no trash icon when displaying photo in ios8/photos
I have an iPhone 6 with iOS 8 and Photos. I can find no way of deleting photos I no longer need. Some of the photos show a trash icon when displayed fullscreen but others have no trash icon. There seems to be no clue as to which photos have the icon and which do not. Some of the photos without a trash icon were taken with the iPhone; some were sync'd from my iPhoto library on the Mac. There's nothing consistent.
Editing the photo only allows a duplicate to be created and with no subsequent function to delete either it or the original.
I can find nothing in the Apple Support web site about this.
iPhone 6, iOS 8