392 SPINY-FINNED GROUP. 



of moderate size, and the caudal vertebrae unusually numerous. While the 

 majority of these fishes are confined to the northern temperate seas, a few extend 

 into the Indian Ocean and as far south as Penang. 



The remarkable fishes known as hairy-backs constitute another 



Hciirv-Bcicks 



small family (Trichonotidce) distinguished from the last by the 

 jugular position of the pelvic fins, which are in front of the pectorals ; there being 

 one or two spineless dorsal fins, an elongate anal fin, which is also spineless, and 

 no papillae in the neighbourhood of the vent. The typical genus is represented by 

 a single species (Trichonotus setiger) from the Oriental seas, characterised by the 

 first few rays of the single dorsal fin being isolated and more or less elongate, and 

 likewise by the lower jaw exceeding the upper in length. The New Zealand 

 thorny-nose (Hemerocoetes acanthorhynchus) represents a second genus, differing 



M 



NEW ZEALAND THORNY-NOSE. 



from the last by all the rays of the long dorsal being in juxtaposition, by the upper 



jaw being longer than the lower, and the presence of horny processes on the 



muzzle. These fishes are not unfrequently found floating on the surface of the 



ocean at a considerable distance from land. 



The most remarkable representatives of a third small family 

 Chirus 



(Chiridce) of this group constitute the genus Chirus, which is peculiar 



in having several lateral lines, the number of these varying in the different species. 

 The family differs from the two preceding ones in that there is a bony stay con- 

 necting the preopercular with the infraorbital ring ; while it is further distinguished 

 by the single dorsal having its spinous and soft portions of nearly equal length ; 

 the anal being nearly equal in length to the soft dorsal, and the pelvics thoracic in 

 position, with one spine and five rays. The compressed and oblong body is scaled, 

 the cleft of the mouth lateral, and the teeth are weak. All the members of the 

 family are small littoral fishes, inhabiting both sides of the Northern Pacific ; the 



