496 



DR. R. BROOM ON THE STRUCTURE 



[Apr. 19, 



the angle is well-developed as in Marsupials, the cartilage is always 

 much in front and above it. Whether the splint bone that forms 

 round the under side of the back part of Meckel's cartilage and 

 the processus gracilis is to be regarded as the remains of the 



Text-fiff. 100. 



'•M.C=Art. 



A. — Mandible of Tlieroceplialiaii (Li/costichus vanderrieti). 

 B. — Mandible of Theriodont {Cipiognatlms 'platyce^ps). 

 C. — Mandible of j'oung Mammal. 



Ang., Angular; Art., Articular; Bent., Dentarj^; M.C., Meckel's Cartilage (omitting 

 Malleus, which is Hyomandibular) ; Men., Meniscus or Interarticular Cartilage ; 

 Qu., Quadrate ; Sq., Squamosal ; S.Ang., Surangular. 



angulare, or whether a tiny little additional splint seen in the 

 foetus of Ornithorhynchus is to be so regarded, is at present doubtful. 

 But there is pretty good reason for regarding the posterior part of 



