138 Mammalia. 



and Cebus Apella (Sajous, Grat.). The third group embraces, Callith- 

 rix, iNyctipithecus, Pithecia (Sagouins, Aotes, Sakis, Grat.). The 

 fourth, the Hapalidse, Hapale (Edipus, and Hapale Jacchus (Pinches 

 and Ouistitis, Grat.). 



The importance of such characters as the slanting direction of the 

 ascending convolutions of the Parietal lobe, the elevation or depres- 

 sion of the Fissure of the Hippocampi, the height to which the 

 summit of the Curved convolution rises, and others of a similar kind 

 put forward in the table, depends on their being indications of the 

 greater or lesser development of certain parts of the Brain ; thus, the 

 convolutions of the Parietal lobe slant when they are pressed back- 

 wards by the increasing size of the Frontal lobe : the Hippocampal 

 Fissure rises high in the connection with the greater development of 

 the Occipital lobe, or is depressed by increase in the lobes placed 

 anteriorly to it : the Curved convolution is beaten down by the 

 development of the superior Bridging convolutions. 



The following is Gratiolet's Classification according to Cerebral 

 Characters : 



1. Homo. 



/ Simia Satyrus (Orang-Outang, Grat.) 

 2 \ Hylobates (Gibbons, Grat.) 



j Semnopitheci (Semnopitheques, Grat.) 



\ Cercopitbeci (Guenons, Grat.) 

 2 { Siruia Troglodytes (Cliimpanze, Grat.) \ Catarrhini (Pith^qiies, Grat.). 



( Macaci (Yrais Macaques, Grat.) [ 



! Gorilla (Gorille, Grat.) 

 Cynocephali (Baboiiins, Grat.) 

 Macacus Ehesus (Macaques U queue courte, 

 Grat.) 

 [ Mycetes (Hurleurs, Grat.) 

 6 I Ateles (Ateles, Grat.) 



( Lagothrix (Lagotriches, Grat.) 

 g ( Cebus Capucinus (Sai, Grat.) 

 ( Cebus Apella (Sajou, Grat.) 



iCallithrix (Sagouins, Grat) [ Platyrrhini (Cebes, Grat.). 



Nyctipithectis (Aotes, Grat.) 

 Pithecia (Sakis, Grat.) 

 J. ( Hapale ffidipus (Pinches, Grat.) 

 \ Hapale Jacchus (Ouistitis, Grat.) 



