AMASTRA. 33 



fully work out the question of its relations with A. cylindrica, 

 but the two are certainly near akin. Well north on the 

 western ridge of Popouwela it is found in typical pattern, 

 together with cylindrica Nc. There is no evidence that they 

 interbreed, and there are no blends in the series collected by 

 Pilsbry. Further up the ridge, southward, in the place 

 where Endodonta is abundant, there are a few spirizona as- 

 sociated with many cylindrica-porphyrea-intermedia, and a 

 very few specimens with the white suture of spirizona and the 

 lighter ground-color and coarse striae of porphyrea. 



The type figure of A. rudis Pfr. (Vol. XXI, p. 219) is 

 photographically reproduced in fig. 17 of pi. 30, Vol. XXII. 



A. CYLINDRICA (Newc.). PI. 8, figs. 12 to 16. 



The series from the western ridge of Popouwela demon- 

 strates that A. cylindrica (Vol. XXII, pi. 29, fig. 11, photo- 

 graphic copy of type figure), A. intermedia (Vol. XXII, pi. 

 29, fig. 13, type fig.) and A. porphyrea (Vol. XXII, pi. 29, 

 fig. 16, type fig.) live in the same colony, no doubt interbreed, 

 and are fully connected by blends. We unite all under the 

 first name, A. cylindrica. The specific identity of these 

 forms has already been recognized by several of the Island 

 conchologistst" Newcomb's figures are reproduced in fac- 

 simile on pi. 29 of Vol. XXII. As they are somewhat ideal- 

 ized, we are giving views of Popouwela shells also, pi. 8, 

 figs. 12-16. 



The outlines of the spire vary in convexity, but are sup- 

 posed to be always more convex than in A. spirizona, which 

 has straight contours. The last whorl at least is coarsely 

 striate. The ground-color varies from nearly white or 

 vinaceous buff to mikado brown, and is either plain or en- 

 circled with lines and bands of a darker shade. The black or 

 black-brown cuticle remains in shreds, emphasizing the stria- 

 tion, or in patches; and it is most persistent in the dark- 

 ground shells such as Newcomb figured as intermedia. The 

 narrow, well-banded shells are Newcomb's cylindrica, the 

 wider more obese ones, banded or not, are his porphyrea. 



A. variegata Pfr. is closely related to the preceding. 



