Revision of Trechus 
55 
Carolina border. Both altitudinally and geographically it is the most 
widely distributed of the Unaka assemblage of Trechus species, ranging 
from the highest summits in the Great Balsams, Plott Balsams, and Great 
Smokies down to 2400 feet (730 m) in the gorge of the Whitewater River. 
Additional collections made since 1962 serve firmly to establish its ubiq- 
uity in the main portion of its range, and I list only the southern 
peripheral records below. 
GEORGIA: Towns County. — Summit of Tray Mountain, elevation 
4400 feet (1340 m) near White-Habersham county corner. Rabun County. 
— Coleman River gorge, 0.4 mile (0.6 km) above mouth of the river in 
ravines on southwest slope of Straw Mountain. Gilmer County. — Quarry 
near summit of Betty Mountain, elevation 3300 feet (1000 m) on crest of 
Cohutta Mountain. Murray County. — Northeast slopes of Grassy Moun- 
tain along Mill Creek, elevation 3100 feet (945 m). NORTH 
CAROLINA — SOUTH CAROLINA: Sassafras Mountain, elevation 
3500 feet (1070 m), Transylvania-Pickens county line. NORTH CAR- 
OLINA- — TENNESSEE; 0.5 mile (0.8 km) south of Stratton Meadows 
on Johns Knob, elevation 4600 feet (1400 m), Graham-Monroe county 
line. 
The larger species of the vandykei group include T. barben, T. tomtru, and 
T. subtilis. The relationship of the latter two species to T. barben is un- 
clear, but probably they represent isolates whose range has been invaded 
by the ecologically more successful and more abundant T. barben. The 
status of T. tomtru needs clarification: it is apparently well within the 
geographic range of T. barben , but the two species have not been taken 
syntopically, and T. tomtru is still known from a single site. On the other 
hand, T. subtilis coexists with T. barben , although it is much less 
abundant. 
Trechus (Microtrechus) tomtru Barr 
Fig. 31 
Barr 1962:79. Type locality, Thunderhead, Great Smoky Mountains, 
Blount County, Tennessee; type deposited in USNM. 
Trechus tomtru is known only from the summit of Thunderhead, eleva- 
tion 5500 feet (1675 m) in the western Great Smoky Mountains, on the 
border between Blount County, Tennessee, and Swain County, North 
Carolina. The entire type series of 19 specimens was collected from 
beneath moss in a scrubby heath thicket just below the top of the moun- 
tain on the north (Tennessee) side. The species is closely similar to T. 
barben , but the apex of the pronotum is a little wider than the base, the 
pronotum sides are slightly sinuate before the right to slightly obtuse hind 
