a small tooth each side of it; outside the latter, two other large 

 truncate teeth,— about four teeth, large and small, on each side. 

 Posterior segments without fleshy respiratory appendages. Anal 

 papilliB not jointed. 



Chironovms, larva (5). 



A very small pupa (.12 inch long) taken August 7 within the 

 mouth of Cedar Creek still retained its larva skin, the labium 

 of which differs from that of all the preceding larvje in lacking 

 the median tooth. Its condition would not permit of more ex- 

 tended comparison with the others, and it may prove the same 

 as (3). 



Cevaiopogon, larva. 



This is an extremely slender, transparent larva, resembling a 

 vinegar eel, with eight long hairs radiating from the posterior 

 body segment. It has been noted by Professor Forbes in the 

 stomachs of fishes. 



Common among algae in Lily Lake, August 15. 



OEDEK COLEOPTEEA. (Beetles.) 



Adults with four wings, the first pair hard and stiff, covering 

 the hind pair when at rest; not used for flight; hind Avings folded 

 both longitudinally and transversely. Mouth parts fitted for bit- 

 ing. Prothorax free. Pupa inactive. Larva aquatic or terrestrial, 

 commonly with three pairs of jointed legs (wanting in certain 

 wood-boring and plant-mining larv?e), with a well-developed head, 

 and biting mouth-parts. Examples: weevils, wire-worms, potato 

 beetles, etc. 



The aquatic members of this order of insects frequently have 

 some or all of their limbs flattened and fringed to fit them for 

 rapid locomotion in the water. Others show little in their struct- 

 ure that is adaptive to aquatic life, and simply creep about under 

 water or cling to submerged vegetation much as a terrestrial 

 beetle might. They are all, when adult, obliged to come to the 

 surface for air, which they take and hold in bubbles by means 

 of antennaj, wing-covers, or legs. Some of the larvcB also come to 

 the surface for air, but others are provided with special respira- 

 tory structures by means of which they are enabled to get oxygen 

 from water. Only the larva) and adult beetles are aquatic. The 

 larva quits the water when ready to become a pupa, and com- 

 monly burrows into the neighboring banks, where it excavates a 

 small chamber in which it pupates. The adult on emerging re- 

 turns at once to the water. 



Many beetles in both larval and adult stages are very destruc- 

 tive to small aquatic animals of other kinds, and even attack 

 fishes of considerable size. Tadpoles many times larger than these 

 insects, are often devoured. Some eat only the dead of other 

 insects,, while still others feed largely on vegetation. 



