BY J. T. WILSON AND VV. J. S. McKAY. 387 



(12) Macalister, a. "The Anatomy of Chlamydo'phorus trun- 



catus,'' Trans. Roy. Irish Acad, Vol. xxv. (1875), p. 247. 



(1 3) Humphry, G. M. " The Myology of Orycteropus capensis^^ 



Journ. of Anat. and Physiol. Vol. ii. p. 301. 



(14) Galton, J. C. " Myology of the Extremities of Orycteropus 



capensis/' Trans. Linn. Soc. Lond. Vol. xxvi. (1870), p. 579. 



(15) Gervais, Paul. " Ost^ographie des Monotremes " (Paris, 



1877-8). 



EXPLANATION OF FIGURES. 



Plate xxi. 



Each of the figures 1-4 has a key-sketch laAa, showing the outlines of 

 the muscular attachments. 



The outlines of muscular attachments were drawn after careful examina- 

 tion of several specimens. 



In figures 3a and 4a the partly broken off suprascapular part of the 

 specimen, from which figures 3 and 4 were drawn, has been traced in. 



Fig. I. — Scapula (left) of Ornithorhynchus^ internal aspect (nat. size). 



Fig. la. — Tracing from fig. 1, with outlines of muscular attachments filled 

 in. 



Fig. 2. — Scapula (left) of Ornithorhynchus, external aspect (nat. size). 



Fig. 2a. — Tracing from fig. 2, with outlines of muscular attachments filled 

 in. 



Fig. 3. — Scapula (left) of Echidna (youngish specimen), internal aspect 

 (nat. size). 



Fig. 3a. — Tracing from fig. 3, with outlines of muscular attachments filled 

 in. 



Fig. 4. — Scapula (left) of Echidna, external aspect (nat. size). 



Fig. 4a. — Tracing from fig. 4, with outlines of muscular attachments filled 

 in. 



Figs. 5-8. — Diagrammatic outlines of sections across long (dorso-ventral) 

 axis of several forms of scapula. 





■.\H 



^y 



