1911.] NATURAL SCIENCES OF PHILADELPHIA. 195 
palatal fold distinct. The larger ones from this place are typical in 
shape; the smaller are shorter than syngenes from any other locality 
in our series. 
Fig. 7.—Pupilla syngenes Pils. Spectacle Cove, near Bass Trail. Lengths 3.8, 
3.5 and 3.2 mm. 
Along the upper slope of the Bass or Mystic Spring Trail, Station 2, 
there is an extensive colony of syngenid forms. We found them most 
abundant in the humus, among low brushwood, about 200 feet below 
the rim. Two forms occur here together, a dextral form, P. s. dextro- 
versa, and a sinistral, P. s. avus, described below, in about equal 
numbers, 272 of the former and 256 of the latter in the lot collected. 
The P. s. dextroversa are typical in shape, but larger than the types; 
the crest is wide and rather far from the lip-edge; a lower palatal 
tooth is developed. Specimens measure: 
Length 4.5, diam. 1.8 mm., whorls 10. 
iT a7: a 18 * 66 9. 
Fig. 8.—Punpilla syngenes form dextroversa P. and V. Bass Trail, about 200 feet 
below the rim. Lengths 4.5 and 3.75 mm. 
The last is the smallest adult seen from this place; most examples 
are over 4mm. long. Specimens of this lot are figured, fig. 8. 
