9476 Insects. 



black spots, and on the upper side of the second and third is a little 

 black line ; the claw is black. 



The three anterior segments have some scattered black spots, and 

 the second and third two larger oval black spots on the sides, as will 

 be more clearly seen from an inspection of figs. 1, 2 and 3, than from 

 any lengthy description. Tlie median segments have seven* rows of 

 little shining black spots, and a few more above the legs, which are 

 blue-green and unspotted (see fig. 5, representing the seventh segment). 

 One row runs along the middle of the back, and on the first and third 

 folds (there are five folds on each segment) are two minute dots; then 

 follows a row of five spots, of which the second is no larger than a dot, 

 then four roundish spots, and under the foremost one the spiracle; 

 below this again is a row of three spots, the anterior of which is very 

 elliptic. Lastly, just in advance of each leg is another elliptical spot, 

 and a similar one just above each leg also. On the last two segments 

 are merely black projecting points, and on the last above the anal 

 valve are two pale orange spines, tipped with black, with a round black 

 spot above (fig. 6). 



The larvae live in company on different species of willow, elevating 

 the abdomen at pretty regular intervals. Their usual position is 

 shown in our fig. 2. Dr. Wttewaal found the larva on Populus vir- 

 ginica and Salix alba. lie remarks that they devour even the midrib 

 of the leaf, not leaving more than a centimetre of the petiole ; this 

 being contrary to the habit of any other species of Nemalus. Almost 

 all the larvae which I found were taken on Salix alba. 



Previous to undergoing their change, my larvae crept into the earth, 

 where they made cocoons thirteen or fourteen millimetres long; these 

 were very rough exteriorly, but inside of this rough covering, which, 

 however, was very smooth on the interior, another case could be seen, 

 so that the cocoon was, in fact, double ; this inner case was very 

 smooth, blacker and shining. 



The larvas taken at Rozendaal, and which began to spin up ou the 

 8th of July, reappeared from the cocoons as early as the 24th. 1 am not 

 able to give any particulars of the pupa, which probably offers nothing 

 unusual worth mentioning. The imago is represented at fig. 8. I have 

 in my possession some specimens of nearly one centimetre in length, 

 expanding to more than two centimetres, and others much smaller. 

 I nevertheless believe this to be the largest of tlie allied yellow species 



* I wish to draw particular attention to this number, as it aflords a characteristic 

 distinction between the larva of this species and that of Nematus tiimaculatus, 

 described furtber on. 



