378 Records of the Indian Museum. [Vol. XXI V, 



suggest almost some sort of " permutation and combination," and 

 I believe similar conditions may be traced in regard to other 

 features, hinting as it were at the working of some Mendelian 

 sorting out of characters. 



Genus Leptogomphus Selys {restr,). 



Genotype : L. semperi Selys. 



Basal antenodal nervure of 2nd series present. A maximum 

 of two rows of cells between Cu 2 and the hinder-margin of the fore- 

 wing, only one row of cells between M t and M lu at level of distal end 

 of pterostigma. Proximal angle of triangle of fore-wing as far 

 distant from the arculus as length of proximal side of subtriangle. 

 Sectors of arculus not approximated after their origin. Forking of 

 M,_.. and M s unsymmetrical in both pairs of wings. One or two 

 cross-nerves in submedian space (number apparently varying). 

 Pterostigma unbraced. Upper anal appendages of male simple, 

 rather Gomphus-Yxke. Hamuli large, vesicle of penis small or 

 moderate. Ninth segment of abdomen shorter than eighth. Size 

 moderate. 



Unfortunately the Museum collection contains no example of 

 this genus. I believe that L. gestroi Selys, from Burma, is certainly 

 to be referred to it and also L. inclitus of the same author. The 

 latter, of which a description of the female only is available, is 

 said by de Selys to be very similar to L. semperi. In addition, Ris 

 has described two species of the genus, L. sauteri and L. perforatum, 

 the former from Formosa, the latter from S. China. 



The type-species, L. semperi Selys, has been recorded from the 

 Philippine Islands, Borneo, and Tonkin. 



Lastly, from Malaya several species are known, of these L. 

 lansbergi Selys, is recorded from Sumatra and Java, the closely 

 allied L. assimilis Kriiger, is from Sumatra. L. kelantanensis 

 (L,aidlaw) is from the Malay State of. that name and L. wittiamsoni 

 Laidlaw, is from Borneo. 



The position of one or two species referred to the genus is 

 doubtful. L. ? maculivertex Selys, from Burma, known from the 

 female only, is possibly a Heliogomphus. L. parvus Kriiger, from 

 Sumatra would seem to belong rather to the Gomphus series ; at 

 any rate the number of cross- veins between M^ and M + is reduced 

 as in that series. 



Genus Heliogomphus, gen. nov. 



Genotype : L. nietneri (Selys). 

 Species examined : H. nietneri (Selys). 



No basal antenodal nerve of 2nd series. A maximum of two 

 rows of cells between Cu 2 and the hinder margin of the fore-wing. 

 Only one row of cells between M, and M lu at level of distal end of 

 the pterostigma. Proximal angle of triangle of fore-wing as far dis- 

 tant from the arculus as the length of the proximal side of the sub- 



