200 



backwards and is closely adherent to the side of the head. In the 45 mm. 

 R.V. specimens the ear is pointed and fleshy ; it is directed backwards and is 

 free of the side of the head. A conspicuous and rounded processus antihelicis 

 is present, lliere is a definite antitragus fold, and a less conspicuous tragus. 

 Foldings of the concha distal to the processus are inconstant. 



Manns (see fig. 6). — The digital formula is 4 > 3 > 2 > 5 > 1 ; in the adult 

 the second digit is as long as or longer than the third. The manus is relatively 

 large. The four inter-digital pads are marked at their highest points by well- 

 defined central areas. The pad at the base of the first digit is the smallest. 

 The hypothenar pad is well developed. The claws are strong and curved. 



Pes (see fig. 7). — The digital formula is 3>4>2 > 5, as in the adult. 

 One large pad with a central trefoil area is situated at the bases of digits 3 and 4 ; 

 and smaller pads, with circular central areas, at the bases of digits 2 and 5. 

 A small pad marks the site of the absent first digit. Claws are not so strongly 

 developed on the pes as they are on the manus in the young animal. 



Mammary Area (see fig. 8). — The four mammary primordia are situated 

 in two furrows which run on the lower part of the abdomen and converge 

 towards the caudal end. The area between these two furrows is elevated ; the 

 "pouch area" being thus marked by a raised wedge-shaped swelling of the 

 abdominal wall, the apex of the wedge being directed caudad. The mammary 

 primordia are marked as rounded elevations in the furrow, the summit of each 

 of the elevations being invaginated so as to form a dimple in the centre of the 

 prominence. 



External Genitalia. — The genital tubercle in the male 45 mm. R.V. embryo 

 is conspicuous beyond the limits of the cloacel margin ; in the female of the 

 same size the condition is similar save that the genital tubercle is rather less 

 conspicuous. 



