76 



GENERAL BIOLOGY 



or epicoracoid, and a clavicle ( ) fused together. 



At the meeting of coracoid and scapula there is a little smooth cavity 

 where the fore arm joins the- girdle called the glenoid fossa ( ). 



Where coracoid and clavicle meet at the mid line on the ventral side 

 of the body, there are four bones. These four actually are a part of the 

 axial skeleton, but are usually classified as a part of the appendicular 

 as well. The most anterior one of the bones is called the episternum, 

 the one between this and the clavicle is the omosternum, while the pos- 

 terior one closest to the omosternum is the mesosternum, and the one 

 projecting farthest backward is the xiphisternum. 



The fore limbs are made up of a long bone, the humerus ( ) , 



joining the pectoral girdle in the glenoid fossa at its proximal end 

 ( ) and with the radio^ulna at the distal end 



( ). This latter bone constitutes the skeleton of 



the fore arm and in reality consists of two bones, the radius and the ulna, 

 fused together. 



Fig. 22. The Pelvic Girdle and Leg. 



A. Pelvic girdle complete. 



B. One side of pelvic girdle : II., ilium ; Isch., ischium ; Pu., cartilaginous 

 pubis ; Ac., acetabulum. 



C. Femur of the frog: p., proximal; d., distal articulating surfaces; s., shaft. ^ 



D. Tibio-fibula, seen from below : p., proximal ; d., distal articulating sur- 

 faces ; t., tibial half of the bone separated by a groove from /., the fibular half. 



E. The right ankle and foot of the frog, seen from below: This figure is 

 drawn to a larger scale than A and B. a., astragalus ; c., calcaneum ; / V., the 

 five principal digits; X., the minute accessory digit. (From Bourne after Ecker.) 



The wrist possesses six bones, the ulnare ( ), 



radiale, ( ), intermedium, and three carpals 



The hand has five proximal metacarpal ( ) 



bones, followed in digits ( ) II and III by two 



phalanges ( ), and in digits IV and V by three 

 phalanges. 



The pollex ( ) or thumb is rudimentary. 



The pelvic ( ) or hip girdle (Fig. 22) supports 

 the hind limbs, and consists of two sets of three parts each, the ischium 



