552 MR. B. w. t. HOLT ON THE [June 21, 



in visible pi'ocess of development. The caudal fin shows features 

 of interest. The extremity of the uotochord forms the axis of a 

 lanceolate mass ; its extremity is bent up at an obtuse angle, and a 

 considerable part projects freely, being succeeded, to the margin of 

 the fin, by fine embryonic rays. Dorsally occur 12 rays, or 11 

 and a mass of embryojiic rays dividing the last true ray from the 

 urochord. None of these show any distinct basal element. Below 

 the ui'ochord is a roughly trigonal hypural lobe bearing five rays. 

 Anteriorly are three smaller oblong lobes, the most posterior 

 bearing two, the others one ray each. In front occur 6 rays. 

 None of these caudal rays are perfectly formed, the anterior rays, 

 dorsally and ventrally, being but little different from the embryonic 

 rays in front of them. The uotochord is still imperfectly segmented, 

 and the myomeres cannot be counted with accuracy. These 

 characters, therefore, like the fin-ray formula, are not available as 

 aids to specific determination. Preserved in formol the specimen 

 natui'ally possesses no yellow pigment, if any ever were present. 

 The black chromatophores have the distribution shown in my 

 figure on the left side. On the right side there are in addition a 

 few scattered chromatophores. The roof of the peritoneum is seen 

 to be denselv black when the specimen is clarified. Mcintosh 

 makes no mention of the caudal pigment-bar which is such a 

 prominent featui-e in the Faeroe Channel Gadus. The chromato- 

 phores above the insertion of the pectoral in the latter probably 

 correspond to " a very distinct area of pigment-points behind the 

 pectorals" in Scottish larvae of 11 mm., and ultimately perhaps to 

 the more posteriorly situate spot of the adult. The development 

 of pigment in Teleostean larvae is undoubtedly influenced to some 

 extent by conditions of light and, apart from this, is variable in 

 individuals. Probably such differences of coloration as may exist 

 between the Paeroe Channel specimen and those attributed to the 

 Haddock by Professor Mcintosh are explicable in this way, but the 

 information afforded, both as to pigment and conformation, in the 

 case of the latter only permits of a conjecture as to their identity. 

 The Scottish examples of 24 mm. and upwards, which are figured 

 and adequately described, are undoubtedly Haddock, and appear to 

 be certainly derivable from such a stage as is exemplified in the 

 larva from the Faeroe Channel. 



Dr. Powler's specimen was taken at 60° 2' N., 5° 49' W., at 100 

 to fathoms. I have myself recorded the capture of spawning 

 Haddock at 154 fath., off the W. coast of Ireland, while Grimsby 

 line-fishermen have told me that they frequently take the species 

 at depths of more than 100 fath. on the wide area which they include 

 in the Paeroe Bank. 



ScoPELUS GLACiAtis Eeiuh. (Plate XLVI. figs. 1-5 ; XL VII. 

 figs. 6, 7.) 



S. glacialis, Giinther, Chall. Eep., Zool. xxii., Deep-Sea Pishes, 

 p. 196 ; Liitken, Spol. Atlant., Scopel. 1892, p. 30 (250). 



Myctophuni glaciale, Smitt, Hist. Scand. Fish. ed. 2, ii. p. 941. 



