[Footnote 2: Sir J. BOWRING'S _Siam_, vol. i. p. 10.] The class of fishes which possess this power are chiefly those with labyrinthiform pharyngeal bones, so disposed in plates and cells as to retain a supply of moisture, which, whilst crawling on land, gradually exudes so as to keep the gills damp.[1] [Footnote 1: CUVIER and VALENCIENNES, _Hist. Nat. des Poissons, _tom. vii. p. 246.] The individual which is most frequently seen in these excursions in Ceylon is a perch called by the Singhalese _Kavaya_ or _Kawhy-ya_, and by the Tamils _Pannei-eri_, or _Sennal_. It is closely allied to, if not identical with, the _Anabas scandens_ of Cuvier, the _Perca scandens_ of Daldorf. It grows to about six inches in length, the head round and covered with scales, and the edges of the gill-covers strongly denticulated. Aided by the apparatus already adverted to in its head, this little creature issues boldly from its native pools and addresses itself to its toilsome march generally at night or in the early morning, whilst the grass is still damp with the dew; but in its distress it is sometimes compelled to travel by day, and Mr. E.L. Layard on one occasion encountered a number of them travelling along a hot and dusty gravel road under the midday sun.[1] [Footnote 1: _Annals and Mag. of Nat. Hist_., May, 1853, p. 390. Mr. Morris, the government-agent of Trincomalie, writing to me on this subject in 1856, says--"I was lately on duty inspecting the bund of a large tank at Nade-cadua, which, being out of repair, the remaining water was confined in a small hollow in the otherwise dry bed. Whilst there heavy rain came on, and, as we stood on the high ground, we observed a pelican on the margin of the shallow pool gorging himself; our people went towards him and raised a cry of fish! fish! We hurried down, and found numbers of fish struggling upwards through the grass in the rills formed by the trickling of the rain. There was scarcely water enough to cover them, but nevertheless they made rapid progress up the bank, on which our followers collected about two bushels of them at a distance of forty yards from the tank. They were forcing their way up the knoll, and, had they not been intercepted first by the pelican and afterwards by ourselves, they would in a few minutes have gained the highest point and descended on the other side into a pool which formed another portion of the tank. They were chub, the same as are found in the mud after the tanks dry up." In a subsequent communication in July, 1857, the same gentleman says--"As the tanks dry up the fish congregate in the little pools till at last you find them in thousands in the moistest parts of the beds, rolling in the blue mud which is at that time about the consistence of thick gruel."