181 [Morrison. 



tending from the tail, similar to those of the fins of fishes. The 

 mtire fin is evidently an extended fold of the body membrane, of 

 ich extreme tenuity and transparency that only the edge can be 

 faintly traced by the aid of the microscope when straightened out 

 upon a glass slide, and it is very doubtful whether any rays exist 

 ■which may be in any sense compared with those of a fish's fin. 



November 4, 1874. 

 Vice-President Scudder in the chair. Forty persons present. 

 The following papers were read : — 

 Descriptions of New Noctuid^:. By H. K. Morkison. 



Aeronycta increta nov. sp. 



Expanse 30-31 mm. Length of body 12 mm. 



This is an intermediate form, between Tiamamelis Guen. and dis- 

 secta G. & K. The latter is distinguished by its smaller size 

 (26-27 mm.), comparatively smooth squamation, and white thorax 

 and median space. Hamamelis is the largest (40 mm.). Its color is 

 uniform dark gray, the markings are confused and interrupted, and 

 the squamation rough, coarse, and raised up. In size increta is be- 

 tween the two just mentioned; its scales are large and raised up in 

 ridges to form the ordinary lines, and the markings are more or less 

 broken, but in a less degree than in Tiamamelis. 



In increta the reniform spot is almost linear, its sides being parallel, 

 and only slightly curved. The median shade is nearly straight, ex- 

 cept at the costa. In hamamelis the reniform is a full lunule, and the 

 median shade is broadly outwardly curved, touching the reniform. 



In the former the coloration is more diversified than in the latter. 

 The interior line is black and well defined; the median space is 

 lighter, approaching dissecta, and the whole wing is more or less suf- 

 fused with olivaceous green, giving it a different color from the plain 

 gray of the larger species. Posterior wings and under surface much 

 as in hamamelis. 



Hab. New York. Several specimens received from Messrs. Fred. 

 Tepper and E. L. Graef. 



Types in the collections of the Buffalo Society of Natural Sciences, 

 and H. K. Morrison. 



