1. MANATUS. 357 



Manatina, Reichb. Syn. Mam. 15. 

 Lea Lamantins, Duver-noy, Tub. Anim. Vert. 

 Trichecus (part), Artedi, Gen. IHsc. 79; Syn. 109. 

 Ilalicoreffi, Brandt, Mini. Acad. PMersb. 1833, 103. 

 Rytineae, Brandt, I. c. 1833, 103. 



Synopsis of tue G-eneea. ^ ,/^ ^ ^vyt 



Grinders distinct. Manatina. ', .J.^t/J--^ 



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



teeth moderate. 



2. Halicore. Tail forked. Grinders |, Hat-tipped ; upper cutting-teeth 



produced, tusk-like. 



Grinders tione. Rytinina. 



3. Rytina. Tail forked. Grinders none. 



a. Grinders distinct. Manatina. 

 1. MANATUS. 



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

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

 ridges. Lips bristly. Back with scattered hairs. Fins with four 

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

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

 bifid at the tip. Cervical vertebra3 6, separate, distant. 



Sirenia deutigera seu Halicorea, Brandt, Sirenohyia, 1847. 

 Manatus, Rondel. Pise. 490; AS'i!o;v, Prudr. 41, 1^80; Cuvier, R. A.; 



Illiyer, Prodr. 140, 1811 ; Rafin. Anal. Nat. Gl, 1815 ; Gray, Cat. 



Cetac. B.3I. 1.39; P.Z.S. 1857,59; 1864,247; Rousseau, May. Zoul. 



1850, 293 ; Schleyel, Abh. 9. 

 Trichechus, sp., Linn. S. N. ed. 6. 39, ed. 10, ed. 12 ; Erxleb. Mam^n. 599. 

 Odobenus (pars), Brisson. 



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

 ? NemodenniLs, Rafin. Anal. Nat. 60, 1815. 

 Oxystomus, G. Fischer, Zuoyn. 19. 

 P Siren, Artedi, Gen. Piscium, 81, from Syi-ene ; Bartholini Hist. Anat. 



Rar. 

 Tricbeclius, 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 Home (PhU. Trans. 1821, 390) 

 describes them as -^ . ^, and CuN-ier as f . |-. 



Dr. Harlan observes : — " Cuvier estimates the teeth at 30, nine 

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

 each side." 



In the very young skull 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 skulls some have eight and 

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



