424 



TUFT-GILLED GROUP. 



cyanopterum) is shown in the accompanying illustration ; the range of this form 

 extending from the coast of Zanzibar to China and Ceram. The female takes the 

 whole charge, not only of the exceedingly minute eggs, but likewise of the newly- 

 hatched fry. Like the members of the next family these fishes generally swim in 

 a more or less nearly vertical position, the dorsal fin exerting the chief propelling 

 power. The family is represented by an extinct genus from the Italian Eocene. 



BLUE-FINNED TUBE-MOUTH (nat. size). 



THE PIPE-FISHES AND SEA-HORSES, Family SYNGNATHID^J. 



From the members of the preceding family the pipe-fishes may be dis- 

 tinguished by the reduction of the gill-opening to a very small opening at the 

 superior hinder angle of the gill-cover, as well as by the single soft dorsal fin, and 

 the absence of the pelvic fins ; some of the other fins being likewise wanting in 

 certain genera. Mainly marine, although frequently entering brackish, and more 

 rarely fresh waters, these strange fishes are to be found on the coasts of tropical 

 and temperate seas in such situations as, from the abundance of seaweed, offer 

 them sufficient shelter. They are naturally poor swimmers, and if carried away 

 from protective covert may be borne helplessly out to the open ocean by the action 

 of currents. Unlike the tube-mouths, the males take charge of the eggs and 

 young, being often provided with a pouch formed by a fold of skin arising from 

 each side of the body and tail, and joined together in the middle line ; in the sea- 

 horses this pouch being completely closed, save for a small aperture in front. 

 In this receptacle the eggs are deposited, and remain there till hatched. The 

 typical genus, as well as Siphonostoma, is represented in a fossil state in the 

 middle Eocene of Monte Bolca, where there likewise occurs an extinct genus 

 of sea-horses. Including several genera, the pipe-fishes are characterised by 

 the absence of prehensile power in the tail, which generally terminates in 

 a fin. In the typical genus Syngnathus, as represented by the great pipe-fish 

 (S. acus), shown in our illustration, the body is marked with more or less distinct 

 longitudinal ridges, among which the one down the back is not continuous with 

 that on the tail. The pectorals are well developed, the caudal present, and the 

 dorsal fin placed nearly or exactly above the vent. In the males the pouch is 

 fully developed, and of the type described above. The great pipe-fish is a 

 common species in European seas, extending westwards across the Atlantic and 



