290 



LOWER VERTEBRATES. 





f^^' 



Fig. 162. — Diodmi maculaius, globe-fish, normal and inflated. 



The most common eastern American species, Cirrhosomus turgidus, has the skin 

 prickly all over, and its abdomen is very inflatable. Perhaps the most common name 



for it is swell-fish or egg-fish. It 

 ranges as far north as Cape Cod, and 

 at some points on the coast is very 

 abnndant ; as at " the eastern end 

 of Long Island, where a hundred or 

 more are sometimes taken in one 

 haul of a fyke-net." It frequently 

 takes the hook. " When drawn up, 

 it immediately inflates its body to 

 a prodigious size by means of sliort, 

 jerking inspirations, the sac becom- 

 ing distended with air if in tlie at- 

 mosphere, or water when submerged. 

 By scratching it on the belly, or 

 pounding it, it "will readily inflate 

 itself several times in succession, and 

 again dischai'ge its load at a single 

 effort through mouth and gills. 

 When inflated and thrown on the 

 water, it will sometimes float to 

 a great distance before collapsing. 

 The skin around the eye of this 

 species is contractile to such an extent as to completely close \\\) the latter by 

 a kind of puckering." When the eye is open, however, it presents rather a pretty 

 appearance, for the iris is of a beautiful reddish brown, and with an inner circle of a 

 coppery or brassy color. 



Another species, often known as rabbit-fish {Lagocephalus Icevigatus), is rather a 

 straggler to the northern American coast. It is, however, a common fish in the Gulf 

 of Mexico. It is one of the largest species of the family, and sometimes " attains the 

 length of three feet and the weight of five or six pounds." It is used for food in 

 some places, especially Cuba. Like its congener, it may be taken with a hook. 



The Tetrodon fahdka is a typical and long-known species of the family, inhabiting 

 the Nile. (See illustration on page 291 .) 



Two other closely related families are the Psilonotid^ and Chonerhinid^. 

 The DionoNTiD^ form another family which is also well distinguished externally. 

 As the name indicates, the jaws are entire, and simulate two teeth coincident with 

 the periphery of the mouth, one above and one below. All the species of this family, 

 too, have well-developed spines, which are generally capable of erection, and, as the 

 fish is able also to greatly dilate its abdomen, these spines then stand outright, and 

 give a really formidable appearance to the animal. The dilatability of the abdomen is 

 at least as great as, and in several species greater than, in the Tetrodontidse. The pop- 

 ular name porcupine-fish is the one in most general use for the various species, but 

 several of them are also called rabbit-fishes on account of a supposed mimicry of tlie 

 head of the rodent by the diodont. Three genera are represented along the American 

 coast : Diodon, whose species are more especially called porcupine-fishes, Chilomycte- 

 rus, to whose members is most applied the name rabbit-fish, and a peculiar genus 



