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Show 1887-] ON THE LARYNX OF THE ANUROUS AMPHIBIA. 491 teeth and the head two frontal tubercles, which, however, are much smaller than in any other species of the group, and followed behind by a broad but shallow frontal cavity. The clypeus is pointed and recurved ; the mandibles without trace of tooth on their outer edge. The thorax is as broad as the elytra, broadly rounded on the sides, slightly narrowed to the base, with acute hind angles; the surface free from furrows and strongly and sparsely punctured, the punctures on the disk larger and transverse-oval or oblong ; on each side of the anterior disk is a small round fovea. The rows of small circular punctures on the elytra are obliterated on the sides posteriorly and on approaching the apical callus. The hind tibiae have no trace of spine on their outer edge (only a few short setse), but there is a long spine at their outer apex. The species therefore is intermediate between Burmeister's subgroups a and b. The basal joint of the hind tarsi is not prolonged into a spine. The pygidium is opaque and punctured ; the apical ventral segment very finely punctured, the rest of the abdomen (except the extreme sides) being smooth. The metasternum is punctured on the sides and clothed with reddish hair. 4. O n a hitherto unrecognized Feature in the Larynx of the Anurous Amphibia. By G. B. H O W E S , F.Z.S., F.L.S., Assist. Prof, of Zoology, Normal School of Science and R. School of Mines, S. Kensington. [Received June 2, 1887.] The general structure of the respiratory organs in the Amphibia was first carefully analyzed by Henle, nearly fifty years ago1. He showed that well-developed laryngeal cartilages are nearly always present, and that the trachea and bronchi, though subject to considerable variation, may be supported by cartilaginous elements also. Conspicuous among recent investigators in the same field is Wiedersheim. He has shown 2 that in the Gymnophiona, as in some Urodeles (e. g. Siren and Amphiuma), trachea and bronchi are well differentiated, and that fully formed cartilaginous rings may be developed in connection therewith. To him we are also indebted for a description of the larynx of Rana esculenta in all its details 3, and for a number of other observations upon the subject generally ; while he has summed up our knowledge of this in his Text-book of Vertebrate Anatomy. Dubois is now engaged upon a searching investigation into the morphology of the larynx. He calls attention in his preliminary notes4 to the presence, among other things, of 1 ' Vergleichende anatomische Beschreibung des Kehlkopfs :' Leipzig, 1839. 2 ' Die Anatomie der Gymnophionen :' Jena, 1879. Cf. also his ' Lehrbuch d vergleich. Anatomie d. Wirbelthiere.' '3 Originally in his ' Lehrbuch,' edit. i. vol. ii. 1882, pp. 640-645. 1 " Zur Morphologie des Larynx," Anat. Anzeiger, vol. i. 1886. See also Van Bemmelen, Zoolog. Anzeiger, vol. x. 1887, p. 91. |
