B. II.] THE HISTOKY OF ANIMALS. 37 



has any other animal mammae that is not viviparous, nor 

 indeed all viviparous animals, but those only that are inter- 

 nally viviparous, and not first of all oviparous. For the dol- 

 phin is a viviparous animal, wherefore it has two mammae, 

 not indeed above, but near the organs of reproduction. It 

 has not evident nipples, but, as it were, a stream flowing from 

 each side. From these the milk exudes, and the young ones 

 suck as they follow the mother. This has been distinctly 

 observed by some persons. 



2. But fish, as we have observed, have neither mamma3 

 nor any external passage for the genital organs. In the 

 branchia they have a distinctive organ, through which they 

 eject the water they have received into their mouths ; and 

 they have fins, most fishes have four, but the long fishes, as 

 the eel, have only two placed near the branchia, and in this 

 respect the cestreus, 1 a fish in the lake of Sipha3, is similar to 

 the eel, 2 and so is the fish called ta3nia. 3 Some of these 

 long fish have no fins, as the muraBna, nor have they divided 

 branchia like other fish. 



3. Some fish with branchia have coverings over their bran- 

 chia ; in all the cartilaginous fishes they are uncovered. All 

 fishes that have coverings have the branchia placed on their 

 sides ; among the cartilaginous fishes some are broad in the 

 lowest part, as the narce 4 and the batos ; 5 some very long in 

 the sides, as all the galeodea. 6 In the batracus, 7 although the 

 branchia are on the sides, they are covered with a coriaceous, 

 not a prickly membrane, like those of fishes which are not 

 cartilaginous. 



4. In some fishes with branchia they are single, in others 

 double, but the last towards the body is always single. 

 Some have but few branchia, others have many ; but their 

 number is always equal on both sides, and those with the 

 smallest number have always one on each side; this is 

 double in the capros ; 8 others have two on each side, some- 

 times these are single, sometimes double, as in the conger 9 

 and the scarus ; 10 others have four simple branchia on each 

 side, as the ellops, 11 synagris, muraena, and eel ; others have 



I Mugil, mullet. 2 Mursena anguilla. 3 Perhaps Cepola tsenia. 

 4 Raia torpedo. 8 Raia batos. 6 The shark tribe. 



7 Lophius piscatorius. 8 Perhaps Cottus cataphractus. 



9 Murgena conger. i0 Scarus cretensis. 



II Swordfish or sturgeon (L. and S. Lexicon), or Centriscus swlopax. 



