922 MR. J. GRAHAM KEUR OW MPIDOSIEEN. [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 ot Paraguay. 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 Cliaco. They had as their 

 objective a point named Waikthlatingmayalwa, where two English 

 missionaries resided, and wliere 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 Le])idosiren w as 

 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 marliedly lai-ger 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 slat\ -black colour. The skin secreted 

 a copious mucus which rapidly precipitated mud in suspension in 

 the w ater. The males during most of the yeor 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 mm. in diameter) and laid in an under- 

 ground burrow, and apparently usually guarded by the male. The 

 segmentation was in its later stages complete, but very unequal. 

 The gastrulation i-ecalled that of the Lamprey and of Amphibians. 

 Eventually there hatched out a tadpole-like larva, devoid of pig- 

 ments, the horny egg-shell undergoing a process of digestion before 

 splitting. The hnwse were remarkable for the extremely well- 

 developed sucker and the large external gills (strikingly Amphilian 

 features said to be absent in Ceratodun). 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 GO mm. long. Eor nearly three months it lived on the yolk 

 in the walls of the 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 clamber- 

 ing 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. 



