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Show 600 MR. G. A. BOULENGER ON THE [Nov. 17, Sc. Angers, (2) xv. 1885, p. 107) suggests as a method of ascertaining their disposition, in cases when specimens can be sacrificed, to strip the skin and spread it out on the convex surface of the bottom of a test-tube, chosen to suit the size of the tadpole; the transparent skin may then be easily studied. Gr. Born (Arch. f. mikr. Anat. xxvii. 1886, p. 207) recommends a method of studying and handling the larvae in their fresh condition, by paralyzing them through immersion in a solution of tobacco, as was proposed by Lataste for fixing the adult in copuld. The little creatures become insensible after a few minutes, and remain so for about half an hour after being transferred to pure water; they recover perfectly if the immersion in the solution has not been too prolonged. As stated above, the object of this paper is to supply comparative descriptions of the external characters of the Tadpoles of Europe, so as to facilitate the identification of the species. But in order to enable the reader to acquaint himself with the rather extensive special bibliography, I have introduced copious references to the authors who have previously dealt with the subject. I have also briefly indicated the habitat and breeding-season of each species. In addition to the extensive material collected by myself, I have been able to study many specimens received from M. Heron Royer, M. E. Bosca, Dr. J. de Bedriaga, Prof. Born, Prof. Liitken, Dr. W. Wolterstorff, Prof. Giglioli, Dr. L. Joubin, and Prof. Camerano, to all of whom I beg to tender my sincere thanks. The tailless Batrachians are represented in Europe by 19 species, belonging to 8 genera and 5 families :- I. RANIDiE. 1. RANA, L., 1766. 1. esculenta, L., 1766. 2. arvalis, Nilss., 1842. 3. temporaria, L., 1766. 4. grceca, Blgr., 1891. 5. iberica, Blgr., 1879. 6. latastii, Blgr., 1879. 7. agilis, Thom., 1855. II. HYLID-E. 2. H Y L A , Laur., 1768. 8. arborea, L., 1766. III. BUFONID.E. 3. B U F O , Laur., 1768. 9. vulgaris, Laur., 1768. 10. viridis, Laur., 1766. 11. calamita, Laur., 176b. |