690 rROCEEDINGS OF THE NATIONAL MUSEUM. vol. x.xvii. 



them, the number between increasing toward the hind margin. The 

 anal triangle is three-celled. In the relative length of the apical seg- 

 ments of the abdomen the nymph seems to resemble Phyllogomphus 

 rather than Neurogomplais. 



OPHIOGOMPHUS BISON Selys. 



Plate XXXVIIl, ilgs. 4, 5. 



Cast skin of female bred specimen. Collection of Hubbard and 

 Schwarz, Lake Tahoe, California (no date); also, a cast skin of a 

 male imago with fragments of the imago in alcohol; also two nymphs, 

 one of which was very near transformation. 



Length, iJ8; abdomen, 17 mm.; hind femur, 45 mm.; width of head, 

 5.5 mm.; of abdomen, 8 mm. 



Body stout, moderately depressed, skin granulate; face strongly 

 declivous; antenna with third segment strongly flattened, twice as 

 long as the two basal segments together; segment four very rudimen- 

 tary; a hairy tubercle between the base of the antenna and the eye; 

 labium (Plate XXXVIIl, flg. 5), with the men turn a little longer than 

 wide; sides parallel, strongly contracted at basal third; median lobe 

 well rounded with a border of flat brown denticles and a fringe of thin 

 scales; lateral lobe small with a short stout movable hook and no end 

 hook at all, but the end obtusely rounded and the inner edge straight, 

 armed with a series of numerous minute, quadrate denticles. A trans- 

 verse row of scars across the rear of the head, ending laterally upon 

 the summit of the prominent hind angles. Legs short, thinly fringed 

 with hair on their edges; burrowing hooks of fore and middle tibife 

 small. The wing cases reach the base of the flfth abdominal segment. 



Abdomen stout, chiefly narrowed posteriorly on the eighth and 

 ninth segments; segments of about equal length as far as the ninth; 

 the tenth nnich shorter, especially on its dorsal side. Appendages 

 longer than the ninth segment, the superior declined at tip, as long as 

 the inferiors, laterals one-fourth shorter. Lateral spines on segments 

 6-9 well developed, fringed with tawny hairs externally. Dorsal 

 hooks strongly developed on segments 2-9, erect ,on the fore, and 

 posteriorly directed on the hinder segments. 



GOMPHUS MINUTUS Rambur. 

 Plate XXXVIIl, tig. 6. 



Male and female specimens bred. Collection of Hul)bard and 

 Schwarz, Crescent City, Florida. 



Length, 30 mm.; abdomen, 20 mm.; hind femur, 5 mm.; width of 

 head, 5 mm.; of abdomen, 6 mm. 



Body slender. Skin scurfy pubescent. Antenna with the slender 

 third segment four times as long as the second, the first twice as long 

 as the second, the fourth segment a verv minute rudiment. Labium 



