164 The Ohio Journal of Science [Vol. XXI, No. 5, 



closely similar in a general way, no specific habits or other obser- 

 vations were noted. A separate larval list was hoped for, but 

 the larvae, given to Dr. Mosher, could not be identified to 

 species or even to genus, but merely to family, with, however, 

 some segregation into presumable generic groups that may 

 assist in future work on beetle larvce. Figures in the table are 

 of adult beetles entirely. 



Family Car ab idee. 



Elaphrus ruscarius Say, "probably the commonest species 

 along margins of streams, ponds and lakes," (Blatchley '10), 

 was found running on the moist, muddy shore close to the 

 water's edge at station 2, but only a few specimens were seen, 

 all in April. Because of their habitat, members of the genus 

 Elaphrus are properly considered in an aquatic survey, possibly 

 as much so as are the shore bugs, Saldidce. 



Family HaliplidcB. 



Peltodytes 12-punctatus Say, a rather conspicuous beetle 

 found in the shallow water among algal vegetation, in the small 

 pond, was fairly common. 



Peltodytes edentulus Lee, a beetle at first not differen- 

 tiated from the preceding, was somewhat more numerous than 

 that species. 



The characteristic spiny larvae of this genus were also found 

 not uncommon in the same situations as the adult. 



Family DytiscidcB. 



No large predaceous diving beetles were present, though 

 there were reports of the one time presence of some form like 

 Dytiscus. Their absence is explicable on examination of various 

 features of the pond. 



That depth of water of a pond is related to the presence of 

 a particular kind, or rather particular sized beetle, was found 

 (Needham and Williamson '07) to hold in a pond worked on 

 at Lake Forest, 111. Dytiscus prevalent in deepest water, then 

 Acilius and then Coptotomus in shallower water, were lacking 

 in Mirror Lake, which was not deep enough; but Laccophilus 

 (the next in their succession, and inhabitating water about a 

 foot in depth) was common in the small pond, where that depth 

 of water prevailed over a large part. Hydroporus they found in 

 still shallower water and Bidesses clung to the very shoreline. 



