126 EXPEDITIOX OF THE "ALBATEOSS," 1899 1900. 



as the young of type 3 from tlie same valley, while two were slightly 

 darker and resembled the ground-color of the young of type 5. Of these 

 seven young, only one exhibited the whorl-stripe, the others being of a uni- 

 form ground-color. All of the adults were sinistral, while of the young three 

 are dextral and four sinistral. There can be no doubt that type 7 of 

 Hamuta valley is derived directly from snails of types 3, 5, and 8, of the 

 same valley, and that together they form a race between the members of 

 which no specific distinctions can be drawn. Snails of type 7 are also found 

 in Pirse valley ; unfortunately, however, only one young one was obtained 

 from the five adults collected. This young snail possessed the ground- 

 color of snails of type 5 with the addition of a very faint whorl-stripe. 



Partula filosa Pfeiffer. 

 Figs. 9, 10. 



This snail is found in Piraj valley. It may at once be distinguished 

 from all other forms in this valley by its small size and the short blunt 

 spire, also the outer surface is furrowed by deep longitudinal strije, and the 

 shells are all dextral. Thirty adults were collected, of which fourteen are 

 dark brown in color and well represented by Fig. 9, while thirteen are light 

 in color and resemble Fig. 10; and two others are intermediate in hue 

 between Figs. 9 and 10. Ten adults of type 9 yielded twelve young, of 

 which five were as light as type 10, while seven were similar to their 

 parents in color. Eight adults of type 10 give eleven young, of which 

 eight were about the same color as their parents, while three were darker 

 and resembled type 9 in color. There can be no doubt, therefore, that 

 Figs. 9 and 10 represent one and the same species of snail. 



Summarizing the preceding observations, we find that thoi-e are but three 

 species of Partuloe in Pira), Hamuta, Fautaua, and Tipnerui valleys. Two 

 of the.se species, represented in Figs. 1, 2, and Figs. 3-8, respectively, are 

 common to all four valleys; while the third, represented in Figs. 9 and 10, 

 is found only in Piroe valley. The snail represented in Figs. 1 and 2 

 (P. hyalina Broderip) is found in .scanty numbers in every valley in Tahiti 

 which the author explored. It is a distinct species, and shows no tendency 



