114 PAUL S. WELCH. 



EXPLANATION OF PLATE. 



FIG. i. Photograph of a nearly full-grown larva of Bellura melanopyga swim- 

 ming on the surface of the water in the aquarium. The undulations of the body in 

 performing the swimming movements are evident. 



FIG. 2. Photograph of the same larva taken a few seconds later. 



FIG. 3. Leaf of Nymphcea americana showing the character of the work of 

 approximately mature larvae. The radiating slits represent the work of the larvae 

 preliminary to the excavation of the petiole. Note the severe injury to the leaf 

 in the region of the petiole. Leaves are sometimes almost completely severed 

 from the petiole in this way. 



FIG. 4. Leaves of Nymphcea americana showing the work of half- to full-grown 

 larvse and the characteristic form of the injury. 



FIG. 5. Leaves of Nymphcsa americana infested by half- to full-grown larvae. 

 The leaf near the center of the figure shows the absence of preliminary cutting in 

 the form of radiating slits. Note on the same leaf the heap of excrement about 

 the hole at the junction of leaf and petiole. This hole is the entrance to the burrow 

 in the petiole. 



