GREAT LAKES COREGONIDS 



375 



case a box (2,250 feet) of 2%-inch gill nets was placed. Only 10 longjaws were taken 

 by these nets, and all but 1 were included in the catch of September 19, 1917, in 

 30 fathoms (record 18). The nets set in 15 and 17 fathoms took only one longjaw 

 on September 26, 1917 (record 26). 



4. Lifts of the pound nets. — These ordinarily have not yielded longjaws, but rela- 

 tively few ever have been examined by me. In collecting herring in Saginaw Bay, 

 Dr. John Van Oosten has found stray longjaws on two occasions in the herring lifts 

 made by the pound nets set in the shallow water at the bottom of the bay (records 

 41 and 42). The fish undoubtedly had strayed into the nets from spawning grounds 

 somewhere along the shore. 



From all the observations made by me, it appears that the depth range of the 

 longjaw, when not spawning, is between 14 and 100 fathoms. Records 5, 45, 46, and 

 47, from the statements of fishermen, suggest also the occurrence of the species in 

 shallow water, but it can not be asserted positively that the fish so reported were 

 longjaws. In the spawning season the species appears to come into the shallowest 

 water. 



RELATIVE ABUNDANCE 



Concerning the proportion of the longjaw to all the chubs in the chub lifts only 

 the following few scattered observations, based on examination of lifts, are available : 

 At Cheboygan, Mich., on July 21, 1917 (record 1), the longjaw was not rare in 35 to 

 50 fathoms. What proportion it made of the total catch is unknown. On September 

 28 and September 29, 1917 (record 2), it was practically absent from the lifts of the 

 same nets. No lifts were examined at Rogers, Mich., except one made on October 14, 

 1917 (record 6), in 35 to 50 fathoms. This lift of about 1,500 pounds, like the lifts 

 of September 28 and September 29 at Cheboygan, Mich., was made on the spawning 

 grounds of zenithicus and contained only half a dozen longjaws. In view of the occu- 

 pation of the grounds by the spawning zenithicus, these records show nothing conclu- 

 sive concerning the occurrence of the longjaw at these depths. The hauls brought 

 into Alpena, Mich., from depths of 60 to 80 fathoms vary in the number of the long- 

 jaws they contain. From the center of the lake, from northeast to east of the city in 

 1917, only an occasional longjaw was brought in on September 7, 10, 12, 14, 17, 19, 

 21, 24, and 26, and October 17 and 20 (records 8, 12, 13, 15, 16, 19, 21, 24, 25, 27, 

 and 28). As these were the only catches examined from the center of the lake, it is 

 not known whether longjaws ever occur there in numbers. Longjaws were uncom- 

 mon also in the catches made from depths of 60 to 70 fathoms on August 7, 1920, 

 19 miles NE. % N. of Thunder Bay Island; in 60 to 65 fathoms in 1923 on June 28, 

 19 miles NE. of Thunder Bay Island, on June 30, 17 miles NE. by N. % N. of 

 Thunder Bay Island, on July 2, 20 miles E. by N. of the can buoy; and from 80 to 100 

 fathoms on July 5, 18 miles NE. % E. of Thunder Bay Island (records 33 to 37). 

 In three lifts made August 30 and September 3, 1919, and on July 7, 1923, 18 miles 

 N. by E. Y 2 E. of Thunder Bay Island in 60 to 64 fathoms, 28 miles E. M S. of the 

 can buoy in 60 to 64 fathoms, and 13 miles NE. ^ N. of Thunder Bay Island in 60 

 fathoms, respectively (records 29, 30, and 38), longjaws comprised 20 to 22 per cent 

 of the haul. A single lift examined at Harbor Beach, Mich., 35 miles NE. by N. % N. 

 from 50 fathoms on October 27, 1917 (record 43), was composed of slightly less than 



