Correspondence, 215 



Devonian and Carboniferous rocks, and a great many new species 

 are described. The fossil plants are not noticed. 



Professor Hall has been assisted in the survey by Mr. Worthen 

 and Mr. Whitney ; the latter of whom acts as chemist and miner- 

 alogist to the survey. j. w. D. 



CORRESPONDENCE. 



Extract of a letter to the Editors of the Canadian Naturalist 

 from Mr, D. W. Beadle, dated St. Catherines, C. W.. 

 February 23, 1860. 



Believing- that the larva oi Argynnis Aphroditehas never 

 been described I send you the following description. 



I found the larvse as early as the 8th. of June 1859, of nearly 

 all sizes from a few days old up to the full grown specimen. They 

 feed on plants of the genus Viola indiscriminately, not hesitating 

 in confinement to use our gadren varieties when the native species 

 are not supplied. 



The full grown larva is an inch and a quarter in length, of a 

 black color and ornamented with parallel rows of black spines, set 

 with minute branches. The head is bi-mucronate, black anteriorly, 

 posteriorly reddish-brown. The second segment has two dorsal 

 spines that are entirely black, the other spines have all a reddish- 

 brown base and are arranged as follows : between the second and 

 third segments are two lateral spines, (one on each side,) on the 

 third segment are two dorsal spices, between the third and fourth 

 two lateral and on the fourth two dorsal spines; the fifth to the 

 twelfth segments both inclusive, have six spines, between the 

 twelfth and thirteenth segments are two dorsal spines, and on the 

 thirteenth two lateral. The spines are so arranged as to form 

 rows both lengthwise and across. The underside of the larva is 

 a little lighter colored than the upper, and the legs are the same 

 color as the underside. The prolegs are black. 



The chrysalis is brown, in shape much like that of Vanessa 

 Antiopa^ suspended, and without any gilded spots. 



