30 CRUSTACEA OF ALABAMA. 



ing a squamous plate posteriorly on either side projecting posteriorly. Shell of the male 

 similar, but the greatest height is near the middle and the posterior outline is very 

 strongly convex near the middle, the lower and upper margins meeting at an acute 

 angle. Lower antennae with very short setae upon the three last segments, the preceed- 

 ing bearing six long, plumose setae. The first foot terminates in two short and one long 

 claw. The second foot is rather stout, bearing three sub-equal apical setae. The man- 

 dibles are of the usual form while the maxillae lack the palp in both sexes and are dacty- 

 late or pediform in the male. The caudal stylets are of moderate length, with two long 

 sub-equal terminal claws and a lateral seta near the end behind. The species is found 

 throughout the circumpolar provinces and is represented in the southern hemisphere by 

 similar if not identical forms. 



Genus Cypridopsis, Brady. 



This genus differs from Cypris simply in the great reduction of the caudal stylets 

 which become mere papillae with long spines. Three species are recognized by Brady 

 though several of the European forms described upon the basis of external form alone 

 may prove to belong here. Two species are identified in America, one agreeing most 

 nearly with C. aculeata of Lilljeborg, the other seemingly identical with the widely dis- 

 tributed C. vidua. 



Cypridopsis hystrix. s P- "■ 



(Plate IV, Fig. 6.) 



The American representative of H. aculeata of Lilljeborg, with which it may prove 

 identical. If the figures given of the post-abdomen of that species are correct ours is 

 certainly distinct. Length equal to about twice the greatest height which lies just be- 

 hind the anterior third, anterior outline much higher than the posterior and evenly round- 

 ed, posterior margin acutely angular, lower outline slightly concave, upper margin twice 

 angled ; shell covered with long curved spines ; color yellowish, with eight lucid spots. 

 Antennae slender, composed of seven segments, of which all but the basal are short and sub- 

 equal, setae not plumose, distributed as follows: to the apical joint two long and two short, to 

 the penultimate four long, to the preceeding and the next following each two long and 

 two short, to the still preceeding one long and one short. Antennules with very short 

 apical segment with two strong unequal claws and a minute seta, penultimate with two 

 equal toothed claws and a number of slender setae, third from end with five long and 

 several short setae, preceeding segment large, with three slender setae. First foot five- 

 jointed, second joint elongated, third and' fourth equal, each with a single short seta, api- 

 cal segment small, with two setae and a long toothed gently curved claw ; last foot mod- 

 erately slender, terminal joint with a small claw and two setae at the apex and a lateral 

 spine. Caudal stylets reduced to minute papillae bearing a slender claw and a flexuous 

 spine. The mouth parts bear the characters of the genus Cypris. 



