DISCUSSION OP SPECIES AND THEIB DISTRIBUTION 431 



in the Trondhjetn Fiord at 200 fathoms, and by tin- Norwegian Expedition at 125-250 fathoms 

 off Kiinnark and the Lofoten Islands. 



[t occurs also in the North Sea and around the British Island-, and France where, 

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

 Arcaehon. 



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



of the deep-water pleuronectoids. 



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

 trawled in the deep water off Salem, Mass., ou La Have Bank, and on the coast of Nova 

 Scotia, off Halifax, 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 ('hristiania, and the Bonaparte Collection, the type of 

 (I. aeadianus, ."> specimens from Massachusetts Bay, 5 from La Have Bank, and 11 from the 

 vicinity of Halifax. 



(1) Height of body. — This is stated to be about --, of length exclusive of caudal, and 3$ 

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

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

 30. An equally wide variation iu the European fish is recorded by Parnell. 1 



The Pleuroneetes elongatus of Yarrell is uot nearly so elongated as No. 2HMil« (the 

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

 described, we place it without hesitation in the synonymy of O. cynoglossus. 



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

 uring usually!). 07 of total iu botli European and American specimens. The most elongate 

 slender forms have it slightly narrower. In No. 126S5 it measures 0.06, and 0.065 in No. 

 21001 b. 



(3) Length of head.— 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 (('hristiania specimen). The smallest pro- 

 portion is represented by specimens from Massachusetts Bay and Halifax. 



(4) Teeth. — Iu number these are extremely variable. No. 12GS5, according' to Gill, had 

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

 specimen, larger and older, had on the blind side above 20, below 28, on the eyed side above 

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

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

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



(5) Length of pectoral. — This is extremely variable within limits of 0.09 and 0.14. 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 in comparative length of the upper 

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

 to 14. 



(0) Length of rentrah. — This is also extremely variable on both sides. The range ou 

 the blind side is 0.0475 to 0.07, and ou the eyed side 0.056 to 0.0775. The difference be- 

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



(7) Contour of lateral line. — Iu 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 Pleuronectes cynoglossus, Dr. Giinther states that the lateral line is straight with 

 out curve. 



(S) Position of the eyes. — Dr. Giinther states that in P. elongatus the upper eye is in 

 advance of the lower. This is doubtless epioted from Yarrcll. Neither the figure of Yar- 

 rell nor that of Couch indicates any such character. 



(!l) .Vfvf/r.v in lateral line.— The number ou the blind side ranges from 109 to 150, on the 

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



'Fishes of tin; Firth < » t' Forth, p. L'lu, pi. xxxui, and iu Memoirs of the. Wernerian Society, VII, \i. 370. 



