1912] Homologies 1n the Wing-veins of May-flies 91 
COMSTOCK AND KELLOGG ’95 built a system upon that of 
Redtenbacher, but they differed from him in certain particu- 
lars as to the homology of some of the veins. These differences 
are shown in a following table. 
KELLOGG ’95 reviewed the work of Redtenbacher and Com- 
stock and proposed to further reduce the number of names. 
The result was a nomenclature which nearly approached that 
later adopted in the ‘‘Wings of Insects.’’ Concerning the 
remnants of tracheation to be seen in an adult wing of Hexagenia 
he says: ‘‘In a mounted wing of Hexagenia sp. I have plainly 
observed the branching trachea of the sector arising from the 
radial trunk at an appreciable distance from the base of the 
radius.’’ This seems incredible since an examination of many 
nymphs of this genus have failed to show this. 
COMSTOCK AND NEEDHAM ’98-’99. In this paper the tra- 
cheation of the nymphal wing-pads was discussed for the first 
time. The wing-veins of the adult were homologized from the 
tracheze which preceded them. It was unfortunate that the 
authors studied only wing-pads in which the bases of the radial 
and medial trachee were approximated, and hence they also 
fell into the error of considering a part of media to be the 
radial sector. 
For convenience in comparing the various systems of nomenclature I have arranged the following table: 
mee ome Redtenbacher ’86 | Comstock '95 Kellogg ’95 Earnie oan 
Ephem. this paper 
Costa 1 Costa 1 Costa 1 Costa 1 Costa Costa 
Subcosta 2 Subcosta IT | Subcosta II | (Subcosta) IL Subcosta Subcosta 
Radius 3 Radius IIT, Radius III (Radius) III Radius Radius 
(R+RS) 
Radius 4 Radial sector III» Radial sector Media, 
Radial sector IIIs Rg 
IV Praemedia IV Access. radial 1 Rs? 
R4 Accessory 1 
Cubitus 5 Cu VI Rs M2 
Praebrachial 6 Praebrachial VII Media V V Media M3 and M4 
Postbrachial 7 Postbrachial VIII | Postmedia VI VII Cubitus Cubitus 
Anal 8 Anal IX Cub VIlab 1st Anal Ist Anal 
Axil 9; Anal X Anal IX 2nd Anal 2nd Anal 
Furrow VIII 
Axil 99 Axil XI Anal Vein IX érd Anal 3rd Anal 
