—and almost black in color. All were secured and taken into camp for further investigation.

Close observation of the larvæ showed that besides being much larger (12-14 mm. long instead of 5-7 mm.) they differed in many other particulars from the larvæ of Anopheles (see Fig. 12). In proportion to the rest of its body, its head is larger than the head of Anopheles. Fig. 13 Last Segment of Larva Profile. It does not turn its head upside down when feeding as does Anopheles. Its mandibles are strikingly large and powerful and are prominently toothed. It lacks the frontal tufts or brushes which are conspicuously present in Anopheles, and its antennæ, which extend directly forward parallel with the sides of the head, are much longer and more slender, and are tipped each with three hairs of equal size. The thorax is broadly elliptical and is much wider in comparison with its abdominal segments than is the thorax of Anopheles. The sides of the thorax and the abdominal segments bear fan shaped tufts of hairs, not plumosed as in Anopheles. The tufts on the last segments, both dorsal and ventral (see Fig. 13), are more profuse in Eucorethra than in Anopheles, especially the ventral tuft which in Eucorethra occupies nearly the whole segment. Only two anal papillæ are present, while Anopheles has four.

A few days before the author returned to Boston, several larvæ died and three changed to pupæ. The pupa resembles that of Culex (see Fig. 14) rather than of Anopheles and its respiratory siphons are of the same shape as those of Culex. When stretched out at full length, Fig. 14. Pupa Eucorethra underwoodi. Original Drawing. the pupa measures ten mm.

On reaching home, the new wigglers, eighteen in number, were put into a quart jar which was placed near a window where it would receive the sunlight for two hours each morning. The temperature of the water now averaged about 70° F., and with this change the larvæ developed a new trait—they began to eat each other up. The act was witnessed on several occasions. The larva would grasp its adver-