416 Mr. R. M'Lachlan on some Odonata 



one next the anal margin above and two placed against it on 

 the other side, the fourth below. 



Length of abdomen {cum append.) 66 millim. ; length of 

 posterior wing 56 millim., greatest breadth of same 

 1Q>\ millim. 



Hah. Mahambe*, West Africa (Rutherford), one male. 



This species agrees with the description of G. vesiculata, 

 Karsch, in the 4-celled anal triangle, and tolerably well in 

 the form of the anal appendages (there is no mention of the 

 strong elevated carina on the tenth dorsal segment) , but its 

 much larger size, darker colour of the body, yellow base or! 

 the wings, and apparently more constricted third segment 

 seem opposed to specific identity. It is the largest African 

 species known to me. 



Assuming that G. quadrina is distinct and G. africana 

 uncertain, G. vesiculata is the only described West-African 

 species I do not possess. 



Gynacantha membranalis, Karsch. 



This fine species is distributed from the Amazons to Panama. 

 As an item in the identification of the numerous American 

 species unfortunately quoted with names in MS. or with " no 

 description," it is well to point out that G. membranalis = 

 "G.falco, Bates, Selys, MS." 



Gynacantha tibiata, Karsch. 



Described from a male from Ecuador. A pair ( £ $ ) in 

 my collection from Chiriqui (Panama) agree with the descrip- 

 tion in all essential points ; the very short and broad inferior 

 appendage of the male is, however, very slightly notched in 

 the middle of the rounded apex. There can scarcely be any 

 doubt as to the identity. 



Gynacantha chelifera (Selys, MS.), sp. n. 



J . Face dingy yellowish, with cinereous pilosity ; seen 

 from above the top of the front is much elevated and almost 

 angulate at its summit ; T-spot ill-defined, the top evident 

 only as a dingy margining of the edge, the tail distinct, dingy 

 blackish ; eyes connected in a very long space, the occiput 

 flat, very small; back of head yellowish. Thorax yellowish 

 fuliginous above, paler beneath and on the sides. Legs pale 

 yellowish, with concolorous spines. Abdomen slender, 

 cylindrical, scarcely thicker at the base, and not constricted 



