CHONDROPTERYGII BRANCHIIS LIBERIS. 331 



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 ai-e large and flattened, with a leathery covering, and 

 having margins. [In fact, 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, 

 pLThaps, a second subgenus, CaUirhynchus, has the snout ending in a fleshy appendage like a toe. The 

 second dorsal begins over the ventrals, and terminates at the comniencement of the fln under the tail. Only 

 one species, from the South Seas, is known. 



THE SECOND ORDER OF CHONDROPTERYGII. 



CHONDROPTERYGII BRANCHIIS FIXIS. 



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. 



THE FIRST FAMILY OF THE CHONDROPTERYGII BRANCHIIS FIXIS,— 

 Selachii (the Sharks and Raits), — 

 Which has been comprised in tw"o 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 

 compose the gill-Ud. They have pectorals and ventrals, the latter behind the abdomen on each side of 

 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 

 into coeca ; the intestinal canal is short, but with a spiral valve. The sexes pair regularly, the females 

 having oviducts highly organized, which supply the place of a matrix in those that bring both their 

 young alive ; such as produce eggs have them with a horny covering, the substance of which is supplied 

 by a larger gland surrounding the oviduct. The males are easily known by large appendages on the 

 inner edge of the ventrals, the use of which is not well known, [though believed to serve as claspers]. 



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- 

 ])ended in the muscles behind the gills, without connexion with the cranium or the spinal column. 

 Some are viviparous ; others produce eggs covered with yellow and transparent horn, of an oblong 

 shape, and with cords of horn at the angles. Their small gill-ribs are apparent, and small ones arc 

 traceable along the spine ; their flesh is dry and leatheiy, and eaten only by the poor. They are 

 numerous, and form many subgenera. 



SnjUixtm (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 

 a shorter one at each side. They all have spiracles, and one anal fin ; the dorsals are far backward, the first being 

 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- 



