EEY. A. E. EATON ON RECENT EPHEMER1D.E OR MAYFLIES. 275 



COMPSONEURIA, Etn. 1881. 

 Illustrations. Adult (details), Pis. XXIII. & XXIY. 42. 



Adult. — Joints 1-4 of the hind tarsus diminish successively in lensth ; first joint of 

 the $ fore tarsus rather shorter than the second, hut longer than the third joint ; ungues 

 each unlike the other. Penis lohes subsimilar to those of Ileptagenia. Cross vcinlets 

 conspicuously few in number in the fore wing. — [Proportions in length of the legs and 

 liody not recorded.] Fore tarsus of 2 almost as long as the tibia, which is f the length 

 of the femur; the joints in the order of their shortening rank 2, 1, 3, 5, 4, and the first 

 is about -|- as long as the second. Hind tarsus of ? little more than ^ as long as the 

 tibia, which is about -f as long as the femur; its joints in the order of their shortening 

 rank 5 equal to 1, 2, 3, 4, and the first is about ly as long as the second joint. Ungues 

 each unlike the other in every tarsiis. Hind wings of the ordinary form ; the axillar 

 region narrow. In the disk of the fore wing, posterior to the radius, are four someAvhat 

 dislocated transverse series of cross veinlets : of these the innermost, commencing near 

 the junction of the sector (4) and cubitus (5), becomes irregularly dislocated inwards at 

 the anal (8) nervure ; the second (the nearest to the bulla), dislocated outwards in the 

 sectorial region, becomes posteriorly, between the cubitus (5) and the hinder branch of 

 the pobrachial (7), more nearly aligned with its commencement, running as a whole sub- 

 parallel Avith the first series ; the third, receding from a point nearly opposite the 

 commencement of the pterostigmatic region, is interrupted between the fourth sectorial 

 intercalary nervure and the cubitus, and its elements are diverted towards tlie fourth 

 series between the cubitus and the anterior branch of the pobrachial ; the fourth series, 

 intermediate between the third and the extremity of the wing, meets the terminal 

 margin between the culjitus and the prsebrachial (6) nervures. Penis-lobes and other 

 genitalia very similar to those of Heptagenia. Caudal sette defective in the specimens 

 .examined. 

 I Type. C. spectahilis, Etn. 



Distribution. Malay Region. 



Etymologij. ko^c^oc and vevp'iov, from the elegance of the cross veinlets in the fore wings 

 of the typical species. Possibly (as in CaUiho'tis) they may vary in number aad 

 arrangement with the species. 



I!oMPSOXErRiA SPECTABiLis, Etn. Pis. XXIII. 42 (wings $ ), XXIY. 42 ( ? fore and hind 

 legs, 6 genitalia). 

 Compsoneuria spectahilis, ! Etn., Ent. Mo. Mag. xviii. 23 (1881). 



Imago (dried), 6 . — Yellowish ochre approaching light straw-colour. Xotum varied 

 vith pitch-brown. Segments 2-8 of the abdomen bordered narrowly in the midst of 

 heir posterior dorsal margin with black, and marked on each side with a black line 

 ecurreut obliquely from that bordering towards the spiracle ; segments 3-7 have also 

 ach a lanceolate black streak produced from the same bordering along the line of the 

 orsal vessel ; segments 9 and 10 pale. Yeuter and forceps light yellow-ochreous. Hind 



