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Show 922 MR. J. GRAHAM KERR ON LEPIDOSIREN. [Dec. 14, by a grant from the Balfour Fund of Cambridge University. The two travellers left England in August 1896 and proceeded to Asuncion, the capital of Baraguay. From there they ascended the river Paraguay to a point slightly above the mouth of its affluent, the Aquidaban, and then struck out in a nearly westerly direction into the interior of the Chaco. They had as their objective a point named Waikthlatingmavalwa, where two English missionaries resided, and where Lepidosiren was in considerable abundance. Having arrived at this point they made it their headquarters for the next few months, Mr. Kerr devoting himself to the study cf Lepidosiren, Mr. Budgett to general zoology, more especially to the Batrachians. A short description of the habits and habitat of Lepidosiren was given, together with an outline of the more salient features in its development. In size the specimens met with ranged up to 105 cm. in total length, the females being markedly larger on the average than the males. In numbers the two sexes appeared about equal, although from the manner of catching them more females were actually obtained. The ground-colour was extremely variable, as a rule very dark, nearly black, but with a greater or less extent of pale mottling, especially ventrally. Occasional specimens showed a deep brown in place of the usual slaty-black colour. The skin secreted a copious mucus which rapidly precipitated mud in suspension in the water. The males during most of the year showed the papillae described by Lankester, but at the breeding-season these grew out into blood-red filaments one or two inches in length. The eggs were large (7 m m . in diameter) and laid in an underground burrow, and apparently usually guarded by the male. The segmentation was iu its later stages complete, but very unequal. The gastrulation recalled that of the Lamprey and of Amphibians. Eventually there hatched out a tadpole-like larva, devoid of pigments, the horny egg-shell undergoing a process of digestion before splitting. The larvae were remarkable for the extremely well-developed sucker and the large external gills (strikingly Amphibian features said to be absent in Cerutodus). The external gills were four in number on each side. About six weeks after hatching the external gills atrophied, as did also the sucker ; the creature assumed a much darker, almost black colour, and its habits became much more active. The young Lepidosiren remained in the nest till about 60 m m . long. For nearly three months it lived on the yolk in the walls of tbe euteron, but did not eat at all. About this time yellow spots appeared on the larva, and it remained so spotted till over one foot in length. The young Lepidosirens had proportionally larger limbs than the adult, and used them much in irregular alternation in clambering through the mud. A remarkable point was that during the night the black chromato-phores all shrank up, so that the creature was of a nearly pure white with round yellow spots, |