34 ANNULOSA JAVANICA. 
PHILHYDRIDA. 
1. Normal groupe ? ; 1. Heteroceride ? 
Palpi antennis breviores 2, Parnide, (analogous to the Gyrinide.} 
2, Aberrant groupe ? 3. Helophoride. 
Palpi antennis longitudine {4 Hydrophilide, (analogous to the Dytiscide.) 
saltem zequales. 5. Spheridida ? 
In this table, although the affinity of Spheridide to Hydrophilida, and of Heteroceride to Par- 
nide@ is incontestable, I have thought proper to mark the place of the Sphe@ridide and Heteroce- 
ride with doubt, as their connection is not very distinct. The fore tibize, however, in both 
families are spinous; and the tetramerous genus Georissus seems to be of some use in uniting 
these discordant groupes. 
Fam. 1. HETEROCERIDZ. 
The type of this family is tetramerous, but its affinity to the Parnid@ has never been con- 
tested. Dr. Horsfield has brought no insects from Java that can be safely assigned to the 
groupe. 
Fam. 2. PARNIDA. Parnipea. Leach. 
In the Genera Insectorum et Crustaceorum M. Latreille has placed the type of this family or the 
true genus Parnus in the same family with Gyrinus, and has called the whole group Otiophari. 
He thus mistook a very obvious relation of analogy for one of affinity ; and accordingly, in 
the Considérations Générales and the third volume of the egne Animal, we find that he sepa- 
rates Parnus and Gyrinus, giving them their proper affinities, but taking little or rather no notice 
of the analogy which exists between them. The genus Potamophilus of Germar (Hydera of 
Latreille) appears to lead off to Octhebius of Leach, and other insects of the next family. 
Subgenus DRYOPS. Leach. 
68. Harpwicxi. D. olivaceo-fuscus aut nigricans, tomentosus, elytris punctorum impressorum lineis octo tar- 
sisque omnibus rufescentibus. 
Long. corp. }. 
Oss. This subgenus is characterized by Dr. Leach in the third volume of his Zoological 
Miscellany, page 88, and may be easily known from Parnus by its wanting the thoracic longitu- 
dinal fossule of the latter genus. Dryops Hardwickii differs from the type and only other 
known species of the subgenus, (that is from D. Dumerilii, which is a South of Europe insect,) 
in having a darker colour, and the points of the elytra impressed instead of elevated. I have 
named this new species after Major-General Hardwicke, a gentleman to whom every naturalist 
is indebted for the zeal and science he has displayed in the prosecution of the several depart- 
ments of Oriental Zoology. 
Fam. 3. HELOPHORID/. 
There are no species of this family among Dr. Horsfield’s insects. The groupe is remarkable 
among the Philhydrida for the metallic lustre which generally characterizes the insects which 
compose 
