Lake Maxinkuckee, Physical and Biological Survey 79 



THE COPEPOD PARASITES 



BY CHARLES B. WILSON, Professor of Biology, State Normal 

 School, Westfield, Mass. 



Three species of Argulus, two of Ergasilus, and one of Ach- 

 theres were found upon the fish of the lake. The species of Argu- 

 lus have all been described elsewhere (Proc. U. S. Nat. Mus., XXV, 

 pp. 709, 715, 718). The life history of one species, A. maculosus, 

 was obtained in full, and a brief account was published in 1907 

 (Proc. U. S. Nat. Mus., XXXII, p. 416). Of the two species of 

 Ergasilus, one (E. centrarchidarum) has been described by 

 Wright*. This species is common everywhere on all fishes of the 

 perch family. The other species was new to science ; it was named 

 E. versicolor, and a full description with figures was published in 

 1911 (Proc. U. S. Nat. Mus., XXXIX, p. 341: pi. 45). 



The single species of Achtheres, A. ambloplitis, has also been 

 described by Wright, Kellicott, and others, but several details were 

 here supplied that had hitherto been lacking. 



The complete life-history was also worked out for both genera ; 

 that of Achtheres had been partially described before by Claus and 

 Kellicott, while not a single detail had ever been published for 

 Ergasilus. 



I. ARGULUS CATOSTOMI Dana & Herrick 



Found in the gill-cavity of the white sucker, Catostomus com- 

 mersonii. The discovery of this species in Indiana, together with 

 those recorded from Lake Champlain and the rivers of Mas'sa- 

 chusetts, Connecticut, and New York, shows the distribution of 

 this parasite to be identical with that of the host it infests. The 

 specimens here obtained and those from Lake Champlain include 

 males, the first of that sex to be recorded for this species. 



2. ARGULUS AMERICANUS Wilson 



Found on the outside surface of the Dogfish or Bowfin (Amia 

 calva) . This species does not appear to be very common at Lake 

 Maxinkuckee, but possibly an examination of a larger number of 

 fish would show different results. This is the first instance of 

 the species having been obtained from fish in their native haunts. 



3. ARGULUS MACULOSUS Wilson 



Found on the outside surface of the Common Bullhead (Amei- 

 urus neblulosus), the Yellow Catfish (Ameiurus natalis) , and the 



*Proc. Canadian Institute (N. S.), I, p. 243. 



