108 8. H. Reynolds — Lower Palceozoic fossils of Yorkshire. 



alternations apparently so rapid, within very minute areas, say to o o o- 

 of an inch, that the hypothesis of any general fluidity or viscosity of 

 the rock-masses in which such inclusions occur is very difficult to 

 reconcile with the phenomena observed. 



As exception has been taken in the columns of the Geological 

 Magazine to my attempting problems beyond my powers, I may 

 mention that I have repeatedly thrown this Dartmoor question aside 

 as too overwhelmingly difficult; on the other hand it has seemed a 

 pity that observations which may be of use to other workers should 

 be entirely lost. 



It may also be borne in mind that the last words written hitherto 

 by Dr. Sorby on the subject of inclusions and crystalline rocks, are 

 the significant ones, as true now as when they were addressed to the 

 Geological Section of the British Association in 1880 — " There is 

 still much to be learned respecting the exact conditions under which 

 some of our commonest rocks were formed." 



Postscript. — Fig. 4 represents five distinct groups of inclusions, 

 drawn separately with the camera lucida, the inclusions of each 

 group being in their relative positions. The five drawings for the 

 purpose of the process block were marshalled on a sheet of white 

 paper and reduced by photography. 



II. — WOODWARDIAN MuSEUM NoTES. 



Certain fossils from the Lower Palaeozoic rocks of Yorkshire. 

 By Sidney H. Reynolds, M.A., F.G.S. 

 (PLATE IV.) 



IUNDEETOOK this description of certain fossils from the Lower 

 Palgeozoic rocks of Yorkshire at the request of Mr. Marr. The 

 late Mr. Thomas Roberts had begun the piece of work, but left it 

 unfinished. Nearly all the fossils referred to were collected by a 

 party of Cambridge geologists, under the guidance of Prof. Hughes, 

 in the Summer of 1889. The fossils come from two horizons, viz. : — 



1. The Fhncops elegans zone=Stockdale Shale series (Valentian) 



of Wharfe. 



2. The Bala beds=Coniston Limestone series of Norber Brow 



and Wharfe. 

 Mr. Marr (Geol. Mag., Dec. IIL Vol. IV. No. 1, 1887) records 

 the following species from the Stockdale Shale series of Whari'e : — 



Fetraia, sp. 



Fhacops elegans, Boech and Sars. 

 Cheirurus bimucronatus, Murch. 

 lEncrinurus piinctatus, Emmr. ? 

 Leptcena qumqutcostata, McCoy. 



To these may be added : — 

 Jllcenus, sp. 



Uncrinurus punctatus. var. arenaceus, Salt. 

 Sm pes judex, Marr and iS'ich. 

 Staurocephalus, cf. Murchisoni, Barr. 

 Cyphaspis, cf. 7-astritnm, Tornq. 

 Cyphaspis, sp., cf. Burmeisleri, Barr. 



