LEMUROIDEA. 



721 



one offspring at a time. The mammae are thoracic, gener- 

 ally post-axillary. As in Insectivora and Rodents, the yolk 

 sac forms a provisional placenta, and the allantoic placenta 

 is discoidal and deciduate. 



Fossil Chiroptera occur in Upper Eocene strata, but are 

 quite like the modern forms. 



The two sub-orders of bats may be contrasted as follows : 



MEGACHIROPTERA. 



Frugivorous bats, usually large. 



The molars have smooth crowns, with a 

 longitudinal groove. 



The thumb is clawed, and generally also 

 the second digit. 



The tail, if present, is below, not bound up 

 with the interfemoral membrane. 



The pylortc part of the stomach is in most 

 cases much elongated. 



Found in warm and tropical parts of the 

 Eastern hemisphere. 



Examples : 



The " flying-foxes " or fox-bats (Ptero- 

 pus), large, tailless bats, distributed from 

 Madagascar to India, Ceylon, Malaya, 

 S. Japan, Australia, Polynesia. The lar- 

 gest species (P. edulis) measures five feet 

 across its spread wings. Dentition, f yff . 



In India, Cynopterus marginatus is 

 very common. Xantharpyia tegyptiaca 

 inhabits the Pyramids. 



MlCROCHIROPTERA. 



Usually insectivorous bats, small in size. 



The molars have cusped crowns, with 

 transverse grooves. 



In the hand the thumb only is clawed. 



The tail, if present, is bound up with the 

 interfemoral membrane, or lies along its 

 upper surface. 



Except in one family the stomach is 

 simple. 



Found in the tropical and temperate 

 regions of both hemispheres. 



Examples : 



The horse-shoe bats (Rhinolophus), the 

 common pipistrelle {Vesptrugo pipistrel- 

 tus), the genus Vespertilio with four 

 British species, Vampyrus spectrum, a 

 large Brazilian form, which seems to have 

 been erroneously credited with blood- 

 sucking habits, the common vampire 

 (Desmodus rufus) an American bat a 

 formidable blood-sucker. 



Order 9. LEMUROIDEA. Lemurs. 



Opinions differ as to whether the monkey-like animals 

 known as Lemurs should be ranked with monkeys as a sub- 

 order of Primates or referred to a separate order. They 

 differ from monkeys and men (Anthropoidea) in the follow- 

 ing points : The orbit opens freely into the temporal fossa 

 (except in Tarsius) ; the lachrymal foramen lies outside the 

 orbit ; the first pair of upper incisors is separated in the 

 middle line (except in Chiromys] the cerebral hemispheres 

 are but slightly convoluted and do not completely overlap 



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