ENTOMOSTKACA OF MINNESOTA. 45 



tempt was made to treat the Copepoda, but two species of Diaptomus 

 are indicated which will prove valid. Occasional papers in the 

 American Naturalist and elsewhere follow, till, in July and August of 



1882, Professor Forbes added two new genera and several species of 

 Copepoda, constituting by far the most considerable addition to the 

 subject yet produced. 



In the Report of the State Geologist of Minnesota for 1881, C. L. Her- 

 rick makes a considerable addition to the knowledge of American 

 Ci/elopid(e, enumerating ten species, of which six seemed new. This 

 writer also describes a new genus and several new species of Calanidce, 

 some of which unfortunately are identical with those described by 

 Forbes and published about simultaneously. 



In April, 1881, V. T. Chambers gave an account of a species of the 

 Sarpacticidce, referred by him to Zachidius. The species is especially 

 interesting on account of its novel habitat. Zachidius (J) fonticola Cham. 7 

 is found in saline waters of Big Bone Springs, Ky., and is thus very 

 distant from its marine congeners. It is perhaps doubtful if its gen 

 eric reference can be sustained, but the species is of great interest. 

 The Biaptomus described by the same author is not recognizable. 



Several articles in the Naturalist bring the bibliography up to May, 



1883, when F. W. Cragin published in the Trans. Kansas Academy of 

 Science, A Contribution to the History of the Fresh-water Copepoda. In 

 this paper ten species of Cyclops are described or mentioned. The 

 author ignored previous American literature and thus adds somewhat 

 to synonomy. The plates are lithographic, and are carefully, if not 

 artistically, prepared. A valuable feature is the translation of the 

 descriptions of Poggenpol's species from the Eussian. 



These papers, together with the outline presented beyond, it is 

 hoped, will form a basis for future work. 



To the above, which is reproduced without change from the first 

 edition, it may be added that there has been a considerable degree of 

 desultory activity in the study of the Copepoda in Europe since the 

 appearance of this work. This has been especially marked in the 

 case of the Calanidce, and, in particular, in the genus Biaptomus, in 

 which the confusion resulting from confounding many species under 

 one name has been finally removed and the real specific characters 

 differentiated. Among the most important of these papers are the 

 following: De Guerne and Richard: Revision des Calanides d'JEau 

 douee: Brady: Revision of British sj^ecies of Fresh-water Cyclopidce and 

 Calanidce; Schmeil: Beutschland'' s Freilebende Susstvasser Copepoden- 

 American literature since 1884 has been but little augmented, the fol- 

 lowing papers being the only important ones: Herrick: Contribution 

 to the Fauna of the Gulf of Mexico and the South, 1887; Forbes: On Some 



