GOMPHUS 101 
nois State Laboratory of Natural History River Survey, between five 
and six o’clock in the afternoon it was transforming in great numbers 
in the sunshine; also in the early morning, from before daylight until 
seven o’clock—which is a much more usual time for Gomphine emer- 
gence. The nymphs live in the sandy bed of the broad river, and cast 
skins thickly covered the sides of the Havana bridges, piers, etc. at 
an elevation of one or two feet above the surface of the water. 
49. Gomphus plagiatus 
Selys ’54, p. 57: Mtk. Cat. p. 95: Wlsn. 712, p. 191: Garm. ’27, p. 166. 
Syn: elongatus Selys 
Length 70 mm. Expanse 80 mm. Ni Y¥2'Gas, Nwc. 
A fine large dark brown species. Face obscure brownish, lighter and some- 
what greenish on the outer sides of the labrum basally. Occiput green, fringed 
with long black hairs. Thoracic stripes of the first pair very broad, especially 
toward the front where they are together widened to form a mid-dorsal triangle 
of brown, confluent with stripe 2 at collar and crest, leaving an oblique pale 
mark each side upon the front. Stripes 2 and 3 conjoined above and below, and 
separated by pale line between. Stripes 4 and 5 complete and distinct. Wings 
hyaline, veins and stigma brown. Legs blackish, except basal half of the femora 
which are paler. Abdomen blackish, with a suggestion of rufous on the slightly 
enlarged terminal segments. Appendages brown. 
50. Gomphus spiniceps Walsh 
Walsh ’62, p. 389: Mtk. Cat. p. 97: Wlsn. ’12, p. 191: Howe 718, p. 35: ’23, 
p. 137: Garm. ’27, p. 166. 
Syn: segregans Ndm. 
Length 57 mm. Expanse 75 mm. N. Y. and Ill. to Pa., Tenn., Mich. 
A pale obscure-brownish elongate species. Face and occiput yellow. Thoracic 
stripes of the first pair confluent, very broad, the two covering the front of the 
thorax, these being fused with stripe 2 around a pair of yellow lines that are 
strongly divergent forward; stripes 2 and 3 confluent; 4 and 5 very broad, com- 
plete, diffuse. Legs brownish, yellowish at base. Wings hyaline, with tawny 
stigma; slightly flavescent at base; veins black. Abdomen with segments 3-7 
with the usual pale middorsal spots, abbreviated behind, nearly obsolete on 7. 
Laterally segments 1-8 or 9 are yellow; 10 wholly brown. Appendages blackish. 
Wilson (’17, p. 191) writes concerning the habits of this species: 
Quite a number were present in the immediate vicinity, but it was practically 
impossible to detect any of them before they flew up out of the grass. One was 
caught accidentally while sweeping the grass for damselflies. It is a strong flier, 
and frequents the vicinity of riffes where the water flows rapidly over small 
stones. 
It frequents the riffles flying back and forth over the swift current, and is sel- 
dom seen in the long stretches of quiet water between. Frequently it dives into 
