58 Bulletin American Museum of Natural History [Vol. XLII 



silk seemed to become more and more sticky, thereby making it appar- 

 ently hard work for the beetle to extricate the spinnerets at the end of 

 each application. 



Not until several egg-masses were procured in the field was I assured 

 that C. fimbriata is in the habit of laying egg -masses without the usual 

 coverings. On April 28, 1915, at McLean, while collecting in leafy 

 pools where Hydrobius globosus, Paracymus subcupreus, Anccena infuscata 

 and Cymbiodyta fimbriata abounded, I turned up a layer of leaves which 

 were moist "but not in the water and noted a mass of thirty eggs similar 

 to those laid in my aquaria indoors. When these had hatched they 

 proved to be the eggs of C. fimbriata. In none of my observations on 

 egg-laying have I noted an egg-mass laid by a Cymbiodyta that had the 

 usual complete covering; which seems to be conclusive evidence that 

 this species does not add the outer protective layer. 



C. fimbriata laid from fifteen to forty-three eggs, which hatched out 

 in seven to nine days. It was interesting to note that, if eggs were not 

 taken out of aquaria and isolated, they were usually destroyed by the 

 adults, although I did not observe them in the act. 



The larvae are apparently not as cannibalistic as the larger members 

 of the group and appear not to notice their brothers and sisters unless 

 they accidentally bump into each other. However, one specimen was 

 observed devouring a larva of Philydrus which was about the same size 

 as itself. The length of life history in this genus is probably about two 

 months. On May 19, 1915. two large larvae, evidently hatched from the 

 egg-cases found the latter part of March, were observed in the aquarium. 

 About the middle of June they seemed fairly mature but died without 

 pupating. 



Although I have not determined the length of the pupal period in 

 either of the two species, it is probably three or four days, as in Philydrus. 

 Upon finding the larvae in all instars on the flats above mentioned, I 

 searched the bank to see if the pupae of the beetle could not be located. 

 The first day brought little reward except the egg-masses of C. blan- 

 chardi. However, on the second day, fortune favored me and several 

 feet from the water in slightly moist loam and an inch or less under the 

 moss, a veritable array of pupae, including more especially those of C. 

 blanchardi, C. fimbriata (few), Dascyllidae and Dytiscidae, was found. 

 All stages, except the egg stage, were present in the cells and so, by dig- 

 ging carefully and saving the pupal and larval skins, the necessary con- 

 necting links in their life history were easily obtained. 



