276 MR. W. p. KIRBT— A EEYISION OF 



Genus 19. Ccenotiata. 

 Buchecker, Syst. Ent., Odonata, p. 10 (1876). 



Frontal tubercle rounded above ; eyes contiguous ; abdomen much shorter than the 

 hind wings, segments 2 and 3 a little thickened, segment 3 transversely carinated, 

 3-5 of equal length, 4 constricted, 5 expanding, 6 a little shorter, and the remainder 

 rapidly diminishing in length, but much thickened, and somewhat depressed, segment 6 

 being the broadest ; segment 8 not perfoliate in the female, pterostigma short and 

 broad, about twice as long as broad: fore wings with 8-10 antenodal and 6-8 post- 

 nodal nervures, the last antenodal not always continuous, and the first three postnodals 

 not continuous, cells of the costal areas simple, triangle wide, on a level with that of 

 the hind wings, traversed, no supratriangular nervures, subtriangular space consisting 

 of three (rarely two) cells, sectors of the arculus rising from a short stalk, gradually 

 curved, lower basal cell with one cross nervure, nodal and subnodal sectors continuous, 

 the intermediate cells bisected towards the hind margin, nodal sector sometimes slightly 

 waved, especially towards the base ; hind wings broader than the fore wings, with 6-7 

 antenodal and 7-8 postnodal nervures, the first three postnodals not continuous; 

 triangle open, followed by two or three rows of cells, no supratriangular nervure ; 

 two (rarely one) cross nervures in the lower basal cell, sectors of the triangle hardly 

 united at base : anal appendages of the male rather short. 



Type Libellula caudalis, Charp. 



Buchecker's genus Coenotiata is equivalent to Leucorhinia; and as he mentions no 

 type, I have retained the name for one of the species which he includes in it, which 

 appears to me sufficiently distinct to rank as a separate genus. 



Genus 20. SniPETRUM. 

 (Neuration, Plate LV. fig. 4.) 

 Newman, Ent. Mag. i. p. 511 (1855). 



Diplaae, Charp. Lib. Eur. p. 12 (1840) ; Hag. Neur. N. Amer. p. 173 (1861); Brauer, Verb, zool.- 

 bot. Ges. Wien, xviii. pp. 369, 719 (1868). 



Frontal tubercle slightly truncated ; eyes contiguous ; abdomen slender, as long as 

 the hind wings, segments 2 and 3 slightly thickened and transversely carinated, 

 segment 8 not perfoliate in the female, pterostigma generally short or moderate: 

 fore wings with 7-8 antenodal (very rarely 9 or 10) and 6-7 postnodal nervures, the 

 last antenodal very rarely, and tlie first two or three postnodals never continuous, cells 

 of the costal area simple, triangle rather broad, on a level with that of the hind 

 wings, traversed (very rarely free), followed by three (rarely four) rows of cells, no 

 supratriangular nervures, subtriangular space consisting of three cells, sectors of the 

 arculus stalked, gradually curved, lower basal cell with one cross nervure, nodal and 

 subnodal sectors a little irregular, the former generally waved towards the base, the 



