Article IV. — The North American Centropagidce belonging 

 to the Genera Osphranticum, Limnocalanus, and Epis- 

 chura* By Frederick William Schacht, B. S. 



INTRODUCTION. 



■ 



In Article III. of this Bulletin the writer discussed the 

 North American species of Diaptomus, and in the present 

 paper, in furtherance of the same purpose, the genera Os- 

 phranticum, Limnocalanus, and Epischura arc treated. In 

 the introduction to the former article was given a short 

 account of the work of writers on the Eutomostraca now 

 included in the family Centropagidce, especially those genera 

 found in North America. No reference is made there to the 

 genera Heterocope and Eurytemora, since at that time I re- 

 garded the presence of these two genera in North America as 

 rather doubtful. 



The only statement that Heterocope was ever found on this 

 side of the Atlantic is made by Cragin ('83) t. After an 

 enumeration of the genera of fresh-water Oopepoda he says : 

 " Of these eleven genera, four — Diaptomus, Limnocalanus, 

 Cyclops, and Canthocamptus — have been recorded as common 

 to the Old World and the New. I add Heterocope on the 

 authority of my friend, Mr. William Patten, who informs me 

 that a species is common in Watertown, Massachusetts." 

 This evidence is not sufficient to justify the treatment of the 

 genus in this paper. 



In regard to Eurytemora (=Temora Temorella) I was per- 

 haps overhasty in my conclusions, but it being now too late 

 to remedy the omission, the following statements must 

 suffice. In his "Final Tieport" Herrick ('84) notes the 

 occurrence of Temora affinis Poppe in the rivers flowing into 

 the Gulf of Mexico as well as in the brackish waters into 

 which these rivers flow. In the "Crustacea of Alabama" 

 ('87) he notes, under the name of Temorella ajjinis, a species 

 which according to his statement is the same. The figures of 



-This paper was accepted by the Faculty of the University of Illinois June 1. 

 1898, ;is ii thesis for the degree of Master of Science in /oology. 



(The parenthetical figures in the text of this paper refer usually to the bibliog- 

 raphy of Article III., which is. however, supplemented bv an additional list appended 

 to this discussion. 



