (females)taken inshore at the head 

 of Keweenaw Bay on the south shore of Lake Superior. 



Cyclops edax, n. sp. (PI. in, fig. 15; PI. IV, figs. 1G-19. ) 



A small species, usually more or less pigmented, moderately robust, 

 with short furca, subequal caudal seta3, seveutcen-jointed antennae, and 

 unusually prominent maxillipeds. 



Length, without caudal seta?, l.l mm . 



Oephalothorax oval, rather compact, broadest before the middle; 

 first segment as long as the remainder; back moderately arched. Last 

 thoracic segment scarcely broader than the first abdominal, slightly 

 emarginate at the sides. First abdominal segment (PL in, fig. 15) very 

 long, equaling the following three; last segment shortest, with a row 

 of spiuules at the posterior margin. Kami three eighths as wide as 

 long, nearly twice the length of the last segment. The lateral spine a 

 trifle behind the middle, the outer seta about as long as the ramus, the 

 inner five sixths the length of the third from within, the latter two 

 thirds as long as the second. 



The antenna? reach to the fourth thoracic segment and are without 

 serrations, acute ridges, or other special armature, except a stout spine 

 at the tip of the sixth segment. The basal joint is as long as the three 

 following, and the last three joints are about as long as the six pre- 

 ceding, joints sixteen and seventeen being equal, and fifteen four fifths 

 as long as sixteen. The fourth segment is as long as the fifth and sixth 

 together, and the seventh a little longer. The tenth segment is wholly 

 destitute of hairs and bristles. The antennules are slender, the first 

 and second segments not distinctly articulated, the first twice as long 

 as the second, the third and fourth equal to each other, and to the first. 

 The two last segments minutely hairy on the posterior surface, except 

 a little space near the tip of the last. 



The first maxilliped is unusually long and slender, the basal segment 

 being very nearly three times as long as wide, and the whole appendage 

 as long as the last five antennal joints. 



The last segment of the outer ramus of the legs of the first pair (PL 

 IV, fig. 16) bears one spine and two setre at tip, one spine without and 



