4 2 4 
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 S yngna thidje. 
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 egg's 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 SyngnatJtus, 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 
