TWO NEW SPECIES OF WATER BEETLES 
FROM FLORIDA 
(COLEOPTERA: DYTISCIDAE)* 
By Frank N. Young 
The two new species of Dytiscidae described below were 
encountered during the course of the writer’s investigations 
of the species comprising the genera represented in the 
Florida fauna. 
The new Hydrovatus is remarkable in that it is apparent- 
ly confined to the peninsular region of Florida and may 
represent an endemic form originally isolated on the Pleis- 
tocene Islands. Examination of the type of Hydrovatus 
indianensis Blatchley convinces me that it is not that species 
although the two are similar. The occurrence of “giant” 
forms within the limits of the populations of H. pustulatus 
Melsheimer and compressus Sharp respectively suggests 
the possibility that they may represent mutant or even 
polyploid species. 
The new Copelatus has stood on our lists for many years 
as C. dehilis Sharp, but a comparison of Blatchley’s speci- 
mens with true dehilis indicates that the two are distinct. 
The form is probably not restricted to the Florida Keys, 
unless those islands represent the remnants of a land mass 
more ancient than we now suspect. 
Hydrovatus peninsularis sp. nov. 
Diagnosis : A moderately large, dark colored Hydrovatus 
resembling in general H. indianensis Blatchley, but differ- 
ing from that species in color pattern and in punctation. 
From H. major Sharp or horni Crotch it differs in lacking 
conspicuous sulci on the sides of the el3rtra. From H. pustu- 
latus Melsheimer and compressus Sharp it differs in its 
* Contribution No. 513 from the Department of Zooloigy, Indiana 
University. Aided by a grant from the National Science Foundation 
and published with a grant from the Museum of Comparative Zoology 
at Harvard College, 
21 
