THE SUBFAMILY LIBELLULIN^. 309 



Although there is an Indian species which agrees with Rambur's description of 

 A. panorpoides, yet I have not ventured to select it as the type of the genus, as I would 

 have preferred to do, because Rambur figures as well as describes it, and he distinctly 

 represents his insect with four cross nervures in the lower basal cell of the fore wings ; 

 if this is correct, it cannot be congeneric with the other species. 



There are several doubtful forms from Africa and Madagascar, in all of which (with 

 the exception of a specimen which I regard as the true A. ascalaphoides of Rambur) 

 the last antenodal is not continuous. Only one of these is sufficiently well marked for 

 me to venture to describe without more extensive materials then I at present possess. 



Genus 78. Neophlebia. 



Selys, in Pollen & Van Dam, Faune Madag., Ins. p. 18 (1869) ; Mitth. Mus. Dresd. iii. p. 315 

 (1878). 



Resembles Tetrathemis, but the fore wings have ten antenodal nervures, the last not 

 continuous, and one supratriangular nervure, the lower median cell has one cross 

 nervure on the fore wings and two on the hind wings ; the hind wings have no supra- 

 triangular nervure, and the wings are partly opaque, at least in the adult male. 



Type Neophlebia polleni, Selys. 



Genus 79. Tetrathemis. 

 (Plate LII. fig. 4 ; neuration, Plate LVI. fig. 8.) 

 Braner, Verh. zool.-bot. Ges. Wien, xviii. pp. 182, 369, 727 (1868). 



Frontal tubercle rounded ; eyes large, contiguous in front ; abdomen longer than the 

 hind wings and rather slender, second segment considerably dilated at the base, seg- 

 ments 2 and 3 indistinctly carinated, segment 8 not perfoliate in female : wings long 

 and narrow, pterostigma thick, more than twice as long as broad ; fore wings with 

 7-9 antenodal and 5-7 postnodal nervures, the first (or first and second) postnodal not 

 continuous, cells of the postnodal area simple, triangle converted into a trapezium by 

 the lower sector of the arculus striking an angle in the middle of its upper side, small, 

 traversed, followed by one row of cells, subtriangular space consisting of a single, large, 

 cone-shaped cell, with the apex directed outwards, its base nearly coinciding with a 

 line descending from the lower sector of the arculus just beyond its origin, and corre- 

 sponding to a supratriangular nervure, sectors of the arculus with a very long stalk, and 

 almost straight, lower basal cell with from one to four cross nervures, nodal sector only 

 waved at base, intermediate cells between the nodal and subnodal sectors only bisected 

 on the hind margin, no closed cells below the lower sector of the triangle; hind wings 

 slightly broader than the fore wings, with 6-8 antenodal and 5-6 postnodal nervures, 

 the first postnodal not continuous, triangle free, followed by two (or three) rows of 

 cells, increasing, a supratriangular nervure nearly always present, two to four cross 



