102 CHARLES MIDLO AND HAROLD CUMMINS 



In Callithricliidae the soles exhibit a separate II 1 , somewhat 

 displaced proximally in association with elongation of the 

 sole. The accessory border pads in all other genera are either 

 absorbed by the adjoining interdigital pads (notably in catar- 

 rhine monkeys) or they are so depressed that their existence 

 is demonstrable only in the fetus (man, Cummins, '29) or in 

 dermatoglyphic evidences. 



Central pads. The central pads (2 P , 3 P , 4 P ) are located just 

 proximal to the respective interdigital pads (II, III, IV). 

 They are confined to prosimians and platyrrhines, but are 

 neither consistently .present in all members of these groups 

 nor is the series fully represented in all the genera which 

 possess these features. 



Aotus may be selected as a primitive example of the central 

 pads (figs. 1 and 2). Both in the hand and foot all three pads 

 of the series are characteristically present as distinctly cir- 

 cumscribed elevations. While all these pads are typically 

 present in hands and feet of the following genera they are 

 lowered, expanded and less discrete than in Aotus : Leonto- 

 cebus, Oedipomidas, Callithrix, Alouatta, Saimiri and Lago- 

 thrix. In Cebus the pads are present in the hand, but not in 

 the foot, while in Seniocebus it is the foot alone which bears 

 these pads. In four of the prosimian genera studied (Dauben- 

 tonia, Nycticebus, Galago and Lemur) the central pads are 

 indicated, and in no member except the hand and foot of 

 Daubentonia and the hand of Lemur is the complete series 

 even suggested. Central pads are inconspicuous in the hand 

 of Daubentonia, but in the foot all three appear as proximal 

 extensions of the interdigital pads, though divided from them 

 by the distal transverse flexion furrow. Lemur has no dis- 

 tinct central pads, but in their morphologic positions there 

 are patches of ridged skin larger than those in other regions 

 of the central area. In the hand 2 P , 3 P and 4 P are lacking. 

 Nycticebus shows pads 2 P and 3 P in both members, and, while 

 small, each pad is a discrete element. In Galago only 2 P is 

 present. 



