1. MANAiirs. 357 



Manatina, Seichb. Syn. Mam. 15. 

 Les Lamantins, JDuvemoy, Tab. Anim. Vert. 

 Trichecus (part), Artedi, Gen. Pise. 79; Sun. 109. 

 HalicoreaB, Brandt, Mem. Acad. PStersb. 1833, 103. 

 Bytmese, Srandt, I c. 1833, 108. 



Synopsis op the Q-eneea. 

 Grinders distinct. Manatina. 



1. Manatus. Tail rounded. Grinders f or f , tubercular ; upper cutting- 



teeth moderate. 



2. Halicobe. Tail forked. Grinders f, flat-tipped ; upper cutting-teeth 



produced, tusk-like. 



Grinders none. Rytinina. 



3. Rytina. Tail forked. Grinders none. 



a. Crrinders distinct. Manatina. 

 1. MANATUS. 



Cutting-teeth 2, very small, rudimentary, early deciduous. Canine 

 none. Grinders | . ^, with two or three transverse three-tubercled 

 ridges. lips bristly. Back with scattered hairs. Pins with four 

 rudimentary hoof-like nails. Toes supported with phalanges. Tail 

 rounded or truncated at the end. Pelvic bones deficient (?). Csecum 

 bifid at the tip. Cervical vertebrae 6, separate, distant. 



Sirenia dentigera seu Halicorea, Brandt, Sirenohgia, 1847. 

 Manatus, Rmdel. Pise. 490; Starr, Prodr. 41, 1780; Cuvier, R. A. ; 



HUger, Prodr. 140, \Sll ; Rafin. Anal. Nat. 61, 1815; Gray, Cat. 



Cetac. B.M.\9Q; P.Z.S.1%67,6&; 1864, 247 ; Rcmsseau, Mag. Zool. 



1856, 293 ; Schlegel, Abh. 9. 

 Trichechus, sp., lann. S. N. ed. 6. 39, ed. 10, ed. 12 ; Erxkb. Mamm. 599. 

 Odobenus (pars), Brisson. 



Trichecus manatus, Ohen, Lehrb. Nat. 687, 1815. 

 ? NemodermuB, Bafln. Anal. Nat. 60, 1815. 

 Oxystomus, G. Fischer, Zoogn. 19. 

 ? Siren, Artedi, Gen. Piscium, 81, from Syrene ; Bartholini Hist. Anat. 



Bar. 

 Trichechus, Artedi. 



The number of grinders varies according to the age or state of the 

 specimens. When complete they are |-.f ; but the three front on 

 each side are often deciduous ; hence flome (Phil. Trans. 1821, 390) 

 describes them as |- . |-, and Cuvier as f . f . 



Dr. Harlan observes : — " Cuvier estimates the teeth at 36, nine 

 on each side ; in both my specimens they do not exceed 32, eight on 

 each side." 



In the very young skuU in the British Museum, which has holes 

 for the rudimentary upper cutting or canine teeth, there are only 24, 

 viz. six on each side; and the two hinder on each side must have 

 been hidden in the gums. In the older skuUs some have eight and 

 others nine on each side ; but in most of them only six on each side 



