Delphinid.e.- 



-MAMMALIA.- 



-MANATID-3E. 



•205 



tingiiished from the common dolphin chiefly by the 

 projection of the lower jaw beyond the upper. There 

 is some reason to believe that the dolphin {D. trunca- 

 ius) described by Mr. G. Montague m the third volume 

 of die Wernerian Society's Transactions, is referable to 

 this species. This specimen was captured off Totness 

 ui Devonshire, in the summer of 1814. After the 

 animal had been exhibited, tlie bones were regarded 

 as rejectamenta, and thro\\-n mto the river Dart. 

 Mr. James Cornish, however, subsequently succeeded 

 in recovering Uie skull, tlie length of which was twenty 

 inches and a half. "On each side of the upper jaw," 

 says Mr. Montague, " there are sockets for twenty 

 teeth, besides a long depression behind the posterior 

 socket." The under jaw was somewhat longer, and 

 contained twenty-three sockets on either side. Such 

 of the teeth as were discovered were for the most part 

 worn and flat on their crowns. The others, it seems, 

 were knocked out, and fi-eely distributed amongst tire 

 cm-iosity-loving people of Totness ! 



SOWEKBY'S DOLPHIN {Diodon Sowerbcci), of which 

 only a single example has yet appeared, is character- 

 ized chiefly by the possession of a single pair of teeth, 

 occup}'iug the lower jaw. It was cast ashore near 

 Brodie House, Elginshire, and is thus described by 

 Mr. Sowerby, in the first volume of his well-known 

 " British Miscellany": — "The animal is oblong; black 

 above, nearly wliite below; sixteen feet long, eleven 

 m circumference at the thickest part, with one fin on 

 the back; head acummated; lower jaw blunt, longer 

 than the upper, with two short lateral bony teeth; 

 upper jaw sharp, let mto the lower one by two lateral 

 impressions corresponding with the teeth ; opening of 

 the mouth, one foot six inches. Under the throat are 

 found two diverging fun'ows, terminatmg below the 

 eyes, which are smaU, and placed si.x inches behind 

 the mouth. Spiracles hmate, the ends pointing for- 

 wards." The specimen was a male. 



Amongst the many other numerous and interestmg 

 members of the present family known to exist, we can 

 only particularize the following : — 



PERON'S DOLPHIN {Delphinapterus Peronii), Eight- 

 whale Porpoise, or white-beaked Dolphln. This 

 species is foimd on the southern side of the equator, off 

 and between the opposite coasts of Africa and Brazil. 

 It is gi-egarious hi its habits, and readily distinguishei.l 

 by the lustrous white beak, abdomen, and pectoral 

 fins, tlie other parts being quite black. The head is 

 pointed and slightly convex, ; the jaws, in different 

 examples, are furnished with from thirty - eight to 

 forty-two on each side, above and below. 



THE INIA {Inia Geofroijii), or BOLIVIAK Dolphin, 

 is a very singular animal, ha\Tng the breathing aper- 

 ture placed far backward on a hue with tlie pectoral 

 fins. The dorsal fin is small. The Ups are deeply 

 cleft to beneath the eye ; the auditory meatus being 

 likemse unusually large. Mr. Blyth observes that the 

 species is also remarkable as " occurrmg thousands of 

 miles from the sea, appearing to inhabit only the 

 remote tributaries of the Amazon, and the elevated 

 lakes of Peru. The singular character of possessing 

 bristly hairs on the snout has also been observed in 

 them when very young. This species has large swim- 



mhig paws, and thirty-four teeth on each side, above 

 and below, all of them rough, marked with deep and 

 interrupted furrows, and of an u-regular, mammfllary 

 shape behind, which is very peculiar. A female speci- 

 men measm-ed seven feet long, and the males are 

 stated to be double that size ; colour variable, com- 

 monly pale blue above, passing into a roseate hue 

 beneath. It comes more frequently to the surface than 

 the marine species, and is generally met with in troops 

 of three or fom' individuals." 



THE SOU-SOir {Platankta Gangctica) or Dolphin 

 of the Ganges, is another cetacean of considerable 

 hiterest, frequenting the mouths, and ascending some- 

 times high up tlie rivers. It is readily distinguished 

 by its elongated and lateraUy compressed snout, swollen 

 at the extremity from enlargement of the jaws, which 

 latter support in front numerous long, conical tcetli ; 

 there being thirty of these organs on each side, above 

 and below. The breatliing opening has tlie form of a 

 longitudinal fissure, whilst the upper borders of the 

 maxillary bones are prolonged upwards in a singular 

 manner. The eyes are very small, and at first sight 

 scarcely discernible. The pectoral flippers are sub- 

 triangular, the dorsal fin being placed far back. The 

 Sou- Sou attains a length of seven feet. It was origi- 

 nally described by Pliny, under the generic title here 

 employed. 



Fajiily IV.— MANATID^. 



It is a matter of opuiion whether it be more coiTect 

 to associate this famUy wth the present order, or with 

 tlie PachydeiTnata ; for whilst its members appear, 

 by external characters and habits, more intimately 

 allied with the Cetacea, their internal structm'e, on 

 the other hand, plainly demonstrates a close alUance 

 with the latter group. Some have suggested, not 

 without reason, tliat they might almost be treated as a 

 separate order ; but, all things considered, it is perhaps 

 better, and certainly more convenient, to adopt our 

 present allocation. AU the members of this family 

 are vegetable feeders, and, in consequence, most com- 

 monly styled Herbivorous or Phjlophagous cetacea. 

 In conformity with their algous diet, we tuid the teeth 

 modified so as to secm'e due mastication of the coarst 

 fuel, the molars, when present, being more or less 

 flattened on the croT\ni. The intestinal canal attains a 

 prodigious length, and in the Rj'tma is said to measm'e 

 upwards of twenty times the enthe length of the animal. 

 The stomach is constricted near the centre, and more 

 or less complicated by coeoa and folKcIes in the difler- 

 ent species. The skin is rather hairy, and tlie face 

 furnished with bristle-Uke whiskers ; but the tail is 

 flattened out transversely as in ordinary cetaceans — a 

 circumstance veiy strongly insisted on by those who, 

 with ourselves, prefer to retain these animals in the 

 present order. The Kmbs or paddles are furnished 

 with claws ; but there is no trace of posterior extremi- 

 ties. The nostrils are quite separate, placed in front 

 of the abrupt snout, opening near the upper lip. 

 The front of the jaws is covered with horny plates. 

 The mamniM are two in number, and situated below 

 the thorax ; and there are from fifteen to nineteen pairs 



