Fa i;ran — Seventh Report on the Fishes of the Irish Atlantic Slope. 185 



Trachyrhynchus trachyrhynchns (PI. VII, figs. 4, 8). 



On tlie thickened, oval, luassive scales from tlie body of large specimens 

 tlie rings cannot be made out ; but on the more circular and tliinner scales 

 from the tail region they are usually visible. Small specimens up to about 

 30 cms. show rings on the body scales. By polarised liglit tlie thickened 

 scales show the bands very indistinctly, as tlie latter coalesce into broad light 

 and dark patches, which obscure tlie normal banding. 



A specimen of 49-5 cms. showed irregular rings, at distances of 

 297 I X I X I X I X I 495, on scales from the tail region, corresponding to 

 ca. 3 + 18 bands, the spaces between the rings corresponding approximately 

 to 8|2|2|2|2|2 bands. Only six bands, and no rings, can be made 

 out on tlie thickened body-scales. 



A specimen of 39 cms. showed rings at relative distances of 167 | '■^67 | 

 313 I 357 I 390 on scales from the tail region, with bands ca. 2+11, the 

 correspondence to spaces between rings being 6 | 3 | 2 | 1 | 1. 



A specimen of 34'5 cms. had rings at 192 | 243 | 325 | 345 and bands 

 ca. 2 + 10 corresponding to spaces 7 | 2 | 2 | 1. 



In a specimen of 25"2 cms. no rings were visible. There were seven light 

 bands, of which the three outermost were broad and widely separated. 



A specimen of 24'0 cms. had one ring dividing the radius in the proportion 

 150 I 240, the outer division corresponding to two liglit bands. Total of 

 bands, four, with a light centre, wliich may represent one or two bands. 



Other specimens, of which no scale measurements were made, showed, for 

 a fish of 24 cms. one ring, 25 cms. no rings, 36 ems. two rings, and 38'5 cms. 

 three rings. 



-For comparison with the Maerurids, the scales of some other deep-water 

 fish from the west coast of Ireland were examined. 



Argentina sihis, with a range from 105 to 337 fathoms off the west of 

 Ireland, has large scales, in which the striae are approximately parallel to 

 the margin throughout their course. In a specimen of 32'5 cms. there were 

 well-marked growth-rings, chiefly recognisable by the striae being crowded 

 together, but also by definite sear-like markings in the same region. The 

 proportionate distances of these rings fiom the centre were x | 164 | 213j 

 262 I 284 I 299 | 314 | 325. By polarised light the whole scale is light, 

 with darker shading corresponding to the superficial rings, and apparently, 

 caused by them ; but there is no definite division into dark and light zones 

 as in the Maerurids. The appearance of the scale by ordinary light is not 

 unlike that of a salmon or trout, in which the year-rings are indicated by 

 the approximation of the striae. By polarised light the resemblance also 



