210 REV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 



AMELETUS, gen. nov. 



Illustrations. Adult (details), PI. XVIII. ? 34 a and LXIV. 22-24. 



j^dulf. — Fore leg of d as long as the body ; tarsvis nearly If as long as the tibia, 

 and this nearly to ^^ long as the femur ; the joints in diminution rank 2, 3, 4, 1, 5, and 

 the first is abou.t \ as long as the second joint. Fore leg of 2 between | and § as long 

 as the body ; tarsus very nearly of equal length with the tibia, which is about ^o as long 

 as the femur ; the joints in decreasing length rank 2, 1, 8, 5, 4, and the first is very 

 nearly f as long as the second joint. Ungues mutually dissimilar in each tarsus. Hind 

 wings well developed ; dilatation of the marginal area angular in front ; axillar region 

 moderately narrow, and with rather scanty neuration. In the $ abdomen the segments 

 are proportioned somewhat as in Chirotonetes ; the first is thoracoid. Pleurge squarely 

 truncate in segments 7-9 ; ventral lobe of the ninth segment subtriangular, with the 

 apex refuse. Forceps-basis of d widely and angularly excised ; its posterior corners by 

 the inner sides of the proximal joints of the limbs are shortly produced ; the limbs are 

 4-jointed, with a short basal joint tumid interiorly, and with the next joint, longer than 

 the remainder, slightly gibbous on the inner side at the base. Penis-lobes narrow, 

 with terminal superior stimuli, as in Slphlurus. Median caudal seta completely 

 aborted ; outer setae about as long as the body in both sexes. Oculi of d obsoletely 

 ascalaphoid, contiguous with each other above. Vertex of ? head a little longer than 

 broad, distinctly wider in front than behind ; occipital margin level with the posterior 

 orbits of the eyes. Median ocellus of ? much smaller than the others, isolated in a 

 small deep depression in advance of and below the anterior edge of the upper surface 

 of the head. Pronotum of $ broadly reflexed upon the meso-pleurge ; its posterior 

 margin (viewed from above) somewhat evenly arched and not receding in a very marked 

 degree in the middle. 



Nijm])h unknown. 



Type. A. suhnotatus, sp. nov. 



Distribution. N. America. 



Etymology. ayueAjjroc, neglected, or overlooked. 



Ameletus dissittjs, sp. nov. Plate LXIV. 22 (forceps-basis). 



\\Iso7iychia Xmanca S ™., ! Etn., Traus. Ent. Soc. London (1871) 134, pi. vi. 5 [excl. ?] (genitalia 

 misdrawn) . 



Imago {dried), d . — Predominant colour of the body bright brown-ochre (perhaps fer- 

 ruginous in life) ; pronotum piceous ; metanotum piceoiis behind ; dorsal segments 2-8 of 

 the abdomen bordered distally with pitch-brown, each with extensions of the same 

 colouring forwards at the sides in the form of triangular spots, which, at least in 

 segments 6-8, occupy the hinder lateral angles of the dorsum and extend to the base 

 of the segment ; the ninth segment has corresponding streaks from the hind border. 

 Ventral segments rather lighter than the dorsum, and seemingly marked each with a 

 light pitch-brown blotch at the base in the middle : forceps-basis, posterior to the oval 

 depression, light yellowish ; forceps-Limbs piceous. Setae medium warm sepia-brown 



