DISCUSSION OF SPKCIES AND THEIR DISTRIBUTION. 431 



iu t he Troudhjem Fiord at 200 fathoms, aud by the Norwegian Expedition at 125-250 fathoms 

 off Fiuniark and the Lofoten Ishmds. 



It occnrs also in the North Sea and aionnd the British Islands, and Fiance where, 

 however, it is rare, esiieeially on the west coast, though it has been found as far south as 

 Arcachon. 



On our own coast, though never found near the shore, it is one of the juost abundant 

 of the deeii-water pleuronectoids. 



The following statistics are the result of a careful study of numerous specimens 

 trawled in the deep water oft' Salem, Mass., on La Have Bank, and on tlie coast of Nova 

 Scotia, oft' Ilalifax, in Halifax Harbor, and in Bedford Basin, Halifax. They are the 

 result of detailed measurements of 22 individuals, including authentically named European 

 specimens from the University of Christiauia, and the Bonaparte Collection, the type of 

 O. acadianns, 3 specimens from Massachusetts Bay, 5 from La Have Bank, aud 11 from the 

 vicinity of Halifax. 



(1) Ueiyht of body. — This is stated to be about 2i of length exclusive of caudal, and 3:^ 

 in total length. In the series studied, the jiroportions of this element varied, stated iu units 

 of hundredtlis of total length (including caudal), from 0.245 to 0.375, No. 12685 having it 

 30. An equally wide variation in the European hsh is recorded by Parnell. ^ 



The rieuronectes elongatus of Yarrell is not nearly so elongated as No. 21061rt (the 

 figure of Couch has height about 0.275) ; and since no other diagnostic characters have been 

 described, Ave place it without hesitation in the synonymy of G. cynoijlossus. 



(2) Height of caudal peduncle. — This element is subject to very slight variation, meas- 

 uring usually 0.07 of total in both European and American specimens. The most elongate 

 slender forms have it slightly narrower. In No. 12GS5 it measiu-es O.OG, and O.OtJo in No. 

 21001&. 



(3) ieH!7</( o/7(rar7.— This varies from 0.15 to 0.175. In No. 12685 the length is 0.15, 

 and in the European specimens 0.15 and 0.1575 (Christiauia specimen). The smallest pro- 

 portion is reiH'esented by specimens from Massachusetts Bay and Halifax. 



(4) Teeth. — In number these are extremely variable. No. 12G85, according to Gill, had 

 on the blind side 17 above aud 20 below, on the eyed side 6 above and 7 below. A Salem 

 specimen, larger aud older, had on the blind side above 26, below 28, on the eyed side above 

 13, below 14. In yonug individuals the teeth present the characters described by Gill, hav- 

 ing the teeth on the eyed side conical aud separated. This peculiarity disappears with age, 

 all large specimens showing closely set incisorial teeth upon both sides of each jaw. 



(5) Length of 2)cctoml. — This is extremely variable within limits of 0.09 and 0.11. This 

 measurement refers to the fin upon the colored side. Its shape is also variable; it is some- 

 times pointed, sometimes obtuse, owing to difference iu comparative length of the upper 

 rays. It is usually black, with a narrow whitish tip. The number of rays varies from 9 

 to 14. 



(6) Length of vontrals. — This is also extremely variable on both sides. The range on 

 the bUnd side is 0.0475 to 0.07, and on the eyed side 0.056 to 0.0775. The difiereuce be- 

 tween the length of the two fins upon the same individual varies from 0.0025 to 0.0155. 



(7) Contour of lateral line. — In some individuals this is essentially straight, in others 

 considerably arcuated above the pectoral. This appears to be an individual variation. 

 The two European specimens show a perceptible difference in this respect. In his diag- 

 nosis of Pleuroneetes eynogloxsus, Dr. Giiuther states that the lateral line is straight with- 

 out curve. 



(8) Position of the eyes. — Dr. Giiuther states that in P. elongatus the upi>er eye is in 

 advance of the lower. This is doubtless quoted from Yarrell. Neither the figure of Yar- 

 rell nor that of Couch indicates any such character. 



(9) Scales in lateral line. — The number on the blind side ranges from 109 to 150, on the 

 eyed side from 110 to 140, there being no relation between the difterent sides of the same fish. 



'Fislies of the Firth of Forth, x>. 210, pi. xxxni, and ia Memoirs of the Werneriaa Society, vil, p. 370. 



