630 CLASS XVII. 



Sc. de St. Petersb. vi. Se"rie, Tome n. 1833, s. 103 118, Tab. I. et Symbolce 

 sirenologicce, ib. Tome v. 1846, pp. i 160, Tab. I v. A remarkable 

 anomaly, but upon which no light can now be thrown, is the absence noticed 

 by STELLEB of fingers in the pectoral fins. 



Halicore ILLIG. Two large upper incisors in adults, lower none ; 



5 5 



canine teeth none, molars -= or fewer, with flat crown. Pectoral 



o o 



fins destitute of claws. Caudal fin lunate. 



Sp. Halicore cetacea ILLIG., WAGN., Halicore indica DESMAB., Halicore 

 Dugong QUOY et GAIM., HOME Lect. on comp. Anat. iv. PI. 52, F. Cuv. 

 Cetac. PL 4, SCHBEB. Sdugth. Tab. 382, GUB. Iconogr., Mammif., 

 PL 46, fig. 2. This animal, named Dugong or Dujong by the Malays, 

 occurs in the Indian Ocean and also in the Red Sea, from whence 

 RUEPPELL has given a careful description of it, Mus. Senckerib. I. 1834, PP- 

 95 114, Tab. VI. This species becomes from 8' to 10' long (it has been 

 stated at even 20'). The long upper incisors are for the most part (in the 

 female entirely) concealed in the jaw. From these teeth the intermaxillary 

 bones are uncommonly large, and the head has the appearance of being 

 swollen forwards. Other smaller incisors in both upper and lower jaws 

 may be observed in young individuals, but afterwards disappear. The 

 surface of the mouth is covered in front with a hard integument, which 

 corresponds to the horny plates of Rkytina. Compare on this animal and 

 its anatomy, besides the memoir of RUEPPELL, BUFF. Hist, natur. xin. 

 PL 56 (skull), P. CAMPEB (Euvres, n. pp. 477 491, PL vn. figs. 2, 3, 

 QUOY et GAIMABD Voy. de I' Astrolabe, Zool. pp. 143 148, PL 27, OWEN 

 Proceed, of the Zool. Soc. 1838, pp. 28 45, BISCHOFF in MUELLEB'S Archiv, 

 1847, s. i 6, Tab. I. (tongue-bone and larynx). 



Manatus Cuv. (Manati BoDD.). Two small upper incisors, 



D O 



acute, in young age, in adults none ; canines none ; molars 7 ^ ; 



o o 



with crown square, divided by a transverse groove. Pectoral fins 

 furnished sometimes with flat, marginal nails, with thumb always 

 unarmed. Caudal fin oblong and rounded. 



The lamantin or sea-cow. The intermaxillary bones, with their much 

 smaller incisors, which disappear in old individuals, are less developed than 

 in the preceding genus. In the under jaw also of young individuals traces 

 of small incisors are seen, of which however the number is not fixed. Here 

 also the anterior part of the cavity of the mouth is covered in both jaws 

 with a hard and grooved integument. 



It is now generally supposed that three species of this genus may be 

 adopted, of which two are from the coasts of America, Manatus australis 

 WIEGM. from Brasil, and Manatus latirostris HABLAN, from the coast of 

 Florida, the West Indies and Surinam. LINNAEUS comprised both these 

 species under the name of Trickechus Manatus. To Manatus latirostris 

 belongs the figure of HOME Phil. Trans. 1822, Tab. 26, 27, Lectures, iv. 

 PL 52, and the interesting anatomical description of W. VKOLIK Bij- 

 dragen tot de DierTcunde, published by the genootschap- te Amsterdam, 4<te 



