My dear Sir

I think I sh^d. have no difficulty in pronouncing on a fair set of extinct fossil Helices whether they belonged to the Madⁿ. group.¹ The Madⁿ. & P^to. Sⁿ. Land Shells—recent and fossil—have a peculiar facies or habit, w^ch., however hard to express (as I need hardly say to you) in words, a practised eye can scarcely fail in seizing—just as you say “this man looks like a Scotchman Frenchman or German”. I might say more: that in the Madⁿ. Helices there are certain definite characters, analogous to the high cheekbones of the firstnamed worthies, vindicating such discrimination. They are generally shells of small or moderate size & flattened shape, thickish in proportion, & above all peculiarly granulated, ribbed or plicate, undulated or reticulated in sculpture— the peristome is generally circinate or continuous &, the aperture consequently regularly round or oval. Of course there are exceptions—species of ambiguous or annectent char^s.— w^ch. seen alone w^d. puzzle: and therefore I used the word set at starting. But I speak confidently, setting aside anomalies, on a fair average.

I think I c^d. at once distinguish a set of 30 or 40 fossil Helices of the Madⁿ. type from a like set of Canarian, Portuguese, French or Italian:—Sicilian w^d. be more difficult. So I suspect w^d. be N. West African (say Mogadorian). But of the latter I have not sufficient data to speak positively.

Are you aware how very few of our Madⁿ. fossil forms (species and vars.) can safely be pronounced to be absolutely extinct? viz. in Mad^a. 10 out of about 35; but of species proper only 6 or 7 out of 35. In Porto S^to. 7 or 8 forms or 5 or 6 species are extinct out of about 60 forms or 55–56 species.

See App^x. to my Primitiæ² (Van Voorst 1851) pp. XIV, XV. In p. XIV observe that I now consider H. fausta b and c to constitute a good species = H. arcinella Lowe.³

I have not very lately restudied the P^to. Sⁿ. Shells so closely as the Madⁿ. proper: but the above numbers cannot be far from accurate.

Thanks for y^r. proposed disposal of the Cirripedia at Wollaston’s⁴ for me where they will be quite safe. Thanks too for saving me a complete set I shall greatly prize them as from you.⁵

Allowing some irregularity or licence, I think the rule is that neuter words in a form neuter compounds. I have not time to look into the matter: but cqalla, vaqacla, uqacla, rparla, arla at once occur in point. Their compounds are I believe all neuter.

Y^rs. sinc^ly | R. T. Lowe

The P^to. Sⁿ. Rabbits⁶ like the Madⁿ. are merely the common Europ. Stock run wild, I believe. But I never examined accurately. There is certainly no outward appreciable difference except size. They are generally small.