and Gyrinidee of Australasia. 215 
appear to be sexual, and in my judgment they sufficiently separate 
the examples which I have been able to examine into six species: 
these are from my own collection, together with others kindly for- 
warded to me by my friends Mr. Bakewell, Mr. Grut, and Mr. Wilson, 
of Adelaide. 
Synopsis of the Genus Enhydrus. 
A. Elytris haud striatis, levigatis. 
1. E. Howittii, n. sp. 
B. Elytris striatis. 
a. Elytrorum apicibus rotundatis. 
2. E. Reichii, Aub., Germ. 
3. E. assimilis, n. sp. 
b. Elytrorum apicibus sinuatis. 
4. EH. latior, n. sp. 
5. H. rwularis, n. sp. 
c. Elytrorum apicibus dentatis. 
6. E. oblongus, Boisd. 
The above (with EZ. sulcatus, Wied., which belongs to the section 
B, a) constitute the whole of the group as at present known to ento- 
mologists. 
Enuyprus, Laporte. 
(Epinectus, Esch. MS.) 
A. Elytris haud striatis. 
1. BE. Howitti, un. sp. 
£. oblongo-ovalis, subdepressus, nigro-zeneus, impunctatus, nitidus ; ely- 
trorum apicibus subrotundatis, haud sinuatis, haud dentatis; corpore 
subtus nigro ; abdomine pedibusque rufo-nigris. 
Long. corp. 53 lin., lat. 23-23 lin. 
Oval, subelongate, decidedly broader in proportion, as well as larger, 
than F. Reich, Aub., subdepressed ; impunctate, of a shining metallic 
zneous black: thorax with the borders of a bluish-green colour; in 
front deeply excavated ; the sides are constricted anteriorly and slightly 
rounded : elytra oval, sufficiently broad; the apex is rounded or sub- 
rounded in form; the colour of the lateral margins is narrowly bluish 
green, that of the margin at the apex narrowly of a bright copper- 
colour; the surface is impunctate, unmarked by any longitudinal strix, 
glabrous; when viewed under a high power, the surface is covered with 
very minute transverse striz: the wnderside of the body is black: the 
abdomen and posterior /egs rufo-fuscous. 
E, Howittii is a very distinct,species, remarkable as being the only 
one of the group that has the elytra unmarked by the deep longi- 
tudinal striz that characterize the genus. A slight variation may 
