ENTOMOSTRACA OF MINNESOTA. 63 
* Diaptomus signicaudatus Lilljeborg. 
PLATES VIII, Fie. 13; 1X, Fie. 10. 
De Guerne and Richard ’89. 
A small species found at great altitudes in the Sierra Nevada 
Mountains of California and forming an obvious transition toward 
Epischura. Form rather robust, greatest width at the second segment. 
Last two segments of the thorax confluent, projecting into lateral lobes 
bearing small teeth. The fourth thoracic segment with a slight dorsal 
gibbosity. First abdominal segment expanded and spined anteriorly, 
and bearing a large retrorse process on the right side posteriorly. 
Second segment short. Caudal stylets about half again as long as 
wide. Antenne 25-jointed, extending little beyond the stylets. An- 
tepenult segment of the right male antenna with a small hook. Fifth 
foot in the female with one-jointed inner ramus as long as the basal 
joint of the outer ramus. The terminal segment of the outer ramus is 
obsolescent. The external ramus of the right foot of the male bears a 
hyaline lamina on the inner aspect of the basal segment. Second 
segment more than twice as long as the preceding. Claws simply 
arcuate. Accessory spine nearer the end than the base of the second 
segment. Inner ramus wide and acute, shorter than the basal segment 
of the outer ramus. The left foot has a slender inner ramus, longer 
than the basal segment of the outer, whose apical joint is pilose and 
armed with two spines. Length of female 1.5 mm.; of male 1.5 mm. 
Diaptomus incongruens Poppe. 
PLATE VIII, Fia. 6. 
Poppe ’88; De Guerne and Richard ’89. 
A Chinese species of moderate size, characterized by the fact that 
the projecting angles of the last thoracic segment are dissimilar on the 
two sides and the possession of a broad mucronate process on the right 
side of the first abdominal segment. The antennz extend far beyond 
the stylets. The antepenult joint of the right male antenna bears a 
hyaline lamella ending distally in a small hook. The fifth foot of the 
female has a one jointed inner ramus as long as the basal joint of the 
outer ramus. The apical joint is distinct and the claw serrate. The 
inner ramus of the right foot of the male is one-jointed and that of the 
left foot two-jointed. The terminal segment of the outer ramus of the 
left foot has two spines apically and a ciliated plate within. Length 
of female 1.4 mm. 
Diaptomus gibber Poppe. 
PLATE VIII, Fia. 1. 
De Guerne and Richard ’89. 
A decidedly unique form from Brazil. The last thoracic segment 
forms on either side a bi-spinose process, the two being dissimilar. 
The first segment of the abdomen is expanded proximad and bears on 
