Californian Beach Hoppers — B owers 
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traits are needed for field identification. Gen- 
erally, the overall pigmentation tone of these 
hoppers tends to match the color of the sandy 
substrate; but even on light sands where pig- 
ment is reduced, there are a few key spots that 
usually show up. I will be concerned mainly 
with the dorsum of the first three abdominal 
segments, which appear in a top view as the 
last three body segments ahead of the urosome, 
and the 7th and 8th thoracic segments. 
A study of the sketches in Figure 3 will show 
that there are two main groups of pigmentation 
patterns. The broad "butterfly” spots of the 1st 
and 2nd abdominal segments of the "calif or- 
niana- like” group are found with modifications 
in O. calif orniana, O. columbiana, and O. bene - 
dicti. The T-shaped spots of the 1st, 2nd, and 
3rd abdominal segments of the " corniculata- 
like” group are seen in O. corniculata and 0. 
pugettensis. 
The calif orniana-/fi£e group. In calif orniana 
and benedicti there is a sagittal line showing in 
most variants of this pattern. Note the absence 
of pigment from the 3rd abdominal segment on 
calif orniana, but the presence of pigment in 
benedicti. In columbiana the midline marking 
is missing and the "butterfly” design is more 
nearly a flattened X, again with no pigment in 
abdominal segment 3. The characteristic mark- 
ings of abdominal segments 1 and 2 are suf- 
ficient to separate calif orniana from columbiana. 
Benedicti, besides being small, is more heavily 
pigmented with discontinuous spots, which thus 
give the impression of a checkerboard design 
along the whole body. 
The corniculata -like group. The two species 
in this grouping, corniculata and pugettensis, 
are the most difficult to separate, although they 
are easily distinguished from all the others. The 
most obvious dorsal pattern differences seem to 
be in the last two thoracic segments in which 
pugettensis has more delicate markings, but I 
have detected no easily recognizable differences 
here. A more consistent and reliable set of marks 
may be found at the lower margins of the lateral 
body wall in the last three thoracic segments of 
pugettensis (see Fig. 4). The third of these is 
missing in corniculata, which thus shows only 
two spots which are usually more diffuse and 
less intensely pigmented than in pugettensis. 
Fig. 4. Side views to show key characters of thoracic 
segments 6, 7, and 8. a, O. corniculata; b, O. 
pugettensis. 
(These spots do not serve to set off these two 
species from the other three, however, for these 
others may have such markings as well. ) These 
two hoppers are found on the same beach oc- 
casionally, and in such cases it may be necessary 
to rely on the key characters presented by Bous- 
field in the papers cited. However, these pig- 
mentation patterns, antennae colors, and other 
more subtle clues allow one acquainted with the 
animals to make fairly reliable preliminary de- 
terminations. 
Whatever "hedging” the reader may detect in 
this presentation is due to the wide range of 
variability to be found in these animals and to 
the fact that exceptions keep cropping up as 
