206 MISS JOAN B. PROCTER ON THE VARIATION 



in M. major. In this species the praecoracoids are reduced, and 

 do not meet each other in the middle ; the scapula is, therefore, 

 longer than the praecoracoid, but not longer than its distance 

 from the edge of the epicoracoidal cartilage. 



M. montana Kuhl. — Form of scapula as in M. major, but 

 slightly larger than the praecoracoid, which is normal in length. 



M. longipes Blgr. —Scapula as in M. major. 



M. feet Blgr. — Form of scapula similar to that of M. major, 

 with the exception of the distal end of the shaft, the lower corner 

 of which is somewhat produced, making the lower border of the 

 scapula once and a quarter the length of the upper border ; 

 lower border of scapula describing an inverted semicircular 

 curve, f~\. Pars acromialis with a semicircular upper edge. 



Although there is specific differentiation within this complex 

 genus, the form of the scapula is highly characteristic. The 

 equal development of the shaft, the pars acromialis, and pars 

 glenoidalis, together with the oval central foramen, pierced 

 horizontally, and the highly developed crest of the pars acromialis, 

 are characters common to all the species. 



Hylid^e. 



In this family the scapula is usually normal in its proportions, 

 and about equal in length to the jDraecoracoid. In some instances, 

 however, it is greatly reduced in length, especially the shaft. 

 The cleft between the pars acromialis and pars glenoidalis is 

 always broad and open, pierced vertically, and visible from with- 

 out and within as a large oval foramen in the middle of the glenoid 

 cavity. The pars glenoidalis is reduced in size, and always 

 shorter than the pars acromialis, part of it presumably giving 

 place to the central foramen. 



Hyla Laur. 



H. maxima Laur. — Scapula normal in its proportions, equal in 

 length to the praecoracoid, and having all the family charac- 

 teristics already described. Shaft once and a quarter as 

 long as broad at distal end ; pars glenoidalis separated from 

 coracoid by cartilage ; superficial articulation and fovea aceta- 

 bulum very distinct. 



Example. 



Length of praecoracoid 10 units. 



,, scapula (upper border) 10 ,, 



„ „ shaft 9-1 „ 



Breadth of ,, (distal end) 6'4 „ 



J (middle) 2-7 „ 



,, pars acromialis 1 "8 ,, 



„ pars glenoidalis 1*8 ,, 



Length of pars acromialis, 2 - 7 ,, 



,, pars glenoidalis 1'8 „ 



<,, supva-scapula 11 '4 ,, 



