76 SOME OBSERVATIONS ON THE GENUS OODEMAS. 
sat subtiliter sparsim punctatis, interstitiis confuse punctatis; subtus abdominis 
parte anteriori sat fortiter punctato. — Long. 5-6 1/4 mm. 
Haleakala, Maui. A few examples at an elevation of 4,000-5,000 feet. 
©. halticoïdes, mihi (Ent. Mo. Mag. vol. XIV, p. 5). 
Præcedenti affine, elongato-ovale, nitidissimum, æncum ad viridi-aureum acce- 
dens; rostro capite thoraceque multo crebrius punctatis; prothorace elongato, 
antice minus angustato; elytrorum punetis seriatim dispositis multo erebrius for- 
tiusque impressis, interstitiis multo fortius punctatis. — Long. 4-5 mill. 
Mountain forests of Oahu. Rare. 
The principal difficulty I have experienced in the study of this 
genus consists in the fact that of all the species (so far as my obser- 
vations extend) examples occur presenting a duller appearance 
than usual, and having the punctuation and striation somewhat 
more strongly defined. I believe these specimens to be females, and 
the distinctive characters alluded to to be sexual. In the two 
instances where they are most strongly defined, I have mentioned 
them in the descriptions. They remind me of the sexual differences 
of some species of Hydroporus (in which genus, however, the cor- 
responding characters are better marked). All the preceding des- 
criptions must be read with due allowance for this variation (1. e. 
it must be remembered that the sculpture of every species 1s liable 
to slight variation). This peculiarity of the genus is most embar- 
rassing to the describer, but on the other hand the characters in 
the antennæ seem to be very constant and well defined, as also the 
color, which it will be observed that I have been very careful in 
describing. I do not possess a color var. of any species. The blac- 
kish, greenish, golden, bronzy, or coppery shade, though only a 
slight tinge, appears invariable. 
Honolulu, H. I. 
