78 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 



outer ramus of the fifoh feet of the female obsolescent, inner ramus 

 one jointed, longer than the basal joint of the outer ramus. The fig- 

 ures of the male feet are imperfect, but indicate small one-jointed in- 

 ternal rami on both sides. 1.6 to 1.4 mm. long. 



DiaptoimiS aiiiblyodoil Marenzeller. 



Plate IX, Fig. 2. 



Marenzeller '73; Kortchaguine '73 and '87 (D. bogdanowi) ; De Guerne and Richard '89. 



A large species very nearly allied to D. gracilis (4.0 to 4.5 mm. 

 long). Last segment of the thorax ornamented with two spines. 

 First abdominal segment with a conical process on either side armed 

 with a long spine. Anteunpe extending to the end of the thorax. 

 Last segment of the outer ramus of the fifth foot of the female well de- 

 veloped, inner ramus one jointed, equaling the basal joint of the outer 

 ramus and bearing three setie; the claw strongly toothed. Inner rami 

 of the male fifth foot one-jointed, short, unarmed. The basal joint of 

 the outer ramus of the right leg with a small lobe. Apical segment 

 of the left leg densely spiny, with two larger spines. 



We receive too late to enter the above list in the appropriate 

 places descriptions of two species of Dlaptomm by Professor Marsh 

 ('94). The descriptions are giv^eu verbatim with a reduced repro- 

 duction of the figures. 



* Diaptoiiius iiiississippiensi.s Marsh. 

 Plate XLVII, Figs. 1-3. 



"Of moderate size. The first two segments of the cephalothorax 

 are nearly equal in length, and together form somewhat less than half 

 the cephalothorax. The last segment of the cephalothorax is armed 

 behind with two minute spines. 



"The first segment of the abdomen of the female is as long as the 

 remainder of the abdomen and the furca; it is dilated laterally and in 

 front, and bears two prominent lateral spines, the right spine being con- 

 siderably larger than the left. The second segment is somewhat shorter 

 than the third, and the third and the furca are of about equal length. 



"The antennie reach beyond the farca. The right antenna of the 

 male is swollen anterior to the geniculating joint, and the antepenul- 

 timate joint is without armature. 



"The outer ramus of the fifth foot of the female is two-jointed, the 

 third joint being represented by two spines. The inner ramus is one- 

 jointed, a little longer than the first joint of the outer ramus, and 

 armed at the tip with minute setie and two rather long spines. 



"In the right fifth foot of the male the basal joint is dilated on the 

 inner margin. The first joint of the outer ramus is slightly broader 

 than long. The second joint is elongated, quadrangular, with the 



