CANNACRIA.—PLATYPLAX. 327 
Taken in February (Teapa, Manaos?), March (Teapa, Barbados, Albemarle I.°), 
April (Piedra Blanca), June (Bodega del Carmen 5), July (Tlacotalpam), September 
(Altamira, San Luis Potosi), and December (Chapada). 
[Cannacria gravida. 
Lepthemis gravida, Calvert, Trans. Amer. Ent. Soc. xvii. p. 35, t. 5. figg. 11-18 (apps. ¢) (1890) '; 
Ent. News, i. p. 73 (1890) *. 
Cannacria gravida, Calvert, Ent. News, v. p. 193 (1894)*; Proc. Calif. Acad. Sci. (2) iv. p. 547 
(1895) ‘. 
Hab. Unitep Sratss, Bay Ridge in Maryland (teste J. S. Hine in litt., Sept. 26, 1899), 
St. Augustine (Johnson?), Tarpon Springs}, Sand Point (12. C. Z.), Punta Rassa?, 
Chokoloskee [Kinney: 1 ¢ ], Biscayne Bay | Mrs. Slosson: 1 ¢ ], all in Florida [7 ¢, 
6 2 |, Corpus Christi! and Nueces River! in Texas [2 6,4 2 | (colls. A. NV.S., P. P.C.).] 
PLATYPLAX. 
Platyplax, Karsch, Ent. Nachr. xvii. p. 268 (1891) *. 
Additional material has slightly modified the generic characters as originally stated 
by Prof. Karsch 1, in so far as the last antecubital of the front wings and the two 
submedian cross-veins [“‘ Medianquerader” |] of the hind wings are concerned. It may 
also be noted that Prof. Karsch speaks of the ‘ Bildung des Pronotums, welche sie 
jedoch mit Sympetrum, Newm. (Diplax, Charp.), und Erythrodiplax, Brauer, gemeinsam 
hat,” which is correct for Sympetrum but not for Hrythrodiplax, which has the hind 
lobe of the pronotum distinctly narrower than the middle lobe and not bilobed 
(cf. pp. 198-204, antea). 
1. Platyplax sanguiniventris, sp.n. (Tab. IX. figg. 55-58.) 
3 (adult). Head, exclusive of the eyes, black, vertex and superior surface of frons metallic-violet, outer surface 
of mandibles yellowish or luteous; thoracic dorsum, interalar area, dorsum of first two abdominal segments 
pruinose-blue ; sides of thorax and first two abdominal segments less pruinose, varied with obscure 
luteous(?); abdominal segments 3-10 and the appendages bright red. Abdomen stout, widening slightly 
from base to apex of segment 4, thence gradually tapering to 10. 
Genitalia of segment 2, in profile view, with the hamule slightly more prominent than the other parts, 
unbranched, an external ridge marking the rudiment of an outer branch, tip acute, curved backward 
and somewhat outward to form a hook; anterior lamina convex anteriorly, entire, somewhat hairy 
anteriorly and along its free edge; genital lobe wider beyond the base. 
Superior abdominal appendages longer than segment 9, not so long as 9+10, nearly straight, with an inferior 
row of seven to nine denticles on the third and fourth fifths, apex tapering rather gradually, moderately 
acute. Inferior appendage five-sixths or less as long as the superiors, reaching to beyond the last denticle 
thereof, its apex in ventral view about one-fifth as wide as its base. 
Legs black, third tibize with 10-12 spines on the anterior (outer) row, 14-16 on the posterior (inner) row. 
Wings hyaline, pterostigma luteous or reddish, membranule blackish, whitish at extreme base; one bridge 
cross-vein which is subnodal in position. Front wings with a trace of reddish-brown at base in subcostal 
and submedian spaces, whose maximum extent is one-third of the distance to the submedian cross-vein 
(larger Altamira example); 9 right and 8 left (Livingston), 10 (Altamira) antecubitals, the last continued 
2u? 
