Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/582

496 496 A. j. jukes-browne's supplementary

Mesochilotoma striata, Seeley.

Mesochilotoma striata, Seeley Ann. & Mag. Nat. Hist. ser. 3, vol. vii. p. 284.

The single specimen to receive which the above genns and species have been proposed, is a small cast, not half an inch long, and imbedded in phosphate, so that only one side of it is exposed to view.

It is, moreover, imperfect, both the apical and anterior portions being broken off, so that only parts of four whorls are visible. The onter lip is therefore not present, although Mr. Seeley describes it as having " a notch which forms a keel round the middle of the whorl ; " this keel he states to be crossed by the lines of growth ; and perhaps it was from the evidence these would afford that he presumed the outer lip to have been notched.

These lines are not very distinct ; there is no doubt, however, about the presence of the keel and of the faint striae above and below it ; but in my opinion the keel bears a greater resemblance to that on some forms of Aporrhais than to that of Pleuroiomaria. Mr. Seeley believes it to have had a short canal ; but he adds, " I have not yet seen the canal, and only predict its being short from an examination of the broken uppermost whorl."

Now, so far as such a small and badly preserved specimen enables me to judge, I should be inclined to consider it the cast of a small Aporrhais carinella, a species which has just such a median keel with striae above and below. At any rate Mr. Seeley's description would apply equally well to the shell above mentioned ; and it is certainly much more likely to belong to this than to an entirely new genus and species, for the existence of which no other evidence is forthcoming.

Brachtstoma angtjlare, Seeley, sp.

Scalaria angularis, Seeley, Ann. & Mag. Nat. Hist. ser. 3, vii. p. 286, pi. xi. fig. 9.

Brachystoma angularis, Gardner, Geol. Mag. dec. 2, vol. iii. p. 160, pi. iv. fig. 11.

In 1861 Mr. Seeley described an imperfect cast in the collection of Mr. J. Carter under the name of Scalaria angularis, one side only of two whorls being visible on this specimen ; another frag- ment in the "Woodwardian Museum exhibited the three uppermost whorls of the spire.

There was also in the Museum a fine and nearly perfect cast, which, from the slight keel on the body-whorl, I supposed to be a new species of Aporrhais ; and last year I obtained a second specimen, but never suspected their identity with 8. angulans. Having, however, sent one of these to Mr. J. S. Gardner, he forwarded me a specimen from the Gault of Folkestone in which the shell was preserved, asking me to compare it with the Cambridge casts, as he suspected they all belonged to the same species. A careful inspec-