314 ENTOMOLOGICAL NEWS. [July, 'l6 



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 kennedii. 

 The mesepisternal fossae. In Plate XVII, figures 10, u, 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 

 cither 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, fi, 8, 11). 



Abdomen $ 24-27, average 25.5, 9 24-25; hind wing $, 15.5-17.5, 

 average 16.6, $ 17-18. 



$ . 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. 



