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 laige 

 process, the outside of the base of the limb, with three similar pro- 

 cesses, inner ramus with five setse on the third and four each upon thfr 

 second third, inner maigin of base of limb produced to form a multi" 

 setose branchial fin. Post abdomen rather small, its teiminal 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 servesasnourishment for the fourth, theephippial 

 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 antennee it is like Latona, which it also somewhat resembles in 

 the number of joints of the antennse and the numerous setse they bear. 

 It 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 crystaUina lives far out in the bay^ 

 and Baphnella is found in pools along shore. 



GENUS LIMNOSIDA Sars. 



Plate XXXV, Figs. 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; antennae very long. Post ab- 

 domen smooth; terminal claw spiny. 



The one species, L.frontosa Sars, is not yet known in America. 



GENUS DAPHNELLA Baird. 



Neither beak nor fornices present, Antennules of female small,. 

 truncate; those of male long, flagellate- Antennae 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 branchyara); Fischer '54 (Diaph- 

 anosoma brandtianum); Sars '65 (Daphnella brandtiana); P. E. Mueller '6& 

 Daphaella brachyura) ; Pavesi '79 (Sida brachyura); Herrick '82; Birge '78. 



