THE NAUTILUS. 43 



in color, size and shape, and it would make a dozen excellent 

 species if the intermediates were left out of account. Those 

 living near the coast and among the cacti of the most arid parts 

 of the district are of whiter and more dull color, are more banded 

 and show a decided tendency to abnormalities, especially about 

 the apertures. Specimens from further inland are more polished 

 and shining, even as though varnished, and are much more 

 given to a dotted or fly-specked type of ornamentation than to 

 bands. A fence-post or a dead tree-limb with a hundred speci- 

 mens closely assembled in aestivation was no unusual sight. 

 We learned finally to pay no attention to them. Upon the low 

 bushes in certain localities the lovely little Cepolis hicipeta Poey 

 cling like berries. These are the largest and finest of the species 

 I have ever seen. The range of color variation in this delight- 

 ful little snail is also very great, but the colors never blaze out 

 in the vivid flash of the Polymitas. The blues and purples 

 and chestnut browns are subdued but very rich and splendid. 

 One very noticeable color form is the subsp. velasqueziana of 

 Poey where the many broken bands of the type coalesce into 

 two broad bluish-black zones of solid color. 



As nearly all the vegetation of this dry region bears thorns 

 we did not at first discover that many of these thorns were in 

 reality Macrocerami. When we did find this out we could 

 see nothing else. Bartsch and I finally agreed, and shook hands 

 upon it, that we would gather no more of them, and a stiff 

 penalty was placed upon any violation of the compact. Two 

 hundred and more from one bush is an earlier record before we 

 really got started. This is the Macroceramus festus (Gundl.) 

 Pfr. , blue and yellow and buff in color. Another arboreal snail 

 of this section is Polymita versicolor Born and it is probably very 

 abundant in places although we never saw more than fifteen or 

 twenty on any one tree. This is to me the least attractive 

 species of that wonderful genus of richly painted snails. The 

 brilliant yellow and pink are too primitive and the two colors 

 do not seem to harmonize very well. It always impresses me 

 as an experimental species that was laid aside in nature's lab- 

 oratory as not wholly a success. 



There were some ground snails too, but to secure living ones 



