a comparison of the parts in the Batrachia, and of the sacral region in certain groups of the birds, and, in a somewhat technical summary, state their belief that, although often very puzzling and complicated from occasional variations in species and otherwise, the true sacral vertebræ may be defined in all Vertebrates above fishes where hind limbs are well developed.
A contribution on Corals, viz. "Notes on the genus Alveolites (Lamarck) and on some Allied Forms of Palæozoic Corals," by Prof. H. Alleyne Nicholson and Mr. Robert Etheridge, Jun., in the absence of those gentlemen, was read by the Secretary. It seems, according to these authors' researches, that the name Alveolites covers a multitude of forms which are not always united by relations of genuine affinity; even definition of the so-called type-forms are subject to different interpretations. To clear difficulties examination of a large series has been instituted, and microscopic sections, whenever available, have been made and carefully compared. Discussing the characters and attributes of the genus, and placing the question in its historical aspect, they proceed by taking the affinities of the several species in groups:—
Group A.—Alveolites suborbicularis (Lamarck), along with which may be placed A. compressa (Edw. & Ham.), A. Labechei (E. & H.), and A. Grayi (E. & H.); these agreeing, however, in many respects with the genus Favosites.
Group B.—Cœmites (Eichwald): not easily separated from the foregoing.
Group C.—Brachypora (Lindström). The A. Fischeri (Bill.) and A. frondosa are referable to this genus.
Group D.—Alveolites septosa (Fleming), with which they add Chætites radians (Fisch.) and A. depressa (Flem.) as natural allies.
Group E.—Chætites (Fisch.), with Monticulipora (D'Orb.) and Stenopora (Lonsd.), have much in common with Alveolites and Favosites.
Group F.—Alveolites Goldfussi (Bill.), with which A. Rœmeri is allied, comes near A. Tongti (E. & H.), which latter Lindström puts with Favosites; but further investigation is necessary as to these latter.
Mr. Alfred W. Bennett exhibited and made remarks on some specimens of abnormal primroses; and Mr. G.S. Boulger read a short paper on the perfoliate pennycress (Thlaspi perfoliatum).—James Murie.
Zoological Society of London.
April 17, 1877.—Osbert Salvin, Esq., F.R.S., in the chair.
The Secretary read a report on the additions that had been made to the Society's Menagerie during the month of March, and called particular attention to a collection of rare Himalayan Passeres, purchased March 8th,
