1874.] 239 [Grote. 



sity in many cases of a careful geognostical study to determine to 

 which class a stratiform rock should be referred, the speaker main* 

 tained the truly indigenous character of the great formations of 

 gneissic rocks, such as, for example, the Laurentian, which, from their 

 wide extent, and from the mode of their association with layers of 

 quartzite, limestone and iron-oxides, were clearly deposited in hori- 

 zontal layers at the earth's surface. 



The following paper was presented by the Secretary : — 



Descriptions and Notes on the Noctuidj5. By Aug. R. 



Grote. 



Acronycta dactylina Grote. 



?. Smaller than A. hastulifera (Americana Harris) ; the primaries 

 of a distinctly bluish grey. The median lines continuous and den- 

 tate. Orbicular small, a black annulet with empty centre. Reni- 

 form vague, with a blackish stain on the cross vein. Transverse 

 posterior line double, with broad, pale enclosed space, the inner line 

 faint, the outer black, distinct with acutely pointed outward denta- 

 tions, more noticeable twice opposite the cell, and once broadly on 

 subterminal fold, opposite which the inner line is accentuated. A 

 (sometimes obsolete) narrow dash on the fold beyond the line. The 

 t. p. line is followed by a diffuse, dark shade. Fringes grey. Ter- 

 minal line marked by interspaceal black dots. Hind wings pale whit- 

 ish grey, with a pale fuscous terminal shade. Veins a little darker 

 marked; terminal dots indistinct; fringes whitish grey. Beneath 

 whitish grey, with faint outer line on primaries, becoming denticulate 

 and more distinct on the hind wings ; blackish discal dots on both 

 wings. 



Expanse, 50 mm. 



Hab. Quebec (F. X. Belanger); N. Y. (E. L. Graef). 



At first sight recalls lepusculina, but the species is larger, the pri- 

 maries darker and the lines continuous, as in hastulifera. 



Acronycta albarufa Grote. 



6 ? Allied to A. ovata but smaller. Primaries pale purplish grey. 

 Transverse anterior line widely geminate, receiving a distinct black 

 dash from the base which attains the outer of the two lines. Orbic- 

 ular white, annulate, contrasting, with a dark central point, approxi- 

 mate to the reniform and divided from it by the black median shade, 



