CETACEA. 



563 



air, and a corresponding modification of the 

 chief organ of locomotion. 



With the lungs are also associated the pre- 

 sence of warm blood, a double circulation, an 

 epiglottis, and a diaphragm, a true viviparous 

 generation, a nourishment of the young by a 

 mammary secretion, and in short all the essen- 

 tial parts of a mammiferous organization. 

 The order is subdivided as follows : 

 Tribe I. PHYTOPHAGA. 



Char. Tee th of different kinds ; molars 

 with flattened crowns, corresponding to 

 the vegetable nature of their food. 

 Mamma, two, pectoral. Lips provided 

 with stiff bristles. External nostrils, 

 always two, situated at the extremity or 

 upper part of the rostrum, which is ob- 

 tuse. 



Genus MANATUS, Cuv. 

 Char. Incisors $ (two superior, deciduous 

 in the foetus, not replaced). Molars f f, 

 grinding surface with tri-tuberculate 

 transverse ridges. Body with a few 

 scattered bristles. Anterior extremities 

 each provided with four nails. Tail-Jin 

 oval. 



Species 1. Manatus Amerlcanus, Cuv. 

 Trichechus Manatus, Linn. : the Ma- 

 natee. Lamantin d'Amerique, Cuv. 

 2. Manatus Africanus, Lamantin du 



Senegal, Cuv. 

 Genus HALICORE, Cuv. 

 Char. Incisors jj. (In the young animal 

 the two superior permanent incisors are 

 preceded by two deciduous ones ; six 

 or eight deciduous incisors in the lower 

 jaw which have no permanent succes- 

 sors). Molars f f ; (in the young ani- 

 mal |); the grinding surface exhibits a 

 rim of enamel at the circumference and 

 a slightly excavated centre of ivory. 

 Body, with a few scattered bristles. 

 Upper lip with bristly mustaches. An- 

 terior extremities without nails. Tail- 

 fin very broad, crescentic. 

 Species 1. Halicore Indicus, Cuv. The 

 Indian Dugong, or, more properly, 

 Duyong. 



2. Halicore Tabernaculi, Ruppel. Du- 

 gong of the Red Sea. 

 Genus RYTINA, Illiger. Incisors none. 

 Molars \ \, large, lamelliform, of a 

 fibrous structure, with the triturating 

 surface roughened by tortuous furrows. 

 Body, without hairs, but covered by a 

 rough and thick fibrous epidermis. An- 

 terior extremities terminated by an un- 

 guiform callosity. Caudal-Jin crescent- 

 shaped, each angle terminated by a 

 horny plate. 



Species. Rytina Stelleri, Le Stellere, Cuv. 

 This species inhabits the seas of Kamt- 

 schatka. It was discovered by the 

 Russian naturalist, Steller, after whom 

 it is named ; and is described by him 

 with much zoological and anatomical 

 detail in the Nova Comment. Petrop. 

 t. ii. p. 294, (1751,) under the name of 

 the Manati or Vacca marina. 



Tribe II. ZOOPHAGA. 



Char. Teeth of one kind or wanting, not 

 adapted for mastication. Mamma, two, 

 pudendal. External nostrils, double 

 or single, situated on the top of the 

 head. 



A. with the head of moderate size. 

 Family DELPHINID^E. Teeth in both 

 jaws, all of simple structure, and gene- 

 rally conical form. No caecum. 

 Genus DELPHINORHYNCHUS. Rostrum 

 very long and narrow, continued not 

 abruptly from the forehead. Teeth very 

 small and numerous. 

 Ex. Delphinorhynchus micropterus. (Fred. 



Cuvier, Cetaces, pi. viii. fig. 1.) 

 Genus DELPHINUS. Rostrum narrow, 

 of moderate length, continued abruptly 

 from the forehead. Teeth conical, 

 slightly recurved, numerous. 

 Ex. Delphinus Delphis, the common Dol- 

 phin; Delphinus Tursio, the Spouter 

 or small Bottle-nose Whale of Hunter. 

 For the other numerous species of this 

 genus consult F. Cuvier, Histoire des 

 Cetaces, p. 147 et seq. 

 Genus INIA. Rostrum, as in the genus 



Delphinus. Teeth mammilliform. 

 Species. Inia Boliviensis; (Fred. Cuvier, 

 Cetaces, pi. x, bis, and xi, cranium); 

 inhabits the great rivers of South Ame- 

 rica. 

 Genus, PUOC^NA. Rostrum short, broad. 



Teeth conical or compressed. 

 Ex. Phocana communis, the common 

 Porpoise ; Phocana orca, the Grampus ; 

 Phocana globiceps, L'Epaulard, Cuv. 

 Phoctena leucas, the Beluga,* &c. 

 The following genera seem to form the types 

 of as many distinct families of Zoophagous 

 Cetaceans. 



Genus MONODON. Rostrum short and 

 broad. No other teeth save two in the 

 upper jaw, in the form of tusks, situated 

 horizontally, and both of which continue 

 in the rudimental condition in the female, 

 while in the male one projects far be- 

 yond the jaws in the line of the axis of 

 the body. 

 Ex. Monodon monoceros, Linn. The 



Narwhal. 



Genus HYPEROODON. Rostrum of mo- 

 derate length, extending abruptly from 

 a very elevated cranium. Two small 

 teeth in the lower jaw; small callous 

 tubercles on the palate. 

 Ex. Hyperoodon Dalei ; the great Bottle- 

 nose Whale of Hunter. 

 Genus PLATANISTA. Rostrum very long 

 and compressed, enlarged at the extre- 

 mity. Teeth numerous; in both jaws 

 conical and recurved. Cranium enlar- 

 ged by osseous processes. A ccecum. 

 Ex. Plutanista Gangetica. The Gangetic 

 Dolphin. 



* This species has no dorsal fin, and on that ac- 

 count has by some naturalists been regarded as 

 forming the type of a distinct genus, under the 

 name of Delphituipterus. 



