332 



PISCES. 



mouthed Dog-fish. Light-brown, with ocellated spots. All the three are peculiarly destructive to the more 

 valuable fishes. Some foreign ones have a slight difference of character. 



The Sharks properly so called include all species with a produced snout, no nasal grooves, and with 



a caudal lohe more or less forked. They form the genus 



Carcharias—a. numerous and notorious tribe, 

 with trenchant-pointed teeth, usually serrated in 

 the margins; the first dorsal before the ventrals ; 

 the second nearly opposite the anals. They have no 

 spiracles ; the nostrils are in the middle of the 

 snout, and the last gill-opening extends over the 

 pectorals. C. vulgaris, the White Shark, is some- 

 times twenty feet long, with isosceles-triangular 

 teeth, ragged at the sides, and the lower ones 

 narrow points placed on w ider bases ; these teeth in 

 the mouth of such a fish forming weapons dreaded 

 by all mariners. Found in most seas. [Its appear- 

 ance on the British shores has been mentioned, 

 but it wants authentication.] C. vulpes, the Fox- 

 shark, or Thresher.— Triangular teeth in both 

 jaws ; upper lobe of the tail as long as the whole 

 body ; second dorsal and anal very small. C. glau- 

 cus, the Blue Shark, with curved -sided teeth 



above, inclining outwards, and straighter ones be- 

 F. K . 147.- The White Shark. ^ . M ^^ on the ^^ 



Lamna, the Porbeagle, differs from a true Shark in the pyramidal snout, and the gill openings before the pec- 

 torals. L. cornubica occasionally appears on the 

 British coast, and its size has caused it to be mis- 

 taken for the White Shark. L. monennis resembles 

 the last, but has the snout shorter. 



Galeus. — Shaped like the Sharks, but with spira- 

 cles and an anal. G. vulgaris, the Tope, is found 

 on the British shores. 



Mustelus, resembles the former in shape, but 

 has the teeth like a close pavement. 

 Milavis, the Smooth Hound, is a British species. 

 Notidanus, wants the first dorsal ; has six gill- 

 openings, triangular teeth above, and like a Fig. 148.— The Thresher. 



saw below. Two species inhabit the Mediterranean. Has the form of the Sharks, and spiracles, with the gill- 

 openings nearly surrounding the neck ; its teeth are small and not notched. It is the largest of the True Fishes, 

 being sometimes thirty-six feet long ; but it is a harmless fish. £. maximus, the Basking Shark, is found in the 

 British seas. 

 Centracion, has spiral teeth like pavement, and a spine before each dorsal. 



Spina* , resembles Carcharias, but has spiracles ; no anal fin ; several rows of small trenchant teeth j and a strong 

 spine before each dorsal. <S'. acantheus, the Piked Dog-fish, is a British species. 



Centrina, resembles the last ; but the second 

 dorsal over the ventrals, and the short tail, give 

 it a clumsy appearance ; its skin is very rough. 



Scymnus, the Greenland Shark, is more abun- 

 dant in the Arctic seas, and is large and vora- 

 cious ; but is understood not to attack Man. 



Zygoena, forms a second genus. Like the 

 Sharks in the body, but with the snout singu- 

 larly produced, forming two pieces like a double- 

 h aded hammer, with an eye in the middle of 

 each extremity. The species of the European 

 seas grow to the leugth of twelve feet, [and we 

 believe larger ones are met with in southern 

 latitudes]. 



Sqitatina, the Angel Fish, has spiracles and 

 wants the anal ; but it has the mouth at the end 

 of the muzzle; the eyes in the upper part of 

 the head ; the head round ; the body broad and 

 flattened horizontally ; the pectorals large and 

 far forward, but separated from the back by a 



Fig U9.-The Hammer-ho vded Shark. ^ j n the gilI _o pe ningS . their tw0 dorsa l s are 



behind the ventrals, and the caudal is attached both to the upper and under sides of the termination of the body. 



