INTRODUCTION. XV 



In the genus Tricenaps alone a very peculiar short bony process 

 projects from the outer side of the proximal extremity of the ter- 

 minal phalanx of the fourth finger. (See p. 124, and plate in Journ. 

 Asiat. Soc. Bengal, referred to in footnote ahove.) 



As might be expected from their aerial mode of locomotion, the 

 pelvic girdle of Chiroptera is very weak. The iliac bones are long 

 and narrow. In most species the pubic bones of opposite sides are 

 very loosely united in front in males, in females they are widely 

 separated ; in the Bhinolojahidce alone do these bones form a sym- 

 physis. The eminentm ileo-pectinea develops in all species a long pec- 

 tineal process ; in the subfamily PTiyUorhinince alone this process is 

 united with a similar one proceeding backwards from the anterior 

 extremity of the Uium, bridging the space between, and forming a 

 large preaeetabular foramen, larger than the obturator foramen 

 which is placed posterior and slightly inferior to it. (See plate vi. 

 figs. 7, 8, 14, in Journ. Asiat. Soc. Bengal, referred to above.) This 

 form of the pelvis (first described and figured by the writer) appears 

 to be unique among mammals, and occurs in no other known species 

 of Bats. 



The acetabulum is small and directed outwards and slightly up- 

 wards,and with this is related the peculiar position of the leg, which 

 is rotated outwards and upwards, so that when the animal is rest- 

 ing on the ground the knee is directed upwards as in a grasshopper. 

 In striking contrast with the great development of the anterior ex- 

 tremities, the posterior limbs are small and generally weak, the com- 

 bined length of the femur, tibia, and foot rarely equalling that of 

 the forearm alone. The femur is, like the humerus, slender and 

 cylindrical, with a small head and very short neck ; the trochanters 

 are prominent and nearly equal in size ; its form differs very slightly 

 throughout the species. The bones of the leg and foot are more 

 variable. In the subfamily Molossince alone, in which the legs are 

 short and strong, is there a well-developed fibula. In all other 

 species this bone is either very slender or cartilaginous and liga- 

 mentous in its upper third, or reduced to a small bony process 

 above the heel, as in Megaderma, or altogether absent, as in 

 Nycteris. 



The foot consists of a very short tarsus, and of long, slender, 

 laterally compressed toes, with much-curved claws ; the os cahis 

 terminates (in nearly all the species) in a long cartilaginous process, 

 the calcaneuni, which acts as a support to the posterior margin of 

 the interfemoral membrane, and is most developed in those species 



