REV. A. E. EATON ON RECENT EPHE]MERID.^ OR MAYFLIES. 211 



with opaque joinings. Fore leg, in opaque view, pitcli-broT^-n ; hinder legs in some lights 

 bronze-brown, in other lights dull yellowish with the femora tinged with bistre-brown, 

 and in transmitted light brownish yellow. Wings vitreous, very faintly tinted with 

 greenish grey ; neuration pieeous. Length of body or Aviug, c? 10-12-5 ; setse, <S im. 

 17-18 mm. 



Sab. North America ; California (Edwards ; M^'Lach. Mus.) ; San Geronimo, Cal., 

 April 20 (Ostcn-Sacken ; Mus. Comp. Zool. Cambridge, Mass.). 



Ameletus subnotattjs, sp. nov. Plate XVIII. ? 34 a' (legs) and LXIV. 23 (forceps-basis). 

 Siphlurus? %femoratus, ! Etn. MS., in the writing of PI. XVIII. loc. cit. 



Subimago (dried), c? . — Wings light sepia-grey with pitch-brown neuration, the latter 

 colour varying with change of light to bistre-brown ; cross veinlets margined with sepia- 

 brown. Setce warm sepia-brown, with ojoaque joinings. 



Imago (dried). — d . Body pitch-brown ; metanotum pitch-black ; the dorsal segments 

 of the abdomen appear to be largely occupied with pale light brownish yellow subtrian- 

 gular blotches, one on each side in segments 2-7, which leave in each of them the 

 terminal border, a median longitudinal stripe, and a triangle that extends along the 

 pleura from the hinder lateral angle to the base, of the dark ground-colour ; pleurae 

 narrowly coucolorous with the venter, which is rather paler than the light dorsal 

 blotches, and is marked in segments 2-6 with two short dark dashes from the base of the 

 segment, and a dark dot on each side of the median tract nearly midway between the 

 base and tip ; the ninth ventral segment, of a light brown-ochreous tint, has indications 

 of two corresponding dark streaks at the base in the form of triangular spots, and is 

 bordered laterally with pitch-brown as far as the joining of the forceps-basis ; the 

 depressions of the forceps-basis are shaded with bistre-brown ; forceps-limbs light bistre- 

 brown. Setse raw-umber brown at the base, lighter distally. Fore leg in opaque view 

 dark rufo-piceous, banded with pitch-black before the knee, the general colour changing 

 in other lights to dark bistre-brown. Hinder legs in opaque view light bistre-brown, 

 varying towards light raw-umber with change of postm*e ; femora banded with pitch-brown 

 before the knee ; tarsi browner than the tibiae in certain lights, especially the terminal 

 joint and ungues. Wings vitreous ; the fore wings close to the wing-roots, and the hind 

 wings to a slightly larger extent at the base, clouded with intense bistre- or pitch-brown ; 

 longitudinal neuration, in opaque view light pitch-brown, in oblique view light raw-umber 

 (excepting the stem of the praebrachial, which in most postures remains pitch-brown) and 

 in transmitted light translucent pieeous ; cross veinlets in opaque view intense pitcli- 

 brown, bordered narrowly with pitch- or bistre-brown, which bordering gives rise to small 

 specks in the fore wing, viz. : — one near the Inilla of the radius (3), one at the proximal 

 3xtremities of each of the two pairs of shorter sectorial intercalary nervures, one at the 

 fork of the prsebrachial (6), and another near the proximal termination of the intercalary 

 lervure contained within that fork : the pterostigmatic portion of the marginal area 

 jontains about 17 branched cross veinlets (counted at the subcosta), which, mutually 

 mastomosing, form a rather dense reticulation, preceded towards the bulla by about 5 

 nore distant simple cross veinlets. 



28* 



