SHOULDER-GIRDLE 



^5 



and the median syniphysial bar of cartilage is lost; tliis is the 

 case in Ifeinisus. 



The scapula is always large and curved into transverse, 

 dorsally broadening blades, the dorsal greater portion nl' wliich, 

 the so-called supra-scapula, does not ossify but calcifies. 



It is very doulitful if the Anura, ])ossess a tiiie sternum, if 

 by sternum we understand a medio -ventral apparatus which 

 owes its origin to the ventral portions of ril)s. The so-called 



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Fic. 5. — Ventral views of the slioulder-ginlles of various Aiiiira. (.Sliiihtly enlarged.) 1. 

 liomhinator ic/neiis, and 2, Bu/o rulriaris, as examples of the arciferous type ; 3, 

 adult, 4, metamorphosing Rama temporaria, showing change from the arciferous 

 into the tirmisternal type ; 5, Hemisrcs guttatum ; 6, llreciceps gibbosus ; 7, Cacopus 

 systoma. (5, 6, 7, after Boulenger. ) Cartilaginous parts are dotted ; ossified parts 

 are left white. 01, Clavicle ; Co, coracoid ; K, epicoracoidal cartilage : //, humerus : 

 M, metasternum ; 0, omosterniim ; /', preroracoid ; Sr, scapula ; S.S. supra- 

 scapula. 



sternal apparatus of tlie Anura consists ol' two pieces. One, 

 anterior, variously named episternuin, presternum, or omosteruum, 

 rests upon the united precoracoids and extends headwards, being 

 either styliform or broadened out. Sometimes it is partly ossified, 

 with a distinct suture at its base ; this is the case especially in 

 the Firmisternia : in many Arcifera the omosteruum remains 

 cartilaginous and is continuous, without a sutural break, with 

 the cartilage of the precoracoids, indicating thereby its genetic 

 relation to the shoulder -f^irdle. Hence o7nosteriiuni is the 



