1963] 
Y oung — Hydrovatus 
187 
borders indistinct. Hind coxae coarsely microreticulate and with large 
punctures separated by from one to two times the diameter of a single 
puncture. Abdominal sternites microreticulate, the meshes irregular 
and not deeply impressed ; first visible sternite coarsely but shallowly 
and irregularly punctate; fused 2nd and 3rd sternites with a few 
coarse but shallow and scattered punctures on 2nd ; last visible sternite 
pointed behind, the point deflexed. Anterior and middle tarsi mod- 
erately expanded ; middle tibiae with a few large setigerous punctures 
on anterior face; antennae not evidently modified, not noticeably 
thicker than in female. Coloration: Head and pronotum light red- 
dish yellow. Elytra darker, light reddish brown except along suture 
and sub-basal and postmedian fascia or spots which are lighter (lighter 
markings more evident in other specimens in series.) Venter light 
reddish yellow including legs and antennae. Male genitalia with 
parameres of usual type for American species but aedeagus distinctive 
(fig. 5) in lateral aspect acuminate to tip and feebly recurved; in 
ventral aspect broadened toward tip and spatulate. 
Allotype female: Very similar to holotype; sex apparently deter- 
minable only by dissection. Clypeus not detectably different from that 
of male except that the clypeal tubercles are reduced. Microsculp- 
ture and punctation very similar to holotype. Color somewhat lighter 
on all parts. Total length 1.98 mm; greatest width, 1.20 mm; width 
at base of pronotum, 1.02 mm; width at apex of pronotum, 0.82 mm; 
length of pronotum at midline, 0.43 mm ; length from base of pros- 
ternal process to apex of coxal lamina, 0.86 mm ; width between eyes, 
O.52 mm. 
Variation: The paratype series varies somewhat in color — some 
specimens being slightly darker, particularly on the elytra, and some 
have light markings more distinct. The types may be slightly teneral. 
Type locality : Holotype and allotype: FLORIDA: Alachua Coun- 
ty, Payne Prairie south of Gainesville, vii.23.1960, F. N. Young (in 
UMMZ). Paratypes: 1 cf same data (U. S. National Museum) ; 
1 cf same data (Museum of Comparative Zoology) ; 1 9 same locality, 
viii. 21.1961 (California Academy of Science ) ; 1 9 same locality, viii. 
21.1961 (BMNH) ; 1 9 same locality, viii. 22. 1961 (American Mu- 
seum of Natural History) ; 2 9 FLORIDA: Dade County, Miami, 
ix. 13.1960, blacklight trap, P. E. Briggs (Florida State Collection). 
Hydrovatus platycornis new species 
Diagnosis: A medium sized, dark colored, and immaculate Hydro- 
vatus (fig. 12) similar to the Mexican concolor Sharp (fig. 13) but 
