:Yeah, Philadelphia is probably not an example, you're right.  There isn't a pair of consonants there eligible for splitting.  I'm also not so hot on archaeopteryx and Neoptolomus now.  While in English, we can't lead a syllable with "pt", we can end them.  "apt" is a perfectly cromulent English word for example.  Agnosia/agnostic is probably still good.  Seems like there should be others with the -gnos- root, but I didn't come up with any.  Maybe apoplexy is another. -