128 THE VOYAGE OF H.M.S. CHALLENGER. 



The typical specimen, which is nearly 17 inches long (head 3^ inches) came from 

 Port Arthur. But the species appears also on the New Zealand coast; whence I have 

 received specimens 21 inches long, the head measuring i^ inches. These specimens 

 offered evidence of the change of the form of the snout which the species of this genus 

 undergo with age, the snout being comparatively longer in old specimens than in young 

 ones, as may be seen firom the following measurements : — 



a. Port Arthur, 



b. Wellington, 



Several very young specimens, 4 to 4^ inches long, were obtained by the Challenger 

 at Station 166, in 275 fathoms. In these the snout is comparatively still shorter, and 

 scales are developed only on the anterior part of the body. There is a fontanelle-like 

 depression between the ventral fins, but it does not seem to persist throughout life in this 

 species, as in Macrui-us ccelorhynchxis. Also in an example 5^ inches long, from Cape 

 Campbell, New Zealand, the ventral foutauelle is still present, but the whole body is 

 clothed with hard and well-developed scales, which, however, show a structure different 

 from that of the scale of the adult fish. Each scale is provided with five radiating keels, 

 prominent, and projecting beyond the margin of the scale. Each keel, beiag in fact a 

 series of imbricated spines, is serrated in its whole length. 



Macrurus caelorhynchus. 



Lepidoleprus ccelorhynehus, Eisso, Ichth. Nice, p. 200, pi. viL fig. 22; Eur. m^rid, iii, p. 244. 

 Macrourus aslorhynchxus, Bonap., Faun. Ital. Pesc. (pL, Macrourus mystieetus). 



„ „ Costa, Faun. Nap., pi. xxxix. 



„ „ Canestrini, Arch. Zool., ii. p. 374. 



„ „ Johns., Ann. and Mag. Nat. Hist., 1862, vol. x. p. 169. 



„ „ Vinciguerra, Ann. Mus. Genov., voL xiv., 1879, p. 619 ; vol. xviii. 



1882, p. 565. 

 Macrurus atlanticus, Lowe, Proc. Zool. Soc. Lond., 1839, p. 88. 



„ „ Gunth., Fish., vol. iv. p. 392. 



D. 10. A. 75-86. P. 20. V. 7. 



Snout moderately produced, angular in front, a little shorter than or equal to the eye, 

 the diameter of which is one-third of the length of the head. Scales of moderate size, 

 covered with minute spines, giving a granular appearance to their surface. There are 

 five or six scales in a transverse series, between the first dorsal fin and the lateral line. 

 Dorsal spine smooth. Abdomen, that is, distance of the vent from the isthmus, equal to 

 the length of the head without snout in specimens about 12 inches long. Outer ventral 

 ray produced into a short filament. 



