On some tree-frogs allied to Hyla caerulea. 215 
character is well shown by the two specimens, male and female, from 
Duke of York Island in the British Museum, and in the 8 specimens 
(Ralum and New Britain) examined by Dr. WERNER, and as it 
appears to afford a safe character for diagnosing species among the 
American tree-frogs, I would, provisionally at least, assign specific 
rank to the Bismarck Archipelago form, which should bear the 
earlier name Ayla militaria Ramsay, specimens from New Britain 
having been described by E. P. Ramsar!) as Pelodryas militarius. 
I may add that A. militaria agrees with H. infrafrenata in the wide 
separation of the nasal bones. 
Leaving out the Bismarck Archipelago form, the distribution 
of H. infrafrenata can be traced as follows: Talaut Islands, Gilolo 
(Halmaheira), Misol, Buru, Ceram, Amboyna, Timor, Tenimber Islands 
(Timor Laut, Larat), Kei Islands, Aru Islands, New Guinea, Islands 
of Torres Straits, Queensland (Cape York, Cooktown). 
The British Museum Collection contains examples of two further 
frogs, which I had first referred to H. dolichopsis, but which I am 
now convinced represent two undescribed species, for which I would 
propose the names of Ayla spengeli and H. humeralis. 
Hyla spengeli sp. n. is based on a single female specimen from 
Dinawa, Owen Stanley Range, British New Guinea, a locality where 
both H. caerulea and H. infrafrenata are known to oceur. Asit isin 
some respects intermediate between the two, it might be thought to 
be a hybrid, were it not for the size of the tympanum, which is much 
greater than in either of the species to which it is most nearly related. 
Head as in H. infrafrenata; the distance between the tip of the 
snout and the eye is twice the diameter of the latter. Eye, tym- 
panum, and disk of third finger nearly equal in size. Outer fingers 
half webbed; no projecting rudiment of pollex. Tibio-tarsal articula- 
tion reaching the eye; tibia not half length of head and body. Skin 
smooth above, stronely corrugated on the sides, granular on the belly 
and under the thighs. From snout to vent 115 millim. Bluish lilac 
above (in spirit); a white streak, edged with dark purple, borders 
the lower jaw, and extends to above the shoulder; a whitish streak 
along the outer side of the fore-arm and outer finger and of the 
tarsus and outer toe, prolonged a short way up the inner side of the 
1) Proc. Linn. Soc. N.S. W., Vol. 11, p. 28 (1878). — MACLEAY’s 
Pelodryas militarius (l. c., p. 138) is, on the other hand, probably a syno- 
nym of H. infrafrenata. 
