EEV. A. E. EATON OX EECENT EPIIEMEEID.E OK MAYFLIES. 37 



the sides of a short deflexible lobe prolonged from the hind margin of the ninth segment ; 

 their jn'oximal joint very short, the second much the longest. Penis extruded and rather 

 similar to that of Campsurus 4<-deiitatiis (PL V. 8 e), without apparent stimuli. No 

 projections at the hinder lateral angles of the abdominal segoiont. 



Nymxili. — Raptorial, furtive ; mandibles tusked ; fore tibia spurred ; 6 pairs of abdominal 

 tracheal branchiae, inserted at the sides of segments 2-7, a little in front of the hinder 

 angles, and arched upwards over the back, each composed of a pair of narrow uniform 

 and subequal lanceolate membranous laminae, folded lengtliwise, and frin"'ed with 

 simple fibrils. Sette rather shorter than the body, pilose to beyond the middle, and then 

 tail-pointed. Palpi of both maxillae 3-jointed. — Head relatively small, narrower than the 

 thorax : pronotum subquadrate, the lateral borders narrowly dilated ; terminal margins 

 of the fore wings free ; body slender. Antennae setaceous, longer than the head. Labrum 

 emarginate, pubescent. Mandibles prolonged into a tusk on the outer side, about twice 

 as long as the head, densely hirsute outside and above with slightly spreading hair, and 

 half encii'cled at its junction with the crown of the mandible by an interrupted verticil 

 of widely spreading bail' ; the fangs are rather distant from the molar protuberance, and 

 are set almost at right angles with the task, which is curved gently and regularly 

 inwards, and tapers to a slightly oblique point ; stipes very short. First masillee weak ; 

 the lacinia small, pubescent externally, ciliated internally, crowned with a dense tuft of 

 short hair and terminated by a few (3 or 4) slender spines ; paljms upwards of four times 

 as long as the lacinia, rather slender, 3-jointed (exclusive of the pedicel) ; the tirst joiut 

 pubescent, the others pilose ; the third joint nearly as long as the other two together. 

 Second maxillse almost in the form of quadrants, densely pubescent; palpus 3-jointed, 

 geniculated at the penultimate joining, and pilose outside ; the distal moiety clavate and 

 truncate, the terminal disk hispid ; the proximal joiut pubescent within. Labium small, 

 the lobes narrow and acute. Tongue perhaps distorted ; medium lobe obcordate ; para- 

 glossia moderate in size and rounded. Legs pilose above and below, the tibiae obliquely 

 truncate, the fore tibia spurred with a long, slender, but strong apical spine ; the fore 

 tarsus very long. (Figured and described from a dried slough in the Mus. iioy. de 

 Bruxelles, measuring, — body (exclusive of mandibles) 30 ; setae 19 mm.) 



Dlstrihution. Tropical America. 



Type. E. Recuha (in Falhigeuia), Ilagen. 



Etymology, evOvTrXoKia, from the evenness of the cross veinlets. 



EuTHTPLOciA Hecuba, Hag. Plate IV. 7 a (wings 2 ). 



Palingenia Hecuba \ Hag., Smithsoo. ]\Iiscell. Coll. (18G1), Synop. Ncuropt. N. Am. 40. 

 Eutlnjplocia [type] Hecuba\\ Etii., Trans. Eut. Soc. Londou (1871), 07; Hag. & Etu., op. cit. (1873), 392. 



Imago (dried), ? . — Head blackish fuscous, antennae pale at the tip ; prothorax glossy, 

 fuscous ; the rest of the thorax with the coxae and trochanters luteous, the femora &c. 

 deficient. Abdomen above blackish fuscous, luteous beneath, the seta3 whitish sepia- 

 grey, with lighter joinings. Wings dull, transparent, tinted faintly with very light 

 warm sepia-grey (" grayish-rosy," Hag.), but rather darker along the anterior margin of 



