Flatfish entire order was John Roxborough Norman's "Monograph of the Flatfishes" published in 1934. New species are described with some regularity and undescribed species likely remain. Hybrids are well known in flatfishes. The Pleuronectidae, of marine fishes, have the largest number of reported hybrids. Two of the most famous intergeneric hybrids are between the European plaice ("Pleuronectes platessa") and European flounder ("Platichthys flesus") in the Baltic Sea, and between the English sole ("Parophrys vetulus") and starry flounder ("Platichthys stellatus") in Puget Sound. The offspring of the latter species pair is popularly known as the hybrid sole and was initially believed to
Pinnoctopus cordiformis appear to be consistent differences between specimens identified as "P. cordiformis" and those identified as "O. maorum" which suggests that there is a second species but this species more closely resembles a species of the genus "Enteroctopus", with the description closely resembling "Enteroctopus zealandicus". The name "the name Pinnoctopus cordiformis" is regarded as unresolved, a "nomen dubium", by some authorities. Pinnoctopus cordiformis Pinnoctopus cordiformis is a species of octopus found around the coasts of New Zealand. "Pinnoctopus cordiformis" is identifiable by their orange-brown or purple-grey colouration; iridescent white spots are also found on the arms and web. No white spots