The claspers seem to be the tergal portions of the ninth segment. On the sides of the seventh and eighth segments may be clearly seen leaflike appendages, which are possibly branchial in their nature (Figs. 5 and 6). They are extremely tenuous, and appear like clusters of filaments, slightly adhering together and forming lamellate appendages similar to the gill-like appendages seen in the early stages of _Potamanthus_, a neuropterous insect, not, however, having the definiteness of these structures. While in _Potamanthus_ one may easily trace the ramifications of the tracheal system, I have not been able to detect a similar connection with these appendages in _Aphrophora_. Certainly the insect does not depend upon these structures for respiration, as when the creature is perfectly dry it seems to suffer no immediate inconvenience, but will crawl about the table or even on the dusty floor and live for an hour or two in this condition. The usually glabrous surface of the body, however, becomes shriveled after a while. On the other hand, it immediately sinks in water, and will live for some time immersed in this way, and this leads me to believe that the appendages above described may perform a slight respiratory function. The fact that the insect immediately sinks may be cited as an additional evidence that it does not emit air. It is interesting to observe that regarding this stage of _Aphrophora_ as an aquatic stage, since it lives immersed in fluid, we have the same behavior that we observe in the aquatic stages of other _Hemiptera_, as well as in insects of other orders. The great water beetle _Hydrophilus_ has an aquatic larva. Myall, quoting Lyonet, says: “They never remain long at the bottom of the water; air is necessary for them, and this they take in by the tail, which they raise from time to time to the surface of the water.” In the larva of _Dysticus_, another water beetle, the only functional spiracles are the last pair, opening at the tail. The little oval beetles, known as whirligigs, from their rapid whirling motion, when swimming on the surface of the water carry down a bubble of air on the end of the abdomen, and when this has been exhausted in the process of respiration rise to the surface for a fresh bubble. The larvæ of some forms are furnished on each side with long respiratory filaments.