96 



Hydroporus consimilis, Lee. 



(LeConte., Agassiz's "Lake Superior," 214, 1850.) 



Yery abundant in crannies of decaying and submerged wool in 

 Willow Slough. 



Hydroporus hybridus, Aube. 



(Aub6, Species G6n6ral des Hydrocanthares et Gyriniens, 573, 



1838.) 



Common in Long Lake Aug. 9. Also found in Broad Lake and 

 "Willow Slough. 



Copioiomus interrogatus, Fabr. 



(Dytiscus inierrogaius, Fabr., Systema Eleutheratorum, i, 267, 

 1801;' Crotch, Trans. Am. Ent. Soc. iv, 413, 1872-73.) 



Very abundant in Willow Slough and common in Long Lake 

 and Cedar Creek. 



Acilius, larva. 



This larva is a trifle more than an inch long (1.12 inch), with 

 a fusiform body terminating behind in a pair of short naked 

 caudal stylets. It agrees very closely with the account of a 

 European species {Acilius sulcatus) given by Schiodte. The 

 head is rather small, with two contiguous brownish black spots 

 in the front, and a median spot of this color midway between 

 these and the posterior margin. Sides of head dusky. Segments 

 of thorax and abdomen pale olive above, the scutes of the 

 abdominal segments narrowly edged with black, under parts and 

 legs chiefly white. It differs from the European species in the 

 form of the ligula, which is produced, and furnished at its tip 

 with two strong setae. 



From Cedar Creek, Aug. 8. 



Thermonectes basilar is, Harr. 



(Harris, N. E. Farmer (as cited by Crotch); Crotch, Trans. Am. 

 Ent. Soc, iv, 402, 1872—73.) 



About .44 inch long, general color black, with front, sides of 

 thorax, and elytra yellowish brown. A line of this color also 

 across the .middle of the thorax. This was the largest beetle of its 

 family taken at Quincy. It was captured in the same locality as 

 the larva preceding, and may prove to be the adult, since the 

 genera Acilius and Thermonectes are closely allied. 



Locality: Cedar Creek. 



Family Gyeinid^. (Whirligig Beetles.) 



These are the shining black beetles so often seen in large num- 

 bers circling about on the surface of the water. The three Ameri- 

 can genera all have representatives in Illinois. The beetles may 

 be recognized bv their flattened bodies, short, stout antenna^ 



