as being confined to tropical and sub-tropical climates. Taking the others in order, we give the following analysis of Libellulida, adopting Rambur's sub-families:

In characterising the genera, we have not thought it necessary to preserve all Hagen's new genera, but have adopted those of Rambur.

Anal angle of the posterior wings of the male rounded off;
second abdominal segment of female not auriculated
(abdomen with a lateral interrupted carina).........
Anal angle of the posterior wings of the male acute; se-
cond abdominal segment of the female auriculated; last
segment not spinous beneath.......

Last segment of the female spinous beneath, otherwise
like Aeschna

Genera of GOMPHINA.

Libellula.

Nannophya.

Anax.

Aeschna.

.....

Gynacantha

It is only necessary to notice the two following, out of seven genera characterised by Rambur, as being alone likely to afford any species to the Canadian naturalist:

Under legs entire; triangle without nervules; eyes separated

Under lip divided at its extremity; eyes slightly touch

ing

Genera of AGRIONINA.

Gomphus.

Cordulegaster

Out of eleven given by Rambur, only three seem likely to occur to the Canadian collector, which may be thus distinguished:

more or less numerous; pterostigma very
small, or only seen in females

Calopteryx.

N. BELLA, Uhler.-Black; front white, with a quadrangular black spot; dorsum of the thorax, each side with an interrupted yel low line on the male; sides with two oblique stripes and a triangular patch behind, interrupted, yellow; abdomen black, with yellow bands and spots-these parts in the female black, pruinose; wings hyaline, fulvous at the base in the male. Pterostigma small, black, terminated with a white nervule at each end in the female : length 18 millimeters; alar expansion 33 mill: rather less in the female.

Hab.: U. S. as far north as Maine.

Gen. LIBELLULA, Linn. (as limited by Rambur.)
a. Perithemis, Hagen.

L. DOMITIA, Drury. (Perithemis Domitia, Hagen.) Posterior lobe of the prothorax large, broad, bilobed; abdomen much shorter than the wings, broad, depressed, narrower at the base; flavescent, villose; dorsum of the abdomen with an interrupted brownish-black line on each side; wings flavesecnt, or at least the basal half, with two fuscous, transverse stripes, the internal one often almost absent in the female; pterostigma rufo-fuscous. In the North

ern var. the sides of the thorax fuscous with two interrupted yellow lines on each side: all the wings of the male with a basal fuscous point. Length 23 millim.; alar expanse 36 millim.; pterostigma 2 millim.

Hab.: U. S. as far north as the States of N. Y. and Mass.

b. Diplax, Charpentier. Posterior lobe of the prothorax large, broad, bilobed; abdomen a little shorter than the wings, slender, triquetral, compressed at the base; feet long, slender; first sector of triangle sinuated; triangle moderate, broad.

L. HUDSONICA, Selys. Very near to the European L. dubia (which is thus described: L. dubia, black; front white, labium black, labrum white, margined with black; vertex and band before the eyes black; thorax obscure brassy-green, with brown villosity; dorsum with a subinterrupted fulvous stripe on each side; sides spotted with fulvous; feet black; abdomen slender, triquetral, the dorsum spotted with yellow; wings hyaline or fumose, anterior pair with two basal points, posterior with a point and a triangular spot at the base, black; pterostigma quadrangular; nigro-fuscous. Length 37 millim.; alar expanse 58 millim.; pterostigma 2 millim.

Hudsonica is smaller; the basal spot of the posterior wings small; the vortex yellow above; the labrum scarcely margined with black. Length 27 millim.; alar expanse 46 millim.

Hab. Hudson's Bay, New Brunswick.

:

L. INTACTA.-DIPLAX INTACTA, Hagen.

Fuscous; mouth and front white; labium of adult male all black, of fem. black in the middle; front with a black band before the eyes; vertex black, with a pale spot, or all black; thorax nigro-fuscous ; dorsum with obsolete fulvous stripe on each side; sides fuscous, varied with black; thorax of adult male brassy-black; abdomen short, somewhat broader before the apex; fuscous, with dorsal phalarate fulvous spots in the adult male black, with a yellowish spot on 7th segment; wings hyaline, posterior ones at the base with a triangular black spot; base flavescent in the females; pterostigma short, quadrangular, black. Length 32 millim.; alar expansion 52 millim.; pterostigma 2 millim.

Hab.: U. S. Wisconsin, Chicago, Mass.

L. RUBICUNDULA, Say.-DIPLAX RUB., Hagen.

Yellowish subrufescent; front yellowish, with a black band before the eyes; thorax rufous, the sides sometimes luteous; feet black; anterior femora luteous beneath; abdomen rather long, slender, sanguineous in the male, or yellowish rufous; the sides with a maculose black stripe; wings hyaline, the extreme base yellowish; pterostigma quadrangular fuscous,, pale at each end. Length 32-37 millim.; alar expanse 50-58 millim.; pterostigma 2 millim.

Hab.: U. S. Mass., &c.

L. ASSIMILATA, Unler.-DIPLAX ASS., Hagen.

Yellowish; mouth and front pale yellow, a narrow black band before the eyes; dorsum of the thorax luteous, its sides yellow; abdomen slender, the base compressed, inflated, yellowish; dorsum of first and second segments black at the base; segments 4-9 each side, with a marginal black stripe; wings hyaline, the base flavescent; males with the basal half flavescent; pterostigma short, yellow. Length 33-37 mllim.; alar expanse 56-60 millim.; pterostigma 24 millim. Hab.: U. S.-N. W. States.

c. Mesothemis, Hagen.-Posterior lobe of prothorax large, broad, bilobed; abdomen a little shorter than the wings, narrow, triquetral, the base compressed, somewhat expanded before the apex; feet long, rather strong; first sector of triangle sinuated; triange moderate narrow; sides of eighth segment of the female not dilated.

L. SIMPLICICOLLIS, Say.-MESOTHEMIS SIMPLICICOLLIS, Hagen. Yellowish-green; mouth and front yellowish; a narrow black band before the eyes; thorax yellowish green, the sides varied with black below; abdomen compressed at the base, vesiculose, triquetral, yellowishgreen, the sutures and margins black; segments 4-10, with a quadrangular black dorsal spot behind; last segments sometimes altogether black; venter obscure; appendages yellow; feet black, anterior femora yellowish beneath; wings hyaline; pertostigma oblong, yellow. Adult male with the thorax and abdomen blue pruinose. Length 41-45 millim.; alar expansion 60-70 millim.; pterostigma 31-4 millim.

Hab.: U. S. as far north as Illinois, Pennsylvania, N. Y., Mass.

d. Libellula, Hagen.-Posterior lobe of prothorax small, entire; abdomen stout, rotundo-triquetral, narrowing posteriorly; triangle narrow, long, first sector sinuated.

L. QUADRIMACULATA, Linn.

Reddish yellow, villose; front pale, terminated with black; sides of thorax yellow, lineated with black; feet black; abdomen attenuated at the apex; fuscous behind; sides yellow; wings yellow at the base anteriorly, a costal spot, and sometimes an apical one; posterior wings with a triangular spot at the base, reddish black, veined with yellow; pterostigma brownish black. Length 48 millim.; alar expanse 80 millim.; pterostigma 4 millim.

Hab.: Northern U. S.; Canada.

e. Plathemis, Hagen.-Posterior lobe of prothorax small, entire; abdomen short, broad, depressed; legs stout, short; pterostigma long, oblong; front sector of triangle sinuated; triangle narrow, long; eighth segment in the female dilated at the sides.

L. TRIMACULATA, De Geer.-PLATHEMIS TRIMAC. Hagen. Rufescent; thorax with two oblique yellowish stripes at each side; abdomen of the male pruinose; female with lateral oblique yellow spots, margined with fuscous; feet black; base of the femora rufescent; wings hyaline, a basal, longitudinal stripe, which is margined inferiorly with lacteons on the posterior wings and a broad band in the middle, in the male; or with the basal stripes a spot upon the middle anteriorly, and the apex fuscous in the female; pterostigma fuscous. Length 40 millim.; alar expanse 70 millim.; pterostigma 5 millim.

Hab. U. S. widely diffused, reaching to Maine and Minnesota.

CORDULIA, Leach.

C. SEPTENTRIONALIS, Hagen.

Brassy-green, hairy; labium luteous; front brassy-green above, each side with a yellow spot; vertex brassy-green; thorax brassygreen, the dorsum having a spot at each side at the wings, and the sides each two maculose stripes, yellow; feet black, anterior femora yellowish at the base; abdomen slender, behind the base inflated; then attenuated, with the apex equal, brassy-black, sides of the base and apex luteous; wings hyaline, the posterior ones with a small basal triangular brownish-black spot; pterostigma small, fulvous; anal