224 GOMPHUS DILATATUS, VASTUS AND LINEATIFRONS (odONATa) 
Males 
If). Latoral labial lobes: in dilatalus ehiefly brown; in linentijrons ehiefly 
f^reen isli. 
1(). Sni)erior abdominal appendages in dorsal view: in dilalatus angnlate 
on the lateral margin at .55 to .07 of their length eorresjmnding to the infero- 
lateral tooth; in Hnentifroas rounded off at the same i)laee; in profile view 
the a])i)endages are more robust and the tooth jdaeed a little more distad 
in Hnealijrons (ef. figs. 1 18, Plate XV). 
17. (Jenital hamnles: in dilalatus less robust; iji litiealifrous more robust 
(ef. Plate X\', figs. 17 and 20). 
IS. Po.sterior margin of the vesiele of the ])enis when fully extended and 
in profile view: in dilalatus 1.53 mm. in height, or .30 as high as the hind 
margin of abdominal segment two; in Hneatifrous 1.7 mm. in height or. 48 
as high as tlie hind margin of segment two (only one male of eaeh form has 
l)een measured iii extended eondition, however. (4‘. Plate XV, figs. 21, 22.^ 
Females 
11). Vulvar lamina: in dilalalus reaching to .47 (drawing of the 9 type) 
or .37 (>S]>ring Creek 9) of the length of the sternite of nine, narrowed dis- 
tad so that at two-thirds’ length it is but half as wide as at base, di.stal fifth 
bifid, the divi.sions acuminate, more aente in the two females I have examinetl 
than in the drawing fnnn Rambur’s type; in liuealifrons reaching to .51 to 
..55 of th(' length of the sternite of nine, narrowed to two-thirds its basal 
width at. one-third of its length, thence widened so that at two-thirds’ length 
if is almost as wide as at base, distal fourth bilobed, each lobe broadly rounded 
(comj)are PlateXlV, figs. 8-10), or even truncated at tip in the Jellico 9- 
20. fliml margin of the occiput, viewed from in front but also from a more 
sup<*rior or dorsal position than that indicated under lu). 1 above: in dilata- 
tus almost, straiglit, and entire, in lineaiiJro)ts widely and shallowly excavated 
in the middle, a. convexity on each side of the nu'diaii excavation (cf. figs. 
3, 5, Plate XIV). (Males of both forms have the himl margin distinctly con- 
vex, although with tin' differtmee iiKMitiom'd umh'r no. 1 above). 
in the lit('raturp to those two forms and the 
inat,(‘rial wliioli I hav(' studied ai‘(' as follows: 
Gomphus dilatatus 
1842. Rambur, Hist. Nat. Ins. Nevr., p. 155. [9 “ r.\meri(|ue septentrion- 
ale”.] 
1851. Selys, Hull. Acad. Roy. Helg., XXI, pt. II, j). 47 (Synop. Comph. 
p. 2.8). [c7>9 '‘Etats-linis”.] 
I8.*)8. Solys A llagmi, Monog. Comph., j). 123, jil. 7, figs. 3 a-m. | Details 
oi both sexes figured. “ L(‘S flUds-lhris, d’apres h' tyjie fmnelle dei'rit 
par M. Rambnr, (|ui fait partie de ma colh'clion, et un nulh' appartenant 
a .\I. Hagen.”! 
18til. Hagen, Syn. Neur. N. .Amer., p. 103. Icf9 ‘‘Ceorgia (.Abbot).”] 
