ORTHALICUS. 205 



Hidalgo's types, and some shells before me. Tlie ground-tint is 

 sometimes a rich yellow with some dusky streaks, sometimes a beau- 

 ful light purple, the bands being deep purple-black with white veins. 

 The peristome in all known forms of the species is reddish-brown or 

 brownish-red, the parietal callus more of a chestnut or blackish 

 color. 



Dohrn, who united the two forms, writes as follows : Narrow and 

 broad, large and small specimens of this species occur; the columella 

 is sometimes strongly folded, sometimes passes in a simple curve into 

 the outer lip; and now green, now yellow predominates in the colora- 

 tion, only rarely a tone of green passing into lead-gray occurring. 

 The number of bands is 4, not 3 as Hidalgo holds, but not infrequently 

 the two lower bands coalesce. The upper whorls may be either white 

 or roseate, In many shells the four growth-periods are very char- 

 acteristically separated by differences in the markings, so that either 

 ground- tint or the decoration of zigzag lines is changed. At the base 

 just behiiKl the columellar callus, there is a long small elongate tract 

 of the shell which is denuded of cuticle, plicate and purplish-red (or 

 ash-gray). As this is present upon all my specimens, I consider it a 

 specific character. Measurements of several specimens are as 

 follows: 



Alt. 71, diam. 34, length of aperture 44, breadth 26 mill. 



Alt. 71, diam. 28, length of aperture 34, breadth 22 mill. 



Alt. 61, diam. 29, length of aperture 37, breadth 24 mill. 



Alt. 58, diam. 25, length of aperture 30, breadth 19 mill. 



Hup6 gives Peru as the locality of the specimens collected by Count 

 Castelnau. They are the form of fungairinoi, but the markings are 

 somewhat reduced, showing more of the ground color than usual. 



GROUP OF O. ATRAMENTARIUS. 



Chiefly a group of central Colombia, distinguished by the blunt 

 lip, but little and gradually expanding, and bordered broadly with 

 violet or purple inside. The species are among the most superb of 

 South American land snails. They vary considerably in color, and 

 are closely allied. 



Key to species. 



a. Aperture pure white within ; shell usually with a peripheral 

 dark girdle. 



