I909-] THE CAYUGA LAKE BASIN, N. Y. 391 



CATALOGUE OF SPECIES. 



A. Class CYCLOSTOMATA. 



I. Order HYPEROARTIA. 



I. Family Petromyzonid.e. The Lampreys. 



1. Petromyzon marinus unicolor (De Kay). Lake lamprey. 



Abundant in the lake, where they are very destructive to the 

 larger fishes because of their parasitic habits. ^^ They are found 

 in great numbers in the lake inlet during the spawning season, which 

 occurs between May 25 and the middle of June. There is, how- 

 ever, considerable variation in this respect according to the season. 

 In 1900 the crest of the spawning season occurred during the last 

 days of May. In 1902 active spawning continued until June 7, 

 while in 1903 spawning was over entirely by June i. Larvae of 

 various sizes are found at all seasons buried in the mud and sand 

 bars below the spawning grounds. Transformation occurs from 

 the last of August to the middle of October. The latest record of 

 transforming individuals is that of three specimens taken October 

 16, 1907. In one of these transformation was just beginning. 

 Judging from the different sizes of larvae found at a given season 

 the larval period is of about four years duration. 



2. Lampetra wilderi Jordan and Evermann. Brook lamprey. 



Common in the inlet, where they may be found in abundance 

 during the spawning season, which occurs during the middle of May 

 beginning, according to Professor Gage's observations, about the 

 eighth of the month and lasting until about the twentieth. The 

 maximum period averages near the middle of the month. This 

 species is not parasitic at any stage in its life-history. It probably 

 takes no food in the adult stage. 



^ See Gage, S. H., op. cit.; also Surface, H. A., "Removal of Lampreys 

 from the Interior Waters of New York," Report of the New York Fisheries, 

 Forest and Game Commission, 1898, pp. 191-243. 



