220 Royal Academy of Sciences of Paris. 



ANALYSIS OF PERIODICAL WORKS ON NATURAL HISTORY. 



J. D. C. Sowerby's Mineral Conclwlogy. No. LXXXVII. 



A singular new genus, Pac/iymya, from the chalk with quart- 

 zose grains at Dowlands, the lowest part of the chalk forma- 

 tion in the vicinity of Lyme Regis, is described in this number. 

 It is thus characterized: Shell bivalved, transversely elon- 

 gated, very thick, sub-bilobate, with the beaks near the ante- 

 rior * extremity. Ligaments partly immersed, attached to pro- 

 minent processes or fulcra:" the species figured is P.gigas. — 

 To the genus Orbicula, before containing two recent species 

 only, three fossil species are added, one from the Alum clay, 

 another probably from the Oxford clay, and a third from the 

 Ancliffe oolite. Five Trigonice from the last-mentioned forma- 

 tion and the Green-sand are also figured ; with two Paludincc 

 from the Weald Clav and the Hastings Sand. 



XXXIV. Proceedings qf Learned Societies. 



ROYAL ACADEMY OF SCIENCES OF PARIS. 



AN. 16 {continued). M. Ramond read a memoir on the 

 state of vegetation at the summit of the Pic-du-Midi. — M. 

 G. St. Hilaire read a paper entitled Zoological and physiological 

 considerations relative to a new genus of monsters called hy- 

 pognallc, and established for three species of double-headed 

 calves, with heads opposed to each other and attached toge- 

 ther by the symphysis of their lower jaws. 



Jan. 23. — The same anatomist made a verbal report on Dr. 

 Granville's memoir on an Egyptian mummy f. MM. Hu- 

 zard, Chaussier and Magendie gave a favourable report on M. 

 Girard's memoir relative to the inguinal hernia? of ruminating 

 and monodactyl animals. — M. Audouard read a memoir or 

 critical examination of the prevailing opinions on the origin 

 and causes of the yellow fever. — MM. Cauchy, Ampere and 

 Legendre, reported favourably on M. Poncelet's memoir on 

 the centre of harmonic means. 



Jan. 30. — M. Paul Laurent presented a memoir on a new 

 process for drawing on stone. — A memoir by M. Aug. de St. 

 Hilaire was read, On the system of agriculture adopted by the 

 Brazilians, and its results in the province of Minas-Geraes. — 

 A memoir by Mons. B. de Chatcauneuf was read, On changes 



* " We purpose in this volume," Mr. Sowerby observes, "to use the 

 terms anterior and posterior in their correct sense, us pointed out by the 

 situation of the month of the animal." 



f For some account of this mummy, sec Phil. Mag, vol, Ixvi. p. 70. 



undergone 



