42 
Thomas C. Barr, Jr. 
SYSTEMATIC ACCOUNTS 
Trechus Clairville 
Subgenus Trechus , sensu stricto 
hydropicus group 
Trechus (Trechus) hydropicus hydropicus Horn, new status 
Figs. 1, 18 
Trechus hydropicus Horn 1883:273. Type locality, “Virginia”; type depos- 
ited in Academy of Natural Sciences, Philadelphia. Jeannel 1931:435. 
Barr 1962: 71. 
Few specimens of typical T. hydropicus were available prior to 1960, 
most of them labeled “Va.”, “W.Va.”, and “Md.” I suggested (Barr 
1962:72) that T. hydropicus and T. beutenmuellen Jeannel might eventually 
prove to belong to a widespread polytypic species, but did not then have 
sufficient fresh material to justify the recombination. The type of T. 
hydropicus bears the label, “Va., Ulke”. I propose restriction of the type 
locality to Bald Knob, Mountain Lake, Giles County, Virginia; T. 
hydropicus is moderately abundant at that locality, and it is within the area 
known to have been visited by Ulke. 
In comparison with other subspecies, T. h. hydropicus has an aedeagus of 
medium length (0.93-0.99 m), the apex of the median lobe straight and 
0 0.5mm 
» -* 
Figs. 18-21. Aedeagi of Trechus species, left lateral view: 18. T. hydropicus hydropicus (Horn), 
Mountain Lake, Virginia. 19. T. hydropicus avus Barr, Grandfather Mountain, North 
Carolina. 20. T. hydropicus beutenmuellen Jeannel, Mt. Mitchell, North Carolina. 21. T. 
hydropicus canus Barr, White Top Mountain, Virginia. 
