430 JOHNSON: HELIX WATSONI, A NEW LAND SHELL. 
diately under the preceding whorl. Below the braiding on the 
lowest whorl of this shell, and on its underside, are about seven 
spiral costee, and these are crossed at right angles by numerous 
feebler ridges, thus forming a cancellated surface. The highest 
of the spiral costee forming a carina is crenate as in HZ. “arel/a, 
whilst in 4. grabhamz it is entire. Sometimes the underside of 
the lowest whorl is only partly sculptured into continuous ribs, 
the rest of the surface being studded with short discontinuous 
ridges, arranged spirally. In one of the eight specimens in my 
possession, the whole of the under-surface is rough, with such 
short discontinuous ridges distributed in a confused manner as 
are often seen in the sub-fossil shells of A. “zavella. The um- 
bilicus is not so wide and open as that of HZ. grabhamt. 
The shell is usually of a dark-brown colour. It has only 
five whorls ; it measures from 5°5 mm. to 6°5 mm. in diameter, 
and 3'5 mm. in height. 
Specimens of the shell here described were detected several 
years ago by the observant eye of Senhor J. M. Moniz, on that 
rocky islet at the east end of Madeira which bears the name of 
Ilheo dos Embarcadores, but as he omitted to note the exact 
locality, he was never afterwards able to find other specimens. 
This is another instance of the narrow limits within which some 
of the species are confined, both in Madeira and Porto Santo. 
The name of this shell has been given to it in compliment 
to one of the most careful investigators of the molluscan fauna 
of Madeira, the Rev. R. Boog Watson, LL.D. 
———_-0-__{_ 
Note on Tellina balthica.—My largest specimen (a white one) is 
13-inch in breadth. This mollusc is a great favourite with the gulls; they 
“line-up” at the water’s edge at the time of the incoming-tide, seize any 
living specimen of 7. dalthica or V. gallina, place it in safety, and when the 
shell gapes, insert the beak to prevent its closing, break out a piece and 
devour the contents at leisure. They care very little for AZ. stultorum, L. 
undata, T. papyracea, T. tenuzs, and 7. fabula, but sometimes attack D. 
vittatus and S. emsis, and always, so far as can be seen from a distance, 
treat 7. dalthica and V. gallina in the above-mentioned manner.-—A. Gs 
Stupps. (Read before the Conchological Society, May 12th, 1897). 
J.C., vili., July, 1897. 
