[Taxacom] Quick question re formation of a family-group name

Tony.Rees at csiro.au Tony.Rees at csiro.au
Mon Dec 20 17:17:25 CST 2010

Dear taxacomers,

For a genus of flatworms (Pericelis Laidlaw, 1902) which is the type genus of a family, the family name is given variously as Pericelidae (e.g. in Parker, 1982 and in the World Register of Marine Species and ITIS) or Pericelididae (as given in other sources e.g. the Turbellarian taxonomic database at this time).

The Zoological Code allows either construction so far as I can tell, and ultimately goes to "prevailing usage":

<snip> If the stem so formed ends in -id, those letters may be elided before adding the family-group suffixes. If, however, the unelided form is in prevailing usage, that spelling is to be maintained, whether or not it is the original spelling.

Example. The family-group names HALIOTIDAE and HALIOTOIDEA are not changed to HALIOTIDIDAE and HALIOTIDOIDEA, even though the stem of Haliotis is Haliotid-, as the latter spellings are not in prevailing usage.


"elided" was not a term I was previously familiar with, but means omitted or eliminated for present purposes.

If that well known authority Google is anything to go by, Pericelidae wins over its longer rival (11,700 vs. 143) but I have a feeling that this may conceivably be skewed by propagation and re-propagation of some high profile listing, e.g. Catalogue of Life  - for example unreviewed names from the original NODC taxonomic code are still present in ITIS and in some cases passed up to CoL without further comment or scrutiny, and this appears to be one such name. (This is not intended to be a springboard for criticism of that system, just a possible indication of how and why such things may happen).

Suggestions, authoritative or not would be welcome as to which name would be more appropriate to follow at this time - at present my preference would be for the longer form since that appears to be used in arguably more authoritative sources, but I am open to other evidence. For example in Zoological Record, a search on "Pericelidae" yields one hit only, but Pericelididae yields none...   Pericelidae has 13 hits on Google scholar, Pericelididae has 3.

Does anyone have a magic bullet here, maybe?

Regards - Tony

Tony Rees
Manager, Divisional Data Centre,
CSIRO Marine and Atmospheric Research,
GPO Box 1538,
Hobart, Tasmania 7001, Australia
Ph: 0362 325318 (Int: +61 362 325318)
Fax: 0362 325000 (Int: +61 362 325000)
e-mail: Tony.Rees at csiro.au
Manager, OBIS Australia regional node, http://www.obis.org.au/
Biodiversity informatics research activities: http://www.cmar.csiro.au/datacentre/biodiversity.htm
Personal info: http://www.fishbase.org/collaborators/collaboratorsummary.cfm?id=1566

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