Page:The Zoologist, 3rd series, vol 2 (1878).djvu/250

228 The Rev. H.H. Higgins exhibited photographs of a large beetle, the Dynastes neptunus of Schonherr, and of an undetermined species of locust from Borneo. The latter has resemblances to the genus Pseudophyllus, but measures nine inches and a half iu the expanse of its wings.

A paper, "On the Geographical Distribution of the Gulls and Terns (Laridæ)" was read by Mr. Howard Saunders. This group, comprising four subfamilies,—Sterninæ (Terns), Rhynchopsinæ (Skimmers), Larinæ (Gulls). and Stercorarinæ (Skuas),—notwithstanding wide marine dispersion, possesses several remarkable isolated forms. In numbers there are about fifty-three species of Terns and Skimmers, fifty Gulls, and six Skua Gulls. After entering into detail as regards various forms, their peculiarities of habit, and distribution, the author pointed out that the majority of the typical Larinæ are found in the North Pacific, where alone the arctic and white primaried forms are connected, through Larus glaucescens, with the group which have distinctly barred primaries. In the same area, also, is it shown where the three-toed Rissa begins to deviate from the typical fourtoed gulls, and the line of connection traced between the only two species with forked tails, Xema. Here, also, can be traced the typical Hooded Gulls, of which L. ridibundus is the Palaearctic representative, and which in L. glaucoides extends to the Magellan Straits, while in the eastern hemisphere it is not found beyond 10° N. lat. Moreover, in the North Pacific there obtains the peculiarly coloured Tern, Sterna aleutica, which connects the typical Sternæ with the intertropical Sooty Terns, S. lunata, S. anæstheta, and S.fuliginosa. Of isolated groups, which have no apparent connection with the Pacific, may be mentioned the New Zealand Larus Bulleri and L. scopulinus, the Australian L. Novæ-hollandia, and the South African L. Hartlaubi. In the Arctic region there are the two isolated specialized genera of Gulls, Pagophila and Rhodostethia (the Ivory Gull and Ross's Gull), which are not known on the Pacific side; whilst amongst the Terns the intertropical genera, Nænia, Anous, and Gygis, although somewhat related among themselves, offer no particular points of union with the typical Sterninæ. The bulk of the evidence collected by Mr. Saunders favours the idea that the North Pacific is probably the centre of dispersion of these chiefly oceanic or shore-frequenting birds.

Mr. J. Clarke Hawkshaw next read—"Notes on the action of Limpets (Patella) in sinking pits in, and abrading the surface of, the Chalk, at Dover." The author states the abrasions and finely-grooved hollows are made by the lingual teeth of the limpet when feeding on the fine coating of seaweed which covers the surface of the chalk between high and low water mark. He described the limpet's track as generally of a zigzag pattern, and exhibited specimens. These bare patches vary from eight to fourteen inches square, and about a line deep. There is, moreover, a