262 H. A. HAGEN. 



The fact that the wing cases of the larger nympha, 27 mm. long, do 

 not cover entirely the 2d segment proves that even this nympha is still a 

 young one, and must, when full grown, belong to a very large species. 



13. Ciionipliiis adelphus (supposition). 

 Selys Syn. Gomphin. iv, p. 52. 



One full grown nympha, male, from Cambridge, Mass. Length 29 mm. 

 Similar to G. vulgatissimus, body flatter and more hairy; head cordate, notched 

 behind, angles blunt; third joint of antennae about twice as long as both basal, 

 little dilated, bent up, fourth verj' short, ovoid ; mask quadrangular, a little longer 

 than broad, channeled a little before tip, retracted near base; middle third very 

 slightly rounded but not produced, with a comb of flat scales; palpus short, broad, 

 bent; a finely dentated end hook is short, stout, not much longer than the teeth ; 

 movable hook bent, long, sharp; wing eases reaching 4th segment; abdomen half 

 as broad as long, flat, sides straight, the last four segments strongly tapering, seg- 

 ments of equal length, the 9th a little longer than 8th and more on its ventral 

 side; segment 10 very short, one-fourth of the 9th, cylindrical; lateral spines on 

 6 to 9, the first very short, the following longer, the 9th very long and sharp, 

 twice the length of segment 10, which appears, consequently, encased in the 9th; 

 side margins of 9th serrated ; dorsal hooks none, except a small tubercle in the 

 middle of apex of segments 8 to 9, a little more jjroduced on 9; scars as usual; 

 genitals marked ; appendages twice as long as segment 10, pyramidal, broad, sharp, 

 the middle one with a tubercle on each side, laterals a little shorter; legs strong, 

 the anteriors shorter, posteriors flattened, long, reaching 9th segment; third joint 

 of its tarsi about as long as the two basal. 



Among the few species known from Massachusetts^ (r. (tddpluis is the 

 only one to which it can be supposed to belong. 



The nympha is very similar to the preceding one. 



14. Goinphiis spec. 



Three nymphse. the larger one probably full grown, from Cairo, 111., 

 July 26, 1876, Prof Forbes. Length 18 to 23 mm. 



Similar to the nympha from Newport, Ky., but surely different; body flat, limbs 

 very hairy: third joint of antennre longer, more cylindrical, fourth nearly black; 

 ocelli well visible; palpus with only two incisions near the strong and sharp end 

 hook ; middle third of front margin of the mask slightly rounded ; wing cases 

 covering fully 3d segment; abdomen similar, flat, side margins very hairy; seg- 

 ment 9 as long as 8, 10th very short; lateral spines on 6 to 9, the last one less 

 sharp, as long as segment 10; no dorsal hooks. at all; appendages as long as seg- 

 ment 9, triangular, broad, not very sharp, laterals a little shorter than the middle 

 one, which is shorter than the inferioi-s; legs slender, longer, posteriors reaching 

 segment 8; end hook of anterior tibiae short; third joint of posterior tarsi as long 

 as the two basals. 



This species, together with the following nympha from Newport, Ky. 

 with the nympha from Cambridge (supposed G. adelphus) and with the 

 European G. vulgatissinnni have a sharp impressed dorsal line seemingly 

 cutting the abdominal segments in two halves. 



