MUSEUM OF COMPARATIVE ZOOLOGY. 193 



I regard these as varieties of one species ; they all possess a small eleva- 

 tion on the columella, with a round button-shaped pillar tooth. They 

 vary in size somewhat, but the dark oblique stria; exist, to a greater or 

 less degree, in nearly all examples. The surfiice in fresh shells is always 

 polished, looking as though oiled. 



From all the examples of P. riifa Less., P. nitens Pfr., P. lignaria Pse., 

 and P. affims Pse., which I have seen, 1 am inclined to consider them 

 varieties of one species. 



P. glutinosa Pfr., in one quart, was uniform in size and color ; and so 

 was P. virgidata Pse. in the same amount from Raratonga. P. elongata, 

 P. simidans, P. striolata, and P. nicdeola Pse., from the island of Moorea, 

 were present in several pints, and doubtless belong to one species, only 

 varying in size and color, the two last being only depauperated ex- 

 amples of the first. Under the microscope all exhibit the thickly 

 crowded waved spiral striae, and all the varieties show the translucent 

 and banded examples which = P. tceniafa Mdrch. P. elongata Pse., in 

 half a pint, shows the most numerous banded examples. ' There were 

 present numerous pale yellow elongated specimens, which dealers send 

 out as P. sjyad/'cea^ Rve. In the parcel of P. simulans Pse., the banded 

 examples equalled ten per cent. 



P. nicdeola Pse. Mss. exhibited several very dark opaque examples. 



All the above varieties from Moorea possess to a greater or less degree 

 the dark oblique striae, the elevation on the columella, the sharp oblique 

 juncture of the labium with the body whorl, and the thicldy crov>'ded 

 spiral striae of the surface of the shell. The latter feature is seen in no 

 other species except P. Mooreana nobis, from tlie same island. 



P. Hebe Pfr., in half a pint, exhibited nearly all the examples entirely 

 denuded of epidermis, and without a rose apex, the specimens being 

 entirely white and solid. These represent the typical P. Hebe. 



P. bella Pse. Mss. = P. rosea var. (according to Mr. Gai-rett). In 

 almost a pint, the shells possessed a rose apex and were thinner than 

 typical P. Hebe. The epidermis of some of the heavier examples was 

 thin and readily separated from the shell. Many of the more mature 

 specimens were without epidermis. They only differ from P. Hehe in 

 possessing the rose apex, and the lot exhibited the easy grade by which 

 the latter merges into the former. A few specimens of P. glohom Garr. 

 Mss. and P. ventrosa Pse. Mss. were found in the parcel. These vari- 

 eties are more stout and heavy than ordinary examples of P. hella. 

 They possess a heavy and more adherent epidermis, with little or no 

 color at the apex. All the varieties from P. Hehe to P. ventrosa present 



VOL. IX. NO. 5. 13 



