194 Journal New York Entomological Society. [Voi.iv. 
is mentioned on the center of the vesicle; none is seen in the Ithaca 
species; the basal fascia of the front is said to be triemarginate, such 
cannot be affirmed of the new form ; nor has the latter a black margin 
on the labrum, and the dorsal carina is not unusually high. However, 
G. amnicola must be more closely related than any of the preceding 
species. G. lividus differs considerably in markings, etc.; it is, rather, 
a southern species. 
To the other three species, G. brevis , albistylus and ncevius, the 
Ithaca form is closely allied. The last two of these are known only 
from the female. But they are all too small; G. albistylus , which is 
the largest, has the abdomen of 29 mm. long; in the Ithaca species it is 
33 to 35 mm. long. G - albist y lus has various black markings around 
front and mouth-parts, also a yellow spot in middle of vertex, these not 
present in the new species; besides the prothorax is differently spotted, 
the stripes on the dorsum of thorax different, different abdominal mark¬ 
ings, and the vulvar lamina is different. G. ncevius is similar to the 
preceding species, but the vulvar lamina is still shorter and rounded at 
the tips; this species is still smaller, abdomen only 25 mm. long; other 
differences the same as in G. albistylus. G. brevis has the abdomen 
26 mm. long, the pterostigma pale yellow, various markings on front and 
near mouth, in the $ a tooth behind the eye near the occiput, the 
border of occiput straight; none of these apply to the Ithaca species, 
nor will the markings on thorax and abdomen agree with it. 
Gomphus descriptus, sp. nov. 
Abdomen $ and 9 32 to 35 mm. long (exclusive of appendages). Hind wing 
30 to 31 mm. long. Pterostigma yellow brown, about 3 mm. long, over 3 to 4 cells 
in $ , over 5 in 9 ; two rows of discoidal cells ; 12 to 14 antecubitals, 10 to 11 post- 
cubitals. Front and mouth-parts uniform greenish, except brown tips to mandibles, 
base of front above narrowly black; vertex black, sometimes pale near base of occiput; 
occiput yellowish ciliated with black; behind eyes yellowish, black toward occiput 
vescicle rounded, slightly rounded and elevated at each end ; border of occiput in 9 
slightly concave in the middle, in $ wholly and evenly convex; no spines on vertex of 
9 . The prothorax black, a long spot in front, a double one in middle, and a larger one 
on each side yellowish. Thorax greenish, more yellowish behind, with dark brown 
stripes as follows : a median one, bifid behind where the carina parts, wider in front, 
narrowly reaching the front margin, and thus connecting to the antehumeral; there 
is always a little portion of the dorsal carina, in front of its highest point, yellow; a 
broad antehumeral stripe projecting inwards above, connecting above to the narrower 
humeral stripe, and sometimes below, leaving only a short green line ; aline on sides 
before the stigmata, bent above ; another line on the posterior suture. The anterior 
femora are usually greenish behind, and in the 9 the posterior ones in front. The ab. 
domen is black, in $ there is a yellow stripe above on 1 and 2, a line, often not reach- 
* 
