Thanks, Coco Maui!
The cast in order of appearance is...Felixia (sp f, approx 14 yrs), Oreo (neut m, approx 7 yrs), Mr. Underfoot (neut m, 9 yrs), and Sylvestra (sp f, 9 yrs). Sylvestra is Mr.'s sister, and yes, she is upside down. She loves to be held that way so you can rub her belly, and it's the only way she'll hold still for a picture (they're kind of camera shy - it's a shame, because they're even cuter when there's no camera in sight!)
Thanks, all, and sorry for the confusion.
Hope you like the pictures.