32 EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 



Ponte de Morcellos (Beira Baixa) ; Italy, Turin, and Breno (Val Oamonica, Brescia to 

 the Neapolitan territory (locality — ? fide Costa) ; Hungary (var. ? pallida, Hag.) ; 

 Galicia, Stry (fide~E. Brauer). The terminal small joints of the forceps-limbs appear to 

 be variable in number, and the specimens from France, Geneva, and Italy are much 

 lighter in colour than some of older date from the Rhine with which I have compared 

 them. This difference in colour may be due to my specimens having been killed with 

 fumes of prussic acid (Potassium-cyanide bottle) ; and the variation in number of the 

 forceps-joints is probably of common occurrence. In the absence of examples in spirits, 

 I failed to arrive at any decision as to the rank of O. ixdlida, Hag., as a var. of 

 0. rhenana or a separate species. 



ELASSONEURIA, Etn. 1881. 



Illustrations. Adult (details) PI. III. 3; also Trans. Ent. Soc. London (1871), 

 p. iii. 9, 9 a. 



Adult 2 . — Fore wing with only three longitudinal nervures, besides the costa and con- 

 cealed subcosta, of which the hinder two are forked ; cross veinlets more restricted in 

 their range than those in the fore wing of Oligoneuria. Pronotum transverse, prolonged 

 on each side into a deflected oblong lobe. Aperture of the anterior thoracic spiracle trian- 

 gular, its upper edge straight, that of the posterior spiracle oval. Setoe nearly coequal 

 in length, about \ as long as the body, the intermediate seta rather slender, all of them 

 glabrous excepting towards their tips, where for a short distance they are sparingly 

 pilose. Eyes oval and remote ; anterior ocellus not much smaller than the others. In 

 other points very like Oligoneuria. 



Distribution. Natal. 



Type. E. Trimeniana (in OUgoucuria), M°Lach. 



Etymology. eXdaawv and vev^'iov, from the greater paucity of the neuration in comparison, 

 with that of Oligoneuria. 



Elassoneuma Trimeniana, M"Lach. Plate III. 3 (wings, ? ). 



Oligoneuria Trimemana,\ M<^Lacli., Ent. Mo. Mag. iv. 177-8 (1868); ! Etn., op. cit. v. 83 (1868); id., 

 Trans. Ent. Soc. London (1871), 56, pi. iii. 9-9 a [penult, veutr. process ? ] ; Joly, Sur une Nouv. Esp. 

 d. Gen. d'Eplie'm. Oligoneuria &c. Nimes (1877), 6 figs. 8vo. [transl. of M^Lachl. 1868]. 



Elassonewia [type] Trmemawa, ! Etn., Ent. Mo. Mag. xvii. 191 (1881). 



Adult {dried) ? . — Head and thorax brown-ochreous aljove, liditer beneath. Abdomen 

 discoloured; eggs formerly green, now brown-ochreous. Sette opaque-whitish. Wings 

 transparent, very slightly tinted with light smoke-grey, giving a faint very light cobalt 

 or ultra ash-blue glance, soft as the gloss of satin ; neuration opaque, light smoky-grey. 

 Length of body, ? , 12, wing 22-5, seta? 4 mm. 



Sab. IVIapumulo IMission Station, Umvoti District, Natal. Captured " at light " on 

 3rd of March, 18C7 (M^Lach. ]\Ius.). 



{b.) Wing-membrane " shot " with blue or purple ; the free epinotal appendage of the 

 membrane decurreut from the wing-roots is easily broken off, but may be regarded as 

 probably absent in LacJilania and Eomoeoneuria. 



