116 Oeohyical Society. 



stems, like some now forming in the alluvial mud of the St. 

 Lawrence. 



Some curious combinations of worm-tracks with ripple-marks and 

 shrinkage-tracks are described ; as also branching or radiating 

 worm-trails, which present some resemblance to branching Fucoids. 

 Finally, the Author describes the formation of rill-marks on the 

 mud-banks of the tidal estuaries of the Bay of Fundy, and indicates 

 their identity with some impressions in slabs of rock which have 

 been described as Fucoids under several generic names. 



May 21, 1890.— Dr. A. Geikie, F.R.S., 

 President, in the Chair. 



The following communications were read : — 



1. " On some Devonian and Silurian Ostracoda from North 

 America, France, and the Bospborus." By Prof. T. Rupert Jones, 

 F.R.S., F.U.S. 



Of the Devonian species herein figured and described, six species 

 and one variety (four being new) from the decomposed Chert of the 

 Corniferous Limestone of Ontario County, in the State of New York, 

 and new species from the Hamilton Group of Clarke Co., Indiana, 

 have been sent by Mr. J. M. Clarke, of Albany, N. Y., as mentioned 

 in the February number of the Quart. Journ. Geol. Soc. p. 14. 

 From Eighteen-mile Creek, Lake Erie, N. Y., there are two new 

 Devonian species among specimens supplied by Dr. Hinde {op. cit. 

 p. 28), and two new Prhnitice from Thedford. Altogether five 

 genera (Bollia, J. & H., Moorea, J. & K., Octonaria, J., Eurychilina, 

 Ulrich, and Ulrichia, gen. nov.) are hereby added to the list of 

 " Hamilton " fossils. 



The Devonian Beyrichia collected some years ago by M. Dumont 

 at the Bospborus, and noticed by Dr. Ferd. Rcimer in the ' Neues 

 Jahrbuch ' for 1863, having been kindly lent by M. Dewalque for 

 examination, is figured and described in detail. It appears to be 

 the same as B. devcnica, Jones, lately described from Devonshire. 



Nine new species from Anticosti, in Dr. Hinde's collection, 

 alluded to above, are here figured and described. They are from 

 Mr. Billings's " Anticosti Group " (Divisions 3, 2, 1, and the lowest). 

 The lowest and Div. 1 are both now regarded as of Lower Silurian 

 .age, and Divs. 2 and 3 are either Middle or Upper Silurian. A 

 .series of Silurian Ostracoda from Canada, submitted by Mr.Whiteaves, 

 F.G.S., and Mr. Ami, F.G.S., have been examined, and critical notes 

 on them are here given. 



The Lower-Silurian Beyricha GuiUeri, named and compared with 

 other species by M. G. de Tromelin at Nantes in 1875, who found 

 it at Domfront and elsewhere in Brittany, is also figured and 

 described in detail. 



