PTEEOPODIDiE. 17 



sternum greatly developed, the manubrium or anterior portion being 

 much extended laterally to afford a strong attachment for the clavicles 

 which are always present and very robust. The ulna is almost rudimen- 

 tary and firmly joined to the radius, and the forearm is quite incapable of 

 any rotation. The metacarpal bones are greatly elongated. The pelvis 

 is straight and long, and the coccygeal bones are lengthened in some to 

 support the membrane, and assist them in turning rapidly. The organ 

 of hearing is greatly developed in the insectivorous species, especially the 

 tragus. The foliaceous appendages to the organs of smell in some 

 {Rhmolophince) may be perhaps intended to give increased power and 

 delicacy to this organ. Their wings form an enormously expanded organ 

 of touch, by means of which they can direct their flight even when their 

 eyes are extirpated, and their hearing blunted, as was proved by some 

 experiments by Spallanzani. 



Bats do not possess a ccecmn. The penis is pendulous and has a small 

 bone in it. The testes only descend during the breeding season. The 

 uterus has two short horns. The supposed additional inguinal teats of 

 the Rhifiolophi are probably only cutaneous glands. The females of many 

 bats have nursing pouches. Many become periodically torpid, hybemating 

 in cold countries. 



The hairs of bats generally appear under the microscope as serrated and 

 jointed, in some almost annulated, mostly so at the tip. Many are infested 

 by insects of the genus Nycteribia. Bats are found throughout the whole 

 world. They are divided into the families Pteropodidcs, Vampyridee, Noc- 

 tilionidcB and Vesper tilionidce. 



Fam. Pteeopodid^. 

 Frugivoeous Bats. 



Molars with the crown flat with a median longitudinal groove. Ears 

 small without a tragus. Index with three phalanges, generally unguicu- 

 late. Tail very short, or none. Interfemoral membrane small, deeply ex- 

 cised posteriorly. Face lengthened. Gape moderate. 



The frugivorous bats, differing so much in their dentition from the 

 insectivorous species, seem to lead through the flying Lemurs directly 

 to the Quadrumana. They comprise the largest species in the order, 

 and are chiefly found in the tropical regions of the East, being very nu- 

 merous in the Malayan islands as far as Australia. Their molars have 

 rounded eminences ; the stomach is complex, long and twisted on itself, 



