122 HELIOTROPIS. 



Subgenus Heliotropis, Dall. 



The essential character of this group is the reversed direction 

 of the spire, placing the aperture on the left instead of the right 

 side of the shell. The principal species have been considered by 

 good conchologists as mere monstrosities of dextral species ; thus 

 Mr. J. Gwyn Jeffreys regards N. contraria as equivalent to N. 

 antiqua. But of this species it has been shown that it has an 

 extensive distribution in Southern Europe, where the normal N. 

 antiqua is unknown, and that the so-called reversed antiqua is 

 very rare where the normal form is abundant. The last two 

 species, in form and want of defined canal appear like reversed 

 Volutopsae, and possibly they are. 



N, CONTRARIA, Linn. PL 50, figs. 291, 292, 



Pale yellowish to fulvous brown ; whitish within. 

 Length, 3-4 inches. 



Atlantic Coast of Spain, Portugal, South France ; Mediterranean f 



Fossil in the English Crag, in Belgium, and in the newer Ter- 

 tiary at Palermo. 



See remarks under Heliotropis, above ; yet the so-called 

 English specimens may be veritable reversed monstrosities of N. 

 antiqua. 



N. DEFORMIS, Reeve. PI. 50, fig. 293. 



Rather thin, with fine revolving striae, and tubercularly swollen 

 beneath the sutures. Yellowish chestnut, the columella and part 



of lip-margin white. Length, 3 inches. 



Spitsbergen. 



N. HARPA, Morch. PL 50, figs. 294, 295. 



Yellowish white, salmon within the aperture. 



Length, 3*75 to 6 inches. 



Sitka. 



Closely allied to the preceding species. Mr. Dall remarks that 

 the u operculum is very small when compared with the size of 

 the animal. Ovicapsules solitary, of hemispherical form, attached 

 by the entire base, smooth above, and maturing only two or three 

 individuals to each sac, although of much greater size than the 

 ovicapsule of any other species of mollusk in the region." 



