44 Reports and Proceedings — 



The Trilotite described was obtained by Dr. W. G. Atherstone, F.G.S., from 

 the Cock's Comb Mountains at the Cape of Good Hope, and was preserved iu 

 a nodule, the impression retained in which, when broken, furnished the most instruc- 

 tive details as to its structure. Each of the eleven thoracic segments was furnished 

 with a long median dorsal spine, giving to the profile of the animal a crested 

 appearance ; on each side of this the axis of the segment bears two or three tubercles, 

 and the ridge of the pleurse four or five tubercles. The tail is terminated by a spine 

 more than half an inch in length, and all the spines are annulated. For this Trilobite 

 the author proposed the name of Enm'iiiurus cristagalli, although with some doubt 

 as to the genus, the head being only imperfectly preserved. 



Discussion. — Mr. Evans called attention to the importance of examining the matrix 

 out of which fossil Trilobites were extracted, as were it not for the matrix the spines 

 on this specimen would have escaped observation. 



Mr. Woodward had not until the day of the meeting been able to examine the 

 Trilobites collected at the Cape by the late Mr. Bain, and had at first sight doubted 

 whether the fossil he had described might not be identical with Typhloniscus Bainii 

 of Salter; but on closer examination he was inclined to consider it distinct. He 

 preferred for the present retaining it in the genus JEnerinurus, but still with some 

 doubt. 



5. "On an Extensive Landslip at Glenorchy, Tasmania." By S. H. Wintle, Esq. 

 Communicated by Professor Eamsay, F.R.S., V.P.G.S. 



In this paper the author described the effects of an extensive landslip from the 

 northern face of Mount Wellington, in Glenorchy, about five miles from Hobart 

 Town. It took place during the night of the 4th June, 1872, after a rainfall of 4| 

 inches in twenty-four hours. The de'h-is descended nearly 2000 feet into the bed of 

 the rivulet of Glenorchy. By the force of the accompanying torrent great quantities 

 of huge trees, some of them 200 feet long, were piled up in vast heaps, mixed with 

 boulders, agricultural implements, fences, and other objects. The trees were de- 

 prived of bark, branches, and roots. The Carboniferous limestone forming the bed 

 of the rivulet was exposed by the washing of the torrent for more than two miles; 

 natural sections showed the blue, shelly limestone, alternating with beds of mudstone 

 and shales. At one part the author found both banks of the rivulet lined with small, 

 sharply angular fragments of dioritic greenstone from the summit of the mountain ; 

 large blocks of the same rock also occurred. The author described the beds displayed 

 in a section close to the base of the great landslip, above which is a smooth surface 

 of greenstone, covered with prostrate trees and immense blocks of greenstone half 

 buried in yellow clay and sludge. The whole neighbourhood was described by the 

 author as presenting evidences of former landslips. The author further described the 

 appearances presented by the upper winding part of the gully traversed by the 

 torrent ; and, in conclusion, noticed certain results of similar phenomena as displayed 

 in the same district. The paper was illustrated by three stereoscopic views. 



Discussion. — Mr. W. T. Blanford mentioned somewhat similar landslips as occur- 

 ring in the Himalayas, and on fully as extensive a scale. In some cases not only the 

 loose soil but large masses of solid rock were carried down. 



Mr, Drew mentioned other instances in India of a similar character, but thought 

 that in the Himalayas frost also assisted in the work of destruction. 



II. — December. 4, 1872. — Prof. P. Martin Duncan, F.E.S., Vice-President, in 

 the Chair. — The following communications were read : — 



1. *' On the Tremadoc Eocks in the Neighbourhood of St. David's, South Wales." 

 By Henry Hicks, Esq., F.G.S. 



The author stated that Tremadoc rocks occur in three distinct places near St. 

 David's, namely in Eamsey Island, at the north end of Whitesand Bay, and over a 

 considerable tract of country about five miles east of St. David's. They rest con- 

 formably on the Lingula-flags, and are about 1000 feet thick in Eamsey Island. The 

 author noticed the fossils found in these deposits, nearly all of which are of new 

 species, and stated that the palseontological evidence proves these rocks to be nearly 

 allied to, if not identical with, the lower part of the Tremadoc rocks of North Wales. 

 The Upper Tremadoc rocks of North Wales seem to be represented at St. David's by 

 the so-called Arenig rocks which overlie the deposits described in the present paper. 



The new species described by the author are as follows : — 



Neseuretiis (g. n. Trilob.) Ramseyensis, quadratus, recurvafus, and elongatus. 

 Niobe Menapice and solvensis. 

 Theca Davidii, 



