ENTOMOSTRACA OF MINNESOTA. 77 



riorly. The second segment is transversely wrinkled. Antenmie ex- 

 tend to the stylets. Right male antenna with an unarmed antepenult 

 joint. Third joint of outer ramus of fifth feet obsolescent, inner ramus 

 slender and as long as the basal joint of the outer ramus. The outer 

 ramus of the right male foot with a small hyaline process; accessory 

 spine near the middle of the second joint small. The inner ramus is 

 short and acuminate. Inner ramus of left foot long, two-jointed, hir- 

 sute apically. Outer ramus short. 



Diaptomiis theeli Lilljeborg. 



Plate VIII, Fig. 11. 



De Guerne and Richard '89. 



A species very much like 'D. laciniatus, except that the last two 

 thoracic segments are not both produced into long projections, as in 

 that species, the last being moderately produced and mucronate. 

 The first abdominal segment is very long (as in the last), and some- 

 what expanded anteriorly. The fifth feet of the female have the ter- 

 minal segment of the outer ramus distinct and the inner ramus gen- 

 erally (in old forms) two-jointed. There is a small hyaline lobe from 

 the inner aspect of the peduncle of the right leg in the male. The 

 inner ramus of this leg is curved and acuminate. The inner ramus of 

 the left leg is shorter than the basal joint of the outer ramus and acute, 

 with a small spine near the apex. 2.0 mm. long. Collected by the 

 Nordenskiold expedition in Sibera. 



Diaptoiiius lobatus Lilljeborg. 



Plate VIII, Fig. 7. 



De Guerne and Richard '89. 



A species occurring with the last, from which we are unable to find 

 any sufficient reason for separating it. The last two thoracic seg- 

 ments are partly fused, and the last segment projects somewhat more 

 than in D. theeli, and there are minor differences in the feet but of very 

 doubtful value. Size the same. Such differences as exist may be 

 gathered from the figures. 



Diaptoiiius affinis Uljanin. 



Plate X, Fig. 10. 



Uljanin '75; De Guerne and Richard '89. 



A small form from Turkestan approaching D. denticornis, but lack- 

 ing the armature of the male antenna. The first abdominal segment is 

 unarmed, while the last thoracic has merely two small spines. Antennae 

 reach the end of the last abdominal segment. The last joint of the 



