268 H. A. HAGEN. 



grown nympha skins have the teeth longer, sharply pointed, divergent, 

 the last longest; genitals marked in the nymphae 15 mm. long and 

 longer. 



22. Goinphiis spec. 



One female nympha skin from the Tapajos River, Amazon, Thayer 

 expedition. Length 35 mm. 



Body large, stout, hairy; head cordate, about as broad as long, hind angles 

 globular, between them two smaller tubercles ; antennae shor^, third joint less than 

 thrice the length of the basal, somewhat dilated in middle, flat above, tip bent up ; 

 fourth very small, cylindrical ; mask large, oblong, one-third longer than broad, 

 sides somewhat convex, basal third a little narrowed, middle third of front border 

 produced in a short rounded lobe with pavement teeth and a comb of flat scales ; 

 palpus strong, short, not meeting, arcuate, with a few molar incisions; end hook 

 long, very much bent, sharp; movable hook long, bent, sharp; wing cases reach- 

 ing 5th segment; abdomen stout, rounded above, one and a half longer than 

 broad, the last three segments slowly tapering ; segments of equal length, 10th 

 conical, a little longer than 9th; lateral spines on 5 to 9, very small on 6, the 

 other longer, very strong, divergent from the segments ; dorsal hooks on 2 to 9 

 very strong, the last pointed; scars as usual ; genitals very little marked ; inferior 

 appendage thin, sharp, as long as segment 10 ; laterals similar, but one-third 

 shorter, the other wanting ; legs short, strong, adapted for burrowing; hind legs 

 flat, reaching 7th segment; third joint of posterior tarsi as long as the two basal. 



A nympha skin long 24 mm. from the same locality belongs probably 

 to a previous stage of the same species ; the only differences are that the 

 rounded middle part of the mask is more produced, nearly semi-circular ; 

 the palpus is larger, inner margin without molar incisions and convex, 

 end hook longer, bent suddenly down at the base and the tip bent again 

 in the opposite direction. The only skin is in bad condition, therefore 

 the. differences may be considered as accidental ones until more specimens 

 will warrant a new species. 



The species belonging to the nympha is probably not yet known. 



23. Ooinphiis Rpec. 



One nympha in alcohol from Carundahy River, Brazil, Thayer expe- 

 dition. Length 22 mm. 



The nympha is very much alike to those from the Tapajos River, but differs as 

 follows: wing cases reaching third segment the nympha is apparently younger) ; 

 lateral spines on segments 7 to 9 ; appendages as long as last segment, very sharp, 

 the superior and the laterals of equal length, very little shorter than the inferiors ; 

 hind legs longer, reaching about 9th segment. 



I would not have separated this nymphae except for the unusual 

 length of the lateral appendages and the smaller number of lateral 

 spines. 



