310 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
bewildering mass of details. So slight are the differences pre¬ 
sented, so great the probability that they are due to age, that it 
does not seem worth while to reproduce the table here. Perhaps 
the most that can be said is that in typical velox the tips of the 
wings are brown for a distance varying from three cells to rather 
farther proximad than the outer end of the pterostigma (), or to 
the pterostigma ( 9 ), while in typical sterilis the extent of the brown 
is less in both sexes. Neither this nor any other difference seems 
to be constant eftough to be specific, so that I here place sterilis , and 
one or two others are mere varieties of velox. 
Variety 1. Sterilis. Hagen, Syn. Neur. N. Amer., p. 317, 1861. 
Calvert, Proc. Cal. acad. sci., (2), vol. 4, p. 522, 1895. A synonym 
is JJyth. broadwayi Kirby, Ann. mag. nat. hist., (6), vol. 14, p. 227 
(1894), of which I have seen the type in the British Museum. 
Variety 2. Tabula. Hagen, Syn. Neur. N. Amer., p. 317, 1861 
(no description). Of this I have seen the types at Cambridge — 
a male from Brazil, three females marked Bahia, Para, Brazil 
respectively. They have the vertex metallic blue, the frons lute- 
ous with a metallic blue point at the base of the superior groove, no 
black spot on the nasus, labrum green ($) or yellow (9), its 
free margin bordered with black, extreme base of front wings yellow, 
of hind wings yellow to the submedian cross-vein, apex of front 
wings hardly darker (J'), or brown of variable extent, reaching at 
most to the inner end of the pterostigma (9). Abdominal seg¬ 
ments 9 and 10 of the female are black, unspotted. Abdomen $ 
(broken), 9 25-26 mm. Hind wing $ 31, 9 28.5-30. 
Distribution. “ Typical ” velox is from Texas: Pecos River, 
Round Mt. (Sehaupp), July, August. Sterilis and the various 
intermediate forms are from Mexico: Tehuantepec, Tepic, Baja 
California in September and October; Guatemala; Colombia: St. 
Fea de Bogota; Venezuela: Porto Cabello ; Guiana: Livingston 
in April; Brazil: Rio, Bahia, Para. Hagen in 1875 gave also 
Panama, Peru, Buenos Aires. 
3. Dythemis rufinervis Burm. PI. 1, fig. 4. Burmeister, 
Handb. ent., vol. 2, p. 850,. 1839. Hagen, Proc. Bost. soc. nat. 
hist., vol. 18, p. 74, 1875. 
Distribution: Cuba, Hayti in May; Jamaica: Kingston by 
E. M. Aaron. 
§ II. Wings uncolored. Anterior lamina of male more promi¬ 
nent than genital lobe. 
