THE NAUTILUS. 15 



OREOHELIX MACULATA, new species. 



Shell below medium size for the genus, spire elevated, 

 whorls 5 l /2, with convex periphery, somewhat flattened above 

 near the suture, resulting in a deeply impressed suture, con- 

 vex below. Embryonic whorls dark brown in most examples, 

 at first nearly smooth, with very fine growth-lines crossed by 

 microscopic spiral lines, which, at about the beginning of the 

 third whorl, develop into beaded ribs easily detected with a 

 low-power lens. The last two whorls of the shell bear numer- 

 ous rather strong, rude, blunt, irregular ribs, parallel with 

 the growth-lines, crossed by about equally numerous rude 

 spiral ribs, this sculpture being especially well developed on 

 the base of the last whorl. This sort of sculpture is typical 

 of the depressa-cooperi group, as distinguished from the 

 sharp-ribbed liaydeni group, but the sculpture is very much 

 stronger in maculata than is usual in either depressa or 

 cooperi, and the two latter are smoother below than at the 

 periphery and above, while in maculata the opposite is true. 

 Aperture rounded, outer and inner lips approaching. Um- 

 bilicus deep and narrow. Color exceedingly variable, a large 

 number seen collectively appearing quite dark because of a 

 preponderance of brown. The great majority of examples 

 have irregular, poorly defined light brown patches on a white 

 ground color, particularly noticeable under a lens, with 

 usually one spiral band or more of the same color above the 

 periphery and stronger bands of darker brown, varying in 

 width and number, just below the periphery and on the base. 

 A few albinos were found, without intergradatioii to the 

 typical color, as is also true of 0. cooperi obscura at the same 

 locality. A considerable number of examples are almost en- 

 tirely dark brown, but, except in a very few specimens, there 

 is a w r ide, conspicuous fighter band at or just above the peri- 

 phery of the melanistic shells, which shows just above the 

 suture on the spires. 



Type, width, 14 mm. ; height, 11.5 mm. Univ. Colo. Mus. 

 Cotype No. 1, width, 13.5 mm.; height, 10.8 mm. Univ. 

 Colo. Mus. 



