1976] 
Carpenter & Richardson — Eucaenus ova/is 
227 
4th, 1.3 mm long and much thinner than the others. 5 Head nar- 
rowed posteriorly; between the head and the pronotal shield is 
a demarcated region (1.8 mm wide and 1.5 mm long), which, be- 
cause of its heavy sclerotization, we consider to be part of the 
prothorax, rather than the cervix; pronotal shield elongate-oval, 
about 5.5 mm long and 3.8 mm wide, with the sides only slightly 
curved and with the maximum width at the posterior half; the 
pronotal shield is very heavily sclerotized. Mesothorax about 
5.5 mm wide and 4 mm long; metathorax about 5.4 mm wide 
and 3 mm long. All legs are short and similar in form. The fore 
femur is 4 mm long and 2 mm wide, with a curved front margin; 
the tibia is 3.8 mm long, and the tarsus, 1.6 mm long; four tarso- 
meres are distinct and there is a suggestion of a fifth. The meso- 
and metathoracic legs are similar to those of the prothorax, ex- 
cept for slight differences in the lengths of the femora. 
The abdomen averages about 14 mm long, the precise length 
depending on the amount of contraction of the segments; the 
width of the first few segments is 5.4 mm and that of most of the 
others, 4.5 mm. The cerci are very small, only about 1 mm long, 
but they appear to consist of 3 or possibly 4 segments. The female 
has a short, external ovipositor, 3.4 mm long, and definitely not 
extending beyond the end of the abdomen. 
The integument of this insect is strongly sclerotized and has 
a distinctly rugose sculpturing, similar to that of many existing 
Orthoptera; the sculpturing covers the femora and tibiae, and 
is especially well developed on the thorax. 
Type: no. 38142, National Museum of Natural History, Wash- 
ington. Scudder saw only the obverse part of this specimen (marked 
“a”); the reverse part (marked “b”), now in the National Museum, 
is much better than the one Scudder studied, and we have been 
able to expose the head and prothorax, which were unknown 
to Scudder. The total length of the body is 30 mm. 
The type of E. mazonus Melander, no. U.C. 9242 in the Walker 
Museum, University of Chicago [now in Field Museum] shows 
nothing to distinguish it from ova/is. Melander stated that the 
5 In specimen no. PE 20790 the 4th segment of the palpus shows faint traces of di- 
vision into 6 or 8 segments. However, since such palpal segmentation is unknown 
in the insects, we believe this apparent segmentation in the fossil is associated with 
the process of preservation. 
