REPORT ON THE DEEP-SEA FISHES. 147 



Subgenus Optonurus. 

 Macrurus denticulatus. 



Macrurus denticulatus, Rich., Voy. Ereb. and Terr., Fisli., p. 53, i^I. xxxii. figs. 1-3. 

 Corypheenoides 'denticulatus, Giinth., Fish., vol. iv. p. 396. 



,, „ Hutton, Fish. ISTew. Zeal., p. 49, No. 80. 



D. 13. P. 17. V. 9. 



Head compressed, with tlie sides vertical ; snout short, convex, but not overLipping 

 the mouth, which has the jaws equal, is anterior and lateral, and extends backwards to 

 below the middle of the eye. The intermaxillary is but little shorter than the 

 maxillary. Eye very large, more than one-third of the length of the head, longer than 

 the snout and much wider than the flat interorbital space. Teeth of the upper jaw in a 

 villiform band, with an outer series of much larger teeth. Lower jaw with a single 

 series of widely-set teeth on the sides ; near the symphysis the teeth are more crowded, 

 small, and of ec[ual size. Barbel very short. 



Scales of moderate size, densely covered with minute spinelets, which are directed 

 backwards ; there are six series between the dorsal fin and the lateral line ; snout and 

 the greater portion of the side of the head scaleless. Anterior dorsal spine smooth; 

 pectoral fin as long as the head without snout ; outer ventral ray not produced. The 

 lower margin of the prreoperculum is membranaceous and finely denticulated. Distance 

 between the vent and isthmus rather more than the length of the head. 



Greenish; sides silvery, lower parts of the head and abdomen black. 



The slit between the outer branchial arch and the wall of the gill-cavity is much 

 narrowed by a membrane attached to Ijoth ends of the arch ; it is only about twdce as 

 wide as the slit behind the fourth arch. The gill-laminse are short, separated from ouo 

 another. Gill-rakers in a double series ; those of the anterior series of the first arch are 

 small tubercles, fourteen in number, those of the posterior series longer, and beset with 

 fine bristles. 



The specimens obtained by the Expedition are all of very small size and still 

 destitute of scales, but the British Museum has received several examples from the 

 Colonial Museum at Wellington, which are probably adult; they are 15 inches long and 

 came from Cook's Straits. Hutton says that this fish is thrown up in immense 

 quantities after heavy gales. 



Habitat.— m^ew Zealand, Station IGG ; depth, 275 fathoms. One specimen, 4^ 

 inches long. 



The Kermadec Islands, Station 170 ; depth, 520 fathoms. Five specimens, 3 to 4 J 

 inches long. 



