382 THE ANATOMY OF VEETEBRATED ANIMAIS. 



Like the Rodentia, the Inseotivora have a great diversity 

 of habit; some Galeo^jitheci flitting through the air after the 

 fashion of the flying Squirrels ; some arboreal, as the Tupaym ; 

 some terrestrial and cursorial, like the majority of the order. 

 A few are swimmers ; and some, like the fflole, are the most 

 completely fossorial of Mammals. 



The most aberrant form of the Insectivora is the genus 

 Oaleopithecus, essentially an Insectivore of arboreal and 

 frugivorous habit, with very long and slender limbs. These 

 are connected with one another, with the sides of the neck and 

 body, and with the tail, by a great fold of the integument, 

 which is called patagium ; and, unlike the web of the Bat's 

 wing, is hairy on both sides, and extends between the digits 

 of the pes. By the help of this great parachute-like expan- 

 sion, the G-aleopitheous is enabled to make floating leaps, 

 from tree to tree, through great distances. When at rest, 

 the Galeopitheoi suspend themselves by their fore- and hind- 

 feet, the body and the head hanging downward ; a position 

 which is sometimes assumed by the Marmosets among the 

 Primates. 



The fore-limbs are slightly larger than the hind-limbs. 

 There are four axillary teats. The male has a pendent penis 

 and inguinal scrotal pouches. The pollex and the hallux are 

 short, and capable of considerable movement in adduction and 

 abduction, but they are not opposable ; and their claws are 

 like those of the other digits. 



The occipital foramen is in the posterior face of the skull. 

 The orbit is nearly, but not quite, encircled by bone. The 

 lachrymal foramen is in the orbit. The bony roof of the palate 

 is wide and its posterior margin is thickened. There is a 

 strong curved post-glenoidal process of the squamosal, which 

 unites with the mastoid, beneath the auditory meatus, and 

 restrjcts the movement of the mandible to the vertical plane. 

 A longitudinal section of the skull shows a large olfactory 

 chamber projecting beyond that for the cerebral lobes, and twc 

 longitudinal ridges, upon the inner face of the latter, prove thai 

 ihese lobes must have possessed corresponding sulci. The 

 tentorial plane is nearly vertical and the floccular fossae are 

 very deep. 



The ulna is very slender infe.riorly, where it becomes anchy- 

 losed to the distal end of the radius, which bears the carpus. 

 When the ilia are horizontal, tlie acetabula look a little up- 

 ward and backward as well as outward. The fibula is com- 

 plete. As in the Sloths and most Pn?7iates, the navicular and 



