283 



DISCOVERY REPORTS 



behind the orbital processes of the frontals, and the temporal line is about level with 

 these processes. 



The permanent canines are absent and only two of my ten skulls retain milk canines ; 

 the incisors are all about the same length and the second cheek teeth are just erupting 

 (Plates VIII, IX, X, figs. 2). 



In the SECOND year the length of the skull is 227-4 ^^-y ^^'7 per cent of the body 

 length; the zygomatic width is 119-3 mm., 52-5 per cent of the length of the skull; 



Table III 

 List and measurements of skulls in the collections of the British Museum {Natural History) 

 and the Museum of the Royal College of Surgeons. The former are marked " B " and 

 the latter'' S'' 



Type. 



f In the dental collection. 



and the hamulo-premaxillar measurement is 145 mm., 63-5 per cent of the skull length. 

 The skull is still smooth, but on the whole much better ossified ; the occipital segment 

 is completely fused, the interparietal part of the sagittal suture is becoming complex 

 and the suture between the basi-occipital and the basisphenoid is sometimes closed. 

 The depression behind the interorbital processes of the frontals is still visible, but the 

 temporal line is higher up, nearer the middle line. The permanent canines are now 

 present but are only a little longer than the cheek teeth, which are all well developed. 

 The third upper incisors are now the longest teeth in the skull, being about twice the 

 length of the first and second incisors (Plates VIII, IX, X, figs. 3). 



