n8 
Psyche 
[September 
is complementary to that of the Trechini. The latter are numerous in 
Tasmania and decrease rapidly northward on the mainland, where 
Tachys increases in numbers. The two groups tend to be complemen- 
tary ecologically too. Most Tachys live beside standing or running 
water or in swamps, often in open as well as forested country. Most 
Australian (including Tasmanian) Trechini live on the ground in wet 
forest but not beside open water. [What I have just said about 
complementarity of Tachys and Trechini is true and important, but 
an oversimplification. The two groups overlap both geographically 
and ecologically in ways that are too complex to describe here.] 
Tachys hobarti group 
In 1921 (p. 193) Sloane mentioned as unknown to him two sup- 
posed Bembidion described by Blackburn: hobarti of Tasmania and 
w'attsense of Victoria. I can now say that hobarti is a Tachys ■, not a 
Bembidion. The oblique truncation of the outer angle of the anterior 
tibia is (as Blackburn said) less marked in hobarti than usual in 
Tachys , but absence of a scutellar stria and presence of a (modified) 
apical stride mark the species as Tachys. I think that the Victorian 
watts ense may be a synonym of hobarti. The former is described as 
having 5 and the latter 6 dorsal striae on each elytron, but both condi- 
tions occur in my series of hobarti from the King River. Sloane’s leai 
may be the same thing, although I do not want to declare the synonymy 
without comparing specimens. Sloane’s murrumbidgensis is a related 
species. And 3 additional species that seem to be new, one of them 
remarkable for reduction of elytral striation, are described below. All 
these species, and perhaps additional ones still to be discovered, form 
what may be called the hobarti group of Tachys. Although they are 
certainly Tachys rather than Bembidion by current classification, the 
species of this group are anomalous (primitive ?) in some ways and 
should be specially considered by students of bembidiine phylogeny. 
Characteristics of the hobarti group are: form subparallel (but ely- 
tra considerably wider than prothorax) , moderately convex; upper sur- 
face usually punctulate (scarcely so in lutus ) . Head large (short but 
wide, with neck very wide and not impressed) ; eyes of moderate size 
but rather prominent; antennae rather short, with median segments 
2 X or less long as wide, and segment 3 usually slightly longer than 
2 ; clypeus truncate or broadly emarginate, impressed at middle anter- 
iorly in some species; mentum not perforated at base, with a simple 
tooth at middle. Prothorax subcordate, more or less lobed across base, 
