DRAGONFLIES AND DAMSELFLIES IN PONDFISH CULTURE. 195 
Fic. 7.—Side view of head of nymph of Libellula luctuosa, mask folded. Fic. 8.—Same, mask extended. Fic. 9.—Side view of 
head of nymph of Anaz junius, mask folded, Fic. 1o.—Same, mask extended. Fic. r1.—Mask of Anaxjunius. Fic. 12.— 
Mask of Libellula luctuosa. Fic. 13.—Mask of Erythemis simplicicollis. Fic. 14.—Mask of Pachydiplax longipennis. 
