256 H. A. HAGEN. 



serrate; movable hook short, sharp; prothorax short, lateral angles rounded; 

 wing eases covering segment 4; abdomen half as broad as long, tapering to base 

 and to tip; convex above; segments of equal length, only tenth less than half as 

 long; lateral spines on segments 6 to 9, the last one half as long as segment 10 ; 

 dorsal hooks strong on segments 2 to 4, only indicated on the following ones, rep- 

 resented on S and 9 by the middle of the apical border produced; segments 2 to 9 

 on each side with a scar and a small linear brown spot; part between the ventral 

 sutures as broad as the lateral ones; appendages twice as long as segment 10, very 

 sharp, the lateral ones very little shorter than the others, female genitals repre- 

 sented by two cylindrical knobs at the end of 8th segment; legs rather slender, 

 the four anterior fitted for burrowing; hind ones reaching segment 7; the whole 

 body very little hairy on the legs and abdominal margin. 



A very small nympha, length 15 mm., from Arizona, belongs to the 

 same species by the number of lateral spines and the dorsal hooks ; the 

 hind femurs are blackish at base and before tip ; the segments have 

 besides the linear spots one spot on each side near the middle line"; the 

 dorsal hooks are dark, a brown spot near the lateral margin of the seg- 

 ments. 



4. Ilerpetogoiiiphiis Iflenefriesii (supposition). 

 Selys Synops. Gomphin. quatr. addit. p. 24. 



A nympha from Guatemala. Length 18 mm. 



The probably young nympha has lateral spines on Gth to Tth segment 

 and very strong developed dorsal hooks, all erected on segments 2 to 9 ; 

 the last segment a little longer than in //. designatm ; appendages all of 

 nearly equal length ; wing cases covering half of segment 4. 



The spines and horns of the abdomen seem to exclude the possibility 

 of bringing the nympha to the other described species, though all other 

 characters agree with the genus. 



The only species known from Gruatemala is H. Menetriesn. 



5. Herpetogoiiiphus coinpusitus (supposition). 

 Hagen Monogr. Gomph. p. 400; Cabot p. 4, No. 6, pi. 2, fig. 6. 



Five nymphse in alcohol, the largest one probably full grown, from 

 Poole's Creek, N. Mexico (formerly W. Texas) by Capt. Pope's expedi- 

 tion. Length 24-14 mm. ; breadth 7-5 mm. 



The largest nympha is described by Mr. Cabot and agrees so well with 

 those of H. desigaatus that there cannot be any doubt about its generic 

 position. H composlfns (imago) was collected also by Capt. Pope ; the 

 size and similarity of H. designatus and H. compositus make the deter- 

 mination very probable. 



The nympha diflPers from H. designatus by joint three of antennfe 

 shorter, more dilated, fourth a little longer, conical ; dorsal hooks on 

 segments 2 to 9 well developed, on the last segments represented by tri- 



