148 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 
female is biramose, the outer ramus being large, its terminal joint 
bearing seven pectinate processes; the preceding segment has two 
processes on the outside, while the short basal joint has a very large 
process, the outside of the base of the limb, with three similar pro- 
cesses, inner ramus with five setce on the third and four each upon the 
second third, inner margin of base of limb produced to form a multi- 
setose branchial fin. Post-abdomen rather small, its terminal claws 
short and armed with three basal spines and a series of spinules along 
the inside, post-abdomen also ornamented with about twelve clusters 
of teeth along the posterior margin and about the base of the claws. 
The eggstalk is long and about three out of every four eggs produced 
parthenogenetically serves as nourishment for the fourth, the ephippial 
females (i. e., the late females which produce eggs coated to resist 
cold or drouth) are smaller than the ordinary examples and produce 
two very large ova. 
The shell is ornamented along the ventral margins with short spines 
and along the free caudal margin with minute hairs. In most respects 
this species is like Sida, which it resembles in size. In the form of the 
female antenne it is like Latona, which it also somewhat resembles in 
the number of joints of the antenne and the numerous set they bear. 
Jt is certainly an interesting transition form. Found only in swamps 
bordering Mobile Bay, Ala., but whether in brackish or fresh water 
my notes do not inform me. Sida crystallina lives far out in the bay, 
and Daphnella is found in pools along shore. 
GENUS LIMNOSIDA Sars. 
PLATE XXXYV, Fias. 9, 10. 
Head crested; eye in a conical prominence. Shell elongated, pro- 
duced above in an acute angle. Antennules small, truncate in the 
female; in the male of enormous size; antenne very long. Post ab- 
domen smooth; terminal claw spiny. 
The one species, L. frontosa Sars, 1s not yet known in America. 
GENUS DAPHNELLA Baird. 
Neither beak nor fornices present. Antennules of female small, 
truncate; those of male long, flagellate. Antenne with two and three- 
jointed rami. Male with a hook on the first foot, and large copulatory 
organs attached to the base of the post-abdomen. 
* Daphnella brachyura Lievin. 
PLATE XXVI. Figs. 11-16. 
Lievin ’48; Baird ’50 (wingii); Lilljeborg ’53 (Sida branchyura); Fischer 54 (Diaph- 
anosoma brandtianum); Sars ’65 (Daphnella brandtiana); P. E. Mueller ’6& 
Daphnella brachyura); Pavesi ’79 (Sida brachyura); Herrick ’82; Birge ’78. 
