Mr. R. T. Lowe on a new Madeiran Helix. 45 
In the paler violet-grey or chalky-whitish-shelled examples, 
the animal is much paler than in the brownish flesh-coloured 
or purplish-shelled individuals. 
Shell rather thin, light, and fragile; opake, but pellucid when 
held up to the light; of a uniform peculiar dull-brownish 
flesh-colour or livid purplish, sometimes, even in living exam- 
ples, of a pale violet-grey or lead-colour or chalky-white, en- 
tirely without lustre or polish. Shape planorbiform, orbicular, 
depressed, with the spire flattened and but slightly convex, 
sharply keeled whilst young, but either without any keel or ob- 
scurely double-keeled when adult, the keel minutely but not 
regularly toothed in the young shell. The sculpture is very 
elegant and complex: above, the volutions are regularly and 
distinctly, but not strongly, plaited at their upper edge with 
short, equidistant, oblique ribs radiating from the suture about 
half-way across their breadth; beneath, they are very regularly 
and strongly ribbed and grooved spirally, the somewhat broad 
or flattened ribs being also beautifully cancellated by regular, 
sharp, equidistant, annular or transverse finer riblets. Whilst 
there is only one larger or more prominent spiral rib above the 
evanescent keel on the last volution, there are usually about 
eight or ten below it ; and sometimes the uppermost of these is 
stronger and a little remote, and separated by a broader or 
deeper groove from the rest below, forming a sort of secondary 
lower keel. Again, on the upper side the volutions, and espe- 
cially the last, are often marked with flexuose or zigzag, very 
oblique waved striz, as in H. Delphinula; and on both sides 
they are found, under the lens, to be covered with excessively 
fine and thickly crowded, close-set, transverse striz, passing 
along the annular and across the spiral ribs and their inter- 
stices. Thus, in well-developed individuals, there are four di- 
stinct systems of sculpture, viz. the spiral and annular ribs, 
and the flexuose and microscopic striz. 
In shape and general aspect, H. delphinuloides bears a marked 
resemblance, as already mentioned, to some of the flattened 
discoidal Cyclostomata, and in colour it is often very like C. ele- 
gans, Mull. The large, open, spiral, beautifully grooved and 
cancellated umbilicus recalls to mind that of the marine genera 
Solarium and Delphinula, Lam. ; and it is as much with reference 
to this analogy as to its affinity with Heliz Delphinula, Lowe, 
that I have named the species. 
H. delphinuloides is at once distinguished from H. Delphinula 
by wanting the sharp, thin, broad, projecting, rim-like keel ; by 
its flattened discoidal shape, and wider, shallower umbilicus : 
and from its much nearer ally, the Desertan fossil, H. coronula, 
Lowe, it differs in being more than twice as large; in the flat- 
