4 8 



ZOOLOGICAL 



OEDER PLAGIOSTOMI. 



MYLIOBATID-S (Eagle-Rays). Plate 26, Map i. 

 The Eagle Rays are represented by about 30 species, which occur 

 principally in tropical and subtropical seas. The best-known species is 

 Myliobatis aquila, which has been taken on many parts of the British coasts, 

 while beyond our seas it has an almost cosmopolitan distribution. 



TRYGONIDuE (Sting-Rays). Plate 26, Map i. 



The Sting-Rays owe their popular name to the strong caudal spines, 

 with which they are capable of inflicting severe and dangerous wounds. 

 About 50 species are known, which have a wide range in tropical and 

 temperate seas. A single species, Trygon pastinaca, occurs not infrequently 

 in British waters, while it ranges also over both sides of the Atlantic, the 

 Mediterranean, and even as far east as China and Japan. A few species 

 live in fresh waters, and these are mainly found in the northern portion 

 of South America. 



TORPEDINID£! (Electric Rays). Plate 26, Map ii. 



The Electric Rays, so called from the presence of electric organs between 

 the head and the pectoral fins, are found chiefly in warm seas, although one 

 species (Torpedo hebetans) has frequently been taken off the British coasts. 

 Seven genera and about 15 species have been described. 



RAIID^E (Rays or Skates). Plate 26, Map ii. 



The species of this family, some 30 or 40 in number, are found in all the 

 cooler waters of the globe, and are more abundant in the Northern than in 

 the Southern Hemisphere. The great majority of the species belong to the 

 typical genus Eaia, as do all the British representatives of the family. 

 The latter are nine in number, the best-known of which are the Common 

 Skate (B. batis) and the Thornback Ray (R. clavata). Most of the Rays 

 are eaten as food. 



RHINOBATID^I (Beaked Rays). Plate 26, Map ii. 



The Rhinobatidee inhabit warmer regions than the True Rays (Raiidee), 

 and are found in nearly all tropical and subtropical seas. About 20 species 

 have been described, belonging to five different genera. The peculiar shape 

 of the body in these Rays has led to their being sometimes called guitar- 

 fishes or fiddler-fishes. 



PRISTID^I (True Saw-Fishes). Plate 26, Map iii. 



This is a small group, containing only a single genus and four or five 

 species. They are formidable fishes, attaining a length of over 20 feet, and 

 are found in all the warmer seas. Carnivorous in habit, these creatures, 

 with their serrated beak, cause much havoc among their defenceless 

 neighbours. 



PRISTIOPHORID.E (Side-gilled Saw-Fishes). Plate 26, Map iii. 



As their popular name indicates, these fishes may be distinguished from 

 the true Saw-Fishes forming the previous family by the position of their 

 gill-openings, which are lateral instead of ventral. In general appearance, 

 however, they resemble the Pristidse. About four species, belonging to a 

 single genus, Prisliophorus, are known, and these are confined to the seas 

 of Australia and Japan. 



RHINID.E (Angel-Fishes). Plate 26, Map iii. 



The members of this family are all very closely allied to one another, 

 and it is doubtful whether more than a single species should be re- 

 cognised. Angel-Fishes have an almost cosmopolitan distribution, occur- 

 ring in practically all the tropical and temperate seas. They attain a 

 length of about five feet. Rhina squatina, the typical species, is not 

 uncommon in British waters, especially off the Scottish coasts. 



SPINACID^: (Spiny Dog-Fishes). Plate 26, Map iii. 



About 20 species of this family are known, belonging to eight genera. 

 They have a world-wide distribution, but are most abundant in temperate 

 seas. The best-known member of the group is the Picked or Piked Dog- 

 Fish (Acanthias vulgaris), a creature growing to a length of three or four 

 feet, and abundant on the British coasts. The Greenland Shark (Lsemargus 

 borealis) is an occasional visitor to British seas, but inhabits principally the 

 Arctic regions. The Spinous Shark (Echinorhinus spinosus) is another well- 

 known member of the family, wandering on rare occasions to Britain. 



RHINODONTID^E (Whale-Sharks). Plate 26, Map iv. 

 The Rhinodontidse have a wide distribution, but are only rarely seen. 

 One, or perhaps two, species may be recognised, belonging to a single genus 

 Rhinodon. These creatures are the largest known Sharks, growing to a 

 length of over 50 feet. Little is recorded of their habits, but the size of 

 their teeth suggests that their food consists of small fishes. They are, at 

 any rate, reported to be quite harmless to man. 



CETORHINID.E (The Basking Shark). Plate 26, Map iv. 

 ^ The Basking Shark (Getorhinus maximus) is the sole representative of 

 this family. It inhabits Arctic seas, but wanders as far south as the 

 Mediterranean and California. It is a huge creature, attaining a length 

 of 40 feet, but is harmless to man, by whom it is regularly hunted for the 

 sake of the oil obtained from its liver. The popular name of this Shark, 

 which occurs fairly commonly in British seas, is due to its habit of lyin^ 

 motionless on the surface of the water. 



LAMNID-2I (The Porbeagle, &c). Plate 26, Map iv. 



About seven species are usually referred to this family, belonging t a 

 or six different genera. They are widely distributed, occurring in nearl ? ^ 

 seas. The best-known species is the Common Porbeagle (Lamna cornub & \ 

 a fierce animal inhabiting the Northern Atlantic and Pacific Ocea a 



common in British waters. Another species, Carcharodon rondeletii " 

 garded as the most formidable and voracious of all sharks attai ' ' 

 length of 40 feet, and found in all tropical and subtropical seas, ran<n n a f f ^ 

 the Mediterranean to New Zealand. The curious, long-tailed Fox Sh° k 

 Thresher (Alopecias vulpes) is not uncommon on British coasts. 



SPHYRNID-ffi (Hammer-Head Sharks). Plate 26, Map iv. 



A single genus (Sphyrna, formerly called Zygsena) of this family i s 

 recognised, with five species. They are widely distributed in all th 

 warmer seas, while one species (Sphyrna zygsena), is occasionally taken off 

 the British coasts. These sharks are remarkable for the curious lat 1 

 extensions of the head, which bear an eye at each extremity, and give th 

 fishes an extraordinary hammer-like appearance, whence their popular nam 



CARCHARIID.E (The Blue Shark, &c). Plate 26, Map v. 

 This family is a comparatively large one, comprising about 60 species 

 These have a world-wide distribution, ranging from Iceland to New Zealand 

 and occurring in all seas. Numerous genera have been formed for the 

 reception of the various forms, the typical one (Carcharias) containing about 

 half of them. The best-known members of this important family Ire the 

 so-called Blue Shark (Carcharias glaucus), the Topes of the genus Galeus 

 and the " Hounds " or species of Mustelus. The Blue Shark is frequently 

 captured in British waters ; Galeus canis, the Common Tope, is also common 

 off our coasts ; while Mustelus vulgaris and M. Isevis are both well-known 

 inhabitants of British seas. 



SCYLLIID.E (Dog-Fishes, &c). Plate 26, Map v. 



About 20 species of Dog-Fishes constitute the present family, and these 

 are found in the seas of the whole world. The members of the typical <*enus 

 Scyllium are of small size, and are sometimes used as food. Two species 

 called respectively the Small-spotted and Large-spotted Dog-Fish (S. canicula 

 and catulus) are common off the British coasts ; while Pristiurus melanostomus 

 known as the Black-mouthed Dog-Fish, is a European species which has 

 several times been captured in British waters. The Tiger- or Zebra-Shark 

 (Stegostoma tigrinum) is a common inhabitant of the Indian Ocean, owin°- 

 its popular name to the handsome coloration of its body, which is of a 

 brownish-yellow, striped with dark brown or black. 



HETERODONTID.E (Bullhead Sharks). Plate 26, Map v. 

 The species of this family, four in number, are confined to the Pacific 

 Ocean, where, however, they have a wide range. The best-known species is 

 that called popularly the Port Jackson Shark (Heterodon philippi), a some- 

 what repulsive-looking creature inhabiting the seas of Australia. Little is 

 known of the habits of these Sharks, but they appear to feed chiefly on 

 Molluscs. None of them exceeds five feet in length. 



NOTIDANID^I (Comb-toothed Sharks). Plate 26, Map v. 



This family comprises about half a dozen species of moderate-sized Sharks, 

 which are found in nearly all tropical and temperate seas. Notidanus griseus, 

 inhabiting the Atlantic and the Mediterranean, is an occasional visitant to 

 British waters. 



CYCLOSTOMATA. 



PETROMYZONTID^E (Lampreys). Plate 26, Map vi. 



The lowly-organised fishes known as Lampreys are found on the coasts 

 and in the fresh waters of a great part of the globe, but most of the 

 records, perhaps naturally enough, have been made in the Northern Hemis- 

 phere. Three species are recorded as British, namely, the Sea-Lamprey 

 (Petrcmyzon marinus), not uncommon off our coasts ; the Lampern or River- 

 Lamprey (P. Jluviatilis), generally distributed in rivers, and the Pride, 

 Sandpiper, or Small Lamprey (P. branchialis), found throughout the rivers 

 and streams of the British Isles. Geotria is a southern genus, occurring in 

 the rivers of Chili, South Australia and New Zealand ; while Mordacia has 

 an equally interesting distribution, being confined, so far as at present 

 known, to the coasts of Chili and Tasmania. 



BDELLOSTOMATID,E (Hag-Fishes). Plate 26, Map vi. 



The members of this family are confined to the coasts of the Pacific, 

 being recorded principally from California, Chili, Patagonia, Japan and New 

 Zealand ; and the South Atlantic, where they occur at the Cape of Good 

 Hope. In general appearance and habits they resemble the Hag-Fishes of 

 the next family, differing in structure principally in possessing six to fourteen 

 pairs of gill-openings, whereas in the MyxinidaB the six pairs of gill-sacs open 

 to the exterior by a common orifice on each side. 



MYXINID^ (Hag-Fishes). Plate 26, Map vi. 

 The principal character which distinguishes these Hag-Fishes from the 

 Bdellostomatidae has been pointed out in the preceding paragraph. A single 

 genus (Myxine) is here included, with at least half a dozen species. They are 

 widely distributed, but chiefly in temperate seas, and one species, the 

 so-called Glutinous Hag or Borer (M. glutinosa), is abundant on the British 

 coasts. It is eel-like in appearance, and enters the bodies of other fishes, 

 especially cod fishes, to feed upon their flesh. 



