314 ENTOMOLOGICAL NEWS. [ July, 16 
to our great surprise, he found that the penis of these Trini- 
dad specimens was entirely distinct from that of gracile. It 
is therefore very appropriate that this Trinidad species, the 
positive recognition of which has been possible only through 
Mr. Kennedy’s work, should be named Acanthagrion kennedit. 
The mesepisternal fossae. In Plate XVII, figures Io, I1, 12 
and 13, I have figured a portion of the right dorsum of the 
thorax of four females. In these four species there is, on 
either side of the middorsal carina, and immediately adjacent 
thereto, and at varying heights on the thorax, a small more or 
less semicircular depression which, in these species at least, 
functions as a socket for the reception of half of the posterior 
dorsal termination of the tenth segment of the male. These 
depressions have the middorsal carina between them variously 
modified. As shown by the figures, and as might be expected, 
the fossae are placed higher on the mesepisterna in gracile 
than in kennedii and still higher in ascendens. The name, mese- 
pisternal fossae, given to these pits or depressions, has been 
suggested by Dr. Calvert. 
Acanthagrion kennedii n. sp. (Plate XVII, figs. 5, 6, 8, 11). 
Abdomen ¢ 24-27, average 25.5, 2 24-25; hind wing 4, 15.5-17.5, 
average 16.6, 2 17-18. 
é.—Genae, labrum and rhinarium green, the rhinarium usually dul- 
ler than the labrum, and the labrum with an impressed posterior me- 
dian spot and posterior lateral margins dark brown or black. Nasus 
black, the extreme posterior lateral corner green. Frons in front with 
a large quadrangular, slightly oblique. bar on either side, varying in 
color from green to obscure green, yellowish or brownish, and vary- 
ing also in size, in rare cases reduced and so obscured as to be scarcely 
evident. Head above black; postocular spots greenish blue rounded, 
with very little variation in size, about equal to a circle enclosing the 
ocelli. Rear of head above level of foramen black; below pale, dull or 
yellowish or greenish tinged. 
Front lobe of prothorax pale or yellowish, with a black posterior 
spot on either side and with the anterior border more or less black; 
middle lobe black with a variably-sized yellow spot on either side near 
the lateral margin, this spot never large, reduced to a mere point in 
many cases, and sometimes wanting; hind lobe black, a small yellow- 
ish spot at either extreme end, this spot almost directly posterior to 
the spot on the middle lobe when the latter is present. Propleuron 
largely yellowish or greenish, black above. 
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