CONTENTS. V 



Pago 



XXI. Siibinaiiiic-Ciible FiUiiia. 15v J. (iwYN Ji:rKni.Ys, I,L.])., 

 F.K.S., and the llov. A. jM. Nohman/M.A. (Plate Xil.) 100 



XXII. Dcsciiptioiis of new Species of Polyzon from tlie Lower and 

 l'])per Silurian liocks of North America. ]{y II. Ai.lkvnk Nichol- 

 son, M.D., D.Sc, F.li.S.E., Profes-^or of Biology in the Durham Uni- 

 versity College of Physical Science, Newcastle-ou-Tyne. (Plate XIV.) 177 



XXIII. Oil some new exotic Sessil-oved Crustaceans. Bv the Rev. 

 TiiosiAS 11. 11. Stkbbing, M.A. (Plate XV. A.) " 184 



XXIV. Descriptions of some new North-American Lithobioida. 



By AxTOX Stuxukro 188 



XXV. Do \'arieties wear out, or tend to wear out ? By Professor 

 Asa Cray 102 



XXVI. Oceanic Sediments, and their Relation to Geological For- 

 mations. By Professor William King, Sc.D. &c 108 



' XXVII. Remarks on Professor Owen's Arrangement of the Fossil 

 Kangaroos. By Gerard Krkfft 204 



XXVIII. Zoologico-Embryological Investigations. By M. Ussow. 200 



XXIX. On some new Species of Butterflies from Tropical America. 



By AuTHVR Gardiner Bltler, F.L.S., F.Z.S., &:r 222 



I'roceedings of the Royal Society 225 



On the Gannnarichc of Lake Baikal, by Dr. B. N. Dybowsky ; On the 

 Mode in which Amccha swallows its Food, by Prof. J. Leidv ; 

 On the Discovery of true Batrachians in Palaeozoic Rocks, by 

 M. A. (laudry ; On the Motive Power of Diatoms, by Prof. J. 

 Leidv; On the Peripheral Nervous Svstem of the Marine 

 Nematoids, by 31. A. Villot .' 2^0—235 



NUMBER LXXXVIII. 



XXX. On the Structure and Systematic I'osition of the Genus 

 i'heirohpia. By R. II. Traquair, M.D., F.G.S., Keeper of the 

 Natural-History Collections in the Edinbuiah Museum of Science 

 and Art. (Plate XVII.) T 2;}7 



XXXI. On a new Species of Lii:hix(ius (Schiodte). Bv the Rev. 



O. P. Camijridge, M.A., C.M.Z.S ' 2-10 



XXXII. On the Geographical Distribution of Fishes. By Thp:o- 

 DORK Gill, M.D., Ph.D 251 



XXXIII. On an undescribed Organ in Limuhix, supposed to be 

 Renal in its Nature. By A. S. Packard, Jun 255 



XXXIV. On some Fossil Fishes from the neighbourhood of Edin- 

 burgh. By R. II. Traquair, M.D., F.G.S., Keeper of the Natmal- 

 Ilistorv Collections in the Edinburgh Museum of Science and Art. 

 (Plate XVI.) 258 



XXXV. Descriptions of new Species of Fish in the Collection of 

 the British Museum. Bv A. JIalv 268 



