CONTENTS. V 



Page 



XVIII. On the Mechanism of Aquatic Respiration and on the 

 Structure of the Organs of Breathing in Invertebrate Animals. By 

 Thomas Williams, M.D. Lond. (With two Plates.) 180 



XIX. Description of a new genus and species of Seal {Heliophoca 

 Atlantica) from Madeira. By Dr. J. E. Gray, F.R.S., V.P.Z.S. &c. 200 



XX. Monograph of the British Graphidece. By the Rev. W. A. 

 Leightoxv, B.A.J F.B.S.E '. 202 



XXI. Notes on the Ornithology of Ceylon, collected during an 

 eight years' residence in the Island. By Edgar Leopold Layard, 

 E.Z.S., C.M.E.S 212 



New Books : — Symbolae ad Monographiam Marseniadarum, Auctore 



Rudolph Bergh 218 



Proceedings of the Royal Society ; Zoological Society ; Botanical 



Society of Edinburgh 219—236 



On Scymntis glacialis {Lcemargus borealis, MiiU. & Henle) and its Pa- 

 rasites, by P. J. Van Beneden ; On the genus Latia, by Dr. J. 

 E. Gray, F.R.S. &c. ; The Anglesey Morris, Leptocephalus Mor- 

 risii, by C. W. Peach ; Figured Pearls of the Chinese, by Dr. J. 

 E. Gray, F.R.S. &c. ; On a Migration of Dragon-flies, by M. C. 

 Morren; Meteorological Observations and Table 236 — 240 



NUMBER LXXVI. 



XXII. On the Structure of the Echinoderms. By Johannes 

 Muller 241 



XXIII. Description of a new species of Closterium {Closterium 

 Griffithii). By the Rev. M. J. Berkeley, M.A., F.L.S. (With a 

 Plate.) 256 



XXIV. Notes on the Ornithology of Ceylon, collected during an 

 eight years' residence in the Island. Bv Edgar Leopold Layard, 

 F.Z.S', C.M.E.S. &c .' 257 



XXV. Monograph of the British Graphidece. By the Rev. W. A. 

 Leighton, B.A., F.B.S.E 264 



XXVI. A Reply to two Statements pubUshed by the Palaeontogra- 

 phical Society, in their volume for 1852; one appearing to accuse the 

 University- of Cambridge of ilhberality in the administration of its 

 Museum ; the other reflecting on Professor M'Coy. By the Rev. Pro- 

 fessor Sedgwick, M.A., F.R.S. &c 280 



XXVII. Notice of the discoverj- of Desmarestia Dresnayi on the 

 coast of Ireland. By R. K. Greville, LL.D. &c. (With a Plate.) 2.92 



