1882.] 207 



To conclude. The " descriptive entomologists " of Britain (and 

 her Colonies) are now nearly equally divided between those who use 

 the English inch (and divisions) and those who employ millimetres. 

 Those who still adhere to the former system of measurement isolate 

 themselves from (and occasion unnecessary trouble to) their brethren 

 of nearly all other nationalities. In addition to this they sometimes 

 inadvertently introduce an item of uncertainty into their descriptions 

 which might be reduced to a practical minimum by the employment of 

 millimetres. When Teuton, Gaul, Sclav, and " our American Cousin," 

 are approximately agreed on a certain course as best suited to the 

 advancement of science, we " Britishers " should not be divided as to 

 its importance. 



Lewisham, London : 9th January, 1882. 



AN ANNOUNCEMENT OF NEW GENERA OF THE JSPSEMERID^J. 

 BY THE EEV. A. E. EATON, M.A. 

 {Supplementary from p. 27). 

 Amongst specimens of foreign Ephewieridce, very kindly lent me by 

 Dr. Hagen, are represented the following new genera : 



Hagenultjs, n. g. 

 Allied to AdenopHebia (Ent. Mo. Mag., xvii, 194), but differing 

 as follows : — Hind-leg scarcely longer than the intermediate-leg, their 

 ungues dissimilar in form and size ; fore tibia of £ about twice and a 

 half as long as the femur. The first axillary nervure of the fore-wing, 

 instead of the anal nervure, receives the extra longitudinal nervures 

 interpolated between them. Hind-wing with a large unciform costal 

 projection, and with very simple neuration. Egg-valve about as long 

 as the last three abdominal segments taken together, narrowed from 

 its base to about its middle, and from thence to its apex, forming a 

 split tube, through which the eggs are discharged ; ventral mem- 

 braneous projection of the $ penultimate segment acutely excised and 

 bifid. Type, H. caligatus, (in Potamanthus), Hag., MS., from Cuba. 



Hagenulus caligatus, n. sp. 

 Potamanthus caligatus (Hag., MS.). 

 Sub-imago dried. S . Wings transparent pale bistre-grey : neuration slightly 

 opaque, some of the cross-veinlets in the first three areas of the fore-wing marked 

 "with black, most of the others in the disc of the wing faintly bordered with greyish ; 

 in $ seven cross-veinlets in the marginal area before the nodal point. Setae annu- 

 lated with black. 



Imago [in life, has olive-brown oculi, light brown ochreous body, with a small 

 black or brown spot on each side of every abdominal segment, &c. : teste Gundlach, 



