Apdomen. beneath whitish or allow: with a dark line ) 
of the segments at the lateral borders. 
Examples of both sexes in fluid do not differ much from the: 
dried specimens. Dark markings on head more clearly defined = 
(see Fig. 4); a small projection on each side at the eyes and x 
two projecting lobes-in front in the middle. The fore legs have 
fine black lines at the base of the cox, trochanters, tibie and 
tarsi, the joints of the tarsi also faintly ‘annulated ; these mark- Sie 
ings less evident on the other legs. Wings almost white and : 
translucent. The abdomen is rather paler than in the dried 
specimens and the segments show on the middle above two pairs — 
of faint paler divergent lines sometimes macular. Sete pubes- 
cent with uniform hair. Wings apparently unfringed. There 
are two elongate tubercles at the apex of the fore tibie in 
the 2. 
Length of body (from front of head to apex of abdomen, ex. 
forceps in ¢ ), 20-21 mm. 
Length of fore wing, 20-22 mm. 
Length of hind wing, 8-84 mm. 
Two ¢ 3 (dried), 7 33,7 2 & (in fluid), Buxton; 8 3 3 
(dried), Evans: All from Amara, April 4th, 1918. 
Ulmer, ‘‘ Ubersicht tiber die Gattungen der Ephemeropteren,” 
‘ Stettiner Entom. Zeit. , Ixxxi, 1920, divides the genus Palingenia, 
Burmeister, restricted Eaton, into three genera: Palingenia, 
Anagenesia (Eaton’s sub-genus), and Plethogenesia, Ulmer. The 
present species does not agree with any of these, and if Ulmer’s 
genera be adopted, a new genus will fall to be erected for its 
reception. The following characters in P. mesopotamica may be — 
noted : es 
(1) Forceps-limbs 7-jointed, a long basal one, the others 
short, as in Palingenia restricted. 
(2) Media of fore wing forked before middle of wing. 
Lower branch of cubitus and intermediate cubital vein 
may arise from anal vein 1 (this character appears to be 
unstable and these veins may sometimes arise as in Palin- 
genia from upper branch of cubitus). 
In anal area 1, usually only one long intermediate vein. 
Female sete half as long as the abdomen (there is a 
minute intermediate seta in both sexes). 
Fore tarsus of ¢ only about as long as the femur (tarsus 
2mm., femur about 24 mm.). : 
These characters are in common with Anagenesia and Pletho- 
genesia. . 
(3) Media of fore wing forked later than sector. 
Sub-costa and radius very close but distinctly separated 
at the apex (not visible in fig. 1, Plate I, but — 
seen when the wing is floated out in scalding water). 
