INDEX TO ARTICLES. 411 



ZOOLOGY. 



Acalephse of North America. Agassiz. Am. Acad.. Vol. III. p. 221. Sill., Sept. 



Acari, without mouths, of genus hypopus. C. R., Feb. 4. 



Actinia, intestinal cavities of. Holland. C. R., Jan. 7. 



Albinos, pile of the head of. Browne. Am. Ass., 108. 



Alpacca, naturalization of, in France. Deville. Ann. Sci. Nat., Jan. 



Animals, geographical distribution of. Agassiz. Christian Exam., March. 



successive appearance of, upon the globe. D'Orbigny. C. R., June 24. 



Annelides, nervous system of. Quatrefages. Ann. Sci. Nat., Jan. 



Aphides, description of. Walker. Mag. Nat. Hist., June and July. 



Arachnides. Blanchard. Ann. Sci. Nat., Nov. and Dec., 1S49. Mag. Nat. Hist , July. 



Araneides of the United States. Hentz. Jour. Nat. Hist,. Vol. VI. No. 2. 

 new species of. Blackball. Mag. Nat. Hist., March. 



Astroea, genus. Dana. Sill., March. 



Batrachia, tailed, of North America. Baird. Acad. Nat. Sci., Vol. I. Part 4. 



Birds, progress in the natural history of, in 1848. Hartlaub. Arch, fur Nat., 3, 4. 



Brachiopoda, new genus of. Chantereaux. Ann. Sci. Nat., Aug., 1849. 



Bryozoa, fresh- water. Hancock. Mag. Nat. Hist., March. 



Bullidae. animals of the. Clark. Mag. Nat. Hist., Aug. 



Carcinoiogical collections of the United States. Gibbes. Am. Ass., 167. 



Crocodilian reptiles, communication between the tympanum and palate in. Owen. 

 Brewster, July. 



Deafness, means of treating in a case of destruction of the membrane of the tympanum. 

 Yearsley. C. R., Feb. 4. 



Description of new species of the genera micrastur, tanagra, and sycohius. Cassia. 

 Acad. Nat. Sci., Vol. I. Part 4. 



Development of the great anterior vein in man and Mammalia. Marshall. Phil. Trans., 

 Parti. 



Development of the retina and optic nerve, and of the membranous labyrinth and audi- 

 tory nerve. Gray. Phil. Trans., Part 1. 



Development of Targipes larcinulatus. Schultze. Arch, fur Nat., 3. 



Distoma, new species of. Leidy. Acad. Nat. Sci., Vol. I. Part 4. 



Doris, anatomy of. Ath., Aug. 



Echinoderms, recent and fossil, of South Carolina. Ravenel. Am. Ass., 159. 



Elephant, means of defence of. Duval. C. R., Feb. IS. 



Entomology, progress of, in 1343. Schaum. Arch, fur Nat., 4. 



" " in the United States in 1350. Haldemann. Proc. Acad. Nat. Sci. 



Entozoa in animals. Arch, fur Nat., 1. 



Eye, theory of. Vallee. C. R., May 27. 



Fishes of Nova Scotia and Labrador. Storer. Jour. Nat. Hist., Vol. VI., No. 2. 



Foraminiferae, recent. Clark. Mag. Nat. Hist., March. 



Frog, nerves of. Waller. Brewster, July. 



Furcellaria fastigiata and Polydies rotundus. Mag. Nat. Hist., Aug 



Head, bony frame of, in different nations. Retzius. Edin. Med. and Surg. Jour., 

 July. 



Helex, new species of. Benson. Mag. Nat. Hist., Oct. 



Herpetology, progress of, in 1343. Arch, fur Nat., 4. 



Hydra, green, production of the eggs of. C. R.. June 24. 



Hypopus, memoir on. Dujarclin/ Ann. Sci. Nat., Nov., '1849. 



Ichthyology, progress of, in 1343. Troschel. Arch, fur Nat., 4. 



Infusoria, development of. Stein. Arch, fur Nat.. 1, 2. 



Insects, aquatic respiration in. Mag. Nat. Hist., Aug. 

 circulation in. Ann. Sci. Nat., Nov.. 1849. 

 new. Haldemann. Sill., Jan. 



Kangaroo, propagation of. Arch, fur Nat., 1. 



Lacunae, observations pri. Clark. Mag. Nat. Hist., July. 



Lamprey eels. Agassiz. Lake Superior. 247. 



Leontidon, monograph of genus. Bell. Mag. Nat. Hist., July. 



Lerneonerna Bairdii. Ma<r. Nat. Hist., Aug. 



Liver, structure of. EdinTMed. and Surg. Jour., Oct. 



Manatus, a pachyderm. Kneeland. Am. Ass., 42. 



Medusss, morphology of. Agassiz. Am. Ass., 119. 



Menobranchus, new species of. Gibbes. Am. Ass. 159. 



Mollusca, terebrating. Clark. Mag. Nat. Hist., Jan. 



" progress of natural history of. in 1843. Arch, fur Nat., 



Moths, British. Curtis. Mag. Nat. Hist., Feb. 



Muscles, formation of, in Vertebrata. Lebert. Ann. Sci. Nat. Oct., 1849, March and 

 April. 



