Appears to be a match for Orthostethus infuscatus as seen here. There was a good fit with the first 6 characters listed on the INFO page under Identification (thanks, Cotinas). The seventh character, listed as the most important character in keying from similar species, was a different matter.
Quote:
"sides of the mesosternal cavity are protruding and suddenly declivous anteriorly" as opposed to being either parallel and horizontal or divergent and gradually declivous.

Since I still had the specimen, I set out to find and photograph this feature. Several hours later I was not sure if I had succeeded. Please check our photo #6 of 6. Arrows placed on both the ventral and ventro-lateral view point to the suspected feature. If I have interpreted the terms correctly, I think the ID is supported. Comments?
Confirmation/correction would be appreciated.
Gayle