36 Reports and Proceedings — Linnean Society of London. 



abundant and widely distributed are boulders of limestone of Silurian 

 age, belonging to wbat is known as tbe Orthoceren-Kalk, the 

 Korallen-Kalk, and tbe Beyrichien-Kalk. Tbe Silurian and Cam- 

 brian erratics have been brought partly from Sweden and partly 

 from the Russian Baltic provinces. Boulders of Devonian age are 

 rare, and limited to the eastern provinces of Prussia ; they have un- 

 doubtedly been derived from Livonia and Courland. Only a few 

 scattered fragments of Carboniferous and Permian rocks have been 

 met with, and their original localities are unknown ; whilst Triassic 

 boulders appear to be entirely absent. Jurassic boulders are only 

 met with in the Eastern half of the Boulder-clay area, as far as the 

 Elbe. Their source is unknown, but they are most nearly related 

 to Jurassic strata in Courland. Cretaceous boulders extend over the 

 entire area ; they belong botb to the Cenomanian, Turonian, and 

 Senonian divisions ; the most abundant are flints, probably derived 

 from the Chalk of Denmark and the South of Sweden. No erratics 

 are known from the Gault and the Neocomian ; but calcareous frag- 

 ments of Wealden age are met with in Brandenburg. These, how- 

 ever, do not correspond with the Wealden strata of N.W. Germany, 

 and their origin is unknown. Tertiary erratics are rare and of 

 limited distribution, but fossil wood and amber are widely scattered 

 in the Boulder-clay. 



The direction in which tbe erratics have travelled is partly from 

 North to South, and partly from North-east to South-west. There 

 is no indication of any movement from N.W. to S.E., and no erratics 

 from Norway are met with in the Boulder-clay of Germany. The 

 author believes that the Boulder-clay bas been distributed by floating 

 ice, a view which is opposed to that held by the large majority of 

 recent investigators of the subject, who maintain that it is due to tbe 

 direct action of glacial or inland ice. G. J. H. 



IR-IEIPOIRTS -A-IriTZD HPIROCIEIEIDIIDsra-S- 



I. — Linnean Society of London. 



November 5, 1885.— Sir John Lubbock, Bart., M.P., F.E.S., 

 President, in tbe chair. 



The first part of an exhaustive Monograph "On Recent 

 Bracbiopoda," accompanied by illustrations, by the late Dr. Thomas 

 Davidson, F.B.S., etc., was read by the Secretary. In this the 

 author reviews the labours of his predecessors in the same field, 

 with regard to the shell, the anatomy of the adult animal, and 

 its embryology. As regards the perplexing question of affinities, 

 be remarks : — " Now, althougb I do not admit tbe Bracbiopoda 

 to be Worms, they, as well as the Mollusca and some other 

 groups of Invertebrates, may have originally diverged from an 

 ancestral vermiform stem, sucb as the remarkable worm-like 

 mollusc, Neomenia, would denote." He lays stress on tbe Bracbi- 

 opodous individual being tbe product of a single ovum, and not 

 giving rise to others by gemmation. He considers that tbe shell, 



