ford, and by him rejected as spurious Spiti fossils. I think this fact quite conclusive, and that all the specimens so hastily rejected as Spiti fossils by Mr. Blanford must be restored to their proper place in this interesting and valuable collection.

I said before that I had only to deal with the facts, what the conclusions derived from those facts may be is not now under discussion, and whether there be in the Spiti district Liassic beds or whether these Liassic species* occur in the same beds with others, supposed to belong to different periods are questions which must await future solution. I regret that the circumstances I have mentioned above, (viz., that this paper by Mr. Blanford in its present state never had come before the Society or Council) prevented my having an opportunity of making the author acquainted with the fact, that in another portion of Dr. Gerard's Spiti collections, several specimens existed of the very species which, on such insufficient grounds, he has rejected here. I cannot, however, conclude without again directing serious attention to the very great mischief arising from dealing with questions of fact in this way. If the fact of the occurrence of certain forms in certain places is to be thus questioned, and fancy or some supposed mineral resemblance is to be accepted as negativing the deliberate statements of those who had collected the fossils, supported by the evidence of careful investigators who had examined these fossils almost immediately after their discovery, (and not thirty years after), there can be no progress. It would be infinitely better, and infinitely safer, to leave such specimens, as they are said to have been found, without labels, or even to throw them out, than to falsify all the landmarks of science by exhibiting them with localities attached which are only imaginative. The specimens referred to are now (September 18th, 1863,) put out in the Society's Museum (by whose authority I know not) mounted and carefully named and marked, Upper Lias, Whitby, England, without any note of doubt, and without any reference whatever to the fact that they had ever been even supposed to come from Spiti. Collections thus treated are worse than useless, they are mischievous.

occur in the Society's collection; also Am. crassus, Phillips, a true Liassic species but of which specimens do not occur in the Society's cabinet.

Ceratites Himalayanus, Blanford, is exhibited in the Society's collection as from the Upper Lias, Spiti valley.

www.

Notes on the variation of some Indian and Burmese Helicidæ, with an attempt at their re-arrangement, together with descriptions of new Burmese Gasteropoda.-By W. THEOBALD, Esq., Junior.

Since my paper on the distribution of our Indian terrestrial Mollusca was read at the February meeting of the Asiatic Society, several new species have accumulated on my hands, which I propose to describe in the present paper, and at the same time, to offer some remarks on certain nearly allied forms, which a careful examination compels me to consider, as merely well marked and persistent types of one species, connected as they are by intermediate forms, whose number is constantly on the increase.

The question of where variation ends and specific separation is called for, is of course not easily settled by any precise rule, and has always been regarded as depending more or less on the peculiar views or idiosyncracy of the individual naturalist, and has resulted in the manufacture of an erroneous number of new species, ostensibly of equal value, but many of them in reality entitled to no higher rank than varieties. I myself have offended in this way; but whilst deprecating for the future the creation of species, in the unqualified manner hitherto too common, I prefer a specific (or sub-specific) name for all well marked local forms, to the method advocated by some, of indicating such shells by a letter of the alphabet, as var A or var B of the type, or first described individual, however little it may merit such distinction save on the ground of mere priority.

My friend Mr. H. F. Blanford, has already done good service by decimating the ranks of shadowy species ranged under the genus Tanalia, in his paper in Volume XXIII. of the Linnæan Transactions, wherein he reduces the twenty-six recorded species of the genus to two, Tanalia violacea, Layard, and T. aculeata, Gmel. which last shell exults in no less than twenty-four synonyms, (twelve contributed by Reeve, nine by Dohrn and three by Layard).

This genus (Tanalia) well illustrates in my opinion the advantage of retaining a distinctive name for well marked types of what, critically viewed, is but one species, for a considerable amount of obscurity, quite unredeemed by superior brevity, results from the use of simple letters, rather than well chosen and distinctive epithets for well marked local types, many of which have hitherto, though erro

neously, stood as distinct species. Whilst therefore concurring in the results of Mr. Blanford's examination of the genus Tanalia, I would prefer retaining the known designations of such well marked types as T. Tennentii, T. neritoides, and the like, to recording them all as T. aculeata, Geml. var. A or var. B.

The alphabetical or numerical method of discriminating varieties, would certainly possess considerable advantages if all the varieties of a species could be arranged in an unbroken right line, instead of one very much given to ramification, but even in that case the type species by priority would often have to be set aside, as falling naturally into some other position, than at the head of the series; I therefore shall retain, in this paper, many names which I now regard as of merely sub-specific value instead of discarding them in toto as soon as their identity, if critically considered, with some previous species is established; and shall on the same principle, bestow distinctive names on those which of the shells herein described I regard as merely local races.

It might at first be imagined that strong support was derivable, from the enormous variation of form of some widely spread species, for the Darwinian view of the gradual extension by migration of all species in space, and the simultaneous change undergone by them, to meet changed conditions of existence, resulting in local types, and ultimately by the decay of intermediate forms, in so called distinct species; but this idea is speedily negatived by the consideration, that though some species exhibit an amount of variation, which might be plausibly accounted for by the Darwinian theory, yet others not less widely spread, either as to time or place, exhibit little or no such tendency, which seems rather a peculiarity (of temperament so to say,) marking certain species, than the result of a general law regulating the development of all. A notable example of this is afforded by the little Helix labyrinthica, Say, which has remained unchanged during the eons which have elapsed since the Eocene period, occurring fossil in the Headon beds on the Isle of Wight, and living at the present day in Alabama. Bulimus punctatus and Bulimus pullus, Gray, may also be quoted, the first species inhabiting, unchanged to any perceptible extent, the plains of India and the shores of Mozambique, whilst the last ranges widely through India and some of the neighbouring countries, (Burma and even the shores of the Red Sea,) and occurs fossil in the alluvial deposits in the Nerbudda valley, where individuals, undis

tinguishable from recent specimens, accompany the extinct fauna which embraced the Hexaprotodon and its congeners: (vide Memoirs of the Geological Survey, Vol. II.)

Of species subject to considerable local variation, Helix Huttoni may be selected, if, as I am inclined to think, it may be regarded as specifically identical with H. rotatoria V. dem Busch; and the highly variable H. similaris, Fer., with respect to which it may here be remarked, that its most variable and dissimilar forms, are not those most widely dissociated in space, as might be surmised from the Darwinian explanation for such variations, as its local Indian forms more widely differ from the type and from one another, than individuals from the far off Mauritius and the Brazils.

HELIX SIMILARIS, Fér.

At the head of the varieties, as I regard them, of this species, I place H. scalpturita, B. This form inhabits the Irawadi valley above the British frontier, and is a stout well marked shell passing by degrees into H. Zoroaster, Th., though in this case as in others, the intermediate forms are usually scarcer individually and more variable than the types they tend to unite. Allied to some extent, but not very closely, is H. Peguensis, B., from I believe, the Eastern parts of Pegu. H. Zoroaster which is intimately related to H. scalpturita on the one hand and H. similaris on the other, occurs in tolerable number about Thaiet mio and the neighbourhood, and passes gradually into the type form of H. similaris. H. pilidion, B., is a thin-keeled shell related to H. similaris, from probably the same locality as H. Peguensis, and last comes the rotund, globular shell common about Thaiet mio, Prome, &c., described by Benson as H. bolus. Several intermediate gradations occur between H. Zoroaster, H. bolus and the type H. similaris, but not sufficiently marked to require special enumeration; the whole may thus naturally be arranged as below, those marked thus being aberrant, the forms required to connect them more closely, having probably to be discovered.

*

Of H. cestus I have but three individuals, but they seem to form merely a well marked local type of the species under consideration. They occur with or without the band; the two varieties differing slightly in other respects as well; somewhat as H. Peguensis does from H. scalpturita, the bandless variety of which it much resembles, H. ROTATORIA, V. dem Busch.

This species, though affording strongly marked varieties, is not a variable one individually. We have in Burma the larger and more common form of seventeen millemeters, which varies very slightly, and a smaller form (H. Arakanensis, Th.) of only thirteen millemeters, with a higher spire, which also varies very little; and evidently connects the species with H. Huttoni, the largest specimen of which from India in my possession is also thirteen mills. but with a flatter spire than the small var. of H. rotatoria. There is also the very variable race of H. Akowktongensis, Th., with its usually flattened spire, holding a place between the large and small forms of H. rotatoria.

H. tapeina and H. Phayrei, Th. also claim a place near the type of the species, the first nearly equalling a large H. rotatoria in size, whilst closely resembling a small one in form, and the second differing from the type rotatoria, in its narrower umbilicus, and more strongly marked sculpture. The little Indian H. Huttoni follows, chiefly differing in its small size, which may be averaged at eleven mills.

Most aberrant of all comes H. Oldhami, B. with its depressed spire, but it hardly differs more widely (save in one extra whorl), from a large rotatoria in form, than specimens of H. Akowktongensis, Th. do from one another. Intermediate forms are, however, requisite to con nect H. Oldhami, B. as closely as the rest are.

H. rotatoria, V. d. Busch. Irawadi valley, below the frontier.
Khasi Hills.

H. tapeina, B.

H. Phayrei, Th.

H. Arakanensis, Th.

H. Akowktongensis, Th.

H. Huttoni, B.

H. Oldhami, B.*

Irawadi valley, above the frontier.
Arakan hills and Irawadi valley.
Irawadi valley.

Himalayas, Southern India.

Irawadi valley, above the frontier. HELIX FALLACIOSA, Fer., is another variable shell, presenting three distinct types, as H. asperella, Pi. and its allied forms II. Nagporensis, Pfr. and H. propinqua, Pfr. H. fallaciosa, Fér., with its varieties and ally H. Helferi, B. and H. ruginosa, Fér. with its ally II. crassicostata, B.