382 LITTORINIM:. 



T. MONTAGUI, Lowe. 



T. Montagui, Brit. Moll. iii. p. 317, pi. 99. f. 1 J (animal) pi. F.F. 

 f. 10 (as T. truncatula). 



Animal, when adult, occupying a yellow or whitish sub- 

 cylindrical shell of four flattish volutions, deeply divided, and 

 furnished with close-set, somewhat irregular costellse ; 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 plain 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-pink. The tongue at its deeply-seated terminus 

 displays a pair of white jaws; it can be seen through the 

 oesophagus, 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 think 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 ossophageal 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 



