ENTOMOSTRACA OF MINNESOTA. 145 



notes Baphnia galeata, D. pellucida and I), pulex; also a species of Bos- 

 mina, Eiiryco'cus lamellatus and Leptodora liyalina. 



A. E. Birge was the first to systematically study Gladocera in 

 America, and his ^otes on Gladocera furnished a basis upon which to 

 build. A few notes were published by the writer a little later. 



A few additional notes and descriptions of new species were pub- 

 lished in the Meventh Animal Beport of the Minnesota Geological and 

 Natural History Survey. 



Professor Birge published other notes in the Medical Journal and 

 Examiner of Chicago, which I have not seen. 



Professor Forbes of Xormal, 111,, in an article in the American 

 Naturalist^ July, 1882, adds a number of facts and one new species. 



In addition to the above, a figure ofiS/cZawas printed in one of 

 Haydeii's Survey Beports, and some account of the Gladocera of Lake 

 Michigan was given by B. W. Thomas, I believe, in one of the oflBcial 

 reports of the Chicago Water Commission. 



Since the publication of the first edition several papers by Profes- 

 sor Birge, Professor Turner and the writer seem to be the only ones 

 requiring notice. 



KEY TO THE ORDER CLADOCERA. 



I. Body enclosed in a bivalve shell. Mandibles truncate belovp. Maxillje 



distinct, spiny. Thoracic ganglia discrete. (Sub-order Calyptoiliera.) 



a. Six pairs of feet, similar, foliaceous, all distinctly branchiate. 



(Tribe Ctenopoda.) 



* Swimming antennaj with two unequal rami, intestine simple. 



Family Sidida', 146 

 ** Swimming antenna? simple, elongate cylindrical (in the male 

 prehensile) ; intestine with two lateral dilations. 



Family Holopedidae, 151 



b. Five (or six) pairs of feet, the anterior pair more or less prehensile 



and destitute of branchiae. (Tribe Alioniopoda.) 



* Rami of antenna? three- and four-jointed; five pairs of feet, the 



last with a curved appendage guarding the branchial sac; 

 antennules of the female short, one-jointed. 



Family Daphnidee, 152 

 ** Six pairs of feet; antennules elongated, many jointed. 



Family Bosmiiiidae, 206 

 *** Antennules of female elongated, but one-jointed; intestine 



simple or convolute. . . . Family Lyncodapliiiidae, 209 

 **** Antenna; with both rami three-jointed; intestine convolute, 



with abdominal but no anterior coeca. Family Lynceidaj, 224 



II. Body without or nearly destitute of a bivalve shell; feet not branchiate, 



spiny; anterior thoracic ganglia in one mass. (Sub-order Gyiliuoniera.) 

 a. Abdomen curved, terminating in two long stylets. 



Family Polyphemidiie, 266 

 h. Abdomen straight, ending in short claws. Family Leptodoridfe, 268 



