66 Din (tor's Annual Report. 



ally contain a sin<^]e yonnj;. A few cases have been found by the 

 writer in which a uterus has contained two young. In this case 

 the young are at different stages of development. In the terres- 

 trial forms, when a specimen is pregnant, there are usually from 

 three to live young. These are always in different stages of develop- 

 ment. In one case the writer found eleven young in the uterus of 

 an Acliatinella {Laniinclla) gravida. 



The colledling thus far has been confined almost entirely to 

 Nuuanu valley. About 3000 shells have been coUedted from the 

 north-western side of this valley. Of these shells 1785 belong to 

 Mr. D. D. Baldwin's Achati)iclla multizonata. Nuuanu valley has a 

 north-easterly trend. The sides are more or less precipitous and 

 rise from a few hundred to more than two thousand feet above the 

 l^ed of the valley. The sides are covered by a low dense mass of 

 trees, shrubs, ferns and creepers. Extending into the valley, at 

 about right angles to the sides, are numerous sub-ridges. The upper 

 portions of these sub-ridges and of the valleys between them are 

 also overgrown with a dense mass of vegetation. The lower por- 

 tions and also the bed of the main valley are covered wnth the intro- 

 duced "Hilo grass" {Paspaluni conji(oatiini) with here and there 

 clumps or isolated individuals of Lehua {Mctrosidcros polyniorpha) , 

 Straussia, Guava ( Psidium giiayava ) , etc. There are about twenty- 

 three of these sub-ridges, which are more or less parallel to one 

 another. In some cases the foot of a sub-ridge expands into a more 

 or less undulating slope. In numbering these sub-ridges the num- 

 bers begin at the head of the valley. 



A. mnltizonata is found on all the upper 17 sub-ridges, a dis- 

 trict of about a mile in length, and from 100 to 400 yards in breadth. 

 There are no permanent streams in any of the valleys between 

 these suV)-ridges. Two of these valleys usually have a little flow- 

 ing water. The valley between sub-ridges XI\' and XV serves as 

 a boundary to several of the color-varieties. That between XVII 

 and XVIII serves as a boundary to the whole species. In some 

 cases a sub-ridge has been divided into two or more localities. 

 This has been done when there has been a group of trees isolated 

 from the rest of the trees growing on the sub-ridge. These locali- 

 ties are designated by adding a letter to the number of the sub-ridge. 

 None of the localities are more than 150 yards in diameter. A. nrul- 

 /i'jonata is found in more or less open localities. Specimens are 



