618 MR. G. A. BOULENGER ON THE [XoV. 17, 



upwards posteriorly, sometimes extending nearly to the origin of the 

 hind limbs. In addition to these lines, a slioit horizontal branch 

 oiiginates above the upper lip, and, bifurcating below the vertical of 

 the anterior border of the eye, forms a hoop which descends to the 

 sides of the throat. The arrangement of these lines is figured on 

 p. 598 of this paper. 



Coloration usually varying from pale grey to olive-brown above, 

 the sides with pale metallic spots ; the lines of crypts whitish ; 

 caudal crests greyish, with blackish spots and white dots and pale 

 metallic spots. Some specimens, however, have the tail almost 

 spotless ; in others, on the contrary, it is very closely spotted, but 

 always less abundantly on the lower crest than on the upper. Lower 

 parts pale grey with silvery spots. Tail and the greater part of the 

 body with fiue black decussating lines, as in Bombinator ; it some- 

 times happens that these lines are altogether absent on the muscular 

 part of the tail. 



But, as in other tadpoles, coloration is subject to a great amount 

 of variation. During a stay of seven weeks in Brittany last summer, 

 I was much struck on finding, in the beginning of July, near 

 St. Enogat, Ille-et-Vilaine, a small and shallow pond, about 15 feet 

 long by 10 feet wide and 2 feet deep, swarming with thousands of 

 tadpoles from 30 to 40 millim. long, of a very dark brown, almost 

 black, which, although I am familiar with the larvse of Pelodytes, I 

 at first failed to recognize. It was only after a careful examination 

 that I ascertained the species to which they belong, my determina- 

 tion being ultimately confirmed by the transformatiou of some of the 

 tadpoles which I had brought home alive. Now several ponds close 

 by, whether large or small, deep or sh.allow, of clear or of thick 

 muddy water, all showed the ordinary type of Pe/of/y^es-tadpole. I 

 constantly visited the spot : the water, which at first was perfectly 

 clear and transparent, became green and dirty, but the larvae did not 

 alter in colour or size ; and I was surprised at the small size of the 

 young immediately after transformation, which did not exceed 1 1 

 to 15 millim. from snout to vent, whilst the other places yielded 

 young varying between 19 and 22 millim. Towards the middle of 

 August the little pond was taken up for those linen-washing opera- 

 tions with which all who have visited Brittany are unpleasantly 

 familiar, and my observations were thus terminated by the wholesale 

 destruction of the tadpoles. But those, still numerous, which had 

 remained up to that time had not undergone any change. As I 

 have said above, these tadpoles were nearly black on the back ; the 

 tail was of a dark brown without any, or with but very small, black 

 spots, and with the black decussating lines so crowded that they could 

 not be detected witho\it a lens ; the belly was of a beautiful steel- 

 blue, and the lines of crypts were quite indistinct, although they have 

 become distinguishable now that the specimens have been for some 

 time in sj)irit. One of these black tadpoles is figured, Plate XL VII. 

 fig. 2. 



The largest measured: body 16 millim., width of body 10; 

 tail 24, depth of tail 8. The young were by no means melanotic. 



