550 ZOOLOGY sect. 



connected by a ligamentous band with the scapula. Its mode of 

 formation from a mass of cartilage — to the anterior face of which 

 the clavicle, formed as usual in membrane, becomes applied — 

 proves that this bone represents a procoracoid as well as a 

 clavicle. In other Insectivora this bone is not developed, and the 

 clavicle is a distinct, long and slender bone, but vestiges of the 

 inner or ventral ends of the coracoid and procoracoid may be 

 recognisable. Sometimes there is a distinct bone intervening 

 between the outer end of the clavicle proper and the acromion 

 process. 



The humerus usually has a supracondylar foramen. In the 

 Moles this is absent, and their humerus is remarkable in other 

 respects, being short, greatly expanded at the extremities, with a 

 prominent deltoid ridge, and with two synovial articular surfaces 

 at the proximal end, one for the glenoid cavity of the scapula, 

 the other for the coraco-clavicle. The radius and ulna are 

 completely developed in all, and are usually distinct, but some- 

 times fused distally. In the carpus the scaphoid and lunar 

 sometimes coalesce, sometimes remain distinct ; an os centrale is 

 usually present. In the Moles the manus is extremely broad, 

 the breadth being increased by the presence of a large, curved, 

 radial sesamoid. 



In the pelvis the symphysis pubis is in some cases elongated, 

 in others short, and sometimes absent, the pubes remaining 

 separated by a wide median ventral cleft. A third trochanter is 

 sometimes represented by a ridge. The fibula usually, though 

 not always, fuses distally with the tibia. 



Skeleton of the Chiroptera (Fig. 1174). — The cervical region 

 of the vertebral column is characterised by the absence of any 

 distinct neural spines, and the same holds good to a less extent of 

 the trunk-vertebrse ; the transverse processes of the lumbar region 

 are also rudimentary. The tail varies in development : when it 

 is elongated the component vertebras are long, cylindrical centra 

 without processes. Sagittal and occipital crests are developed in 

 the skull £)f some species. The facial region is rather elongated, 

 especially in the Megachiroptera (Fig. 1175). Post-orbital pro- 

 cesses of the frontal are present or absent : the zygoma is long and 

 slender : the malar is small and applied to the outer surface of 

 the zygoma. The long and narrow nasals are in some cases 

 united ; the premaxillse are small. The mandible has an angular 

 process in the Microchiroptera, not in the Megachiroptera. The 

 segments of the sternum are sometimes distinct, sometimes united : 

 the presternum has a mesial keel developed in co-ordination with 

 the great size of the pectoral muscles. The sternal ribs are 

 ossified. 



The scapula is large and oval in shape : the spine is near the 

 anterior margin : the post-scapular fossa has ridges for the origin 



