Fishes of Cayuga Lake Basin. 299 



2. PETROIWYZON: MARINCS * Linnaeus. 



(Sea Lamprey: Large Lake Lamprey.) 



A., 348. B., 11. C, 4. 



Petromyzon nigricans. A., 349. B., 12. 



This lamprey is found in much larger numbers than the pre- 

 ceding; it also reaches a much larger size. 



During the spring of 1886, more than one thousand speci- 

 mens were taken from Cayuga Lake Inlet, and all of them within 

 five miles of Ithaca. They began to ascend the inlet, for the pur- 

 pose of spawning, on May 21st, and continued to do so until 

 late in June. 



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

 where the water is shallow, and usually just above ripples. In 

 the fine sand and gravel at the bottom of these nests, eggs are 

 deposited by the females, and the embryos developed. The 

 larvae live in the sand along the edge of the stream, just below 

 the water-line. 



This species is frequently taken by the fishermen. It is 

 usually found attached to the bull-heads, suckers, and other 

 large soft-rayed fishes. It seldom attacks the spiny-rayed 

 fishes. 



The following count was made of a number of the lampreys 

 which were caught during the spawning season and brought to 

 the University by fishermen, within two weeks: 



May 21st, 156 males and 69 females. 



'' 25th, 132 '' '' 110 '' 

 Later, 106 " '' 37 



Total, 480 males and 265 females. 



Length of longest male specimen, 42 cm. 



" shortest " '' 23 cm. 



^' *^ longest female '^ 35 cm. 



" shortest " " 25 cm. 



One small female, 18 cm. in length, was captured; the ova in 

 it were quite immature. 



