The Fernbach-style culture flask (invented around 1900) provides a larger liquid surface and hence a better oxygen transfer, albeit at the price of needing more space for the same amount of liquid.

Erlenmeyer flask with two side tubes designed for vacuum filtration. The inscription reads "Pilling-Phila / Pyrex ... CH.316056.092 catalog number 316056.092 accession number 217523 Object Name ...