CONTENTS. 



Page 



Art. XLIX. On the vestiges of a placental Organization, 

 and of an umbilicus, discovered in a very small Foetus of 

 the Didelphis Virginiana. By M. E. Geoffroy de 

 Saint-Uilaire 403 



Art. L. Observations on the Structure of the Pholades. By 



John Edward Gra y, Esq. M.G.S. 406 



Aut. LI. Descriptions of some rare, interesting, or hitherto 

 uncharactetized subjects of Zoology, by N. A. Vigors, 

 jun. Esq. 31. A. F. L.S. With Figures by James De 

 Carle Sowerby, Esq. F.L.S 409 



Art. LII. Proceedings of Learned Societies : — 



Zoological Club of the Linnean Society 418 



Royal Academy of Sciences of Paris 421 



Art. LII I. — Scientific Notices: — 



New Species of Procelluria; 425 



Bulla Haliotoidea 427 



On the Genera Sigaretus and Cryptostoma , . 427 



EXPLANATION OF THE PLATES. 



Plate XII. — Fig. 1. Cyprsea lentiginosa. 



2. albuginosa. 



3. Turdus. 



4. arabicula, n. 4. 



5. sulcidentata, n. 20. 



6. arenosa, n. 19. 



7. eontroversa, n. 15. 



8. zonata, n. 53. 



9. pulchra,n. 14. See n. 42, p. 380. 



10. picta, n. 54. 



Plate XIII. — Muscicapa Lathami, p. 410. 



Plate XIV. — Antlius Richardi, p. 411. 



Plate XV. — Fig. 1. Cicindela princeps, p. 413. 



2. Ritchii, p. 414. 



3. Lyonii, p. 414. 



4. Gymnetis undulata, p. 415. 



5. hieroglyphica, p. 416. 



6. Macvaspis clavata, p. 416. 



7. Rutela nitescens, p. 417. 



8. Lamia V notata, ib. 



9. perpulchra, p. 418. 



Plate XVI.— P.-ittarula Kuhlii, p. 412. 



