1968] 
Roth — Oothecae of Lophoblatta 
105 
1967a). However, it is probable that there are Blattellinae whose 
oothecae contain <50% water initially, which are carried attached 
externally by the female for the entire embryogenetic period, and 
which have an S-shaped water uptake curve. Such blattellines when 
eventually found will add additional support to the hypothesis that 
ovoviviparity also arose from a blattellinae-like stock. 
Lophoblatta arlei (R. S. — Albuquerque), a closely related but 
much larger species than L. brevis , was collected in an oriole nest near 
Serra Tamendaui, Rio Negro, July 18-19, 1967. Its ootheca is 
similar but larger (Figs. 4-6) than that of L. brevis , and it too is 
carried externally for the entire embryogenetic period. The water 
content of the ootheca when first formed is 38.6dz0.o (N = 2). 
Calcium oxalate crystals appear to be absent, or if present, are 
very sparse in the wall of the ootheca. There is only 1 oocyte in 
Zone V, and 5 in Zone IV of the ovariole. Unfortunately, I could 
not establish a culture of this species, but, undoubtedly, water up- 
take is similar to that of L. brevis. 
SUMMARY 
The blattellids Lophoblatta brevis , and L. arlei are the first mem- 
bers of the Plectopterinae found that carry their oothecae externally 
until the eggs hatch. Except for the absence of rotation of the 
ootheca, their oviposition behavior is similar to Blattella and Chorisia , 
both genera of Blattellinae. 
The structure of the ovaries and ootheca, as well as the oviposi- 
tion behavior of L. brevis and L. arlei show that, except for not 
rotating the ootheca, reproductive evolution in the Plectopterinae 
has followed the same general pathway as that undergone in the 
Blattellinae. 
The water uptake curve of the eggs in the ootheca of L. brevis 
is sigmoid-shaped and typical of species that have a low water content 
( < 5°% ) at the beginning of embryogenesis. This is the first dem- 
onstration in the Blattellidae that the curve for water uptake by 
eggs in an externally carried ootheca can be S-shaped and similar to 
ovoviviparous species that incubate their eggs internally. 
Because rotation of the ootheca was a necessary prerequisite for 
the evolution of ovoviviparity in the Blaberidae, Blattellinae-like 
species were probably the forerunners of this family. However, 
though they likely exist, no Blattellinae are known whose oothecae 
initially have low water contents, are carried by the mother during 
embryogenesis, and whose eggs have an S-shaped water uptake curve. 
