192 ANATOMY OF VERTEBRATES. 



palatal furrows on its dorsum and of the grinding teeth on its 

 sides : the free apex is short and usually obtuse, seldom if ever 

 protruded beyond the scalpriform incisors. In the coipu (Myo- 

 potamus) it is acuminate and covered with small retroverted shining 

 velvety papilla? ; the free part is three quarters of an inch in 

 extent : the basal portion of the dorsum is less abruptly elevated 

 than usual : it has but two fossulate papillae, as in the capybara 

 and LeporidcB. The squirrels and most other Eodents have three 

 fossulate papillae forming a triangle, but in marmots they range 

 almost in a line. In Capromys the apex is rounded, free for half 

 an inch, and impressed by small follicular apertures : the conical 

 papillae are minute, but near the base become larger and retro- 

 verted: here numerous delicate lines converge toward the epi- 

 glottis : the intermolar part of the dorsum is* less elevated. 

 The Agoutis (Dasyprocta) differ from the Cavies, Beavers, and 

 Hares, in the gradual elevation of the intermolar part of the 

 dorsum: the apex is subacuminate, minutely papillose above, 

 with a middle longitudinal furrow: at the root are many elon- 

 gated processes covered by a thickish epithelium. In the beaver 

 the membrane on the sides of the tongue descends a very little 

 way, and is reflected upon the inside of the cheeks, in advance of 

 the molar teeth. In the porcupine (Hystrix) one sees a series of 

 scale-like or wedge-shaped processes, with the free margin divided 

 into two or three points, on each side of the tongue. 



In Insectivora the tongue offers little worthy of notice : most have 

 three basal fossulate papillae, in triangle with retroverted apex. 

 Tupaia shows a long fraenum continued to near the apex, and 

 having, on either side, a thickish fimbriate fold. In Vesper tilio 

 murinus, among the Bats, the papillae at the fore part of the tongue 

 have a firm epithelium ; some soft obtuse fungiform papillae show 

 a serial arrangement: two fossulate papillae are near the base. 

 In Phyllonycteris Poeyi the papillae are retroverted and espe- 

 cially long and setose on the edges of the tip ; which is narrowed 

 and canaliculate. In Artibeus the fore part of the tongue is 

 roughened by very short papillae ; those behind are larger. In 

 Monophyllus the apical papillae are so long as to give a pennicellate 

 character to the tip of the tongue, but this relates rather to its 

 prehensile function, as in probing night-blowing flowers for 

 minute insects. The same brush-like character is observable in 

 the conical papillae of many other Bats : in the Vampires (Des- 

 modus) such modification is subservient to suction. In some 

 kinds of Pteropus the conical papillae have a hard epithelium 

 and terminate in many points : the fossulate papillae at the base 

 are three in number in this genus. 



