ENTOMOSTKACA OF MINNESOTA. 67 



much thickened. The antepenaltimate joint bears a small hook and 

 the last two joints are relatively very small. The antennules are of 

 the usual form, the two-jointed branch being much the shorter. The 

 first feet of both sexes have, as usual, the inner ramus two jointed. 

 The external spines of the outer ramus are longer in the male. The 

 fifth feet of the female have the inner ramus very long and two jointed, 

 armed apically with two very long, setose, equal spines. The apical 

 segment of the outer ramus is distinct and armed with two subequal 

 spines, and is protected by a spine from the preceding joint near its 

 base. The claw is strongly toothed and straight. The right foot of 

 the male is much longer than the left and has a short toothed apical 

 claw. The accessory spine is near the base of the claw. The inner 

 ramus is very small and spatulate. The preceding segment bears a 

 smiU spine externallj^ and a lamellate appendage within. The inner 

 ramus of the left foot is larger and nearly as long as the basal joint of 

 the outer ramus; it is corrugate internally and bears a short spine 

 apically. Opposite this ramus on the basal segment of the outer are 

 small setai. The apical segment of the outer ramus bears two curved 

 sjjiues and numerous setae apically and a hairy plate internally. 

 Length 3.0 to 4.0 mm. 



This species has been found in Minnesota, Illinois, Ohio, Kentucky 

 and Alabama. 



*Diaptoinus albuquerqueusis Sp. n. 

 Plates VI, Figs. 1-3; VII. 



Magnitudine mediocri, Cephalothorax latitudine maxima ad medium sita; seg- 

 merto ultimo feminaj ad latera extante, utrinque mucronibus 2 armaM. Segmentum 

 abdomiaale 1-mum partem reliquam abdominis, setis exceptis, longitadine superans, 

 utrinque mucrone distincto prseditum; segmentum 2-dum per breve. Rami furcales 

 segraento antecedeute fere ajquantes, intus ciliati. Antennte 1-mi paris extremam 

 furcam attingentes, vel superantes, 25-articulalse. Articulus antepenutimus anten- 

 nge prehensilis maris processu recto vel subanguiformi sat longo prteditus. Pes 5-ti 

 paris feminai ramo exteriore triarticulato, articulo 3-tio perspicuo, et aculeo interiore 

 circiter ad medium processus unguiformis articulo 2-di porrecto. Processus ungui- 

 formis modicis arcuatus, dentibus ad partem medium armatus. Ramus ejus interior 

 extra medium sed non ad finem articuli 1-mi rami exteriores porrectus, biarticulatus, 

 et ad fiaem ciliatus. Pes dexter 5-ti paris apud marem ramus interior 1-articuIatus, 

 per breve, articuli antepenulti rami exterioris longitudinem ajquant. Unguis (vel 

 segmentum 3-duai) per magnum, in longitudine pars reliquis pedis superans. Pro- 

 cessus lateralis segmenti 2-di magnus, ad basin intus dentibus minutibus affectus. 

 Pedis sinisteri 5-ti paris apud marem, articulus ultimus rami exterioris conicus, in- 

 tus lamina ciliatus instructus, ad apicem mucronibus duobus affectus. Segmentum 

 2-dum ejus ramus, intus granulosus. Ramus interior previs, uni articulatus. Ani- 

 mal pleurumque pellucidum, colore albido. Longitud. feminte 1.4-1.6 mm. 



This medium sized species occurs in the water reservoir supplying 

 Albuquerque, New Mexico, together with D. novamexicanus in large 

 numbers. The last segment of the thorax is protuberant and bears 

 5 



