1920] Richmond, Studies on the Biology of the Aquatic H ydrophilidce 57 



abundant that they may be taken readily from dead leaves, where the 

 cling to the under side, apparently avoiding the sunlight. Thej^ have 

 been observed in both still and flowing water but seemed to be most 

 frequent dwellers in the little pools formed by rain-water or springs. One 

 record shows a specimen captured in moss which was under a small fall 

 in a swiftly flowing stream, but this evidently is not its most common 

 habitat. 



The best collecting grounds encountered for these two species 

 were located at the base of a steep hill where the rain-water and springs, 

 which trickled down over the surface of a small plateau, had formed small 

 pools. The plateau was composed of a sandy loam and covered with a 

 mat of dead leaves, etc. It was here in the middle and latter part of 

 July 1916, that all stages of C. blanchardi and C.fimbriata were observed. 

 Miss Ruby B. Hughes reported to me the presence of larvae, which 

 climbed up her tent-trap, 1 in abundance. The larvae proved, in due 

 season, to be C. fimbriata, as well as C. blanchardi, and a thorough ex- 

 amination of the surrounding area disclosed eggs and pupae in unusual 

 abundance. The larvae in all stages were found under the leaves and 

 stones; the eggs, in the moss on the bank; and the pupa-, as well as the 

 emerging adults, in the bank. 



Cymbiodyta fimbriata Melsheimer 

 Plate XII 



The arrangement of the eggs laid in the aquaria by members of 

 this genus was rather puzzling at first because of the fact that no case 

 seemed to be completed. The eggs alone were deposited and covered 

 by a loos° spinning of silk, such as is found within an egg-case, but with 

 no outer covering, which is characteristic of the family. 



On March 24, 1915, C. fimbriata was noted ovipositing in the aqua- 

 rium on the under side of a stone which was lying out of the water. The 

 beetle seemed to be having difficulty and, supposing from its actions 

 that it was drying up, I placed a drop of water in such a position that it 

 would roll on to the eggs. This, however, caused the beetle to leave its 

 position immediately and it failed to return to its interesting occupation. 

 When spinning, the spinnerets are protruded far out and the silk, which 

 seems to be coming from the tips of the organ, is applied somewhat as 

 paint is by a brush. When the drying up began, as noted above, the 



'Mi.-s R. B. Hughes was at that time taking a census of the population emerging from damp places 

 by placing a tent-trap and examining the catch at intervals. 



