1891.] TADPOLES OF THE EUROPEAN BATRACHIANS. 611 



acutely pointed, attenuate or mucronate at the end ; upper crest 

 very convex and extending far forwards on the back, ahnost to between 

 the eyes ; lower crest as much developed as the upper, and extending 

 on to the belly considerably beyond the anus ; the depth of the 

 muscular portion, at its base, one third or rather less than one third 

 the greatest total depth. 



Beak broadly edged with black. Lips bordered with papillae, 

 which are absent in the middle'of the upper border \ and usually form 

 two rows on the lower hp. Series of labial teeth g, all except the first 

 lower occupying nearly the whole width of the hp ; the second 

 upper is narrowly interrupted in the middle, and so is sometimes the 

 third lower ; the first lower series only one third to half as long as 

 the second. 



The lines of muciferous crypts can usually be traced without much 

 difficulty : a hoop-shaped one on each side of the head, passing above 

 the nostril and bordering the eye above and below, both ends nearly 

 meeting close to the upper lip, and another along each side of the 

 body to the middle of the muscular portion of the tail. 



Olive above, with golden gloss ; sides with golden spots ; belly 

 white, with pearl-coloured or golden spots ; muscular part of tail 

 yellowish, with or without blackish dots and frequently with a median 

 black line at its base ; caudal crests whitish, immaculate or more 

 or less profusely dotted and spotted with grey or blackish. 



Total length of the largest specimen from Brittany 49 millim. : 

 body 16, width of body 12'; tail 33, depth of tail 15. 



The Southern form, var. meridionalis, Boettger, regarded by some 

 authors as a distinct species {H. perezi, Bosea, H. harytonus, Heron 

 Royer), differs in its tadpole state, to judge by several specimens 

 from Nice (which I owe to my friend Dr. de Bedriaga), in having the 

 second series of upper labial teeth more broadly interrupted in the 

 middle, and in having the muscular part of the tail bordered above 

 and below by a black line ; these two black lines together with a 

 third running along the middle of the tail, which is immaculate or 

 but scantily spotted, give it a pecuUar appearance. 



The tadpole of the common Tree-Frog has been exquisitely figured 

 by Bosel (Hist. Ran. pi. x., 1758). Far inferior figures are to be 

 found in the works of Lataste (Actes Soc. Linn. Bord. xxx. 1876, 

 pi. X. figs. 4-6) and Lessona (Atti Ace. Lincei, 3, i. 1877, pi. ui. 

 fio-. 18). The best descriptions are by Lataste (l. c. p. 219), Heron 

 R^er and Van Bambeke (Arch, de Biol. ix. 1889, p. 245, pi. xv. 

 fig. 1), and Bedriaga (Bull. Soc. Nat. Moscou, 1889, p. 476). 



Hi/la arborea inhabits nearly the whole of the temperate parts of 

 the Palaearctic Region, but is absent from the British Isles. 



The eggs are deposited in the end of April or beginning of May, 

 and the young are ready to leave the water from the middle of July 

 to the end of August. A case of hibernation in the larval state has 

 been recorded by Lessona (Atti Ace. Torin. xii. 1877, p. 322). 



1 I have never seen an uninterilipted series of papillse on the upper lip, as 

 figured by Heron Eoyer and Van Barebeke. 



