PLACOSTYLUS, LORD HOWE ISLAND. 25 



128 HECTOR, Catal. Landmoll. N. Z., 1873, p. 20 BUTTON, 



Man. N. Z. Moll. p. 14 (1880) Placostylus bovinus var. neozelani- 

 cus Pfr., HUTTON, Trans. N. Z. Inst. xvi, p. 190 P. bovinus var. 

 novoseelandica SUTER, Journ. de Conchyl. 1893, p. 237. 



Probably a mere phase of variation rather than a true sub-species. 

 I am unable to see that the following form differs in any respect save 

 absolute dimension*, which vary widely in all species of this group. 



Var. candidus (Crosse). Columella subvertical, peristome white ; 

 aperture buff- whitish within, the basal margin with a single tubercle, 

 right lip slightly siriuated within, above. Length 86, diam. 36 mill. 

 ( Crosse. ) 



Resembles the typical form in size and contour, but differs in that 

 the columella is a little more vertical, and more especially, the 

 peristome is completely white. The interior of the mouth is very 

 light yellowish white. 



P. BIVARICOSUS (Gaskoin). PI. 12, figs. 1, 2, 3, 4. 



Shell imperforate, oblong-conic, rather solid; cuticle tawny 

 chestnut colored with dark chestnut streaks, paler or lost on the buff 

 or flesh tinted earlier whorls. Surface scarcely shining, with 

 moderate growth- wrinkles, stronger near the suture, and sometimes 

 faint, low, coarse spiral sulci ; the spire occasionally decussate. 

 Spire rather long, the apex obtuse. WhorJs 5^ to 6, the nepionic 

 2J whorls sculptured with fine, close, waved and somewhat 

 brandling and anastomosing vertical wrinkles, becoming finer and 

 more crowded on the latter portion ; distinctly demarked from the 

 subsequent growth when unworn. Last whorl oblong, tapering 

 above and below. Sutures parallel, or the last one more oblique. 

 Aperture ovate, slightly oblique, red-orange within the outer lip, 

 ochraceous in the throat ; peristome reddish with a dull white outer 

 edge, thickened and slightly reflexed, flattened on the face, the outer 

 lip with a blunt, thick flange within, interrupted near the upper 

 termination, and lower toward the base. Columella and parietal 

 callus cherry-red, the former oblique, more or less folded above, 

 abruptly truncated basally. 



Alt. 61, diam. 27, longest axis of aperture + peristome 31 mill. 



Alt. 51, diam. 25, longest axis of aperture -}- peristome 27^ mill. 

 Lord Howe Island, in sheltered places under stones, abundant. 



Bulimus bivaricosus GASKOIN, P. Z. S. 1854, p. 152, pi. 29, f. 4, 



