234. Bulletin American Museum of Natural History [Vol. LITI 
aperture is somewhat effuse below, the outer lip but little thickened, 
noticeably expanded, and somewhat sinuous in profile view. The colu- 
mellar and parietal margins are calloused and continuous. Columellar 
fold is rather strong, emerging nearly to the edge. Inside it diminishes 
rapidly upward, and disappears in the third whorl from the last. There 
are two deeply immersed and rather strong palatal folds. 
Length, 5.0 mm.; diameter, 1.9 mm.; 7)4 whorls. 
AG e a 4.6 66 66 17 ar 7 a 
This form differs from the sculptured specimens of S. minuta by 
the broader contour and the greater prominence of the carinz, but it 
may be doubted whether any definite line can be drawn. There seem to 
be nearly intermediate specimens in the series examined, and Ancey, 
who was no lumper, thought it merely a variety of minuta. 
In one specimen opened we find no palatal folds (Fig. 306); possibly 
they were removed in filing it, as several others show them (Fig. 30a). 
C 
Fig. 31. Syrnolopsis gracilis Pilsbry and Bequaert. a, type; 6, c, two smaller 
specimens. Tanganyika. 
Syrnolopsis gracilis, new species 
Text Figure 3la-c 
Lake Tanganyika: without more definite locality (L. Stappers 
Coll.). ; 
The shell is thin, very slender, resembling a Turritella in miniature; bluish under 
the thin, pale brown periostracum, somewhat glossy, with only very faint traces of 
growth-lines. The high initial 144 whorls are strongly convex, smooth; then two 
' Spiral angles appear, the lower one continuing to the penult whorl in the type (but in 
other examples disappearing sooner, or continuing to the last whorl). The whorls are 
