494 ON THE ZOOLOGICAL rOSITIOiV 



the extei'iial genitalia the affinities of Tarsius are far nearer 

 to the highest members of the series than they are to tlie lowest, 

 (v.) In the absence of a penile ossicle or penile cartilage, the 

 likeness is with Homo alone, (vi.) In the arrangement of the 

 aortic trnnks Tarsius differs from a,ll monkeys, and finds an 

 absolute parallel only in Man normally and certain Anthropoids 

 occasionally. Various points in myology are of interest as 

 showing retention of muscles in Tarsius and Homo in a primitive 

 condition not preserved in other members of the Anthropoidea. 

 (vii.) Tarsias retains, like Homo, a well-developed pulmaris 

 brevis. (viii.) The flexor accessorius is confined to Tarsius and 

 Man alone among the Primates, (ix.) The supinator brevis is 

 pierced by the posterior interosseus nerve exactly as it is in Man, 

 and the condition differs widely from that whicli is occasionally 

 present in the Chimpanzee, and which is otherwise the most 

 human manifestation of this muscle within the limits of the 

 Anthropoidea. (x.) The paJmaris longus and plantaris ai'e both 

 well developed, (xi.) The levator anguli scapulae is in its Innnan 

 condition, (xii.) The flexor pollicis longus, though judging from 

 published accounts displaying a variability in different specimens, 

 approaches the human form and difiers from the Simian in a very 

 remarkable manner. 



In conclusion, Tarsius appears from a summation of its 

 anatomical characters to belong to the Anthi-opoidea, of which 

 group it constitutes one of the most primitive members. ]n the 

 retention of primitive features of bodily architecture it finds its 

 parallel in Homo ; and it difiers from the rest of the Anthro- 

 poidea in which Simian specialisations have effected definite 

 alterations. 



Tarsius appears to be a \'ery primitive member of the Anthro- 

 poiilea in which early specialisation of vision and arboreal leaping 

 a.ctivities absorbed the phylogenetic development of the species. 

 Homo appears also as an extremely primitive form in which 

 cerebral advances, and lack of unequal physical specialisation, 

 save tliat of bipedal progression, is the phylogenetic keynote. 

 The Anthropoid Apes have departed more from the primitive 

 mammalian type in definite " Simian " specialisations — which 

 specialisations become increasingly conspicuous in the "lower" 

 members of the Order. 



R. I. PococK,Esq.,F.R.S.,F.Z.S.:— In the 'Proceedings' of this 

 Society, Aug. 1918, I pointed out that Tarsius differs from all 

 the Lemurs and resembles the higher Primates in the structure 

 of the nose and muzzle and in the mobility of the lips ; and that 

 the external genitalia of the female in the concealment of the 

 small clitoris and the orifices of the urethra and vagina, by a, 

 pair of labia are unlike those of the Lemurs, especially of the 

 Oriental and African forms (Lorisiformes), and recall rather those 

 of the Old-World Pithecoid Primates. 



These differences between Tarsitts and the Lemurs, added to 



