442 PYRAMIDELLIDZ. 
Exmouth, June 15th, 1853. 
A lively specimen shows that the foot is deeply notched in 
front, forming divergent acute auricles, imstead of beimg 
gently concave ; when fully extended, it reaches to the second 
volution, terminating in two symmetrical distinct pointed 
tails or streamers, which describe an angle of separation 
equal to that of the fore and middle fingers when placed 
as far apart as possible. This structure is of normal cha- 
racter, and not a mere emargination. 
Cu. opiiqua, Alder. 
Odostomia obliqua, Alder. 
, Brit. Moll. i. p. 291, pl. 96. f. 1; and iv. p. 280. 
The animal inhabits a very pale yellowish-white smooth shell 
of four rather tumid volutions, besides the apical reflexion, 
which is less than usual; the divisional lines are by no means 
oblique, and the body exceeds the length of the spire; its 
colour is a brilliant frosted subhyaline-white. The mantle is 
even, except a conspicuous tubular fold at the upper angle of 
the aperture. The rostrum is short and cloven in the centre 
almost to the eyes: each segment forms an arcuation to each 
side equal to an angle of 40°. The tentacula are strong, 
rather long, without much auriform folding, subrotund and 
taper, terminating with minute circular snow-white spots or 
inflations on the tips; the eyes are close together at the 
internal basal angles: the great peculiarity attached to the 
tentacula is, that instead of a moderate divergence on each 
side the rostrum, they form large arcuations, and are carried 
at right angles to the axis of the shell. Foot thin, rather 
concave in front, slightiy auricled, long and broad, and, when 
fully extended, reaching beyond the body whorl, terminating 
in a distinct bifurcation, which is very apparent in slow march, 
but on a quicker pace being attained, the fork m some mea- 
sure decreases in consequence of the greater extension of the 
foot: on asmall simple lobe, close to the junction of the 
foot with the body, is fixed an elongated, narrow, corneous, 
delicate ight yellow operculum with close-set oblique strize of 
growth. 
