CHONDROPTERYGII BRANCHIIS LIBERIS. 
331 
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I regular. The first dorsal, containing a strong spine, is placed over the pectorals ; and the males, as in 
the Sharks, have a bony appendage to the ventrals ; but these are divided into three branches, and they 
have spinous appendages before the base of the ventrals, and small spines on the point of a fleshy 
appendage between the eyes. Their eggs are large and flattened, with a leathery covering, and 
having margins. [In faet, with some singular peculiarities, they approach pretty closely to the fishes 
with fixed gills.] 
C. monstrosa, the King of the Herrings, and Cat of the Mediterranean, is three feet long, and of a silvery 
colour spotted with brown. It inhabits the European seas, the northerly ones most abundantly. Another, forming, 
perhaps, a second subgenus, Callirliynchus, has the snout ending in a fleshy appendage like a toe. The 
second dorsal begins over the ventrals, and terminates at the commencement of the fin under the tail. Only 
one species, from the South Seas, is known. 
j THE SECOND ORDER OF CHONDROPTERYGII. 
! 
I CHONDROPTERYGII BRANCHIIS FIXIS. 
I These have their gills attached at the outer edge, with a separate opening, through which 
! the water from each gill escapes. They have also small arches of cartilage suspended in their 
{ muscles, opposite the gills, which may be called gill-ribs. They form two families. 
I' 
I THE FIRST FAMILY OF THE CHONDROPTERYGII BRANCHIIS FIXIS,— 
I Selachii (the Sharks and Ravs), — 
j Which has been comprised in two genera, has many common characters. The palatals and postmandi- 
bularies are alone armed with teeth, supplying the place of jaws, the usual bones of which are mere 
rudiments, a single bone representing the tympanal, jugal, and temporal bones, and the preoperculum. 
The os hyoides is attached to this pedicle, and supports gill-rays as in ordinary fishes, although not 
distinctly visible externally. It is followed by branchial arches, but has none of the three pieces which 
I compose the gill-lid. They have pectorals and ventrals, the latter behind the abdomen on each side of 
j the vent. Their membranous labyrinth is inclosed in the cartilage of the cranium, and their cavities 
;[ contain starchy masses and not stony ones. The pancreas is a conglomerate gland, and not divided 
I into coeca ; the intestinal canal is short, but with a spiral valve. The sexes pair regularly, the females 
I having oviducts highly organized, which supply the place of a matrix in those that bring both their 
I young alive ; such as produce eggs have them with a horny covering, the substance of which is supplied 
j by a larger gland surrounding the oviduct. The males are easily known by large appendages on the 
ij inner edge of the ventrals, the use of which is not well known, [though believed to serve as claspers~\. 
ij Squalus, the Sharks properly so called, have a long body ; a thick, fleshy tail ; moderate pectorals ; 
! and resemble ordinary fishes in their form, having the gill-openings on the sides of the neck, not 
below, as in the Rays, and the eyes in the sides of the head. The snout is supported by three carti- 
laginous branches arising from the fore part of the cranium, and the rudiments of maxillaries, inter- 
maxillaries, and premandibulars, may be traced in the skeleton. The bone of the shoulder is sus- 
pended in the muscles behind the gills, without connexion with the cranium or the spinal column. 
I Some are viviparous ; others produce eggs covered with yellow and transparent horn, of an oblong 
|j shape, and with cords of horn at the angles. Their small gill-ribs are apparent, and small ones are 
i traceable along the spine ; their flesh is dry and leatheiy, and eaten only by the poor. They are 
I numerous, and form many subgenera. 
Scyllium (called Dog-fishes on the British coast). — Snout blunt and short ; nostrils near the mouth, continued in 
a groove to the edge of the lip, and more or less closed by membranes ; teeth with a long point in the middle, and 
I a shorter one at each side. They all have spiracles, and one anal fin ; the dorsals are far backward, the first being 
I even before the ventrals ; their caudal is long and truncated, and their gill-openings under the pectorals in the 
British ones ; the anal is against the interval between the two dorsals. The species are : 
S. canicula, the Small-spotted Dog-fish, with numerous spots and the ventrals truncated. — S. cutilis, the Large- 
spotted Dog-fish, with the spots larger, sometimes ocellated, and the ventrals square.— /S. melastomum, Black- 
