Anatomy: Casts of the Pelvis
Casts of the pelvic urinary space, however, reveal the presence of a series of leaf-like extensions.

Hamster Cast
There is an enormous variation in pelvic spaces which range from the simple funnel shape to the most elaborate of pelvic extensions. Secondary pouches and fornices are found in all types of mammalian kidneys. They are urinary spaces in which the urine can contact the very thin epithelium covering outer medullary tissue.

Simple funnel cast

Complex pouches
(Felix tigris)