148 



far apart as the Marquesas and New Caledonia, always asso- 

 ciated in lots with specimens lacking it. 



A more important variation, probably, is the position of the 

 basal fold. In some lots (pi. 25, figs. 5, 8) among which I 

 may mention the Society Is., Hervey Is., Samoa, Guam, New 

 Caledonia, the basal is rather large and decidedly subcolu- 

 mellar in position, being nearer the columellar lamella than 

 in the typical pediculus. 



The angulo-parietal varies among specimens of the same lot 

 in degree of concrescence of the two lamellae and height of 

 the angular. The variation of this tooth is perhaps greater 

 than in any other species of the genus. 



Range and Station. The distribution of pediculus in Poly- 

 nesia is known chiefly by the work of Dr. Ed. Graeffe, collect- 

 ing for the Godeffroy firm, whose material was reported on by 

 Mousson and Boettger, and by the collections of Andrew 

 Garrett. Sixteen lots in the collection of the Academy fairly 

 cover the distribution of the species, extreme points being 

 Port Jackson, New Caledonia, Marquesas, Oahu, Guam and 

 Bohol. For notes on the Australian forms, see p. 158. 



It has been found on nearly every inhabited atoll and high 

 island of Polynesia, Micronesia and Melanesia where small 

 land shells have been looked for. On the high islands it occurs 

 in the lower zone, probably never in the high mountain forests. 

 Andrew Garrett reports that he "found them in vast num- 

 bers on stony ground in a grove near the seashore, but com- 

 paratively rare in the mountain ravines" of Cook's Islands, 

 The Hawaiian form was found abundantly on the coastal 

 border and in the lower parts of the valleys, but not in any 

 of my gatherings from high ridges. It lives on stones, garden 

 walls, or under wood, leaves and the like, in somewhat shaded 

 places. On Tongatabu Dr. Graeffe found it especially among 

 the stems of small plants which cover the coral reefs of the 

 southern coast. Montrouzier reports it from Art Island 

 under leaves and sprouting cocoanuts. 



Since the following races have been named, they are recog- 

 nized here, though their differential characters are slight. 



