14 NEW YORK STATE MUSEUM 



The lake lamprey is found in larger numbers than the brook 

 lamprey, and reaches a much larger size. 



During the spring of 1886 more than a thousand individuals 

 were taken from Cayuga lake inlet, and all of them within 5 

 miles of Ithaca. They began to ascend the inlet to spawn on 

 May 21, and continued to do so until late in June. 



Their nests are excavations made in the bed of the stream, 

 In shallow water, usually just above ripples. The eggs are 

 deposited in the fine sand and gravel at the bottom of these 

 nests, and the embryos developed there. The larvae live in the 

 sand along the edge of the stream just below the water line. 

 This species is parasitic on bullheads, suckers, and other large, 

 soft-rayed fishes. 



Of the whole number captured and brought to the university 

 by fishermen within two weeks, 480 were males and 265 females. 



The longest male specimen was 17 inches, and the shortest 

 9 inches. The longest female measured 14 inches, and the short- 

 est 10 inches. A small female 7 inches long, taken later, con- 

 tained eggs which were quite immature. 



During the spring a crest is developed upon the back of the 

 male between the nape and the dorsal fin. A smaller crest is 

 developed upon the ventral surface of the female, between the 

 Tent and the caudal fin. This was at first supposed to be char- 

 acteristic of the males of Cayuga lake, and was made the basis 

 of a new specific name; but it has since been found in specimens 

 from the Atlantic slope, and it is said by Seeley to occur in 

 European specimens during the breeding season. This crest 

 is seasonal and sexual. The sexes, at other seasons, can not 

 T^e easily distinguished, if at all. 



More recent accounts of this lamprey are those of Prof. H. A. 

 Surface in the Bulletin U. S. Fish Commission for 1897 and the 

 4th annual Report of tlw Commissioners of Fisheries, Game and 

 Forest of the State of New York. 



Genus ICHTHYOMYZON Girard 



Differs from Petromyzon in having the anterior lingual 

 tooth divided by a median groove and the dorsal fin notched, 

 but not separated into two portions. Size small. Habitat, 

 fresh waters of eastern United States. 



3 Ichthyomyzon concolor (Kirtland) 

 Silver Lamprey 



Ammoccctes concolor KIRTLAND, Bost. Jour. Nat. Hist. Ill, 473, 1840, 



with plate (larva). 

 Petroniyzon concolor JORDAN & FORDICE, Ann. N. Y. Ac. Sci. 282, 1886. 



