OR ANIMALS WITH BLOOD. 231 



the Greeks and Rana piscatrix of the Eomans, is described 

 by many other ancient writers, especially Oppian of Cilicia, 

 Pliny, and Cicero. Aristotle seems to have included it 

 among his Selache partly on account of its sharp and 

 rather large teeth, and its tuberculated skin, free from 

 scales, and partly because he considered it to be cartila 

 ginous. However, he admits that it is an exceptional 

 member of his Selache, for he says that it has covered gills 

 and that it is not ovoviviparous. It may be mentioned 

 that, with respect to the nature of its skeleton, the fishing- 

 frog occupies a position intermediate between the typical 

 bony fishes and the cartilaginous fishes. 



The term Galeos is of wide meaning, and includes many 

 long, cartilaginous fishes, in contradistinction to the flat 

 ones. Aristotle mentions several kinds of Galeos, and 

 distinguishes them by names such as asterias, akanthias, 

 and leios, having an analogy to the specific names used by 

 modern zoologists. 



The smooth dogfish is still called Galeos by modern 

 Greeks. Aristotle says, in one passage, that Galeos has 

 many pyloric cseca ;* he can scarcely be referring to the 

 dogfish here. The name was used, in fact, for more than 

 one kind of fish, in several ancient authors, e.g., Archestratus 

 speaks of a Galeos caught off Rhodes and sold for not less 

 than a thousand Attic drachmae.! This could scarcely be a 

 dogfish. Aristotle also uses a group-name, Galeoeides, to 

 denote several fishes having affinities with Galeos. In this 

 group he included Alopex, Kuon, and Skylion.i 



In H. A. vi. c. 10, s. 5, Aristotle shows that he knew of 

 the existence of placental fishes, for he says that the Galeoi 

 (dogfishes) which are called leioi (smooth) have their young 

 attached by an umbilical cord to a kind of placenta, and 

 that, when taken away, they appear like the embryos in 

 quadrupeds (mammals). It is well known that most of the 

 species of Hustelus, and some other cartilaginous fishes, are 

 placental ; Aristotle anticipated this modern discovery. 



Aristotle asserts that Narke lies concealed in sand or 

 mud, and numbs any fish which comes near it, by some 

 means within its body. 



This sufficiently clearly shows that Narke is the torpedo. 

 Theophrastus, Julian, and Oppian of Cilicia refer to this 

 fish, but exaggerate its powers ; the most interesting 



* H. A. ii. c. 12, s. 13. f Deipn. vii. 44. 



| H. A. vi. c. 10, ss. 4 and 10. Ibid. ix. c. 25, s. 2, 



