Gregarina polymorpha from the mealworm Tenebrio molitor.  This species co-exists with Gregarina cuneata and is larger. This is a transverse section, revealing the corrugated nature of the cell surface, called epicytic folds.  These are not tubular structures but long folds that extend lengthwise along these elongate cells.  The arrows point to myonemes which extend along the folds.  70,000x