TEHTIAJiY VEliTEliKATA OF THE FAYtEM. 
(frontal) |)ortion (/'/.) and a lateral (tcni])oral) ])roininence {f.l.) by a •\vell-niarkcd 
(loi)ression, Avliicli seems to be liomolooons with the “ ])se\i(losylvian ” * depression (^>.) 
in the brains of recent Sirenians and Proboscidea. 'J'lie cerebellum {eb.) is small, but 
its limits are not w('ll sbown in the cast. d'lie base of the brain also is not \\ell 
preser\ ed, only the roots of one i)air of nerves, ])robably the fifth, being sbown. 
Text -fig. fio. 
A. ti 
Cast of the cranial cavity of Eosiren Jihijat : A, fi-oiii above ; B, from riglit side. 
ch., cerebellum ; f.l., frontal lobes ; ol., olfactory lobes ; ji., pseudosyh ian depression ; 1.1., temporal lobes. 
“ nat. size. 
In Entherium the general form of the brain is not unlike that figured, but tin' 
pscudosylvian depression is very slightly marked, so that the se])aration of the hemi- 
spheres into anterior and lateral lob(‘S is obscure. 'J he chief interest of the brain of 
Eosire'n lies in its remarkable similarity with that of JUo'i-itheriuni (if. text-fig. 41, 
p. 1 00). In both animals the hcmis])heres are dividc'd in a, (piite similar way by the 
pseudosjlvian depression, and the cerebellum is redativedy small. In Afwrit/icriuni, as 
* Elliot Smitb, ‘Catalogue of the Physiological Series, Mii.scum, C(dl. Surgeons,’ vol. ii. cd. 2 (IbOip 
p. 34 t. 
