382 LITTORINID AL. 
T. Monracut, Lowe. 
T. Montagui, Brit. Moll. iii. p.317, pl. 99. f.1 5 (animal) pl. F.F. 
f. 10 (as T. truncatula). 
Animal, when adult, oceupyimg a yellow or whitish sub- 
cylindrical shell of four flattish volutions, deeply divided, and 
furnished with close-set, somewhat irregular costelle ; when 
young, before the apex is truncated, of 6-8 smoother and 
more taper gyrations. The peristome, in the completed shell, 
is entire, having the outer lip blunt and a little reflexed ; with 
respect to colour, it is of the palest yellowish-white, aspersed 
with very minute flake-white points, particularly the foot, 
with a patch of pink on the neck, caused by the colour of the 
buccal corneous plates showing through the pellucidity of the 
tissue. The mantle is plaim and even with the shell, but 
rather tumid at the margin: I did not observe much approach 
to the mantellar collar of the Helices. The rostrum is ridged 
or annulated, long, very broad, flat, emarginate at the end, 
forming on each side a curved compressed auricle, and cloven 
underneath vertically and slightly crosially; buccal appa- 
ratus reddish-pmk. The tongue at its deeply-seated terminus 
displays a pair of white jaws; it can be seen through the 
cesophagus, and is accompanied on each side by a linear 
streamer floating loose posteally. I am not certain whether 
these narrow, tape-like additions proceed from the buccal 
membrane or tongue,—I thmk the latter,—or they may 
possibly be salivary glands. 
The branchial plume is single, of an elongated, kidney- 
shaped figure, and has the usual constriction or sinus at the 
end nearest to the heart ; it can be detected with high powers 
in sunlight, through the body volution of pale, clear, thin 
shells; all the rest of the organs, including the single pale 
brown ganglion on each side the cesophageal collar on its upper 
surface, may be easily seen through the hyaline tissue of the 
neck and head. The flexible neck, and rostrum from its corru- 
gations, can be protruded to an extraordinary extent beyond the 
aperture. The head far exceeds the tentacula in length ; these 
are short, flat, broad, subtriangular, and diverge greatly, scarcely 
