THE MOLLUSCA—HEDLEY. 431 
thrown out of symmetry with most Rissoina. 
Sculpture—as usual with the genus, the longi- 
tudinal sculpture predominates to begin with ; 
the third, or first sculptured, whorl show- 
ing a few stout plications. On the following 
whorl fine spiral threads are visible in the 
interstices ; on the whorl beneath these are 
magnified to substantial lyre ; and on the next 
or penultimate they have doubled in number, 
and rival the longitudinal in stature, at their 
intersection beads appear. On the last whorl 
the longitudinal, as such, have faded away, their 
influence showing in fine beads perceptible on 
the sutural and less distinct on a few of the 
nearer lyrze; the spiral lyre have now increased 
to nearly thirty, the anterior smooth, the pos- 
terior with evanescent beading. These are sharply raised threads, 
half the width of their interstices, evenly arranged, extending 
from the suture to the anterior point of the shell where they are 
smaller and more crowded. Aperture almost perpendicular, oval, 
anteriorly with a short perpendicular spout which falls short of 
the anterior margin; columella broad, obliquely and sharply 
truncated. From this truncation a wide and thick callus extends 
across the body whorl to the posterior angle of the aperture. Here 
the lip is sharply bent. The outer bevelled lip projects broadly as 
a heavy varix crossed by fifteen of the spiral lyre, the central 
couple of which are smaller and nearer together. Length 44, 
breadth 2 mm. 
Five specimens in shallow water in the lagoon. 
The extinction of longitudinal and the supremacy of spiral 
sculpture is unfrequent in the genus. Such species have been 
separated by Nevill as the Section Morchiella. From all there 
included the novelty differs by smaller size, more numerous lyre, 
and truncated columella. 
Rissorina PLICATA, Adams. 
(Fig. 13). 
Adams, Proce, Zool. Soc., 1851, p. 264; Mohrenstern, 
Denk. Akad. Wiss., xix., 1860, p. 125, pl. iii., 
fig. 21; Weinkauff, Conch. Cab., i., 22, 1885, 
p. 23, pl. viii., figs. 5, 6. 
Rissoina turricula, Pease, Proc. Zool. Soc., 1860, 
p. 438, 
Two specimens from Funafuti are thus deter- 
mined. The species appears to vary greatly in size. 
Whereas the type is described as being 54 mm, 
long, the Ellice examples are but 2} mm. The 
