ENTOMOSTRACA OF MINNESOTA. 77 
riorly. The second segment is transversely wrinkled. Antenne 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. 
Diaptomus theeli Lilljeborg. 
PEATE VITT, Pie. 1 
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. 
Diaptomus lobatus Lilljeborg. 
GACH VAL ENT Geeta 
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. 
Diaptomus affinis UJjanin. 
PLATE X, Fie. 10. 
Uljanin ’75; De Guerne and Richard ’€9. 
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 twosmall spines. Antenne 
reach the end of the last abdominal segment. The Jast joint of the 
