PALM AND SOLE STUDIES. 403 



S pattern, with the loop facing as in Fig. 17, but eventually 

 curving upwards instead of downwards. There may be, in 

 these cases no trace of either a degeneration triradius or of the 

 separation of the whole area into the two halves resulting from 

 an elongated S, and it may be simpler to refer this form to a 

 simple A loop of an unusual shape and position. 



FIG. 21. In this area there is a degeneration triradius, and the lower pattern has 

 retained its loop. This suggests an explanation for a common type, in which the 

 hypothenar region is made of parallel lines, but has a small loop very low down. 



The Migration of Triradii. Thus far we have contented our- 

 selves with the selection, and somewhat with the classification, 

 of types of patterns, and have separated and grouped the follow- 

 ing: 



W The Whorl Type (primitive). 

 A The A -Type, a loop opening upward. 

 B The 5-Type, a loop opening laterally. 

 C The C-Type, a loop opening downwards and inwards. 

 AB The AB Type, a lenticular figure, extending between the 

 positions of triradii a and b, but with the triradii them- 

 selves represented only by converging lines, and with 

 the two embracing radiants wanting. 



A C The A C Type, same as before but with the missing triradii 

 a and c, and represented only by converging lines in the 

 two positions. 

 BC The BC Type, same as the two foregoing, but with the 



missing triradii b and c. 



S The 5-Type, a whorl with an S in the center. This S figure 

 may be confined to merely a few of the central circles, 



