CYANOGOMPHUS.—EPIGOMPHUS. 169 
1. Cyanogomphus (?) tumens, sp.n. (Tab. VII. figg. 11, 114, 41.) 
¢ unknown. 
Q. Head and thorax pale green, obscure on the face and on the sides of the thorax; vertex, occiput, and 
thoracic dorsum brown, darker on the last, where the brown forms a pair of submedian stripes only 
separated by the pale carina, a complete antehumeral stripe reaching from the antealar sinus to the 
anterior mesothoracic margin, and an ill-defined line on the humeral suture. The pale green antehumeral 
area thus left between the dark submedian and antehumeral stripes is about one and a half times wider 
at its lower than at its upper end and is narrower throughout than either of the two dark stripes, of its 
own side of the body, between which it lies. 
Abdomen dark brown, evidently much faded, but the following pale markings can be detected: all of seg- 
ment 1, a mid-dorsal line and the sides inferiorly of 2, the sides of 3-5 inferiorly from base to transverse 
submedian suture of each, a mid-dorsal line on 3-5, for the whole length of 3, but shorter on 4 and 5. 
Legs pale, distal ends of the femora and the tarsi black. 
Rear of the head superiorly swollen on each side behind the eyes, the swollen portions continuous with the 
occiput and extending outward and downward along each posterior eye-margin to about the level of the 
upper surface of the frons; when the head is viewed from the side, the point where the swelling ceases 
inferiorly is seen to coincide with a posteriorly-directed obtuse angulation of the posterior eve-margin. 
Abdomen widest at the base of segment 2, thence narrowing to the middle of 3, thence of uniform width to 
the base of 7, thence gradually widening to the base of 10, which is not quite so wide as the base of 2, 
7-10 of successively decreasing length, posterior margin of 9 produced in the mid-dorsal line to 
overlap 10. ‘Appendages slightly shorter than the lateral margin of segment 10, dark-coloured. 
Vulvar lamina reaching to half the length of 9, bifid in its apical two-fifths, the two divisions separated by an 
angular interval of less than 90°, their tips subacute and directed slightly outward, the distance between 
them almost twice the width of either division at base. 
Wings clear, reticulation dark; pterostigma dark brown within black veins, surmounting 4-5 cells, its costal 
edge on the front wings 3°5 mm. long. Front wings: 15 antenodals, 8-10 postnodals, Hind wings: 
11-12 antenodals, 9 postnodals. cot 
Dimensions. —Abdomen 35; hind wing 25 mm. 
Hab. Mexico, Atoyac in Vera Cruz (H. H. Smith: 19). 
Mr. McLachlan saw a photograph of the venation of this insect and wrote 
(28. vii. 03): “Ido not recognise the... photo.” . 
The specific name alludes to the peculiar character of the rear of the head. 
EPIGOMPHUS. 
Epiyomphus, Selys, Bull. Acad. Belg. xxi. pt. 2, p. 59 [40] (1854)?; (2) xxviii. p. 188 [25] 
(1869) ?; (2) xxxv. p. 754 [27] (1878)*; (2) xlvi. p. 468 [63] (1878) *; Monogr. Gomph. 
p. 84 (1858) °; Kirby, Cat. Odon. p. 71 (1890) °. Calvert, Ent. News, xiv. pp. 184, 186 
(1908) *. 
In a synopsis of this genus’ published in 1903, six species were distinguished, 
extending from Mexico to Bolivia and Southern Brazil. Since then an additional 
representative has come to light from Costa Rica. ‘The colouring is almost identical 
in all the species, so that the descriptions of de Selys will in this respect also answer 
for those more recently described. The females of only two species of the present 
fauna are known. 
BIOL. CENTR.-AMER., Neuropt., June 1905. Z 
