242 
PACIFIC SCIENCE, Vol. IX, April, 1955 
acter exhibits a north-south dine but my 
impression is that there is a sharp break north 
of the Loyalties. 
To summarize: T. melanesiensis has a wide 
variety of larval habitats over its entire geo- 
graphical range. It is found generally in tree 
holes and artificial containers of many types 
as well as in dead plant material, such as 
coconut shells, cut bamboo and cacao pods. 
It can also utilize for breeding, at least tem- 
porarily, small ground pools and rock holes. 
Also it has been reported breeding in bamboo 
stubble. As has been noted above, the larvae 
reported from "palm-bracts” may represent a 
distinct species. T. melanesiensis apparently 
tolerates brackish water as well as water with 
high organic content such as in septic tanks. 
Distinct larval morphological features are as- 
sociated with the type of larval habitat at 
least over part of the range. Thus tree-hole 
breeders generally have a longer siphon; 
shorter anal gills; darker pigmentation; a 
greater development of stellate tufts, acces- 
sory siphonal hairs and pecten teeth; and 
longer and more pointed comb scales. Breed- 
ers in coconut shells, bamboo and cacao 
pods represent the other extreme, while 
the larval forms from artificial containers 
are intermediate but are generally closer to 
the tree-hole breeders. On the other hand 
parallel ecological types in different portions 
of the range are usually distinct in other fea- 
tures, indicating in all probability distinct 
isolated genetic stocks on practically every 
island. There appears to be a sharp demarka- 
tion between the populations in the New 
Hebrides and those to the south, not only in 
larval but also in adult characters. In New 
Caledonia and adjacent islands the different 
larval ecological types are quite similar while 
in the New Hebrides, particularly in the north- 
ern islands, the ecological types are more 
numerous and are sharply differentiated from 
each other. 
Attempts to segregate these various forms 
into ecological or geographical races are com- 
plicated by the fact that melanesiensis is a very 
plastic species for there is a great deal of 
individual variation within single collections 
as well as in different collections from the 
same habitat in at least some geographical 
areas. Differences in the development of stel- 
late hairs, metathoracic spine, anal gills, comb 
scales, pecten teeth, length and shape of si- 
phon, number and branching of accessory 
siphonal hairs are sometimes so striking that 
larvae from a single collection may appear to 
represent a very distinct species. Furthermore 
it is very likely that there is some contamina- 
tion and mixing of local races through human 
agency. With the scanty material and the 
many geographical and ecological gaps it does 
not seem worthwhile to distinguish at the 
present more than the clearly marked typical 
race in the northern and central New Hebrides, 
the northern atypical races throughout the New 
Hebrides, the southern atypical races in New 
Caledonia, Loyalties and probably Belep 
group, and the " palm-bract ” race in New 
Caledonia. 
Distribution 
New Hebrides, Espiritu Santo : 3L, 3M, 7F 
(K-755), 10 miles north of Bomber 3, Sept. 
5, 1943 in cut bamboo shoots (K. L. Knight); 
94L, 16M, 19F (K-759), Segond Channel area, 
Sept. 21, 1943, tree holes (K. L. Knight, J. G. 
Franclemont, JNB) ; 3M, 4F (K-774), stream 
north of Bomber 3, Sept. 14, 1943, cut bam- 
boo shoots (K. L. Knight); 2L, 1M (K-781), 
Base 6 Hospital, Segond Channel, Oct. 10, 
1943, cut bamboo shoots (K. L. Knight); 
15L, 6M, 10F (K-785), north of Bomber 3, 
Oct. 17, 1943, cut bamboo (R. L. Ingram, 
J. Laffoon) ; 23L, 4M, 6F (K-788), Segond 
Channel area, Oct. 23, 1943, cut bamboo 
trunks (R. L. Ingram); IF (K-790), Segond 
Channel area, Oct. 25, 1943, tree holes (J. 
Laffoon); 30L, 5M, 4F (K-794), Turtle Bay, 
Oct. 24, 1943, tree hole (R. L. Ingram); 1L 
(K-935), Sarakata Valley, July 29, 1943, foul 
water in cold storage house (K. L. Knight); 
3L (K-946), Segond Channel area, Aug. 15, 
1943, tree hole (R. L. Ingram); 3L, IP, lM, 
