THE FISHES OF THE <.1NG0LF» EXPEDITIONS. 



13 



of the length of the head (to the posterior border of the gill-cover); the length of the snout from the 

 eye to the point of the snout is 13""' or '/a oi the total length of the head, from the mouth to the 

 point of the snout about the half (6"""); the mouth is small, semilunar in shape and situated on the 

 lower side of the snout, the corners of the mouth are vertically below the anterior nostrils. The 

 nostrils are placed close together before the eye. The teeth are fine. The upper jaw ends posteriorly 

 with a rather strong spine. 



The pectoral fins have a length of 18"""; their ra}-s are 14. The ventral fins number 10 rays, 

 none of which can be termed a spinous ray, the external one being however thin and delicate. The 

 row of spinous dorsal rays begins exactly over the posterior border of the branchostegal membrane; 

 it numbers 33 spinous rays (the specimen of Collett had 27, that of Goode & Bean 28 — 31, 

 jV. Challengeri 34, N. rissoanus 37), they are short and isolated, their mutual distance somewhat 

 surpassing their length, but they become longer and more distant from each other posteriorly; the 

 connecting dermal part is very slight. The spinous rays of the anal fin are also short, but nevertheless 

 much longer than those of the dorsal fin, and they are much more closely approximated to each other 

 than the dorsals. As they approach to the soft rayed portion the connecting dermal skin becomes 

 more distinct. The number of these spinous rays can be reckoned to be about 45 (in Collett's spe- 

 cimen 53, in that of Goode and Bean it is given as 42 — 53; in A''. Cliallciigrri 54, in N. rissoatnis 27), 

 but an absolute limit can not be drawn between the .spinous and the soft-rayed part of the fin, when 

 the rays, preserving their undivided shape, become longer, more delicate, articulate and united with a 

 full fin-membrane. The number of rays in this anal fin may be counted as about 190 (perhaps 192 — 93). 

 In the last part of the tail the hight of the anal fin considerably exceeds that of the tail itself. A 

 caudal fin of 4 rays ma)' be pointed out. 



The scales are very delicate. A distinct lateral line may be traced forwards from a point 

 under the last spinous dorsal ray but three; after this point it is less distinct, and is likewise becomes 

 indistinct towards the eye, but reappears then distinctly as an infraorbital line. On the trunk proper 

 its position is nearer to the back than to the belly, but as the body decreases in height its position 

 becomes nearer to the middle height of the body. On the snout are seen several pores, especially a 

 distinct series of such along the inferior margin of the preopercle and of the lower jaw. The colour 

 is a light chocolate colour, somewhat spotted, the opercle is internally black, pellucid towards the 

 margin; also the lips; the inferior portion of the anal fin is also relatively dark. 



Our only specimen of this Polyacaiif/ionofus or Alacdonaldia was taken at a depth of 362 

 fathoms on station 35 (65° 16' Lat. North, 55° 05' Long. West). The bottom was a brownish mud with 

 arenaceous foraminifera and pebbles; the temperature was 3^.6 C. The specimen of the prince of 

 Monaco was taken off Newfoundland on a depth of 1267 metres, those of Goode and Bean at 551 

 and 563 fathoms, at 39° 47 — 48' Lat. North and 70° 30 — 36' Long. West. The vertical distribution may 

 therefore be fixed provisionally at 360 — 960 fathoms, the geographical distribution to the western part 

 of the Atlantic from Newfoundland to the Baffin Bav. 



