192 EEV. A. E. EATON ON EECENT EPHEjVIEEID^ OR MAYFLIES. 



placed obliquely with regard to the larger ; the next four are each composed of a large 

 subovate lamiaa, with a flap turned over on one side close to the base, which constitntes 

 the much smaller division ; the seventh has the larger lamina narrowly ellipsoidal and a 

 much smaller turned-over flap than the others ; each of the larger lamiuce is supplied with 

 a single main trachea with long branches and short brauchlets. Antennae about as long 

 as the head and thorax comliined. Seta) subequal to one another and about f as long as 

 the body, fringed for about f of their length, with the fringes gradually shortened to a 

 point, and then tail-pointed. Mandibles terminated by slender, compressed fangs, with a 

 tuft of hair in place of the endopodite. Palpus of maxilla i. longer than the lacinia, 

 slender, apj^arently 2-jointed, with joints of very nearly equal length ; lacinia armed at 

 the tip with slender fangs, and with other slender fangs mingled with hau* along the inner 

 edge. Laciuise of maxillae ii. obtusely falcate, rather shorter than, but nearly of equal 

 width with, the obtusely lanceolate lobes of the labium : proximal joint of the palpus stout, 

 compressed, narrowed slightly and evenly from the base distally; second joint about 

 thrice as long as the third joint, slightly gibbous at the base on the inner side as far as 

 the oblique line of muscular attachment ; third joint almost as broad at the base as the 

 end of the second joint, and subacute at the tip. Tongue somewhat similar in form to a 

 closed ecclesiastical biretta ; median lobe subrotund, bluntly mucronate, and broader tban 

 the rounded paraglossae. Hiud tarsus, claw excluded, little shorter than the tibia, 

 which is not quite § as long as the femur ; the whole leg not much longer than the 

 fore leg. 



Ty])e. C. pictus (in Baetis), Etn. 



Distribution. America from Canada to the Argentine Republic and ChUi ; also [unde- 

 scribed sp.] Australia. 



Etymology. koXoq and Bcetis, a proper name, with reference to the beauty of many of 

 the species. 



The generical identification of the nymph was ascertained by examination of the hind 

 wings of one of the alcoholic specimens received from Dr. Hagen, subsequent to the 

 phot olithogra piling of Pis. XVI., XVII. It then became evident that the genus had 

 better be ranked at the close of the section, instead of at the beginning, 



Callib^tis Hageni (renamed), Etn. MS., in the writuig of Plate XVI. 28 a (wings and 

 part of femur). 



Baetis \\ tessellata, ! Hag., Smithson. Miscell. Coll. (1861) Synop. Neuropt. N. Am, 50; Etn., Trans. 

 Ent. Soc. London (1871) 84 [note to Lept. Colombia'], and 150, note ; Hag., op. cit. (1873) 395. 



Subimago (dried). — Wing-membrane cinereous, or blackish grey ; cross veinlets white, 

 and narrowly bordered with white ; the pale borders of a few that may happen to be close 

 together side by side near the base or the middle of the wing are occasionally confluent, 

 but only sparingly so ; in some lights the longitudinal nervures also in great measure 

 appear to be whitish, especially towards the terminal margin. Legs sublutescent, with 

 the tarsi somewhat blackened. Setse pale sepia-grey, with black joinings. 



Imago (dried). — ?. Wings ornate; femora densely, minutely, and inconspicuously 

 dotted ; tarsi to a large extent black. — Body piceous ; the dorsal sutures of the thorax 



