DISCUSSION OF SPECIES AND THEIR DISTKIBUTION. 2C7 



bifurcate or multifiircate. Grill-incmbraiKis broadly united, free from the isthmus, no slit 

 behind fourth gill. Ventral rays i, 3. 



In addition to the type species, an Arctic form, descending in the North Atlantic below 

 the 100-fathom line, there are ttvo or three others, found in moderately deep water off tlie 

 California coast. Jordan unites with this genus Arteditis, but we prefer, for the present 

 at least, to consider it distinct. 



ICELUS BICOBNIS, (EEiNnAiiDT), Jordan aud Gilbert. 



Coitus bicornis, Reinhardt, Vicl. Selsk, Natur og Math. Afh., vni, Ixsv. 



Centridcrmichtliys hicornU, Gunther, Cat. Fish. Brit. Mus., ii, 17J. 



Icelus bivoniis, .hiRD\s aud Gilbert, Bull, xvi, U. S. Nat. Mu-s., 693. 



Icelus hamiitus, Kroyer, Nat. Hist. Tidsskr., 1844, i, 253. — Gunther, Cat. Fish. Brit. Mus., ii, 112; Chal- 

 lenger Reijort, XXII, 63.— Collett, Norges Fi»k., 3.5; Forh. Vid. Selsk. Christ., 1880, 14; Norsk Nordh. 

 Exped. Fisk., 34, tab. i, fig. 8; Nyt Mag. f. Naturvid, xviii, 1884, 56. — Lutken, Kara-Havets Fisk. iu 

 Dijmphna-Togtet, 123; Vid. Med. Nat. For., 1876,92.— Strom, Norsk. Vid. Selsk. Skrift., 1884, 18.— Lill- 

 JEBORG, Sverig. och. Norg. Fisk., 164. 



Icelus fiirciger, Malm, Forhaudl. Skaud. Naturf., 9 Mote, 1865, 410. 



Coitus pohiris, Sabine, Parry's First Voyage, 213 (Jidr Liitkt'u). 



Head naked, its length 3 times in that of body. Preoperculum with 4 spines, the 

 uppers hooked, the uppermost bifurcate; two blunt, occipital spines. luterocular space 

 narrow, its widtli 4 in eye. Dorsal separated; pectorals shorter than head. No air-blad- 

 der. Gill-membranes broadly joined, free from isthmus. 



Radial formula: D. is, 20; A. 16; V. i, 3. 



Color, j-ellowish, with many brown spots. 



This form, first described from Spitzbergen, has since been found also iu Alaska. It 

 is common iu Arctic seas at small depths; of late years it has been frequently found on 

 the Norwegian coast in 50 to U.jO fathoms. Liitkcn examined numerous examples ti'om 46 

 to 106 fathoms, obtained iu the Kara Sea. 



ARTEDIELLUS, Jordan. 



ArtedieUus, Jordan, Cat. Fish. N. Araerioa, 1887, 110; Rep. IT. S. Fish. Coram., xiii (for 1885), 1887,898 (type, 

 Cotlus UHcinutiis, Kciuhardt). 



This genus or subgenus differs from TccIks proper, apparently its nearest ally, in having 

 the skin naked aud smooth. Cenfridcrmkhthi/s, Richardson, an Asiatic genus to which this 

 and other American species have been sometimes referred, has the skin prickly and a large 

 sht behind the fourth gill, the gill membranes being fully united to the isthmus. 



ARTEDIELLUS UNCINATMS, (Rhinitari>t), Jordan-. (Figure 255.) 



Cotlus uncimtus, Reinhardt, Vid. Selsk. Natur. oeh Math. Afhaudl., 1833, 44.— (TrN'Tirr.it, Cat. Fish. Brit. 



Mas., II, 173; Challenger Report, x\ii, 1887, i)2. 

 Centridermichthiis unciuatus, Collett, Norsk. Nordh. Exped. Fisk. ,23, t.ih. i, tig. 7; Forh. Vid. Selsk. Christ., 



1880, 14; N>-t.Mag. f. Naturvid., xviii, 1884, 54.— LCtkkn, Kara-Havets Fisk. iu Dijmphua-Togtet, 124.— 



Lilueborg, Sverig. oeh Norg. Fisk., 161. 

 Icelus unciuatus, Kroyer, Nat. Tid., 1844, 253.— Jordan aud Gilbert, Bull, xvi, U. S. Nat. Mus., 693. 

 Coitus bicornis, Reinhardt, loc. cif., viii, 75. 

 ArtedieUus uucinatns, Jordan, loc cit. 



Body fusiform, its height contained 4J times in its total length. Head broad, its length 

 one-third that of the body; lower jaw included. Palatine teeth well developed. Maxillary 

 extending to opposite middle of pupil. Byes very large, separated by a, narrow ridge; 

 occiput with two blunt ridges, in front of which the vertex is concave; upper i)reopercnIar 

 spine large, strongly hooked upward, more than half length of eye; downward-directed si>ine 

 onpreopercle long and sharp; skin perfectly smooth. Pectorals reaching front of anal; 

 spinous dorsal rather high; vent midway between snout and midtUe of caudal. {Jordan 

 and Gilbert.) 



Radial formula: D. viii, 1.3; A. 11. 



"An Arctic littoral species," writes Giinther, "more or less common iu the sea between 

 Greenland, Spitzbergen, Nova Zcmbla, aud Norway, extending iu the western part of its 



