cun ; a s sed g u r n a rds . 
205 
AGONUS DECAGONUS. 
Fig. 59. 
Form of the body very elongated, shallow and- narrow: number of paired and unpaired plates in a row on the 
bach from the occiput to the caudal fin above 40“ ; least depth of the tail, in adult- specimens , 2 % (or slightly 
more ) of the length of the body and at most 10 % (or slightly more) of the length of the head; breadth of the 
body at the base of the pectoral fins less than 16 % of its length- or than 75 % of the length of the head. Ridges 
on the head and on the plates of the body, even in adult- specimens, raised into spines pointing in a backward 
direction. The two dorsal fins quite distinct-; at least 3 b pairs of plates on the back between them. First dorsal 
fin set rather far forward; the distance between it and the tip of the snout- less them 30 % of the length- of the 
body , and the length of the head more than 70 % of this distance. Eyes large: the longitudinal diameter greater 
than the least breadth- of the interorbital space and also more than 5 % of the length of the body, while the least 
depth of the tail, in adult specimens, is less than 40 % of this diameter. Only two nasal spines c . About 5 barbels, 
simple or branched, on each side of the head, one on each- side of the lower jaw and three or four on the dermal 
fold at the corner of the mouth-; none on the branchiostegal membrane, in the middle of which (bcloiv the isthmus) 
small plates, each with- a tubercle at the middle, are set- so as to form an angle (A). 
Fig. 59. Agonus decagonus, seen from above, from the side and from beneath, natural size, together with a part of the tail, seen from the 
side and magnified to show the pores of the lateral line. Specimen from North Fjord off Disco (Greenland), taken at a depth of 146 
fathoms on a loose, clayey bottom, on the 10th of July, 1871. Josua Lindahl. 
“ 41 — 45, according to Lutkisn; 43 or 44 in the specimens belonging to the Royal Museum. 
b 3 — 5, according to Collett; 3 or 4 in the specimens belonging to the Royal Museum. 
c Corresponding to the posterior pair in the following species. In adult specimens, however, there are two blunt protuberances on 
the anterior part of the tip of the snout. 
