﻿334 Reports and Proceedings. 



3. " On the Remains of Hypsodon, Portheus, and Iclithjodectes 

 from British Cretaceous strata, with descriptions of new species." 

 By E. TuUey Newton, Esq., F.G.S., of H.M. Geological Survey. 



Hypsodon lewesiensis, as established by Agassiz in the " Poissons 

 Fossiles," it appears, includes two forms which are generically 

 distinct, and the author felt justified in adopting Prof. Cope's sug- 

 gestion for their separation. It is proposed to retain the above 

 name for the specimen upon which the genus and species was really 

 founded, and to refer to the genus Portheus (Cope), the upper jaw, 

 with large irregular teeth, which had already been described by 

 Dr. Mantell in 1822 as " an unknown fish." To this the specific 

 name of P. Mcmtellii is to be given. Another maxillary bone from 

 the Lower Chalk, characterized by its greater proportionate depth, 

 and the convexity of its dentary border, as well as by the more 

 equal size of its teeth, it is proposed to name P. Daviesii. 



A very fine specimen from the Gault belonging to this same 

 genus was described in detail. This fish is closely allied to P. lestris 

 (Cope), but differs in the form of its maxilla and premaxilla, and is 

 chiefly remarkable for the peculiar incurving of the points of the 

 mandibular teeth. The parts of this specimen which are preserved 

 are — both upper and lower jaws, parts of the palato-quadrate arch, 

 of the hyoid bones, ethmoidal region, brain case, etc. Portheus 

 gaidtinus is the name suggested for this species. 



Hypsodon minor (Egerton), figured in Dixon's "Fossils of Sussex," 

 will now, it is thought, on account of the regularity of its teeth, 

 have to be placed in the genus Iclithjodectes (Cope). 



Another small mandible from the Lower Chalk of Dorking, which 

 is distinguished by the regularity of its slender, incurved, and 

 oblique teeth, it is proposed to call Ichtliyodectes elegans. 



4. " On the Precarboniferous Rocks of Charnwood Forest." Part I. 

 By Rev. E. Hill, M.A., F.G.S., and Rev. T. G. Bonney, M.A., F.G.S. 



The authors described a mass of slates, grits, and volcanic brec- 

 cias, accompanied by some knolls and dykes of Syenite, spread over 

 a space of about 50 square miles. They showed that the patches 

 marked on the Survey Map as Greenstone of Bardon, BirchwoocI, 

 and Buck Hill, except a very small portion of the latter, are really 

 altered rock; that the Syenite knoll of Bawdon Castle carries a mass 

 of breccia in its centre ; and that the area of the Syenite in Bradgate 

 House Woods must be enlarged. 



Several writers have noticed that part of the porphyritic region of 

 the north-west corner is altered rock. The authors showed that 

 there is in it no igneous rock at all, and that the same is the case 

 with every one of the smaller patches marked as porphyry on the 

 Survey Map. All ai-e volcanic breccias, ashes, or agglomerates, 

 some of enormous size. The extent to which volcanic materials 

 enter into the rocks of the district is remarkable. 



The authors endeavoured to correlate the stratified rocks, and 

 adduced evidence to prove that the pebble and ash-beds of Forest 

 Gate, the grit and pebble-beds of the Hanging Rocks, the similar beds 

 in the grounds of A. Ellis, Esq., at Swithland, and the quartzites of 

 Bradgate Stable Quarry, Groby Pool, and Steward's Hay Spring, 



