I'HVSOSTU.MES. 



689 



TELBOSTBI PHYSOSTOMI 



Osseous fishes with the air-bladder (if present) furnished with pneumatic duct. Ventral fins (if present) ab- 

 dominal. No spinous rays proper (unarticulated) in the fins". 



I'.acli dl' iIr'su tliree cluiracter.s culls to iiiiiid an 

 era in the liist(ir\- of iclithvologv. Tiic las! was Aiirr.ni s'' 

 ciiarac-tiT cit'tlic urclci' Mahuitpfeijiiiii (iiiuiiis iiici-iiiiliiis): 

 it was hy the second tliat LixN.i'.rs' detincd the order 

 Alidoiiiinales (pinna' \'ciitralcs ])one jiinnas pcctorales); 

 and the first-uicntioncd (■haractci- was MOli.ku's'' ex- 

 pedient t'oi' the lietter detiniticjn of 3f(il(i(<ij)frri/(j/ci!s 

 (iliildiiiiiKiii.i \ tile order \vliicli CrviKK*' had adopted in 

 his system, and for the comhination therewith of Cr- 

 viiai's Malacnptt'ri/fiieiis apodcs. 



to the sti-iicture of the arterial hulli of the heart, a 

 structure which in this suhorder mux he almost Ganoid. 

 Tliese resemlilanees to the (ianoids ranae the Flnso- 

 stoines low<'r in the system, assuming that the sj'stem 

 sliould l)e an ex|iression of the development. But for all 

 this we must not I'egard the sti'ucture of tlie I'lnso- 

 stomes as more |)rimiti\'e; man\- of them on tlie con- 

 trary possess more hiuhly de\ eloped origans than the 

 corresponding organs in the Physoclysts. Among these 

 organs w'e find, for example, the stronger supporting- 



Thc order or rather suborder which has thus arisen, apparatus which the jiectoral fins have acipiired in 



is hardh more natural than that of the Physoclysts, several Phvsostomes by the addition to the scapular 



just as the whole Teleosteous order is merely an ex- I disk of a special bone for this purpose (os j^recora- 



])ression of the community' of those characters whicli ((lidcum"). Another example of this is the far more 



the fishes belonging to the sever;d directions of deve- fre(|Uent occurrence in the Phvsostomes than in the 



lopment of this tvpe have retained or ac(|uii-ed during i Physoclysts of the connexion between the air-l)ladder 



their development from a common prototype, the Ga- and the organs of hearing, a connexion which is ef- 



noids. Tiie independence of the directions of develop- fected in several of them by a special chain of bones'', 



ment asserts itself evervwhere, and the charai'ters cjf the ' The preponderant part of the Physostomes, as op- 



system nuist therefore be emploved with discrimination, 



The Phvsostomes in general stand nearer the (ia- 



nuids, which \vere probably also furnished with a pneu- 



posed to the Physoclvsts, is composed of fresh-water 

 fishes; but the famih' most important among marine 

 fishes in an economical respect, that of the Herrings, 



niatic duct from the air-bladder. This connexion with I is Physostomous. This order also contains the families 



the Ganoids ajipcars in the al)dominal position of the of the Salmons, Carps, Pikes, and Eels, all of which 



ventral fins, wdiich have besides retained not unfrequently have been of great importance in human economy since 



a greater number of ravs, just as the pectoral fins may \ time immemorial. 



display more numerous transverse rows of basal bones, I The Physostomes are not so numerous as the Physo- 



though the outer (distal) ro\vs are not ossified-'. An- | clysts — we know about 1,9<)0 species of the former, as 



other sign of this connexion is given by the exceptions I opposed to 3,;'>00 of the latter — - l)ut the distinction of 



whicli occur in certain Physostomes, to the character i form is sufficiently wide to require the establishment 



that otherw'ise distinguishes the Teleosts with regard of several independent series which we here give jjrin- 



" Tlie rays wliicli in lliese tislies are teniied spines, as being- liard and stiff, sliow Uieir Malncoptcrygian iiatnre in tlieir internal struc. 

 tiire. being articulated, altlioiigli the joints are coalesced. 



* Gen. Pise, p. 1. 



' .Si/st. X<il., ed. X, torn. I, p. 241. Ci'vier completed the Linmoan character by tlie addition lliat tlic ventral (ins not only lie be- 

 hind the pectoral fins, but are also destitute of any immediate connexion with the shoulder-girdle. 



'' Abh. Akad. Wiss. Berl. 1844, Pliys. Abh., p. 175. 



' R'egne Animal, ed. 1, torn. II, p. 159; ed. 2, toiii. II, p. 200. 



■' Cf. Gegenbaur, Unters. Vergl. Anat. Wirbelth., 2:te Heft, p. 153. taf. VIII. figg;. 8 et 9. 



" Pr.a>coracoiil, Pahker. Slioi'!der-,/ir(/le and Steviiiiin, p. 56, pi. II, fig. 8, p. cr; Knochenspange, Gege.vbaur, 1. c, p. 117. tof. VII. 

 figg. 1—5, .!•■ 



'' Sac.kmeiii. (llorphol. .lalirb.. Bd. X. p. 22) gave these fishes the name of 0.-<tan'ophi/.^-ete Teleosts, from oGluytor, a small bone, and 

 cpiaa, bhiddev. 



