1869.] SCDPDEE COAL-FOKMATION MYEIOPODS. 441 



tnisive igneous rocks of the north of "Wales ; and it certainly appears 

 to me to be the one which applies to the rocks in question in the 

 Lake -district. He says : — " Lying, as they invariably do, either 

 amid the true volcanic rocks or in lower stratigraphical horizons, 

 and being for the most part felspathic, some of them may well be 

 the deep-seated masses from whence the lavas and ashes of the 

 volcanoes came ; and I do not see why this should not holdj even 

 though they may only, in certain instances, have been Cambrian or 

 Lower Silurian strata that passed into a state of fusion." 



Upon the whole, then, and in the meanwhile, I should be deci- 

 dedly disposed to regard this as the true explanation of the pheno- 

 mena which I have endeavoured to describe in this communication, 

 and to look upon the igneous masses in question as the roots of the 

 ancient vents from which were derived the alternating ashes and 

 traps which together compose almost the whole of the green slate 

 series. Whether they are to be regarded as being produced by an 

 alteration and fusion of the Skiddaw Slates in situ, is another ques- 

 tion, and one which is at present incapable of solution. Phenomena, 

 however, are not wanting which would appear to favour this view ; 

 and evidence sufficient for its establishment may yet be obtained, 

 when the district shall have been examined in greater detail. 



10. On the PossiL Mykiopods of tlie Coal Foemations of Nova 

 Scotia and EnglaisT). By Samuel H. Scudder, Esq. 



(Communicated by Sir Charles Lyell, Bart., F.K.S., F.G.S.) 



[Abstract.] 



In this paper the author discussed and described the species of 

 Chilognathous Myriopods which have been detected in the Coal- 

 measures. Of these he recognized 6, viz. Xylobius sigillarice (Daws.), 

 X. similis, sp. n., X. fractus, sp. n., X. Dawsonii, sp. n., X. Woocl- 

 wardii (^=. sigillarice, Woodw.), and a species upon which he founded 

 a new germs, Archiulus xylohioides. He regarded these forms as 

 constituting a peculiar family, for which he proposed the name of 

 Archiulidce, 



11. On the Geology of the Coir:fn:iiT sueeoundln^q the Gulf op 

 Cambat. By Alexander Eogers, Esq., F.G.S., Bombay Civil 

 Service. 



'The publication of this paper is deferred.) 



[Abstract.] 



The author described the surface of the country as consisting 

 chiefly of deep alluvial soils, derived from the denudation of the 

 primary and metamorphic rocks surrounding the district, the former 



