198 SMITHSONIAN iMISCELLANEOUS COLLECTIONS \0L. IO3 



B. Vertical Variation 

 I. EMBRYONIC WHORLS 



No vertical variation in the color of the embryonic whorls occurs 

 in regions I, II, Ila (fig. 7, p. 194). Vertical variation occurs between 

 regions Ilia and the portion of region III immediately above Ilia, 

 and on the North- South Kaukonahua Ridge between regions IV and 

 Illb. The lower regions have shells with unicolored embryonic 

 whorls (region IV) or with embryonic whorls that are intermediate 

 between the bicolored and unicolored condition (region Ilia). The 

 upper regions III and Illb on the other hand have shells with bicolored 

 embryonic whorls (fig. 7, p. 194). 



In area ']'/, between regions IV and Illb, shells of A. a. tuberans 

 var. 3 have either unicolored or bicolored embryonic whorls. In 

 the Gulick collection specimens of A. a. polymorpha have either 

 bicolored or unicolored embryonic whorls. This may indicate that 

 at a low elevation (zone I) in the region of Waiawa and Kipapa 

 Gulch shells with unicolored embryonic whorls existed below the 

 present-day forms with bicolored embryonic whorls in zone II of 

 region III. 



Region IV contains only shells with unicolored embryonic whorls 

 but northwest of North Kaukonahua Stream to Opaeula Gulch in the 

 lowest areas (areas 85, 86, 89, 90, 91 ??, 92, 93, 95, 96, 106, 107, 109, 

 fi^- 5^^ P- 1 05)? the shells have dark embryonic whorls which are 

 some shade of brownish yellow such as ochraceous tawny or buck- 

 thorn brown. The upper localities have lighter embryonic whorls 

 with such colors as white, light buff, or pale pinkish buff. An excep- 

 tion to this rule is area 88, which contains shells with darker embryonic 

 whorls than lower area 87. Area 97 of Opaeula Gulch (ridge complex 

 18, fig. 8, p. 195) has shells with darker embryonic whorls than those 

 of area 99 above it. But area 97A ??, which is below area 97, has shells 

 with white embryonic whorls. So that in the region of Opaeula and 

 Kawailoa Gulch three distinct types of embryonic whorls occur : High- 

 land white or buff, lowland brownish, and finally white in the extreme 

 lowland shells. Northwest of Kawailoa Gulch no vertical variation 

 is noted in the color of the embryonic whorls in shells found today. 



2. COLOR PATTERN OF THE POSTEMBRYONIC WPIORLS 



The postembryonic whorls show more vertical variation than the 

 embryonic whorls. At different elevations along a ridge different 

 colonies or areas with distinct color patterns are encountered. The 



