326 EEV. E. A. EATON ON EECENT EPHEMEEID^ OE MAIFIJES. 



DESCRIPTION OF THE PLATES. 



The figures in Plates I.-XXIV. (witli two acknowledged exceptions) are mainly photo-litliographs of 

 drawings made with the camera liicida from the specimens by the Author. Being designed to illustrate the 

 genera, a distinctive numeral is appropriated to each genus ; and, when necessary, a special letter is affixed 

 to the generical numeral, to indicate what species are concerned in the illustrations appertaining to that 

 genus. Numerals written smaller than the generical numerals are used to designate particular legs and 

 wing-uervures. The fore leg, intermediate leg and hind leg are numbered respectively 1, 2, and 3. 

 The wing-nervures are numbered in accordance with the plan set forth in page 4 of this volume : — 

 1, the Costa, 2, the Siibcosta, 3, the Eadius, 4, the Sector, 4', the hindermost of the adventitious 

 branches of the Sector, 5, the Cubitus, 6 and 6', the Praibrachial and its hindermost branch, 7 and 7', 

 the Pobracbial and its hindermost branch, 8, the Anal, 9', 9", and 9^ Axillary nervures. The natural 

 lengths of the wings arc shown by hair-lines. 



Plates XXV.-LXII. and part of LXIII. (with a single acknowledged exception) are from drawings by 

 HoUick, from the specimens, executed under the Author's supervision. The figures in each of these 

 Plates are numbered consecutively, and certain letters are uniformly used to designate particular parts of 

 the insects, viz. : — a, the antenna, Ibr, the labrura, r. md, the right mandible, I. nid, the left mandible, mx^, 

 the first maxilla, mx', the second maxilla, Ibm, the labium, /, the tongue, /', the fore leg, /', the inter- 

 mediate leg, r, the hind leg, tb, tracheal branchiie [those of the abdomen numbered pair by pair suc- 

 cessively from the foremost], c. s. caudal setse. In some of these Plates detached views of certain regions 

 of the body are uniformly lettered as follows : — A, dorsal view of the insect, B, ventral view of the same, 

 C, side view of the head, D, head from beneath, E, head from above, P, front view of head. The 

 natural lengths of the insects arc shown bj' hair-lines, and to the figure of each detail is annexed an 

 indication in numerals of the scale of enlargement. 



Plates LXIV., LXV. and part of LXIII. are from drawings by the Author from the specimens, litho- 

 graphed by HoUick. They are essentially supplementary to earlier plates. 



N.B. — The wings of dried specimens, in some of the genera, arc apt to be completely shrivelled up 

 {e.r/. those figured in Plate III.). "When such is the case, rccurse may be had to the following method 

 of preparing them for examination. The wing detached from the specimen is first of all floated upon 

 scalding water, and induced to expand as fully as possible whilst it is floating. It is next taken up 

 upon paper or a strip of glass and transferred to cold water, and then spread out to dry upon paper or 

 glass. If upon paper, the wing can presently be separated therefrom by bending the pajjer away from 

 it, and it can either be mounted permanently as an object for the microscope, or be placed temporarily 

 for examination within a compress-cell, care being taken to flatten it out by only vertical and gentle 

 pressure. If the result be then unsatisfactory, the whole process can be repeated. 



Plate I. 



Neuration, limbs, external $ genitalia, and J" head of 1. Palingenia (adult) : — all enlarged. 



Figs. 1 a. P. longicavda : — wings, legs (1-3) of ^ , fore leg of ? with a larger view of the fore tarsus 

 and a much larger one of the ungues, a penis-lobe and forceps-limb (underside view), [the 

 two dots on the 4th joint of the limb are due to a flaw in the stone] , vertical view of the cJ 

 head, and side view of the same. 



Fig. 1 b. P. lata : — fore wing. 



Fig. 1 c. P. ampla : — fore wing. 



Fig. 1 d. P.javardca : — xmdcrside view of c? genitalia. 



