19(j [February, 



uncinate. Proximal joint of £ forceps' limb sub-equal in length to 

 the rest put together. Nymph latent, with seven pairs of abdominal 

 tracheal branchiae, all nearly alike in form ; each one bifid into unequal 

 segments, which are divided into slender filaments. Type, H.fusca 

 (in Ephemera), Curt. Syn., Leptophlebia, ser. 5, with L. Bicteti, Etn., 

 1871 ; also misprinted HalecoplileUa (Etn., MS.), by Eostock, 1880. 

 Distrib., Temperate and Southern Europe. [N.B. — The citation here 

 given of L. Bicteti is based upon recollection only.] 



As I have suggested (in private correspondence) the possibility 

 of Dr. Joly's Ccenis maxima nymph being the young of a Tricorythus, 

 I take the opportunity of stating that (judging from specimens in a 

 better condition of preservation than those upon which I relied in the 

 first instance), it is, after all, more likely to be a real Ccenis. The 

 examples previously examined by me, were all of them defective. 



Callib^tis, n. g. 

 Allied to Bae'tis. Two long caudal setae, in <$ two and a half 

 times, in $ twice as long as the body. Fore-wing w r ith several cross- 

 veinlets in the marginal area before the nodus, in both sexes, and with 

 single (if any) interneural veinlets at the terminal margin. Hind- 

 wing tri-nervate, with several cross-veinlets, and with the costal 

 shoulder very obtusely rounded off (compare Trans. Ent. Soc. London, 

 1871, pi. v, 27 — 29). Fore tibiae in $ about one and one-sixth, in $ 

 three-quarters, as long as the femur ; the tarsus in £ about as long 

 as, in $ about two-thirds as long as, the tibia, the 3rd joint in J shorter 

 than the 2nd joint. Type, G. pictus (in Bae'tis formerly), Etn. 

 Distrib., North and Central America and Australia. 



Baetis, Leach (restricted). 

 Two long caudal setae, in $ two to two and a half, in $ one and 

 one-fourth to two and a half, times as long as the body. Fore-wiug 

 without cross-veinlets in the marginal area before the nodus (as a rule, 

 almost without an exception) in both sexes, and with interneural 

 veinlets in pairs at the terminal margin. Hind-wing bi-, or tri-nervate 

 (the intermediate nervure in the latter case sometimes forked), and, 

 generally speaking, destitute of cross-veinlets ; usually oblong-ovate, 

 with an acute costal projection, seldom (B. atrebatinus) without any 

 costal shoulder at all (compare Trans. Ent. Soc. London, 1871, pi. v, 

 16 a to 26 a). Fore tibia in £ about one and one-third times as long, 

 in $ the same length "he femur; fore tarsus in $ about one and a 



