268 Illinois State Laboratory of Natural Ilistory. 



ly larger, has the ends turned hackward. The spinous- 

 fringes of the abdomen are very scanty; but there is 

 alwaj's a pair of large spines present behind each spir- 

 acle. The abdominal sculpture is simply a strongly 

 roughened surface, scarcely transverse. The last seg- 

 ment ends in a square flattened truncate broad tooth, 

 each side of which is a hand-shaped tubercle bearing five 

 thick spines; there are also smaller spines above on this 

 segment. 



The three following species of larvae evidently belong 

 in this connection, according to Brauer's synopses and 

 figures, showing various combinations of the charac- 

 ters figured ; and without further speculation on their 

 identity, I will close with a statement of the observations 

 made and the prominent characteristics of these larvae. 

 They all agree in being quite white, moderately slender, 

 C3iindrical, tapering anteriorly and truncate posteriorly, 

 usually with four fleshy teeth at the margin of the trun- 

 cation; 12 segments, increasing gradually in length up 

 to the penultimate, the anterior margins of the segments 

 thickened and more or less elaborately provided beneath 

 with teeth and hooks for crawling; the head with a 

 median pair of black posterior prolongations, ending 

 anteriorly in a lunate transverse bar, in front of which 

 are the hook-like mandibles ; the maxillae and their palpi 

 at the anterior angles of the head; the labrum narrow; 

 and the antennae short and pale-colored, borne upon 

 the whitish sides of the head. They are usually sluggish. 



Larva {a). 



This species bores in the decaying and w^ater-soaked 

 floating stems of rushes. The larvae look much like the 

 white calcareous masses which form in the decaying 

 tissues, and are easily overlooked. They were found 

 April 13 and 15. 



