35 



Localit. fra Nordh. Exped. Jan Mayen ; Spits- 



bei-eeu. 



Bemærkninger til Synonymien. Slaegten Icelus, 

 opstillet i 184-i af Kroyer (Natiirh. Tidsskr. 2 Række. 

 Iste B.) for ovennævute, hidtil eneste bekj endte Art. dan- 

 ner ved sine Rækker af skarpe Bentorne langs Ryggen og 

 i Sidelinien blandt de aretiske Cottoider en Tilnærmelse til 

 Slægten Triglops, med livcm den ogsaa har tilfælles det 

 noget sammentrykte Hoved ; i Tandbygning er den nærmest 

 overensstemmende med Centridermirhthys. Arten er ndiør- 

 ligt beskreven allerede af Krøyer paa ovenna^vute Sted. og 

 lierefter er dens Diagnose i Giintliers Cat. l^'isli. Brit. Mus. 

 vol. 2 (1860) affattet. Senere ei'e a f Here Forfattere med- 

 delte Bemærkninger vedrørende dens Optræden, saaledes 

 ved Spitsbergen og de norske Kyster af Malmgreu (Ofv. 

 Kgl. Vet. Ak. Porh. 1864). af Esmark (Porh. Skand. Na- 

 turf. 10de Møde 1868), og af Collett (Norges Fiske 1874), 

 ligesom Dr. Liitken liar behandlet dens Synonymi etc. i 

 1876 (Vid. Medd. Naturli. Forh. Kbhvn.. 1876. p. 380). 

 Den er afbildet, (men ikke tilfredsstillende) i Gaiiuards Plan- 

 cheværk til Corvetten la Recherche's Reise (Voyage Scand. 

 Lap. etc. pl. 1). Endelig har Malm i 1877 (Goteb. och 

 Boh. Fauna. p. 393) givet udforlig Beskrivelse af sin i 

 1863 (Forh. Scand. Naturf. 9de MOte 1863. p. 410) un- 

 der Navn af /. furciger opstillede Ai't fra Bohuslen, der 

 alene ved Tilstedevan-elsen af en Ra^kke Bentorne ogsaa 

 langs Analen adskiller sig fi-a /. haniafus. en Character, 

 der dog ikke viser sig constant, men synes at være af 

 ganske individuel Natur. 



Bemærkninger til Beskrivelsen. De under Nord- 

 havs-Expeditionen erholdte Individer havde følgende Maal: 

 a. (Hun), b. (Hun). c. (Han), 

 Spitsbergen. Jan Mayen. Jan Mayen. 



Totallængde . ; . . 

 Længde nden Caudal . 

 Hovedets Længde . 

 Øjets Læugdediameter 



43""" 



36 - 



ll.r. - 



4 - 



Flere af de ydre Characterer ere hos denne Art i 

 en mærkelig Grad varierende, saaledes Hudens mere eller 

 mindre rigelige Beklædning med Bentorne, de sidstes Byg- 

 ning i Rækkerue langs Ryggen og i Sidelinien. ligesom 

 ogsaa Sideliniens Længde; endelig er Straaleautallet temme- 

 lig lidet constant. 



Locality (North Atl. Exped.): 



Spitzl)ergeii. 



Jan Mayen aud 



Bemarks on the Synonymy. — Among the family 

 of the Arctic Cottoids the genus Icelus. established, in 1844. 

 by Kroyer, for the only species then and yet known, 

 approximates the genus Triglops in the rows of shariJ- 

 poiuted osseous spines extending along the dorsal ridge and 

 lateral line, another salient character common to both being 

 the somewhat compressed head. In the structure of the 

 teeth it bears greatest resemblance to CetdrkJermichiliys. The 

 first to give a full description of the species was Kroyer 

 (ride list of synonyms), and from the above description Dr. 

 Gtiuther has compiled a diagnosis in Cat. Pish. Brit. Mus. 

 vol. 2 (1860). Gbservations have been subsequently fur- 

 nished by several authors on its occurrence, by Malmgren, 

 off Spitzbergen and the shores of Norway (Ofv. Kgl. Vet. 

 Ak. Forh. 18t]4); by Esmark (Forh. Skand. Naturf. lOde 

 Møde 1868); and by Collett (Norges Fiske 1874); a paper 

 by Dr. Ltitken, treating of the synonomy of the species 

 &c. appeared, too, in 1876 (Vid. Medd. Naturh. For. 

 Kbhvn.. 1876, p. 380). Icehts hamatus is figured, but 

 somewhat imperfectly, in the series of plates to Gaimard's 

 Narrative of the voyage oftlie "Recherche" (Voyage Scand. 

 Lap. etc., pi. 1). Finally. Malm furnished i 1877 ((jtoteb. 

 och Boh. Fauna, p. 393) a detailed description of the form, 

 from Bohuslen, described by him as /. furciger. which is 

 distinguished from /. Jiamatus chiefly by a series of osseous 

 spines along the anal fin, a character, however, which has 

 not shown itself constant, but would seem to be altogether 

 individual. 



Descriptive Observations. ~ The individuals obtained 

 on the Expedition measured as follows: — 



a. (female) b. (female) c. (male) 

 Spitzb. Jan Mayen. Jan Mayen. 



43 



36 - 



11.5 - 



4 - 



Many of the external characters in this species vary 

 to a remarkable extent in different individuals, for instance, 

 the space furnished with osseous denticles; the form and 

 structure of these spiuules in the rows along the dorsal 

 ridge and the lateral line; the length of the lateral line; 

 and the number of fin-rays. 



Total length 



Length exclusive of caudal 

 Length of head .... 

 Longitudinal diameter of eye 



