The flightless bird with forelimbs modified as paddle-like structures suited for swimming is known as:

The question asks for the name of the flight‑less bird whose forelimbs are shaped like paddles and are used for swimming.

First, consider the meaning of each option:

• Neophron – This is the genus of the black vulture, a soaring bird that can fly.

• Psittacula – This genus contains several species of parakeets, which are small, flying birds.

• Struthio – This is the genus of the ostrich, a large, flight‑less bird but its forelimbs are simple wings, not paddle‑like for swimming.

• Aptenodytes – This genus comprises the true penguins (e.g., the king penguin, the emperor penguin). Penguins are flight‑less birds whose wings have evolved into stiff, flattened flippers that function like paddles for efficient swimming.

Since the description matches the unique adaptation of penguins, the correct answer is the genus Aptenodytes.