376 Reports and Proceedings — 



figure of a horse described in a former paper. The authors finally 

 dwelt briefly upon the characteristics of the caves in prehistoric and 

 historic times, and indicated some of the anthropological points of 

 interest connected therewith. 



3. "On the Pre-Cambrian Rocks of Shropshire." Parti. By C. 

 Callaway, Esq., D.Sc. Lond., F.G.S. 



The author commenced by describing the physical geography of the 

 ridges intervening between the vicinity of Wellington and the Long- 

 mynds, viz. Lilleshall Hill, the Wrekin, and the chain of the Caradoc 

 Hills. He passed on to describe the stratigraphy. At Lilleshall are 

 slaty beds dipping about N.N.W., and a rhyolitic agglomerate. At 

 the N. end of the Wrekin a granitoid soil, probably of clastic origin, 

 with a mass of decomposed intrusive rhyolite. The Wrekin consists 

 of rhyolitic agglomerates, with (probably) lava-flows and a few basalt 

 dykes, the general dip of the bedded rocks being to the north. At the 

 southern end (Primrose Hill) granitoid gneisses (some closely resem- 

 bling the hornblendic gneiss of Malvern) occur. In the Caradoc range 

 intrusive greenstones are more largely developed ; but here also are 

 bedded Pre-Cambrian rocks. Other smaller exposures in this vicinity 

 were also described. The prevalent strike is over the whole district 

 about E.N.E.-W.S.W. The evidence of their age is often very clear, 

 as they are overlain (with marked unconformity) by quartzites (some- 

 times containing rhyolitic fragments) which are clearly much older 

 than the Hollybush Sandstones. 



4. "On the Occurrence of a Remarkable and apparently New 

 Mineral in the Rocks of Inverness-shire." By William lolly, Esq., 

 E.R.S.E., etc., and J. Macdonald-Cameron, F.C.S., etc. 



In this paper the authors refer to a blue mineral of a somewhat 

 remarkable character, which was specially noticed at an excursion 

 of the Inverness Eield Club in September, 1877. This excursion was 

 made to Englishton Moor and neighbourhood, distant westwards, from 

 Inverness, about five miles, where the mineral occurs in scattered 

 blocks. It has since been noticed at Moniack Burn, Reelig Glen, and 

 South Clunes Farm, all in the same direction, but distant from Inver- 

 ness about ten miles ; also near Dochfour House, at the north end of 

 Loch Ness, close by Dochgarroch Lock on the Caledonian Canal. In 

 colour and general appearance this mineral resembles crocidolite, but 

 analyses point to its being more nearly related to aegirite, a member of 

 the amphibole group, which has the general formula Si3(^R7-|-R 3 ). 



The mean of several analyses shows it to have the composition 

 6Si0 2 , Fe 2 3 , 2MgO. 



II.— June 25, 1879.— Prof. P. Martin Duncan, M.B., F.R.S., Vice- 

 President, in the Chair. — The following communications were read : — ■ 



1. "On the Evidence that certain Species of Ichthyosaurus were 

 Viviparous." By Prof. H. G. Seeley, F.R.S., F.G.S. 



In this paper the author described certain specimens of Ichthyosaurs 

 in which the remains of one or more small individuals have been 

 preserved within the body-cavity of larger ones. One of these was 

 described and figured in 1822 by Jager ; a notice of another was 

 published in 1846 by Dr. Chaning-Pearce, who suggested that it 

 furnished evidence in favour of the viviparity of the Ichthyosaurs. 



