Phyllodesmium longicirra? or -cirrum?

Erwin,
Thanks for picking up the anomaly. I should have changed P. longicirra a long time ago. When I put the Gallery up it was the accepted spelling, but as I was the one who changed the spelling, I can't blame anyone else! To those who are unfamiliar with such things, scientific names are governed by International Rules which, in the case of animals, are overseen by the International Commission on Zoological Nomenclature.

Part of the Rules tries to standardise the way names are "latinised" which is particularly difficult when most practising taxonomists have no knowledge of classical Greek and Latin grammar.

For those interested in the detail here is an explanation from Rudman (1991):
"Unfortunately Article 31 of the International Code of Zoological Nomenclature requires species-group names to agree in gender with the generic name with which it is presently combined. Adherence to this rule required me to alter the spelling of a number of well-known names in this genus. Phyllodesmium horridus, P. serrata, and P. cryptica, all based on Latin or
Latinised adjectives must end in -um. The name P.longicirra was more problematical. It could be treated as a noun in apposition and so stay unchanged, but Bergh apparently modified the ending from the correct 'longicirrus' to match the feminine gender of the original genus name, Myrrhine, suggesting that he was using the name as an adjective. For this reason I changed the ending to 'longicirrum'. The name of another species placed in Phyllodesmium by me for the first, P. briareus, was complicated. Bergh (1896) when naming this species gives no indication of why he used the name. However as one of the alcyonaceans it feeds on is from the genus Briareum, I assume that 'briareus' is to be treated as an adjectival form of that genus name. To agree in gender with the name Phyllodesmium (neuter) the name must also change to 'briareum.'"

You may think this has very little to do with biology - and it's a pain to sort out, but it's an attempt to keep order in the world of scientific names. Although we grumble about the problems, the International Code is one of the longest surviving international agreements - and on the whole, it works. Perhaps the fact that politicians are not involved, is the recipe for its success?

Reference:
Rudman, W.B. (1991) Further studies on the taxonomy and biology of the octocoral-feeding
genus Phyllodesmium Ehrenberg, 1831 (Nudibranchia: Aeolidoidea). Journal of Molluscan Studies, 57(2): 167-203.