1966] 
Whitehead, — Halocoryza 
219 
3A(3). Small beetles, length of elytra less than 1.50 mm.; second 
article of antenna plurisetose; pygidium without a series of 
fine paramedian longitudinal striae Halocoryza. 
Larger beetles, length of elytra more than 1.65 mm.; second 
article of antenna at most bisetose; pygidium bearing a 
series of fine paramedian longitudinal “striae” (actually 
rows of small tubercles, possibly used for stridulation) 
Schizogenius. 
The most diagnostic characters of Halocoryza are the nonstriate 
pygidium and the plurisetose second antennal article. But many 
additional characters may be used to separate the genus from Schizo- 
genius, including the following. 1. Mandibles prominent, nearly 
straight laterally, abruptly bent near apices. 2. Lacinia without setae 
along outer margin. 3. Frontal carinae almost perfectly regular, 
parallel, equidistant, and equally raised, the frons appearing evenly 
convex. 4. Neck not pitted or punctate dorsally, and not extended 
along posterior margin of eyes. 5. Eyes reduced, and bordered dorsally 
by a distinct carina. 6. Gula broad, at narrowest point more than 
0.4 maximum width of mentum. 7. Mentum not deeply emarginate 
at middle, with median tooth obsolete, and with the epilobes reduced. 
8. Tarsi short, the hind leg with tarsus less than 0.6 length of tibia. 
9. Paramedian carinae of second abdominal sternum short, widely 
spaced and usually weakly developed. 10. Median lobe of male 
genitalia neither arcuate nor abruptly deflexed in apical third. 
Although Halocoryza and Schizogenius are very similar, their 
separation is justifiable for several reasons. Morphologically, the 
division results in two unequal but reasonably homogeneous groups. 
( Schizogenius could be further split into perhaps four genera, but I 
think subgenera would be better). The limited available biological 
evidence suggests that the species of Halocoryza are probably all 
inhabitants of the coast, whereas the species of Schizogenius live in 
non-saline habitats. Also, their distribution patterns are best inter- 
preted if they are treated as separate genera. 
Measurements were made with an eyepiece micrometer mounted 
in a Leitz stereoscopic microscope at 150 magnifications, as follows: 
total length (TL), represented as the sum of the head length from 
Explanation of Plate 15 
Fig. 1. Body of H. acapulcana (dorsal view). 
Fig. 2. Same for H. arenaria. 
Fig. 3. Median lobe of male genitalia of H. acapulcana (lateral view). 
Fig. 4. Same for H. arenaria (but internal sac everted). 
