Zoology.-] NATURAL HISTORY OF VICTORIA. [Fishes. 



Plate 122: 



TRACHYPTERUS TCENIA (Bloch). 

 The Southern Silver Ribbon-fish. . 



[Genus TRACHYPTERUS (Gouan). (Sub-kingd. Vertebrata. Class Pisces. Sub-class 

 Teleostea. Order Acanthopterygii. Fam. Trachypteridae.) 



Gen. Char. — Body very long, tapering gradually from the head to the tail ; excessively 

 compressed laterally to a thin band ; no scales ; eyes large, lateral ; muzzle truncated, pro- 

 tractile ; mouth small. Teeth few, small, conical, on jaw and palatine bones ; one large dorsal fin 

 of delicate, simple rays (not jointed nor branched), extending from head to base of tail, with 

 smal^ semi-detached anterior portion of few elongated rays ; caudal not in line of body, inclined 

 obliquely upwards and backwards, of long, slender, branched rays ; -no anal ; pectoral very 

 small, rounded ; ventrals large, of 5 or 6 branched rays, nearly under base of pectoral. Bones 

 of head, preoperculum, operculum, and suboperculum radiatingly ridged ; few conical teeth on 

 jaws and vomer, and a patch of smaller ones on each palatine bone ; branchiostegal rays, 6 ; 

 large pseudcbranchia? in a pouch of mucous membrane. Pyloric appendages very numerous. 

 No swim-bladder. Surface silvgry, with fine transverse granulations. Bones of skeleton and 

 muscles soft and brittle. Deep sea.] 



Description. — Greatest depth of body a little behind the head, and one-fourth 

 more than length of head with jaws retracted, and is contained 5| times in the total 

 length, excluding- caudal fin. Six conical teeth in front of upper jaw, and 8 in lower 

 one; 4 smaller on vomer, and 2 oblong patches of very small, numerous teeth on 

 each palatine bone. Eye. about one-fourth the length of head, a little behind the 

 middle and close to upper margin. Interoperculum nearly as large as operculum, 

 suboperculum small, triangular, all the bones of the head radiatingly ridged ; gill- 

 opening reaching to vertical under middle of eye. Fins: First 5 rays of dorsal 

 more elongated than following rays of continuous dorsal, from which it is also 

 separated by a marked space of membrane ; hinder portion of dorsal of about 

 170 rays, rapidly increasing to its greatest depth at about the 20th ray, where its 

 height equals about half the depth of the body; the rays rough and granular, 

 with a small spinous tubercle at base of each ; caudal having an upper portion of 

 about 6 or 8 very long branching rays directed obliquely upwards and a little 

 backwards ; and a lower portion of 6 short rays directed backwards ; pectorals very 

 short, rounded, of about 10 rays; ventrals about equalling the depth of the body, 

 of 5 to 7 branched rays, the first one with a row of spinular granules on front. 

 Lateral line of a row of conical spines, stellate at base, extending from upper edge 

 of operculum to join that of other side below and in front of caudal, where a spine 

 marks the junction of the two lateral lines, with a point directed forwards and 

 another hooked backwards; a double row of small tubercles along ventral edge. 

 Vent a little in front of middle of length. Color: Whole surface bright silvery; 

 greyish-lavender on nape and head, and with transverse grey lines corresponding 

 with neural spines of vertebrae; 2 spots on top of head, an oblique band across eye, 

 and 3 large, rounded spots above lateral line ; the 1st about one-third the length 

 from snout, the 2nd a little in front of middle, the 3rd spot about half way between 

 second one and tail, nearly black; and one oval paler one near abdominal edge behind 

 the vertical of 1st upper spot; belly and behind gill-opening faintly tinged with 

 brown ; rest of surface rendered finely granular by very fine, close, transverse lines 

 extending obliquely downwards and backwards from the back; fins rosy-scarlet, 

 membrane paler than the rays. Measurements : Length, 10 ins. 3 lines; head, 1 in. 

 10 lines when snout retracted, 2 ins. 3 lines when protruded; greatest depth of 

 body, 2 ins. ; diameter of orbit, 6 lines, 6 lines in advance of hind edge of operculum, 



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