30 ANNULOSA JAVANICA. 
Fam. 1. GYRINIDZE. 
Degeer, in his immortal work, has observed, “ Les Tourniquets approchent beaucoup de: 
Scarabés-d’eau ou des Dytisques ;’’ but the remark was neglected by Latreille until lately. In 
his Genera Crustaceorum et Insectorum he placed the Gyrini and Parni in the same family, 
named by him Otiophori, thus confounding a relation of analogy with one of affinity. 
I know not whether I am quite right in considering these insects as belonging to the norma! 
groupe of Hydradephaga ; but certainly, both in their perfect and larva form, they are farther 
distant from the Carabi than Dytiscus. As however it is imposible to proceed naturally in 
a linear series of description, I begin with this Hydradephagous family, which is known to every 
entomologist by its gregarious sportive nature and its auriform antenne. 
The larvee of Gyrinide are exactly Scolopendre in appearance, the tracheal branchice 
answering to the false feet of the Chilopoda. The perfect insects are almost the only Hydra- 
dephaga that possess a metallic lustre. 
Genus DINEUTUS Nobis. Gyrinus Lat. 
Antenne brevissime apice subacute. 
Labrum semicirculare haud ciliatum. 
Palpi clavati. 
Pedes antici fere corporis longitudine. 
Oss. These few characters, although merely external, will sufficiently separate this genus 
from Gyrinus. M. Latreille has observed that, the exterior biarticulated lobe of the mavxillee. 
or (as it is more commonly called) the internal maxillary palpus becomes evanescent in the 
exotic Gyrini, as well as in certain exotic generaof Geodephaga such as Therates. 
57, Poxrrus, D. nigro-cneus levissimus, clypeo nigro-piceo angulis rugosulis awreis, pedibus anticis piceis posticis 
pallidis. 
Long. corp. 3 
Genus GYRINUS. 
58. Denrirennis, G. niger vix eneus elytris postice unidentatis apice truncato-sinuatis punctulatis substriatis. 
Long. corp. % + 
Labrum nigrum. Corpus subtus nigro-eneum vix cupreum ano hirsuto. Pedes antici picei posticis 
quatuor rufis. 
Oss. I am uncertain whether this species be sufficiently distinct from the Gyrinws Indus of 
the supplement to the Ent. Syst, a species which Fabricius afterwards abandoned in the Sys¢. 
Eleutheratorum. 
59. Liuparus. G. elytris apice truncato-sinuatis striatis ad suturam eneis, vittd media sub-cuprea margineque 
viridi. 
Long. corp. vix. fs. 
Caput viride vertice subcupreo labrique margine viridi. g Caput punctis duobus sub-impressis. 
Fam. 
