330 



PISCES. 



THE FIRST ORDER OF CIIONDROPTERYGII,— 



CHONDROPTERYGH liRANCHIIS LIBERIS,— 



(Ofj with free gills), have m then- g^ills a sln^rlc uiile opening, and a j^ill-liil, like tlie Bony 

 Fishes, but they have no gill-rays. There are two genera. 



Accipensor. rlic Sturgeon.— General form like tliat of the Siiark, but the body more or less covered 

 witli hony plates in ]onL;-itudinal ro\\s, and tiic heail externally armed \'»ith tlie same. Tlieir month, 

 placed under the muzzle, is small and toothless; and the palatal bones, soldered to the maxillarips, 



form the upper jaw, while 



^r'"!f^'^^^^^^^^^«^^5^^wriVv„_ /\ J/j^' there arevestiges of tlie in- 



' " "^^ ^^ ^^^^^%e8^^ ■ h>-. .^^stfB?^^ termaxillaries in the tliick 



lips. Placed upon a pedicle 

 of three articulations, this 

 mouth is more protractile 



the eyes and no^^trils are on the sides of the head, and barbules are suspended from the muzzle; the 

 labyrinth within the cranial hones is perfect, hut there is no external car — the liole lichind the temple 

 leading merely to the gills. The dorsal is beliind the ventrals, and has the anal directly opposite to it ; the 

 caudal siirroiimls the extremity of the spine, and terminates in the upper lol.)e of the tail, liut an under 

 lolie gives ihe (ail the appearance of being forked. Internally, we tind the spiral intestinal valve, and 

 the single iiaiirriM'^ nf the Shark family; and there is a very large airddadder, which communicates 

 with the gnlht liy a large opening. Sturgeons ascend some rivers in vast naml]ers, and are the object 

 of valii;ihh; fislirrics. The flesh of most is agreeable, their eggs or rocs are made into caviar, and their 

 airdiladdrris furnish the finest isinglass. 



A. .\fnri'i, till' ('(inuimn Sturo;eon, occasionally found in the west of Europe and on the British shores, is about 

 six feet lon^, lias a iiointed muzzle, live rows of plates with stronp: spines, and its tiesh is much esteemed, being 

 soiuewlnit hke vfal. The rivers falling- into the Black and Caspian Seas produce this and three other species, if not 

 more. .(. ml In- mis, tlip Sterlet, is seldom more than two feet long, with the plates on the lateral line numerous and 

 kf-eled, and ihiisf in tiie belly flat. It is considtred delicious, and caviar made from it is reserved for the 

 Russian rourt. Tliere is reason to believe that this is the Etops and Acctpcnserso much celebrated by the ancients. 

 A. stelaltis, the seroregia of the Russians, and the sriicrp of the Germans, g:rows to the length of four feet, has the 

 plaits rougher and the snout more slender than tlie others. It is very numerous, but less; e.steemed than the 

 Common Stnrj^eon. A. huso, the Great Sturgeon, has blunter plates, a smoother skin, and shorter snout and cirri, 

 than the Common Sturgeon. Jt is frequently found more than twelve, or even lifteen, feet in leuj^th, and weii^hui^ 

 more than twelve hundred pounds. One speiduLm is mcntidiird whieli wciu'-hed near 3,000 pounds. Its flesh is not 

 mnrh esteemed, and it is sometimes unwhole^onH; ; Imt its air-hladiler yields the very finest isinglass. It is found 

 in the I'o ns well as in th:' northern rivers. 



Several Siiir^''c(itis ;iri.- I'onnd in North America, wlnrh arc pn-nliar to that quarter of the W()r]d. 



JU)!'iniliHi, nniy he considered as a snbg;enus of Accipeuser, These fishes are distinguished by the great prolong- 

 atidii di' llirir anout, the broad margins of which give it the figure of aleaf. In the general form and tins they re- 

 seiJil'ie tlie Sturgeons; but their gill-openings are wider, and the gill-lid is prolonged in a membranous flap, which 

 extrnds to half the length of the body ; their gape is much cleft, and furnished with a number of small teeth. 

 Their upper jaw is formed by the union of the palatals and maxlllaries with a pedicle of two articulations. There is 

 a spinal cord like that iu the Lamprey, and the same spiral valve which is common to most of the order ; but the 

 pancreas is partially divided into caeca. They are furnished with an air-bladder. Only a single species is knu\\ n, 

 P. foliiini, which is found \n the Mississippi. 



Ch'uiucra. — This second genus of cartilaginous fishes with free gills, closely resembles the Sharks in 

 form, and iu the disposition of the fins; but the gills open externally by one apparent hole in 

 each side, though, if we examine more closely, we find great part of their edges attached, and that the e 

 are five separate liolcs terminating in the common a|n'rtiire: still the}' ha\e a veslige of an operculum 

 concealed in the skin. Their jaws are more reiluei'd tlian in the bliarks, for tlie palatals and tcmjM-i- 

 rals are mere sinijile vestiges suspended to the sides of the muzzle, and the upper jaw is represented by 

 the vomer ntdy : hard and undivided plates supply the place of teeth, four of them alM)\e, and t\\o below. 

 The niii77.1e, supported as iu the Sharks, projcrls forwards, and has pores arran/cil in -vov;: ne;irlv 



