236 ACHATINELLA CASTA. 



Oahu: Waimalu-Waiau ridge to the Waipio district (col- 

 lections of Spalding, Cooke and A. N. S.). 



Achatinella casta NEWC., P. Z. S. 1853, p. 134, pi. 22, f . 12 ; 

 Ann. Lye. N. H. of N. Y., vi, 325. PFR., Monographia iv, 

 538; vi, 174. THWING, Orig. Descriptions, p. 64. Eburnella 

 casta Newc., HARTMAN, Proc. A. N. S. Phila. 1888, p. 36. 

 Achatinella cuneus PFR., P. Z. S. 1855, p. 205. SYKES, Fauna 

 Hawaiiensis p. 323 (mountains behind Ewa, Perkins). Acha- 

 tinella concolor E. A. SMITH, P. Z. S. 1873, p. 75, pi. 9, f. 1. 

 Achatinella pygm&a E. A. SMITH, P. Z. S. 1873, p. 75, pi. 9, 

 f. 11. Achatinella ligata E. A. SMITH, P. Z. S. 1873, p. 76, pi. 

 9, f. 13; and var. a, fig. 12. GULICK, Evolution, Racial and 

 Habitudinal, p. 41, pi. 2, f. 8. 



A. casta differs from A. bellula by being sinistral as a gen- 

 eral rule, but eastward there are dextral shells among the 

 sinistral in some places. It has a somewhat different range 

 of color-forms. There is often a dark sutural band or line, 

 but more frequently none. Newcomb's figure, reproduced in 

 pi. 29, fig. 12, is now a rather uncommon color-form, if found 

 at all in recent collections. It is nearly white with a chestnut 

 sutural line and an olive band below the periphery, with 

 several indistinct spiral lines above it. One from Newcomb 

 is illustrated in pi. 49, fig. 1. Others of the same lot have the 

 base yellow, tinged with chestnut, or the last whorl pale yellow, 

 bandless ; white ; or white with two to four chestnut bands. 

 Perhaps the lot represents several localities, though casta 

 colonies are notoriously polychromatic. 



Dr. Newcomb apparently included the later-described bellula 

 in his conception of casta. Indeed the locality given by him 

 applies to A. bellula alone, if I am right in identifying his 

 ' ' Mouna Rua ' ' with Moanalua. He says : ' ' Its northern limit 

 is the valley below Mouna Rua, and half a dozen ravines 

 south, in the district of Ewa. " It is practically certain how- 

 ever, that Newcomb's figured type came from west of Moana- 

 lua ; moreover, the ravines south of Moanalua can not properly 

 be said to be in Ewa. Newcomb's specimens look like Wai- 

 mano or Waiawa shells. Just eastward of the casta area is 

 the habitat of A. juddii, and still further east, that of A. bel- 



