458 



ZOOLOGY. 



ton ; a single opercnlar bone, while the snout and lower 

 jaw are prolonged into a tube, with the mouth at the 

 end. The chief peculiarity, however, is the gills, which are 

 developed in the form of a row of tufted lobes on each side 

 of the branchial arches. The scales are large, forming an- 

 gular plates arranged in longitudinal rows (Gill). In ,Wr- 

 nostoma of the Indian Ocean the female carries the eggs in 

 a pouch formed by the union of the ventral fins with the 

 integument of the breast. 



The male of the pipe-fish (Syngnathus ]><'rki<oins Storer) 

 receives from the female the eggs, and carries them in a 

 small pouch under 

 his tail, which is 

 open beneath 

 through its whole 

 length. This sin- 

 gular mode of mas- 

 culine gestation is 

 still farther per- 

 fected in the sea- 

 horse (Hippocam- 

 pus hudsonius De 

 Kay, Fig. 416), 

 which lives off- 

 shore from Cape 

 Cod to Cape Hat- 

 teras). The pouch 

 is situated on the 

 breast. The male, by simple mechanical pressure of its 

 tail, or by rubbing against some fixed object, as a shell, 

 forces the fry, to the number of about a thousand, out of its 

 brood-pouch, the young at this time measuring about twelve 

 millimetres (5-6 lines) in length. In the young the head is 

 at first rounded, the snout being short and blunt (Lockwood). 



Order 8. Plectoynathi. This group, represented by a few 

 singular forms, such as the trunk-fish, file-fish, puffers, and 

 sun-fish, is characterized by the union of the bones of the 

 upper and especially the lower jaws. There are few verte- 

 bra?, the scales are often modified to form spines, and the 



Fig. 416. Sea-horse, male, with the young issuing 

 from the brood-pouch. After Lockwood. 



