46 



Legemet er betydelig! slankere og mere langstrakt, 

 end hos A. cataphradus ; den største Bredde, der falder 

 over Nakken, indehold.es omtr. 8 Gange i Totallængden. 



Af Skjægtraade har denne Art paa hver Side 5; i 

 Mundvigerne sidde 2 i Over-, og 2 i Underkjæven ; den 5te 

 sidder langt fortil i Underkjæven. Den sidste er altid 

 klovet, de øvrige ere enkelte. (1 Individ havde ogsaa den 

 indre Traad i Overkjæven kløvet, et andet Individ havde 

 Underkjævens forreste Traad ikke dobbelt, men endog 

 5-kløvet). 



Ligesom det er Tilfældet med flere Cottoider, synes 

 ogsaa hos denne Art Kjønnene at være ganske ulige repræ- 

 senterede i Antal. Af de 9 erholdte Individer var nemlig 

 blot det ene (c) en Han. hvad der strax fremgik af de 

 forlængede Ventraler. Medens de 2 Straaler, der danne 

 denne Finne, hos alle de øvrige vare af lige Længde, og 

 saa korte, at Finnens Længde ikke synderlig oversteg en 

 Øjendiameter. havde hos dette ene Individ den ydre Stranle. 

 der var betydeligt længere, end de indre, en Længde a f 

 17""". eller omtrent 2 Øjendiametre. 



Farven var i det væsentlige ens hos alle. Bundfar- 

 ven er gulgraa. og forsynet med 2 — 3 større Tverpletter. 

 der danne Antydning til Baand. men idethele ikke ere 

 særdeles skarpt markerede. Det forreste af disse ligger 

 over Roden af Pectoralen. det andet (ofte utydeligt) over 

 Slutningen af Iste Dorsal, det 3die over Midten af 2den 

 Dorsal. Mellem disse tindes mindre, utydeligt begramdsede 

 Petter og Skygninger. Finnerne ere nd mod Spidsen 

 brunsorte : især er dette Tilfældet med Pectoralen og Cau- 

 dalen. Undersiden af Legemet er uplettet graagul. Paa 

 Hovedet gaar en temmelig bred. sort Streg fra Spidsen af 

 Smulen gjennem Øjet. og fortsætter sig bagover paa Prae- 

 operculum. 



Levemaade og Føde. Den synes at være en afgjort 

 Dybvandsart ; de under Expeditionen erholdte Individer opto- 

 ges fra en Dybde, der laa mellem 123 og 260 Favne, medens et 

 Par Yngel -Individer fra Varanger fjorden (1874) erholdtes 

 fra det noget grundere Vand (50 — 120 Favne). Som oven- 

 for nævnt. erholdtes et af Nordhavs-Expeditionens Indivi- 

 fra den iskolde Area. hvor Våndets Temperatur var un- 

 der 0" c. 



I Ventrikelen af et af Individerne fandtes Amphi- 

 poder. væsentlig Themisto libellula, Mandt, og enkelte Indi- 

 vider af Erythrops goésii, G. 0. Sårs. 



Udbredelse. A. decagonus er allerede af Fabricius 

 omtalt fra Grønland i 1780 i hans Fauna Groenl. (under 

 Navn af A. cataphradus), og den er senere gjentagne Gange 

 nedsendt fra disse Landsdele til Musæet i Kjøbenhavn. Paa, 

 samme Side af Atlanterhavet gaar den idetmindste ned til 

 Newfoundland. Fremdeles er den. ifølge Dr. Liitken. er- 

 holdt ved Island. Ved Spitsbergen er den niaaske ikke 



The body is much more slender and elongate in form 

 than is the case with A. cataphradus; extreme breadth, 

 across the nape, about one-eighth only of total length. 



The cirri in this species number 5 on each side, 

 disposed as follows: 2 on the upper and 2 on the lower 

 jaw. at the angle of the mouth, and the fifth far out on 

 the lower jaw. This barbel is always cleft, the rest con- 

 sist each of a single filament; in one specimen .the pos- 

 terior barbel on the upper jaw was likewise cleft; an- 

 other had the anterior cirrus on the lower jaw not doubly, 

 but quintuply cleft. 



As is the case with several species of Cottoids. 

 the sexes appear to be very unequally represented in 

 A. decagonus with regard to number. ( )f the 9 individuals 

 obtained, one only (c) was a male, a fact immediately 

 apparent from the elongated ventrals. In all the other 

 examples the 2 rays composing this fin were of equal length. 

 and so short, that the length of the fin hardly exceeded the 

 longitudinal diameter of the eye. whereas in this individual 

 the exterior ray, which was considerably longer than the 

 inner, had a length of 17'"'". about equal to twice the 

 diameter of the eye. 



The colour was in all these specimens essentially 

 the same. Ground -colour yellowish -grey, relieved with 

 two or three comparatively large transverse spots or bands, 

 not very clearly defined however. The first of these 

 spots occurs immediately above the origin of the pec- 

 torals, the second (in many individuals indistinct) above 

 the termination of the 1st dorsal, the third above the 

 central portion .of the 2nd dorsal. In between these 

 patches are a number of small indistinct spots and cloud- 

 ings. The fins brownish-black towards the points; this is 

 the case more especially with the pectorals and the caudal. 

 •The under surfaee of a uniform greyish-yellow. A black 

 streak extends from the point of the snout through the 

 eye, passing from thence backwards over the preoperculum. 



Habits and Pood. — This species decidedly appears to 

 be a deep-sea fish ; the specimens obtained on the Expedition 

 were brought up from a depth of 123 — 260 fathoms; three 

 individuals in the fry stage of growth, from the Varanger 

 Fjord (1874). • were taken in shallower water (50 — 120 

 fathoms). As before stated, one of the examples taken 

 on the Expedition was brought up from the cold area, 

 where the temperature was below that of ice. 



In the stomach of one of the individuals examined 

 were divers Amphipods. chiefly Themisto libellula, Mandt, 

 and examples of Erythrops goésii, G. 0. Sars. 



Distribution. — A. decagonus was mentioned, as 

 occurring on the coast of Greenland, as far back as 1780. 

 by Fabricius, in his Fauna Groenl. (the name given it 

 being A. cataphradus), and since then specimens have been 

 repeatedly sent from those regions to the Zoological Museum 

 in Copenhagen. On the shores of North America its range 

 extends at least as far south as Newfoundland. According 



