on the Ephemeride. 65 
meso- et meta-thoracibus mitriformi, et in abdomine 
marginibus serratis, claudente in segmentis singulis api- 
calibus lineas duas breves divergentes atras. Venter 
sub-hepaticoloratus, striga longitudinali testacea, atque 
apicibus seementorum obscuratis. Ale vitrine, pallide 
fuliginoso tincte, nervis piceis ; anticarum coste fusce ; 
posticarum nervi transversales obscure marginati. Pedes 
testacei ; antici fuscescentes, tarsis atris, ultimis articu- 
lorum fuscis. Sete cervine, fusco cincte. 
Long. corp. ¢ 15, al. 15; set. im. 35, subim. 23 mm. 
Hab.—The Amazons and Texas. 
Mr. M’Lachlan has a specimen of an undescribed In- 
dian species, in some respects closely related to this. 
Heaagenia (?) atrostoma. 
Ephemera atrostoma, Weber, 1801; Palingenia atrostoma, 
Pict. 1843-5. 
«K. flava, dorso alisque fuscis, ore oculisque atris. 
Thorax marginatus canaliculatusque. Abdomen cauda 
biseti, setis longissimis flavis.”? (Weber.) 
Hab.—Brazil (Weber). 
Hewxagenia decolorata. 
Palingenia decolorata, Hag. 1861. 
Imago in spiritii ztheris conservata. ‘ Lutea; caput 
fusco-nigrum ; pedum antici nigricantes, posteriores 
lutei; abdomen luteum, strigis lateralibus obscure fuscis, 
et setis luteis; ale vitrinew, flavescenti tinct, nervis 
luteis, subcostis fuscis exceptis.” (Hag.) 
Long. corp. 16, set. 30 (?); exp. al. 30 mm. 
Hab.—Mexico; Matamoras; Tamaulipas. Common. 
(Hag.) 
Perhaps this is only a colour variety of the following 
species, but I am unable to decide the point. 
Hexagenia limbata. 
(Forceps, Pl. IV. fig. 3, 3a.) 
Bphemera limbata, Guer. 1829-43 ; Palingenia limbata, 
Pict. 1843-5. Palingenia bilineata, Hag. 1861. 
Subimago, v.s.s. Al pallide flavicantes, plurimis 
nervorum transversalium corvinis. Setz pilose. 
TRANS. ENT. soc. 1871.—parRTI. (MARCH.) F 
