192 ACHATINELLA FULGENS. 



area. Nearly every colony is hybrid, and in some the mixture 

 is very complex. If any gametically pure colonies exist, they 

 must be rare. Segregation of the elementary patterns is 

 often incomplete, and in assorting any large lot, one en- 

 counters specimens which seem to be blends, often in large 

 proportion. 



In general, one may say that forms obliquely streaked and 

 lineate with various shades of vinaceous or cinereous (plu- 

 mata patterns) predominate in the east, and fade out west- 

 ward, where they finally appear chiefly in blends with other 

 patterns. Green and yellow cuticle is mainly developed in 

 the western district. Some other mutations, such as the 

 augusta,, fulgens and crassidentata patterns, have had their 

 rise in the intermediate district, and have not spread over the 

 whole area of the species. 



The numerous names proposed by Gulick and others have 

 no validity in existing taxonomic usage as standing for 

 species or subspecies, because the forms occur only as con- 

 stituents of mixed colonies, and not as pure strains; even 

 though one or two of the patterns may predominate in one 

 or another colony. These names, however, provide conveni- 

 ent terms for the designation of particular patterns. The 

 chief patterns are as follows. How many of them would 

 turn out to be elementary patterns, if tested by suitable 

 breeding experiments, is of course quite uncertain. 



1. Plumata pattern. Finely streaked with vinaceous, purple 



drab or plumbeous gray, pi. 36, figs. 4a, 5, 6, 6a. 



2. Varia pattern. White above, yellowish or olivaceous be- 



low the periphery; obliquely streaked with cinnamon or 

 tawny; usually with a dark line below the suture. PL 

 36, figs. 1, la. 



3. Diversa pattern. Base and a band above the periphery 



green, olive or yellow, elsewhere white. PL 37, figs. 4a, 

 4c. 



4. Augusta pattern. Green or olive with a yellowish or 



white band below the suture. PL 37, figs. 12, 12a. 



5. Trilineata pattern. Yellow below, white above the periph- 



