1977] 
Thayer — Redescription of Xenicopoda 
147 
side of the tarsus (including anterior protarsal claws) dorsal and 
posterior side ventral to the lateral edge of the body. The bifurcate 
nature of the second to fourth protarsal segments of the male and 
the lack of setae along the midline of the tarsus lend some credence 
to the latter hypothesis, but of course only direct observation of 
mating can confirm or deny any of this speculation. Why only one 
genus, out of all known Omaliinae, has these tarsi remains a mys- 
tery. The large strap-like setae on male Xenicopoda protarsi also 
may be an aid to grasping females in copulation. The presence of 
modified protarsal setae in at least the males is characteristic of 
nearly all omaliine genera I have seen (approximately 40, of which 
at most 5 lack these setae entirely). The form of the modified setae 
varies: some, like those of Xenicopoda, are strap-like, while others 
are spatulate, more or less like those of Xanthonomus Bernhauer, 
as illustrated by Steel (1955). Those of other genera form a con- 
tinuum between these two types. Rarely, females also have modi- 
fied setae on the protarsi, and in Eusphalerum, Amphichroum, and 
Pelecomalium, modified setae are found on all tarsi of both sexes, 
although in all these cases the setae of the males seem to be broader 
than those of the females. Males of several genera have modified 
setae on their mesotarsi as well as on their protarsi. 
Most Omaliinae have a pair of paratergites on the second through 
seventh abdominal segments. In their description of Xenicopoda, 
Moore and Legner (1971) stated that paratergites are present on 
the fourth and fifth “visible abdominal segments” (=sixth and sev- 
enth segments), although their figure seems to show paratergites on 
the seventh and eighth segments. Examination of a cleared Xeni- 
copoda specimen reveals that only the third and seventh segments 
bear paratergites. The second segment appears at first to have 
paratergites, but closer examination reveals that the sternite ex- 
tends continuously onto the dorsal surface, whereas there is a mem- 
branous articulation between paratergites 3 and 7 and their respec- 
tive sternites. Xanthonomus appears to have a similar abdomen, but 
has paratergites present only on the seventh segment (Steel, 1955, 
description and figs. 1-2; also I have examined specimens of an 
apparently undescribed Xanthonomus sp. in the Bernhauer Col- 
lection). I do not intend to imply, however, that these two genera 
are related because of their similarity in abdominal structure. 
To include females of Xenicopoda in Moore and Legner’s (1974) 
key to North American omaliine genera, couplet 29 should be 
