92 REPORT— 1873. 



On ilie Whin Sill of Northumherland. 

 By W. TopLET, F.G.S., and G. A. Leboub, F.Q.S. 



. This paper gave the results of work by the authors during the progress of the 

 Geological Survey, and it was communicated to the Section by permission of the 

 Director-General of the Survey. 



The Whinstone or Basalt of the north of England occurs in two forms, either as 

 chjhes cutting through the rocks, or as beds lying amongst them. The intrusive 

 character of the fonner is undisputed ; but there has always been considerable un- 

 certainty as to the character of the latter. The authors affirmed that in Northum- 

 berlandthere could be no doubt whatever that the sheet or sheets of ba.salt known 

 as the " Whin Sill " were intrusive, and that the trap had been forced through the 

 rocks long after their deposition and consolidation. The evidence of this was 

 found in the altered nature of the rocks above the whin, especially when they 

 consist of shales, and in tlie fact that the whin does not lie at one uniform level 

 amongst the sedimentary strata, but frequently comes up in bosses, cutting through 

 the rocks, and shifting its relative position amongst them to the extent of 1000 feet 

 or more in short distances. 



An account of the literature of the subject was given; and reference was parti- 

 cularly made to a paper by Sir W. C. Trevelyan, published in 1823 in the ' Werne- 

 rian Transactions,' in which the intrusive nature of the basalt of North Northum- 

 berland was clearly shown. 



A note by Mr. S. AUport, F.G.S., was appended to the paper, giving an account 

 of the microscopic structure of the basalt, showing it to be precisely similar in 

 character to the intrusive sheets of trap which occur in the coal-field of the midland 

 qounties. 



Note on ihe Occurrence of Thanet Sand and of Cracf in the S. W. j^art of Suffolk 

 (Sudbury), ByW. Whitakeb, B.A. (Loud.), of the Geological Survey. 



The author had observed near Sudbury some sections proving the existence of 

 Thanet Sand in that district. None had previously been observed on the northern 

 outcrop of the London basin. The sand is fine and loamy, just like that of West 

 Kent. The author also noticed the occurrence of Crag at Sudbury, at many miles 

 froiU; and at a higher level than, any previously known. 



On some Specimens of Dithyrccaris /rom the Carboniferous Limestone Series, 

 East Kilbride, and from the Old Bed Sandstone (f) of Lanarlshire ; with 

 Notes on their Geological Position ^c. By Hekey Woodwakd, F.R.S., 

 F.G.S., and IIobeet Etheeidge, jun., F.G.S. 



The authors described nine specimens of Phyllopodous Crustaceans, eight of 

 which are from the Carboniferous series of East Kilbride, and the remaining fonu 

 from the Old Eed Sandstone (?) of Lanarkshire. They are all referable to the 

 genus Dithyrocaris ; and the authors described four new species, namely : — 



Dithyrccaris granulata, W. & E. Carboniferous Limestone series. East Kilbride. 



• oralis, W. & E. Carboniferous Limestone series, East Kilbride. 



glabra, W. & E. Carboniferous Limestone series, East Kilbride. 



striata, W. ^- E. Old Red Sandstone, Lanark. 



The other examples are referred to Dr. Scouler's Bifhyrocaris tricomis and D. 

 tesiiidinea, both of which were also obtained from the Carboniferous Limestone 

 series of East Kilbride. 



With regard to D. tricomis, one of the authors (Mr. Woodward) had made the 

 interesting discovery that the carapace in Dr. Scouler's specimen was folded 

 together, and that Dr. Scouler had mistaken the true anterior border of the cara- 

 pace — the three spines, on which the specific diagnosis was founded, being really at 

 the posterior end of the carapace — the body-segments having been twisted out of 



