050 



PROSIMIAE. 



face. It has been asserted that the Madagascar lemurs differ 

 from others by the fact that the tympanic bone is reduced to 

 a ring, and the bulla is formed by the periotic (F. Major, P.Z.S. 

 1899, p. 987). 



The hind-legs are always longer than the fore. The humerus 

 has an entepicondylar foramen and the femur a small third 

 trochanter. The carpus usually has a centrale, and in some 

 living species the tarsus is extraordinarily elongated {Tarsius, 

 Galago, etc.), the elongation implicating the navicular and 



Fig. 328. — Chiromys madagascarensis 

 (from Vogt and Specht). 



Pig. 32^.— Galago (OtoHaius) galago 

 (from Vogt and Specht). 



calcaneum. In the pes, digit No. 2 often differs from the others 

 in size and always bears a claw-hke nail ; while in the manus, 

 digit No. 2 may be vestigial (Potto). 



The cerebral hemispheres* are relatively small and do not 

 completely cover the cerebellum (except in the Indrisinas). 

 Their surface is only feebly convoluted, but the calcarine 

 sulcus is indicated. 



* Flower, Trans. Zool. Soc, 1863, p. 130. Beddard, P.Z.S. , 1895, 

 p. 143. Oudemans, Verh. Ak. Amsterdam, 27, 1890. 



