PLECOPTERA NYMPHS OF NORTH AMERICA 113 
hairy; femora and tibiae with a sparse fringe of long hairs on 
the margins; first tarsal segment about twice as long as second; 
third about twice as long as first and second combined. 
Abdomen nearly cylindrical, uniformly brown in younger 
nymphs but transversely banded in mature ones; segments 
widened posteriorly ; surface somewhat hairy, with a fringe of 
long hairs on the posterior margin of the segments. Cerci of 
about twenty-six segments, each terminating in a whorl of hairs. 
Mouth parts. Labrum not quite twice as wide as long; anterior 
margin slightly emarginate in the middle, and fringed with hairs. 
Mandibles slightly asymmetrical, with four to five unequal, rather 
bluntly pointed teeth. These teeth are followed by a well-de- 
veloped molar which bears very short spine-like hairs on the 
eenter, and on the outer margin is fringed with longer hairs. 
Maxillae: lacinia with two or three small terminal teeth followed 
by a few short spines and a fringe of stout hairs. Galea as long 
as lacinia, rather wide in the middle, rounded at the tip, which 
bears a few long hairs; maxillary palpus nearly twice as long as 
galea, stout; first and second segments about as wide as long; 
third segment a little less than twice as long as wide; terminal 
segment about as long as third but much more slender. Labium 
much longer than wide; submentum very large, a little wider than 
long; mentum a narrow transverse band; the paraglossae extend 
slightly beyond the glossae; tips of the glossae and paraglossae 
with long hairs and a few papillae; palpus short and stout, nor- 
mally not extending beyond the tip of the paraglossae. Hypo- 
pharynx broadly rounded, closely beset with short hairs and 
normally extending beyond the glossae. 
This is the most common species of the genus. 
Allocapnia recta Claassen 
Length of body up to 7.5 mm.; antennae up to 3.5 mm.; cerci 
up to 4 mm. 
General color brown with the appendages somewhat lighter. 
This species very closely resembles A. pygmaea.in appearance, 
but the caudal protuberance of the male in recta is much shorter 
than in pygmaea. | 
Head a little wider than pronotum; surface nearly smooth, 
with a feeble coating of fine hairs; antennae composed of about 
forty-seven segments; hind ocelli about twice as close to the eyes 
as to each other. 
Pronotum widened posteriorly; angles broadly rounded; sur- 
face hairy; anterior marginal groove rather prominent; wing 
