138 
Psyche 
[December 
river and 75-100 feet above it on a fairly steep slope. 
There were no lesser streams or other standing bodies of 
water in the part of the forest I worked. Most of the 
samples were taken in a level area with numerous small 
rocks and moist leaf litter several inches deep”. The 
nymph is too young to have been wandering away from 
the river in search of a place to transform to the adult. 
The morphology would suggest either a burrowing or 
terrestrial habitat. However, in consequence of the locality 
in which it was collected, it seems reasonable to consider 
it terrestrial, in this being similar to the specialized 
Hawaiian species of Megalagrion McLachlan. 
The nymph had been preserved in alcohol, and as a 
result, the tissues were very poorly fixed. It was post- 
fixed in Carnoy’s fixative in an attempt to preserve some 
of the few remaining internal structures. 
Total length 11.2 mm., body length (minus caudal gills) 
8.7 mm., abdomen length 4.5 mm. Head broad, median 
length 1.6 mm., maximum width 2.6 mm., well covered with 
heavy setae (PI. 13, fig. 3). Antennae 6-segmented. Scape 
and pedicel longest antennal segments ; thickly covered with 
long setae. Relative lengths of antennal segments 12:12: 
5:5:4:6. Mentum of labium broad, almost square in out- 
line (PI. 13, fig. 1). Mental setae absent. Distal margin 
of the mentum minutely crenelate with short, thick setae 
between each projection. Small median cleft present. Just 
proximal to distal margin and located on each side of the 
cleft is a minute tooth similar to that found in Cora and 
Thaumatoneura. At each corner on the distal margin, 
near the base of the lateral lobes, is a tuft of 8 setae. 
Lateral lobe slender, with a long movable hook (PI. 13, 
fig. 2) . Of the 3 teeth, the center one is longest and sharpest. 
End tooth of left maxilla with 3 basal teeth (PI. 13, fig. 4). 
Incisor region of the mandibles with 5 teeth. Molar 
region separated by a membranous area from the rest of 
Explanation of Plate 12 
Megapodagrionid nymph, Ciu, New Caledonia. Fig. 1, dorsal view. 
Fig. 2, ventral view. Magnification, (x9). 
