Penguin classics with the Greek/Latin plus English?

One of my professors swears these exist, but so far my searches for them are coming up empty. He tells me that they are collected works, and essentially like Loebs except with a much more literal English translation included, which helps to be able to figure this stuff out while you don't have a dictionary handy.

Problem is, I can't seem to find out anything about them online, which is a shame because I'd love to take them on the road with me this summer.

FWIW: I've never seen one.

(I do know of a Penguin Beowulf in Old English though, so I guess it's possible).

he wouldn't mean these would he? The Penguin Book of Latin Verse & The Penguin Book of Greek Verse have the text of poems in latin and greek, with a literal english gloss on the bottom of the page.
Edit: it looks as though they do exist, in more modern editions. search penguin's site for "dual language" or "bilingual" and you should find at least the eclogues and fragments of heraclitus in greek/english editions!

Aha! Those must be it, thanks Binders! He'd mentioned them more than once, but he specifically brought up the Greek one yesterday when we were talking about my brief upcoming trip to Greece, and he said it would be nice to have because you can sort of chart the language change over time, right up to modern Greek.