200 Mr. J. Miers on the Tribe Colletiese. to attain a larger size in our own seas than in the south of Europe : viz., Murex corallinus, Lachesis minima, Rissoa stri-atula, Donax politus, Avicula Tarentina, Galeomma Turtoni, and Trochus striatus. These are, according to the late Professor Edward Forbes, some of the principal representatives of the " Lusitanian " type. To these may be added species of Artemis, Cylichna, Mactra, Mangelia, Nassa, Natica, Neara, Pecten, Pectunculus, Syndosmya, Tapes, Tellina, Tornatella, Trochus, Turritella, Venus, and proba-bly of every other genus which is common to the European seas. I have purposely omitted any of the species which Mr. M 'Andrew may consider as " Arctic," " Boreal," or " Celtic," although I apprehend such geographical distinctions have no foundation in fact or in nature. The difference between Mr. M f Andrew and myself (or the error into which one of us has fallen) may have arisen from our respective collections being better furnished with specimens of the shells which each has had greater opportunities of procuring ; and it is to be hoped that further experience will show which of our conclusions is correct. XXIII. On the Tribe Colletiese, with some Observations on the Structure of the Seed in the Family of the Rhamnacese. By JOHN MIERS, F.R.S., F.L.S. &c. [Continued from p. 95.] In regard to the general structure of the flower in the Colle-tiecB, there is little to add beyond what we find recorded on the subject ; but it may be remarked that the lobes of the calycine border in that tribe, as in others of the Rhamnacea, have a prominent keel along the middle of their internal face, which terminates below the apex in an elevated callous gland, con-nected with two other raised lines that run along the border. These medial keels and glands have been supposed by some to be so many sterile stamens ; but Brongniart, with more truth, considers their appearance to be the result of the impression left upon the soft fleshy lobes of the calyx, while in aestivation, by the indentation of the enclosed petals and stamens : that such is the real cause, is shown in the instance of Gouania, where a similar carinal prominence exists in the calycine lobes, and, in addition, at the base of each keel is seen an acute scale, which is really the rudiment of an abortive stamen. Similar impressions are frequent in many other families where the floral envelopes have a valvate aestivation. We meet with another point of structure in the Colletiece, which, as far as I am aware, has not been noticed by botanists : I refer to the peculiar deve-
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