272 



same as the corresponding parts of the fore -limb. The joint between 

 the cannon-bone and pastern of each limb has small sesamoids be- 

 hind, and is covered by a horny growth which bears a tuft of hair ; 

 this is the fetlock. 



See Classification, page 264. 



NOTE. For Orders Sirenia and Rodentia, seeClassification, page 264. 



Order Cheiroptera (Bats). 

 Mention some of the Special Features of the Cheiroptera (Bals). 



The fore -limbs are modified as wings. The wing is an extension 

 of the skin (the patagium) stretching from the shoulder to the base 

 of the thumb and between the elongated digits of the hand, and 

 continued between the limbs and to the tail (when present). The 

 bones of the fore -limbs are very long; the ulna is rudimentary, 

 there are six carpals and five digits, four of which have long meta- 

 carpals bearing two long phalanges. The short thumb and the 

 (5) digits of each foot have claws. The hind -limbs are turned out- 

 wards, consequently the knees are directed backwards ; the pubes 

 show a corresponding inclination outwards, and do not generally 

 form a ventral symphysis. The clavicles are long. The retina of 

 the eye is poorly developed ; the sense of touch is superlative. 

 Nocturnal, and almost cosmopolitan in distribution. 



See Classification, page 264. 



Order Primates. 



State the Chief Characteristic Features of the Primates. 



Mainly arboreal; and mostly gregarious and uniparous. Planti- 

 grade. Limbs free from body and long. Hands and feet usually 

 have five digits, and are more or less prehensile ; the thumb, or the 

 great toe, or both, being opposable to the other digits. All or some 

 of the nails are flat. Orbits directed forwards, and (except Lemurs) 

 completely shut off from temporal fossa (by ingrowth of frontal 

 and jugal to meet alisphenoid). Clavicles always well developed. 

 Brain large, and generally well convoluted. Testes in a scrotum ; 

 penis pendent. Two breast mammae (certain Lemurs have addi- 

 tional teats on abdomen). Placenta deciduate (except most Lemurs). 

 Sub-tropical and tropical distribution. 



Mention the Features which distinguish the Lemuroidea (Lemurs) 



from the Anthropoidea. Where are Lemurs found. ' 

 Small furry creatures, somewhat like monkeys, but with fox-like 

 faces. Arboreal and mostly nocturnal. Orbit is only encircled by 

 a bony rim (except Tarsius, in which the orbit is almost entirely 

 shut off from the temporal fossa). ^Lachrymal foramen is outside 

 the orbit. Upper incisors separated in middle; line (except Tarxiii*}. 

 Second digit of foot has a claw, the others generally have flat nails. 



