114 TEMPERATURE AUD FISH VERTEBRAE JORDAN. 



Still further roductiou, the lowest niunber, 14, existing in the short in- 

 flexible body of the trunkfish,* in which the vertebral joints are mov- 

 able only in the base of the tail. In all these forms, the process of 

 reduction of vt rtebra^- has been accompanied by specialization in other 

 iesi)ects. The range of distribution of these fishes is chiefly though 

 not quite wholly coutined to the tropics. 



A very few spiny-rayed families are wholly confined to the northern 

 seas. One of the most notable of these is the family of viviparous surf 

 fishes, t of which numerous species abound on the coasts of California 

 extending to Oregon, and Japan, but which enter neither the waters 

 of the frigid nor the torrid zone. These fishes seem to be remotely con- 

 nected with the Labridal of the tropics, but no immediate proofs of their 

 origin exist. The surf fishes have from 32 to 41i vertebra?, numbers 

 which are never found among tropical fish*^s of similar api)earauce or 

 relationship. 



The case of the Lahridcv, in which the fact was first noticed, has been 

 already mentioned. Equally striking are the facts in the great group 

 of Cataphracti, or mailed-cheek fishes, a tribe now divided into several 

 iamilies, diverging from each other in various respects, but agreeing in 

 certain ))eculiarities of the skeleton. § 



Among these fishes the family most nearly related to ordinary fishes 

 i>< that of the Scorp(mid<v.\\ 



This is a large family containing many species, fishes of local habits, 

 swarming about the rocks at moderate depths in all zones. The species 

 of the tropical genera have all 24 vertebra^.^l Those genera chiefly 

 found in cooler waters, as in California,** Japan, Chili, and the Cape of 

 Good Elope, have in all their species 27 vertebra^, while in the single 

 Arctic genus there are 31. tt An Antarctic genus J| bearing some rela- 

 tion to iSebastes has 39. 



Allied to the Scorpa'uidce, but confined to the tropical or semitropical 



with the latitude. Thus, in the uortheru angler, Lophius piscatorius, which is never 

 fouiiil south of Cape Hatteras, there are 30 vertebnu, while in a similar species, inhab- 

 iting both shores of the tropical Pacilic, Lnphionms sefujerus, the vertebne are but 19. 

 Yet, in external appearance, these two hslies, are almost ideutical. It is, however, 

 a notable fact that some of the deep-water Pediciilaics, or augliug fishes, have the 

 body very short and the number of vertebrae correspondingly reduced. Dibrarichtis 

 al tan tic US, from a depth of ?,,C)00 fathoms, or more than 4 miles, has hut 18 vertebra', 

 and others of its relatives in deep waters show also small numbers. These soft- 

 bodied fishes are simply animated mouths, with a feeble osseous structure, and they 

 are perhaps recent offshoots from some stock which has extended its range from 

 muddy bottom or from lloating seaweed to tbe depths of the sea. 

 * Oslracion. t Embiolociila'. 



I Wrasse fishes, old wives, parrot fishes, cuuners, tautogs, redfishes, seDoritas, etc. 

 ^Notably by the formation of a bony "stay" to the preopercle by the backward 



extension of one of the suborbital bones. 



II Sea scorpions, rockfishes, "rock cod," rosefishes, etc. 



H Scorpana, Sebastoplus, i'leruis, Sfivaiiceia, ''^ynancidiiim, etc. 



** Schastichthys and its otl'slioots, Schntttodes, Sebdatop-sin, etc, the "rock cod" of Cali- 

 fornia. 



ttThe roae&sh, Sebasles. It Agriopus. 



