I 
1977] Porter — Mesostenines 87 
growth and particularly in areas covered by Serjania vines. Of 
these, five occurred exclusively in Salix-Celtis-Fraxinus gallery 
woods ( Crypt anura compact a, C. vallis C. lament aria, Bicristella 
texana, and Diapetimorpha picta) while the other 16 generally in- 
habited not only gallery woods but also the Celtis lindheimeri-C. 
pallida association, Pithecellobium thickets, and other compar- 
atively dense types of woods. Perhaps significantly, of the five spe- 
cies limited to gallery woods, all but Diapetimorpha picta are trop- 
ical forms unrecorded north of the Valley. Some or all of these 
thus really may prove restricted to the narrow zone of slightly 
warmer and much more humid micro-climate immediately along 
the Rio Grande. 
Semi-open fence rows and woods-edges yielded eight species: 
Joppidium brochum, Lanugo picta, Compsocryptus texensis, Dia- 
petimorpha introita, D. acadia, Listrognathus rufitibialis, Pachy- 
somoides fulvus, and Agonocryptus discoidaloides. Only one of 
these, J. brochum, appeared exclusively in this habitat. A. dis- 
coidaloides also was found abundantly in deep woods while D. 
acadia was collected both in deep woods and open fields. The 
other five species were shared with open fields only. 
Open sunny, weedy, or grassy places provided nine species: 
Gambrus bituminosus, Joppidium rubriceps, Lanugo picta, Comp- 
socryptus texensis, Mesostenus longicaudis, Diapetimorpha in- 
troita, D. acadia, Listrognathus rufitibialis and Pachysomoides ful- 
vus but only G. bituminosus, J. rubriceps, and M. longicaudis were 
taken exclusively from this kind of habitat. It should be noted that 
the one specimen of G. bituminosus occurred in a sandy area near 
the Rio Grande and that bituminosus in other parts of its range 
also seems associated with river banks, lake shores, and sea shores. 
With regard to other habitats, Trachysphyrus mesorufus was the 
only mesostenine found in xeric Celtis pallida-Condalia obovata 
scrub and Mesostenus opuntiae the single species collected in the 
even drier Prosopis-Opuntia association. 
The Valley mesostenine fauna thus includes an exclusively or 
primarily sylvan component of 21 species plus a smaller series of 
12 species that shows a variably marked preference for drier and 
more open habitats. Logically, the Neotropic element predomi- 
nates in humid situations while the Sonoran genera are conspicuous 
in and mostly restricted to woods-edge or field habitats. However, 
the Neotropic genus Diapetimorpha shows differentiation into both 
