38 JOHN B. SMITH. 



are females, and in fact only two males are before me at the present 

 time. The range of variation really consists only in the intensity 

 of the brown shading. It may verge to red and it may tend to 

 blackish. In the lighter specimens the lines are somewhat better 

 define^; in the darker specimens they are almost lost. In other 

 respects the markings are very constant. 



Il.i droecia cerrusata Grote, pi. 2. fig. 25, % genitalia. 



1864.— Grote, Proc. Ent. Soc. Phil., ii, 431, pf* 9, f. 1, Gortyna. 



1873.— Grote, Bull. Buff. Soc. Nat. Sci., i, 110„ Ihidra-cia. 



1874. — Grote, Bull. Buff. Soc. Nat. Sci., ii. IS^Umpida. 



1875.— Grote, Bull. Buff. Soc, Nat. Sci., ii. 2JG, sp. (list. 



1881. -Grote, Bull. Geol. Surv., vi. 269, Gortyna. 



1893.— Smith, Bull. 44 U. S. Nat. Mus., 178, Hydrcena, 

 Ground color a very deep purplish brown, the median space of primaries more 

 red-brown, hut yet very dark. Head and thorax without markings, save that 

 the collar is white tipped. Primaries with white blotches at the extreme base, 

 within the basal half line, which is geminate and marked with white scales. T.a. 

 line geminate, outcurved between the veins, with a long inward tooth in the sub- 

 median interspace and a long outcurve below that point. The line is emphasized 

 by slightly paler scales between the ordinary defining lines. T. p. line geminate, 

 with a broad outcurve over the cell and a slight incurve below. It is feebly 

 lunulate between the veins. S. t. line irregular, outwardly toothed on the veins, 

 in some cases forming a vague W, marked on veins 3 and 4. Marked further 

 by yellowish or reddish scales, which form a pale apex to the wing and pre- 

 ceded by blackish scales, which form a more or less broken series of dots or an 

 imperfect shade. A blackish line at the base of the fringes. The median shade 

 is blackish, bent below the cell, not very well defined and yet easily traceable in 

 every instance. The reddest portion of the wing is the median space below the 

 submedian vein. The ordinary spots are contrasting, while, the orbicular almost 

 triangular, the angles a little pointed, the base resting on the median vein. The 

 reniform is unusually long and narrow, obliquely set, the center yellow, around 

 which are grouped white spots. As a whole the lower pari of the spot is broader 

 than the upper; but in all cases the spot as a whole is very narrow. The clavi- 

 form has the usual double white mark, and in all the specimens before me the 

 two spots are of almost equal size. Secondaries smoky, the veins yet darker, a 

 discal lunule visible. Beneath purplish, gray powdered, with an outer line, 

 which is most distinct on the secondaries, and a discal lunule, which is also more 

 prominent on the hind wings. Expanse l.ti8-2.20 in. ; 42-55 mm. 



Hab. —Middle and Eastern States, south to the District of 

 Columbia: Washington, D. C, August 10th; Massachusetts in 

 September; Iowa; Illinois. 



This species is a close ally to limpida, and there is very little in 

 the general appearance to distinguish the two. The color is practi- 

 cally the same, the markings are almost identical, except for the 

 shape of the reniform, and this in cerrusata is unusually long and 

 narrow. In limpida it has the more usual form, and there is noth- 



