TROCHOBOLA. 9T 



posterior margin at the tip of the seventh longitudinal vein ; in 

 the second basal cell (near the great cross-vein) ; in the discal 

 cell ; at the tip of the wing and on both sides of the fourth brown 

 spot ; a subhyaline longitudinal streak crosses the second brown 

 spot in the first basal cell and the round spot at the inner end 

 of the subinarginal cell is encircled in pale. The subcostal cross- 

 vein is almost in one line with the tip of the auxiliary vein. 



Hab. California (Mr. Alex. Agassiz). A single male. 



This species belongs to the relationship of L. cinctipes and 

 immatura, but is easily distinguished by its larger size and by 

 its brownish wings, marked with subhyaline spots. 



Gen. V. TROCHOBOLA. 



One subinarginal cell ; four posterior cells ; a discal cell ; the tip of the 

 auxiliary vein is far beyond the origin of the second longitudinal vein ; 

 the marginal cross-vein is some distance anterior to the tip of the first 

 longitudinal vein ; a supernumerary cross-vein connects the sixth and seventh 

 longitudinal veins (wing, Tab. I, fig. 4). Antennse 14-jointed. Feet slender ; 

 tibiae without spurs at the tip ; empodia indistinct ; ungues with teeth on 

 the under side. 



Trochobola is most closely allied to the Limnobias of the 

 second group (those with the marginal cross-vein removed from 

 the tip of the first longitudinal vein) ; like these species, it has 

 pictured wings, browm bands on the femora, a long auxiliary 

 vein, etc. But it is easily distinguished from them by the 

 presence of a supernumerary cross-vein. The antennae have less 

 elongated joints, and look almost moniliform ; the feet are more 

 slender than in the majority of the Limnobiae; the structure of 

 the male forceps is somewhat intermediate between Limnobia 

 and Dicranomyia ; the fleshy lobes of the latter are somewhat 

 reduced in size here and the rostriform appendage is compara- 

 tively larger. (A figure of this forceps has been given by me in 

 the Stett. Entom. Zeitschr. 1854, Tab. I, fig. 1 ; it represents the 

 forceps of the European T. annulata Lin.) 



The number of species belonging to this genus is small, they 

 have a remarkable distribution all over the world, and they all 

 (as far as known) have the same eye-like spots on the wings. T. 

 annulata Lin. (imperialis Lw.) and T. csesarea 0. S. (perhaps 

 only a variety of the former), occur in northern Europe. T. 

 argus Say, is almost identical with the former. I have seen, in 

 f July, 1868. 



