PARTULINA, MOLOKAI. 27 



colonies. They are present in the lots of the typical form which 

 I have seen. 



8a. Var. halawaensis Baldwin (pi. 6, figs. 7, 8, 11), which 

 occurs further east at Halawa, is white or pale straw-colored, 

 becoming darker towards the outer lip, without post-embryonic 

 bands, or with them narrow and few; lip brown-edged within. 

 Dark band on the embryonic shell normal, or rarely much 

 reduced. Contour long. Length 28, diam. 15.2, aperture 

 15 mm. 



A peculiar form (pi. 6, fig. 2) from the University of Wis- 

 consin collection has the embryo white with a narrow chocolate 

 band, the last 2 or 3 whorls fawn w r ith many narrow longi- 

 tudinal darker streaks and only faint traces of spiral bands. 

 The shell is very glossy and small, length 19.7 to 20.5 mm. 

 Exact locality of these specimens unknown, but Herr Borcher- 

 ding, who has given a magnificent plate of 40 figures to the forms 

 of virgulata, figures this race from Pelekunu, on the northern 

 water-shed, together with small, slender, nearly white examples. 



It is evident that a good deal of local differentiation has 

 taken place among the colonies of virgulata. 



A. rohri was acknowledged by Pfeiffer to be a synonym of 

 virgulata. It was thus described: "Shell perforate, ovate- 

 conic, rather solid, longitudinally striatulate, decussated by 

 very close spiral striae; whitish fulvous, variously ornamented 

 with narrow chestnut bands; spire conic, rather acute. Whorls 

 6, but slightly convex, the last about as long as the spire, com- 

 pressed in the middle. Columella twisted, callous. Aperture 

 subtetragonal, glossy white within; peristome slightly expanded, 

 labiate within, the margins subparallel, the right margin shortly 

 arcuate above, columellar margin reflexed, nearly closing the 

 perforation. Length 24, diam. 13, aperture 13 mm. long, 6f 

 mm. wide inside.' 



Group of P. tessellata. 



Embryonic whorls unicolored or having obliquely axial 

 stripes. 



