1953] 
Young — Water Beetles 
27 
debilis, but relatively stouter and more expanded behind 
the anterior coxae. Anterior and middle tarsi moderately 
dilated; protarsal claws simple. Anterior tibiae constricted 
at base as in debilis. Genitalia : Parameres similar to those 
of debilis. Aedeagus distinctive (see Fig. 1). Color: Head 
reddish brown, eyes dark. Pronotum dark reddish brown 
to fuscous on disk, lighter yellowish brown at anterior 
angles and along margins. Elytra very dark reddish brown 
to fuscous with a narrow, transverse yellowish brown area 
at base not quite reaching the suture; margins and apices 
diffusely lighter. Appendages and undersurface nearly 
uniformly reddish brown, a little darker along sutures and 
on abdominal sternites. 
Allotype female : Similar to male except that specimen 
is teneral and almost uniformly light yellowish brown above 
and below. The specimen is in poor condition, but the 
structural characters are distinct. The anterior and mid- 
dle tibiae and tarsi are simple. Total length 4.59 mm. ; 
greatest width 2.40 mm. Width of pronotum at base 2.11 
mm.; width of pronotum at apex 1.24 mm.; length of pro- 
notum at midline 0.81 mm. Length of prosternal process 
0.70 mm. ; length from apex of prosternal process to apex 
of coxal laminae 1.51 mm. Width between eyes 0.78 mm.. 
Variation : The series of specimens before me is rela- 
tively uniform. Both of the females are teneral and lighter 
in color, but do not seem to differ significantly otherwise. 
The largest male measures 4.75 by 2.54 mm.; smallest 
female 4.56 by 2.38 mm. 
Type locality: Holotype, allotype, two male and one 
female paratypes, all from Florida: Monroe County, Key 
West, Mar. 3, 1919, W. S. Blatchley. (These apparently 
represent all but four of the specimens collected by Blatch- 
ley and recorded by him as debilis.) 
Location of types: Holotype and allotype in the W. S. 
Blatchley Collection at Purdue University. One male and 
one female paratype in the University of Michigan Museum 
of Zoology, Ann Arbor, Michigan. One male paratype in 
the Museum of Comparative Zoology (Type No. 29,019), 
Cambridge, Massachusetts. 
