OCR Text |
Show 904 MR. STANLEY S. FLOWER ON THE [Nov. 14, Eyes. Distance of eyes apart 7*5 mm. The eyes are on the side of the head (looking out horizontally), and are visible from above and from below. Spiraculum. Distance of opening of spiraculum from the eye 10-5 m m . The spiraculum is median, on the lower surface of the body, opening into a transparent sheath of skin directed backwards and downwards; the opening being in a vertical line drawn behind the body. The width of the opening of the spiraculum is from 2 to 3 m m. Anus. Median, opening into a dark-coloured sheath of skin directed backwards and downwards, behind and nearly parallel to the sheath of the spiraculum, but longer than it. The opening is a longitudinal cleft. These two tubes are very prominent in the live tadpole. Tail. The tail is of remarkable appearance, owing to its coloration, the pigment in the crests ending abruptly, and also being continued further along the outside of the crest than along the part nearest the muscular portion; consequently the tadpole when seen alive in the water has apparently a trifurcated tail, a ver}' long centre point and short upper and lower one. The end of the tail is prolonged to a very fine point or filament, which in life is almost continuously being vibrated rapidly from side to side, the end frequently curving round so as to be almost parallel with the rest of the tail. The upper crest is convex and does not extend on to the back. The lower crest is deeper than the upper, and forms a double curve, the deeper being that behind the opening of the anus. Mouth. The mouth is 3*5 to 4 m m . in width. The mouth is situated at the extremity of the head, and not on the lower surface; the lower lip projects beyond the upper: this is particularly so in young specimens, where the mouth appears to be on the upper surface of the head. These young tadpoles frequent the surface of the water, and their mouths are constantly expanding and contracting (which words seem to imply the motion better than " opening and shutting " ). There are no papillae round the lips, labial teeth or horny beak, but the mouth consists of simple upper and lower lips, the latter with a very deep notch in the centre which expands when the mouth is open. Colour (in life). These tadpoles are very transparent and the amount of colouring varies in individuals. The upper surfaces and sides of the hinder parts of the body are generally yellowish brown, mottled along the vertebral line with very dark brown. The lower surfaces and sides of the head are colourless or a pale dirty buff. The muscular portion of the tail is pale yellowish brown, getting darker towards the point. The crests are buff mottled with yellowish brown, along both edges are irregular dark brown marks ; the brown mottling gets more continuous and darker towards the point of the tail till it ends abruptly, as described above. Iris bright yellow. |