418 Mr. R. M'Lachlan on some Odonata 



Heliceschna fuliginosa (Selys) , Karscb. 



I have before me five males and three females (collected 

 by the late D. G. Rutherford), as follows : — 



(1) One very mature male from Cameroons. — The wings 

 entirely brownish fuliginous ; 25 ante- and 18 postnodals in 

 the anterior, and 22 and 20 in the posterior. Length of pos- 

 terior wing 41 milHm., greatest breadth 12 millim. 



(2) One less mature male (wings not tinged) and one highly 

 mature male and similar female (wings darkly tinged) from 

 " Cameroons," and two highly mature and tinged males from 

 " Mahamb^." — In these there are about 31 or 32 ante- and 

 21 or 22 postnodals in anterior wings, and about 24-26 and 

 23 in the posterior. Length of posterior wing 51-54 millim., 

 greatest breadth 15-16 millim. 



(3) Two transitional (?) females (one from Old Calabar, 

 and the other from Cameroons), in which the wings are 

 strongly marked with blackish fuscous in the costal and sub- 

 costal areas nearly up to the arculus, and with a large smoky- 

 yellowish space from the nodus to the pterostigma, extending 

 half across the wing (somewhat as in Amphiceschna ampla) . 

 There are 31 or 32 ante- and 23-25 postnodals in the ante- 

 rior wing, and 24-26 and 26-28 in the posterior. Length of 

 posterior wing 56 millim., greatest breadth 16 millim. In 

 these examples the abdomen has conspicuous pale markings 

 (almost obliterated in the others) ; the sides of the third 

 segment are broadly whitish yellow ; a like-coloured geminate 

 spot at the base of segments 4 and 5 and a half-ring at the 

 apex of segments 3 to 6. In these also the appendages are 

 present (broken in the other), very long (11 millim.), some- 

 what similar in form to the superior pair in the male, but 

 more slender at the base and less widened afterwards. 



It will be seen from the foregoing that the range of size is 

 almost as given by Dr. Karsch (Ent. Naclir. xix. p. 194) 

 from a single pair only, and the neural details practically 

 ao-ree also ; but the size is not dependent upon sex, as my 

 statement proves. The two females (3) with parti-coloured 

 wings have a different appearance, but 1 think are not speci- 

 fically distinct. 



It seems to me that the oreilettes in the male are 5- (not 4-) 

 toothed. On the tenth abdominal segment in the male there 

 is a slight raised longitudinal median carina, at the base of 

 which on either side is a transverse elongate fovea with raised 

 edge externally, and the apical margin is slightly notched in 

 its middle. The legs have piceous-red femora and black 

 tibige and tarsi. In one of the large females there are two 



