PIPE-FISHES. 683 



brane on the lower side of the tail, without a pouch being 

 developed. 



Three species from the coasts of Australia. The protective 

 resemblances with which many Lophobranchs are furnished, 

 attain to the highest degree of development in the fishes of 

 this genus. ITot only their colour closely assimilates that 

 of the particular kind of seaweed which they frequent, but 

 the appendages of their spines seem to be merely part of the 

 fucus to which they are attached. They attain a length of 

 12 inches. 



Hippocampus. — ^Trunk compressed, more or less elevated. 

 Shields with more or less prominent tubercles or spines. Occiput 

 compressed into a crest, terminating at its supero-posterior corner 

 in a prominent knob (coronet). Pectoral fins. The males carry 

 the eggs in a sac at the base of the tail, opening near the vent. 



A singular resemblance of the head and fore part of the 

 body to that of a horse, has given to these fishes the name of 

 "Sea-horses." They are abundant between and near the 

 tropics, becoming scarcer in higher latitudes. Some twenty 

 species are known, some of which have a wide geographical 

 range, as they are often carried to great distances with fioating 

 objects to which they happen to be attached. — Acentronura 

 is a genus closely allied to Sippocampus. 



SIXTH OEDEE— PLECTOGNATHI. 



Teleosteous fishes with rotujli scales, or with ossifications of 

 the cutis in the form of scutes or spines ; skin sometimes entirely 

 naked. Skeleton incompletely ossified, with the vertebrce in 

 small number. Gills pectinate ; a narrow gill-opening in front 

 of the pectoral fins. Mouth narrow ; the hones of the upper 

 jaw generally firmly united. A soft dorsal fin, belonging to the 

 caudal portion of the vertebral column, opposite to the anal ; 

 sometimes elements of a spinous dorsal besides. Ventral fin 

 none, or reduced to spines. Air-bladder without pneumatic duct. 



