482 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 113 
Material examined: Illinois, Elgin, Trout Spring, Mar. 7, 1936, 
4 larvae (INHS). New Hampshire, Twin Mountain, Zealand Camp- 
ground, small stream, May 18, 1957, 7 larvae. New York, Dryden, 
Ellis Hollow, Jan. 31, 1957, 2 larvae—May 4, 1957, 4 larvae—May 
29, 1959, 3 larvae, 2 prepupae, 1 pupa—July 14, 1956, 1 prepupa; 
Cortland, Fish Hatchery, July 8, 1959, 1 larva. 
Remarks: The larvae of this species were collected only in springs 
and the small brooks below them. I have not taken the larvae from 
streams more than 2 feet wide. 
Adults of vibox have been collected in June and early July, but 
probably could be taken in August. Larvae have been collected 
from January until early July, with prepupae found from late May 
and into July. 
Rhyacophila invaria (Walker) 
Figure 8,a,b 
Polycentropus invarvus Walker, 1852, p. 101. 
Rhyacophila invaria (Walker) Ross, 1938b, p. 6 (male genitalia). 
This species has only been recorded a few times from the North- 
eastern states: Maine, Massachusetts, New York, Nova Scotia, 
Pennsylvania. 
Several male metamorphotypes were collected in Massachusetts, 
and thus the larval and adult stages were linked. The larvae are very 
similar to those of mbox. The invaria larvae studied have the ante- 
tior half of the frontoclypeus pale and have a small second ventral 
tooth on the anal claw. 
Description: Length, 15mm. Head, brownish yellow, darker along 
anterior margin and mesally; muscle scars pale, inconspicuous; head 
capsule distinctly widening toward posterior (fig. 8,4); second segment 
of maxillary palpus twice as long as first; left mandible with 2 apical 
teeth, right with 3 apical teeth, middle one being longest (like fig. 
11,6). Thorax, pronotum brownish yellow, with oval dark mark 
posteromesally; fore femora much broadened. Abdomen, anal 
proleg with both basoventral and apicolateral processes, neither free 
of membrane; claw with 2 ventral teeth (fig. 8,0). 
Material examined: Massachusetts, Sunderland, Fish Hatchery, 
Aug. 6, 1954, 2 prepupae, 3 o'? pupae—Aug. 9, 1954, 7 o'9 pupae— 
Oct. 20, 1954, 2 larvae—Nov. 9, 1953, 1 larva; Montague, Feb. 7, 
1959, 1 larva. 
Remarks: The two streams where the larvae of this species were 
collected are small, about 2 feet wide, clear, and cold. 
Adults were collected at the Sunderland locality from early July to 
early August. The larvae collected in October were nearly half 
grown; those collected in November and February appear to be fully 
erown. 
