1976] 
Porter — Thyreodon from South Texas 
307 
Fig. 1 Thyreodon laticinctus Cresson, female. Dorsal view of mesonotum 
showing weakly impressed and finely rugulose notauli and peculiarly modified 
prescutellar ridge. 
Fig. 2 Thyreodon niger Cresson, female. Dorsal view of mesonotum, showing 
deeply impressed, coarsely foveolate notauli, raised crest at anterior end of notauli, 
and unmodified prescutellar ridge. 
Fig. 3. Thyreodon niger Cresson, female. Posterior view of propodeum, show- 
ing the median and lateral channels. 
