HYMENOPTERA. 419 



and it may turn out to be really a mere variety of the Euro- 

 pean insect. Professor Peck was aware that it did not agree 

 with the description, given by Linnffius, of the latter ; and it 

 appears to me that the difference between the two insects, in 

 their winged state, is enough to entitle them to be considered 

 as specifically distinct from each other. For this reason I 

 shall retain for our insect the specific name adopted by Pro- 

 fessor Peck, because this slug does really live upon the 

 cherry, in this country, as well as on the pear tree; and shall 

 merely prefix to it the gcnerical name which it should bear 

 according to modern nomenclature. The fly of our slug-worm 

 may therefore be called Selandria (Blennocampa) Cerasi. The 

 meaning of the word Selandria is unknown to me. Blenno- 

 campa signifies slimy caterpillar, a name which, it will be seen, 

 may be applied with great propriety to our slug-worm. 



This slug-fly is of a glossy black color, except the first two 

 pairs of legs, which are dirty yellow or clay-colored, with 

 blackish thighs, and the hind legs, which are dull black, with 

 clay-colored knees. The wings are somewhat convex and 

 rumpled or uneven on the upper side, like the wings of the 

 saw-flies generally. They are transparent, reflecting the 

 changeable colors of the rainbow, and have a smoky tinge, 

 forming a cloud or broad band across the middle of the first 

 pair ; the veins are brownish. The body of the female meas- 

 ures rather more than one fifth of an inch in length ; that of the 

 male is smaller. In the year 1828, I observed these saw-flies, 

 on cherry and plum trees, in Mflton, on the tenth of May ; but 

 they usually appear towards the end of May or early in June. 

 Soon afterwards some of them begin to lay their eggs, and all 

 of them finish this business and disappear within the space of 

 three weeks. Their eggs are placed, singly, within little semi- 

 circular incisions through the skin of the leaf, and generally 

 on the lower side of it. The flies have not the timidity of 

 many other insects, and are not easily disturbed while laying 

 their eggs. On the fourteenth day afterwards, the eggs begin 

 to hatch, and the young slug-worms continue to come forth 

 from the fifth of June to the twentieth of July, according as 

 the flies have appeared early or late in the spring. At first 



