258 



DE. C. I. FORSYTH MAJOR ON 



[Mar. 19, 



all the Oi-iental and Ethiopian Lemurs, as well as in the Malagasy 

 Microcebus, an os planum is always very evident, so long as the 

 sutures in the orbit remain distinct, adding that, with the ex- 

 ception of CJiiromys, I had observed the os planum in all the 

 Malagasy Lemurs in which sufficiently young stages could be 

 examined. In the majority of the Malagasy Lemurs the frontal, 

 and here and there to a slight extent the orbito-sphenoid — 

 not the maxilla — overgrow the medial part of the planum. The 



Text-fig. 65, 



'^n/ae..^' 



'Tncc 



OS. 



Left orbital region of Lepidolemiir musielinus (Br. M. 97.9.1.18), | nat. size. 

 wiff.=malar ; ma?. = maxillary ; other letters as in text-fig. 61. 



Left orbital region of Lepidolemur globiceps Maj. (Br. M. 97.4.6.1), ^ nat. size. 

 mx.=ma,xiUarj ; «?«.=; malar ; other letters as in text-fig. 61. 



lateral part has become united with the palatal at a very early 

 stage ; a remnant of the suture with the latter bone is seen in the 

 adult at its antero-medial extremity ; in exceptional cases, e. g. 

 Lemur catta and young specimens of Lejndolemur, the planum 

 remains completely (pi., text-fig. 62, p. 256) or almost completely 

 (pZ., text-fig. 63, p. 257) distinct fi'om the palatal (text-figs. 61, 



