34 ANNULOSA JAVANICA. 



pHILEYDltlVA. 



1. Normal groupe? (1. Heteroceridce ? 



Palpi antennisbreviores \% Parnidce, (analogous to the Gyrinidce.) 



2. Aberrant groupe ? f3. HelophoridcE. 



Palpi antennis longitudine < 4. HydropHlidm, (analogous to the Dytiscida.) 



saltern Eequales. ^5- Sphmrididts? 



In this table, although the affinity of Sphcerididce to Hydrophilidcc, and of Heteroceridce to Par- 

 nidcc is incontestable, I have thought proper to mark the place of the Sphceridida and Heteroce- 

 ridce with doubt, as their connection is not very distinct. The fore tibiae, however, in both 

 families are spinous ; and the tetramerous genus Georissus seems to be of some use in uniting 

 these discordant groupes. 



Fam. 1. HETEROCERID.E. 



The type of this family is tetramerous, but its affinity to the Parnidoe has never been con- 

 tested. Dr. Horsfield has brought no insects from Java that can be safely assigned to the 

 groupe. 



Fam. 2. PARNIDJE. Parnidea. 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 Otiophori. 

 He thus mistook a very obvious relation of analogy for one of affinity ; and accordingly, in 

 the Considerations Generates and the third volume of the Rtgne 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 Octhehius of Leach, and other insects of the next family. 



Subgenus DRYOPS. Leach. 

 68. Hardwicku. D. olivaceo-fuscus aut nigricans, tomentosus, elytris punctorum impressorum lineis octo tar- 

 sisque omnibus rufescentibus. 



Long. corp. J. 

 Obs. 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 fossulse of the latter genus. Dryops Hardiuickii differs from the type and only other 

 known species of the subgenus, (that is from B. 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^S. 



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 tlie insects which 



compose 



