ENTOMOSTRACA OF MINNESOTA. 5 
* Eurytemora affinis Poppe. 
PLATES I, Frias. 5-10; LX, Fias. 8-15. 
Lilljeborg ’53 (Temora velox); Poppe ’80 (Temora affinis) ; Claus ’81 (Temora affinis); 
Giesbrecht ’811 (Eurytemora hirundo). 
Form rather robust, about 1.60 mm. long, variously ornamented 
with colord markings; head separated by an obvious suture from the 
thorax, rounded anteriorly, with small forked beak; antenne about as 
long asthe thorax, 24-jointed, the twelve basal joints being quite short 
and uniform, in the right male antenna geniculated and thickened be- 
yond the twelfth, the geniculation being between the eighteenth and 
nineteenth, the seventeenth and eighteenth segments furnished with 
comb like or file-like plate against which plays a similar shorter plate 
on the nineteenth; the antennules short, three-jointed ramus with 
twelve set, two-jointed ramus with about fifteen; jaw. with eight 
acuminate teeth and a small spine; mandiblar palp with a two-jointed 
and four-jointed ramus, the former with seven terminal and four lat- 
eral setve; maxilliped very small, six-jointed; first pair of feet with the 
inner ramus one- the other three-jointed, remaining swimming feet, 
two- and three-jointed; fifth foot in the female with three joints (appar- 
ently four), the basal bearing a single external spine, the second, two 
external spines and a strong internal process, the terminal joint a long 
pectinate seta and a small spine; the fifth feet of the male both four- 
jointed, the right terminating in a long, irregularly excised claw and 
the left in a fan-shaped expansion with a central spine. The abdomen 
is five jointed in the male and terminates in two long slender stylets, 
but sparsely beset with bristles along the inner margin, while in the 
female the abdomen is three-jointed and the shorter stylets are densely 
spinous and bear numerous fine setze medianly. The second segment 
of the abdomen in the female is produced into a spiniferous process 
with small spines on its sides. The caudal stylets are about six times 
as long as wide in the female and nearly eight times in the male, the 
preceding segment being densely covered with short spines in the 
former, while in the latter there is on either side a cluster of longer 
stylets. The eggs are carried in a large spherical mass beneath the 
abdomen as in Osphranticum (Potamoichetor). The one-jointed ramus 
of the first foot bears seven sete, the terminal joint of the other ramus, 
five setee and three spines; the second segment of the inner ramus of 
second and third feet bears six sete, its predecessor three, while the 
terminal segment of the outer ramus carries five set, one long, ser- 
rated, apical spine and a short external spine; the fourth foot has but 
five setze on the apical segment of inner ramus and five sete, a ser- 
arted spine and two small spines upon the opposite branch, 
4 
4 
