GASTROCOPTA, EAST INDIES, POLYNESIA. 147 



Zool. Soe. Lond., 1860, p. 439 (Ebon Is.}. --Pupa hyalina 

 ZELEBOR, in Pfeiffer's Monographia Heliceorum Viventium, 

 vi, 1868, p. 329. Vertigo nacca GOULD, Proc. Boston Soc. N. 

 H., 1862, p. 280; Otia Conch., p. 237 (Hawaii). Bifidaria 

 pediculus var. nacca Gld., ANCEY, Proc. Malac. Soc. London, 

 vi, 1904, p. 126 (Waipio Valley, Hawaii). -- Pupa artensis 

 MONTROUZIER, Journ. de Conchyl., vii, 1859, p. 288, pi. 8, f. 4. 

 CROSSE, J. de C., 1894, p. 301. Pupa (Vertigo) rossiteri BRA- 

 ZIER, Proc. Linn. Soc. N. S. Wales, i, 1877, p. 18. 



The Marquesas shells may be taken as the types. PI. 25, 

 figs. 1, 2, 3 represent specimens collected by C. D. Voy in the 

 Marquesas, exact island not stated. The parietal and angular 

 lamella? are separate and parallel anteriorly, the angular 

 being sigmoid, and high where it joins the parietal ; the pari- 

 etal is somewhat curved, the concavity of the curve being 

 towards the columella (fig. 2). In a front view, the parietal 

 lamella is seen to lean towards the columella. In some ex- 

 amples there is an extremely low, scarcely noticeable infra- 

 parietal nodule, in others none. The columellar lamella is 

 stout, short and horizontal. From its inner end a very low 

 callous ascends, obliquely receding, on the axis. The lower 

 palatal plica is rather long and strong; the upper is shorter 

 and converges a little towards the lower, inwardly. The basal 

 plica is much smaller, tubercular, and set rather deeply. The 

 palatal callous is rather diffuse and indistinct. Length 2.6, 

 diam. above aperture 1.3 mm. 



A more slender specimen in the same lot is drawn in pi. 25, 

 fig. 3. The angular lamella is more closely joined to the 

 parietal than in the typical form. 



The most conspicuous variation is in the basal plica, which 

 may be well developed, minute, or wholly wanting among 

 specimens of the same lot, in the Society, Samoa, Hervey, 

 Fiji and other groups; yet in Polynesia it is absent in a 

 minority of examples in every case, so far as I know. In the 

 varieties from the Philippines and Hawaii the basal fold 

 seems to be always absent or quite minute. 



The infraparietal tubercle is also found in a minority of 

 the specimens, but I have noted its presence in localities as 



