NO. 2192. DRAGONFLIES, CALIFORNIA AND NEVADA-^KENNEDY. 579 



This species is peculiar to Lower California and the coast of Cali- 

 fornia. In spite of its peculiarities in color and structure its vena- 

 tion shows it to be a near relative of the cosmopolitan genus Gomplius. 



The figures show the structural oddities of this species. In the 

 male the superior appendages are bifurcate, the two outer hooks fit- 

 ting into narrow recesses on the dorsal edge of the postocular sur- 

 faces of the female, while the spmes on the inner rami fit into special 

 depressions lower down on the postocular surfaces. The four prongs 

 of the inferior appendage hook over the four tubercles on the vertex 

 of the female. (See figs. 330-333.) The coloration is unusual in 

 gompliines in that the middorsal thoracic stripe is yellow instead of 

 being dark. Figure 329 shows tlie male genitalia on segment 2, and 

 figure 324, the female genitalia. 



Measurements of 10 males and 2 females are as follows: Length of 

 abdomen: Male, 36-39 mm.; average, 37.3; female, 35 and 38 mm. 

 Length of hind wing: Male, 29-31 mm.; average, 30.1; female, 

 30-32 mm. 



The nymph is as interesting as the imago, as it does not show the 

 short crooked legs and other features characteristic of most gom- 

 phmes, which are correlated with their burrowing habits. In habits 

 and appearance it is more corduline than gomphine. 



Nymph. — Length of exuvia, 24 mm.; abdomen, 15; width of ab- 

 domen, 7 mm. ; length of hind femur, 5 mm. 



Body flat, deeper and more cyhndrical in the exuvia than in the 

 live nymph. (See figs. 342-352.) 



Head broad cordate, flat above, conspicuously granidated over 

 entire surface. Occiput sHghtly concave, postocular angles rounded 

 and postocular areas each entirely covered by a large scar wliich is 

 characterized by from two to four vertical ridges. Antennae: Two 

 basal joints globular, second smaller than the first, tliird joint 

 three times as long as combined length of first two and one and a 

 half times as wide, depressed, elongate-obvoate when viewed from 

 above, its inner edge less convex than its outer; fourth segment a 

 mere tubercle set in the end of segment 3. Head naked except 

 for long hairs on genae and a series of mixed long and short hairs on 

 the edges of the tliird antennal segment, and numerous short hairs on 

 the labrum. Labium reaching to the posterior side of the fore coxae. 

 Anterior segment of mentum only shghtly less broad than long, its 

 posterior end two-thirds as wide as the anterior end. Median lobe 

 regularly convex; its edge with from 30 to 40 long bristles among the 

 bases of which are numerous shorter bristles ; four large conical teeth 

 on its middle third, these placed just below or outside the double row 

 of bristles. Lateral lobe short and broad, its end squarely truncate 

 but no inner apical hook, the outer three-fifths of its inner edge with 



