-ellus, -ella, -ellum +

(Latin: a suffix; little)

agnellus (s), agnelli (pl)
A little lamb.
blattella
Small cockroaches.
circellus
A small ring, or circle.
columella
1. A tiny bone in the middle ear of all land vertebrates that transmits sound waves from the eardrum to the inner ear and corresponds to the stapes in mammals.

The stapes is a small stirrup-shaped bone in the middle ear of mammals, the innermost of the three small bones that transmit vibration to the inner ear.
2. A small column (or structure resembling a column) that is a part of a plant or an animal.

fabella
One of the small sesamoid (seed like) bones situated behind the condyles (rounded articular surfaces at the extremity of bones) of the femur (large bone in the thigh that articulates with the pelvis above and the knee below), in some mammals.
fenestella
1. An oval or circular opening; to allow light into a dome or a vault.
2. A small opening for holding relics at the south side of an altar in a Roman Catholic church.
labellum
1. A small lip-like part, such as the tip of the proboscis of various insects, used for lapping up liquids.
2. A small appendage beneath the upper lip or labrum of certain insects.
ocellus
1. An eye-like marking (as on the wings of some butterflies); usually, a little spot of color inside a ring of another color.
2. An eye having a single lens.
3. An eye-spot or eye-like color patch.
4. The simple eye found in some insects and other arthropods.
5. An eye-like marking as seen on many insects, on fish, on feathers, etc.
pipistrellus
A nearly cosmopolitan genus of very small bats.
rostellum
1. A small part of an animal or plant that resembles a beak; for example, the hooked projection from the head of a tapeworm.
2. A small beaklike part, such as a projection on the stigma of an orchid, a tubular mouthpart on some insects, or the hooked projection on the head of a tapeworm.
sacellum
1. A small monumental chapel in a church.
2. An unroofed space consecrated to a divinity.
scutellum
A hard small plate or scale; for example, on the thorax of an insect or a toe of a bird.
tessella
A small tessera (a small square tile of stone or glass used in making mosaics).