1892.] NATURAL SCIENCES OF PHILADELPHIA. 239 



655a 23, 696b 3 6, 697a 8, 517a 1, 476a 2, 489b 6, 505a 13 5, 

 695b 4, 489b 30, 676b 3 4 5, 520a 17 18 19, 564b 20, 718b 35, 

 733a 10, 754a 33, 733a 8 11, 537a 30, 535b 24, 538a 29, 540b 19 

 10 12, 621b 25 28, 570b 32, 4S9b 16, 718b 33, 754a 23 32, 564b 15 

 16, 492a 27, 503b 3, 511a 4 7 9 12, 516b 15, 475b 20, 676b 2, 718b 

 32, 732b 1, 754a 23, 755a 12, 755b 2, 676b 2, 566a 24, 570b 32, 

 566a 15, 565b 30, 566a 26, 571a 1, 540b 14, 755b 8 12, 539a 29, 

 505a 26, 489b 6, 540b 17, 505a 3, 517a 1, 540b 6 8 10 12 17, 565b 

 28, 489b 30, 565b 24-31, 695b 9, 1527b 40 44. Cf. also aeXaym.hi^, 



liXayo^ is a term much used by Aristotle in a broad sense to 

 include a wide variety of fishes. leXa/ax^g is also used, whether 

 as equivalent to fjiXw/o? or in a still more comprehensive sense, is 

 not clear. Pliny ix, 24 (78), says : " There is another kind of fiat 

 fishes which have cartilage for the spine (pro spina), as the rrn'cp, 

 pastinacce, sqxiatince, torpedo and those which the Greeks call by the 

 names hovis (l^oo?), lamia, aquila (asro?), and ra7ia (^dzpayo^), in 

 which number are also the sr/rta^i although these are not flat (^/ojii). 

 All these collectively Aristotle called asXAyji, he first having given 

 them this name. We (Latins) can not give them a distinctive 

 name unless we may be permitted to call them cartilaginous (carti- 

 laginea)." 



I gather the following points from Aristotle: Any animal is 

 called a (yi).ayo^ which, being without feet and having gills, is vivi- 

 parous (or ovoviviparous). All the askdyr^ except the [id-payoq are 

 externally viviparous, having first produced eggs within themselves 

 (i. e. are ovoviviparous). 



Their uterus, or oviduct, is forked and extends to the o-oZoJiia 

 (diaphragm, peritoneum). 



The fJz/.dyri are fidzo^i, Tfi'jyw'yi, pi'-'T^, ,jul>^, Id'j.ta, d.£z6^, •^dfi/.r^, fld-pa- 



yoi; and all the yahwo-i}. They have uncovered gills ; some are 

 elongated in form, e. g. the yakzui; others flat, e. g. the jSd-o'.. Some 

 of the (Jz Adyrj do not have fins, viz., the flat ones and those having 

 tails, such as iSdrois and t/jo/w'^. These swim by means of the " flat- 

 ness itself." But the [-id- pay u^^ has fins, and so do all which do not 

 have the flat parts thin. Some are rough, others smooth. The 

 viviparous fishes, such as the (jzXdyr^, have cartilaginous bones (are 

 yoydpd/.a-Ala), but the oviparous ones have a spine like the back- 

 bone (pdyii) of quadrupeds. The liver of the ffskdyvj becomes fatty 

 and an oil is melted from it, although the <Tt)yi.yq themselves are 

 very free from fat both in their flesh and abdomen. 



