I just looked up medusa on OrchidWiz and there must be twenty of them around. They include:
Cyrtogramcymbidium [Cgc.] Jumbo Medusae
Cattleya [C.] Medusa
Cymbidium [Cym.] Medusa
Dendrobium [Den.] Medusa
Masdevallia [Masd.] medusa
Paphiopedilum [Paph.] Medusa
Nanodes [Na.] medusa This is an Epidendrum
And the list goes on. Ursula did mention the two most popular and here are their photos:
Bulbophyllum medusa
Habenaria medusa
I have found Bulbophyllum medusa hard to grow. It seems to sit there and pout for months at a time and only bloom every 3 or 4 years.
Habenaria medusa is easier for me but remember it is a terrestrial orchid that goes dormant in the winter.
Jim