NORTH AMERICAN NEUROl'TERA. ZOO 



of tlie skin. Perhaps they belong to some of the large Indian species, 

 Macrogomphus or Heterogoniphus ; the place after or near Onychogom- 

 phus seems to be indicated by the palpus and the front border of the 

 mask. 



Sub-genus Herpetogomphus (raised). 



The species belonging now to Herpetogomphus were at first described 

 in De Selys Synops. Gromphin. p. 20, as a separate group of Ophiogom- 

 phus. Later (Monogr. Gomphin p. 70) a new sub-genus Herpetogom- 

 phus was proposed because the male organs proved to be remarkably 

 different. Ophiogomphus and the larger part of all sub-genera of Gom- 

 phus have the second joint of the penis longer than the third and below 

 with a long basal tooth directed to the tip of the joint. Herpetogom- 

 phus, Ceratogomphus, Onychogomphus and Anormogomphus have the 

 second joint of the penis siiorter than the third and without tooth, but 

 the third joint has two small spines directed to the base of the joint. 

 The conse(|uence of such differences in the male organs lead us to sup- 

 pose analogous differences in the female organs and are, as far as I know, 

 generic differences. Later De Selys, in four additions Synops. Gomph. 

 and in Compt.-Rend. Soc. Ent. Belg. May 3, 1879, has denied the generic 

 importance of this character and has given other characters to separate 

 the sub-genera Herpetogomphus and Ophiogomphus. There are known 

 now ten species belonging to each of those sub-genera. All Herpeto- 

 gomphus are North American species, and as I believe representing in 

 America the sub-genus Onychogomphus, which belongs to the old world. 

 I have to confess that the previous stages seem not to confirm my views. 

 The nymphfe differ essentially from those of Onychogomplius, and are 

 so entirely alike to those of Ophiogomphus, that I am not able to find 

 any difference between them. 



3. fIeri>eto$;oin|>liiis <Ii'Nig;iiatiis (raised). 

 Hagen Monogr. Gomphin. p. 401. 



Two nympha skins, one with the teneral female on the same pin. 



San Antonio, Texas, by Mr. A. Agassiz ; a male nympha skin from 



Dallas, Texas, in McLaclilan's collection. Length 25 mm. 



Head strongly cordate, deeply notched behind ; eyes very prominent; antennae 

 stout, little longer than labrum, third joint less than twice as long as the two 

 globular basal ones, somewhat larger on tip, flattened above; fourth very short, 

 pyramidal; mandibles with four teeth at tip, the interior longest, the others suc- 

 cessively shorter ; second row narrower, curvate ; mask quadrangular, little nar- 

 rower at base, middle third produced in a short rounded lobe, with fine pavement 

 teeth and a comb of scales; palpus short, straight, rounded on tip, very finely 



