806 REPORT UKITED STATES GEOLOGICAL SURVEY. 



thoracic segment is nearly as wide as long, much rounded in front; 

 this and each following segment reddisli, with three yellowish lines, viz, 

 a faint, straight, median one, and two curved lateral ones; these lines 

 on the abdominal segments more diffuse and indistinct. The mandibles 

 are long, sickle-shaped, ?.cute, much curved. The maxillary and labial 

 ^.palpi project considerably beyond the curve of the mandibles. Maxillary 

 palpi long and stout, three-jointed; the two terminal joints long and 

 slender, and of equal length ; the terminal third joint projects its entire 

 length beyond the end of the labial palpi. The latter are three jointed, 

 the third joint very minute. The terminal segment of the body is small, 

 one-half as wide and one-half as long as the preceding joint. The feet 

 are well developed, ending in a single claw. There are nine pairs of 

 spiracles. Length, 0.50 inch. 



The Teansfoemations of Donacia peoxima Kirby. (Plate LXX, 



Figs. 17-19.) 



None of the species of Donacia, so interesting from their living in 

 their early stages in the roots of aquatic plants, have been studied 

 biologically as yet in this country. For the first information we have 

 regarding the transformations of any of our species we are indebted to. 

 Mr. W. L. Wilder, of Clinton, Mass., who kindly sent me living speci- 

 mens of the larva of Donacia proxirna, found June 23 in the roots of the 

 cow-lily (Ntqjhar advena). Mr. Wilder writes me under date of May 23, 

 187G : " I send you the life-history of an insect, except the egg, which I 

 hope to add to as soon as I have the mud in which the larva first ap- 

 pears. As you open the inclosed box, if all is right, you will find the 

 perfect insect, which I hope will remain alive; 2d, you will find a cap- 

 sule like body attached to a bit of lily-root; examine it by transmitted 

 light, and you will see the perfect insect ready to emerge. You will 

 next come to another capsule, in which a white maggot has inclosed it- 

 self while in my possession ; and at the bottom of the box is a ball of 

 mud inclosing a maggot, which has hatched out in the mud within a 

 few days." 



Afterward he writes, June 19 : "I have not been able to find the 

 eggs, but think I have found their i)la('e of deposit in small cavities in 

 the large fleshy roots of the yellow lily, into which the larva burrows, 

 and in which it feeds, excavating large chambers after it emerges, and 

 almost invariably fixes itself on the tender rootlets beneath, where it 

 covers itself with its cocoon and remains until mature. I have found 

 the larvae in the root and with no outlet but the small puncture where 

 the eggs were deposited. I could have sent you hundreds of the pupne 

 just ready to emerge." 



Afterward the cocoons containing the beetles were found October 24, 

 187G, attached to the roots of the cow-lily {Miphar advena), in a pond at 

 Salem, Mass., and presented by Mr. S. B. Buttrick to the museum of the 

 Peabody Academy of Science, so that we probably have nearly the entire 

 history of the insect. The females probably winter over in the dense, 

 tough, parchment-like brown oval cocoons (Plate LXX, Fig. 17, natural 

 size), and in the spring lay their eggs in such a position that the larvai on 

 hatching bore into the roots of the lily; the larvae, becoming fully de- 

 veloped by the end of June, transform into chrysalides, previously spin- 

 ning a cocoon much like that of the saw-flies, and assuming the beetle 

 condition in the autumn. 



Thebodyofthelarva (Plate LXX, Fig. 18, enlarged, seen from beneath) 

 is white, thick, fleshy, cylindrical. The head is small, reddish, one- 



