1920] Richmond, Studies on the Biology of the Aquatic Hydrophilid.ee 59 



The adults of C. fimbriata upon emerging are light brown below; 

 the thorax is light brown; their head is darker brown; the second pair 

 of wings are gray; the first pair are white; and the eyes quite dark 

 brown. Until fully colored, about two days, the adults seemed to re- 

 main in their cells, as many were noted as being very dark when removed 

 from their underground home. 



On April 11, a number of adults of C. fimbriata were dug out from 

 the bank of a pool about five or six feet from the shore-line. This tends 

 to show where the beetles spend their winter days. 



Eggs. — There seems to be no special arrangement of the eggs except that they 

 are usually placed like logs in a pile and covered sparsely with fine white silk, through 

 which the eggs may be seen. 



Xewly Hatched Larva. — Length, 3 mm.; width, 0.4 mm. Whitish. Head 

 and mandibles light yellow; sclerites of thorax and abdomen light brown (mesocerci 

 darker) ; integument dotted with minute spines, which are more abundant on the 

 top of the folds than in the furrows. 



Head square, elevated slightly; fronto-clypeal sutures weakly indicated; frons 

 limited by the frontal sutures, gradually narrowed towards the median line, semi- 

 circular behind; epicranial suture very short, almost absent; gula reduced with its 

 sutures fairly prominent and confluent; two, small, horizontal, elongate, cervical 

 sclerites present. 



Labro-clypeus irregularly toothed, possessing usually seven teeth (the most 

 lateral tooth on each side indistinct), some of which tend to be toothed again, and 

 with four short spines, a little longer than the teeth, regularly placed, arising dorsally 

 between the bases of these teeth and projecting forward. The lateral expansions are 

 similar to each other, with anterior margin straight and slightly inclined laterally. 

 Epipharynx spinous. 



Ocular areas in groups of six but rather indistinct. They are arranged more or less 

 in a circle. The anterior three have their axes more horizontal and the last, or sixth, 

 area is more remote than the others, which are nearly equidistant from each other. 



Antenna? fairly short, not attaining the tips of mandibles but exceeding the distal 

 inner tooth; first segment equal in length and width to the second; second segment 

 not noticeably swollen in the middle and bearing a small colorless, two-segmented, 

 finger-like antennal appendage, the basal segment small, in addition to the sense-cones, 

 and a single, small, slender appendage at the latter's base and at the inner anterior 

 angle; third segment a little longer than the appendage of the second segment, which 

 is three times as long and wide as the former, and bearing at its extremity three long 

 setae and several sense-cones. 



Mandibles nearly symmetrical, fairly prominent and stout, sharply pointed at 

 their tips, and each bearing two inner teeth, the basal one smaller; the left basal tooth 

 seems to be slightly smaller than the right basal tooth; inner surface of anterior 

 piece and anterior tooth serrate; molar area not serrate. 



Maxillss with joint-like palpifer; stipes large, swollen, narrowed slightly towards 

 the apex, longer than the palpifer and palpus together, and its inner surface provided 

 with a row of five stout setse and several more slender seta? near the externo-distal 

 angle; palpifer small, a little wider than long, bearing a single, stout, inner, lateral seta, 



