Morph 30. Plate xlv. 



This population was derived from the second of several reefs 

 and rocky promontories extending from the shoreline in the 

 vicinity of Olga, on Orcas Island in the San Juan group. 



The shells in this morph exhibit considerable variation in 

 sculpture, ranging from quite smooth to markedly imbricated 

 forms. The spire in the majority of individuals is rather elon- 

 gated. The coloration shows the widespread range from white 

 to dark brown, with the banded forms and darker shades pre- 

 dominating, thus developing a cline as regards color. 

 Specimens available, 100. 

 Morph 31. Plate xlvi. 



The breakwater at Victoria, on Vancouver Island is an arti- 

 ficial structure, and presumably has been populated by strays 

 from neighboring colonies. As is true of many other Thais pop- 

 ulations the coloration exhibits a range from brown to white, 

 with various intermediate types of banding, indicating the 

 compound character of the genes controlling color in these 

 forms. The sculpture and spire form also present a wide range, 

 as might be expected, even in the small number of shells avail- 

 able for comparison. 

 Specimens available, 25* 

 Morph 32. Plate xlvii. 



Turn Reef is located to the eastward of Turn Island, from 

 which it is separated by a narrow channel. Turn Island itself 

 lies ck)se to the eastern shore of San Juan Island. 



Turn Reef is a massive group of irregular metamorphic 

 rocks, which are for the most part exposed only at the lower 

 tide levels, and as a result the nutritive conditions are quite 

 favorable, and consequently the snails attain a greater than 

 average size on reaching maturity. Along with this increased 

 growth the sculptural elements are increased in amplitude. The 

 coloration exhibits the common type of clinal integration. 

 Specimens available, 300. 



