Catalogue of the Living Bivalvia of the Eastern Pacific Ocean ...

No comprehensive inventory of the bivalve fauna of the
entire eastern Pacific has appeared, and it is more than 44
years since A. M. Keen's Check list and bibliography of the
northwestern American marine Mollusca (1937). The
present catalogue was started over fifteen years ago to provide
data for a re-interpretation of bivalve geography using
new distributional data, segregated by depth to resolve
effects of submergence of northern species at lower latitude,
and submitted to computer techniques for analysis. This
work is now in final preparation (Bernard & McKinnel MS),
but it appeared useful for taxonomic workers to issue the
data, and setting down in juxtaposition the northern and
southern representatives of various groups may stimulate
further study leading to monographie reviews.
I have attempted to include all binomina used regionally,
though the early literature is replete with extralimital analogues.
I have built on the important faunistic works of
Carpenter (1872), Dall (1921), Keen (1937), and Burch
(1944-46) for the northern fauna; Olsson (1961) and Keen
(1971) for tropical America; and Carcelles & Williamson
(1951) and Osorio & Bahamonde (1970) for the southern
fauna. Other records were obtained by abstracting the literature
and more than 5000 titles were searched. I have avoided
mere lucubrations of published records, that so often repeat
and perpetuate errors, and wherever possible type material
was examined and collections consulted contemporaneous to
writings of authors where original material is unavailable or
lost. In some cases the total nomenclatural confusion makes
determination of identity a matter of idle but not uninteresting
speculation.
A critical review of each group is impossible on so large a
scale and would result in several volumes of heroic proportions.
I have let stand a number of incorrect generic
usages, as these long-established errors require erection of
new taxa for their correction. However, I have corrected
homonyms and have merged a number of species. Doubtless,
synonyms and other oversights have crept in. Besides such
outright errors, two further difficulties will try the readerpertinent
literature may have been overlooked, and the lag in
publication time will result in omission of newly described
species. I apologise for these shortcomings and hope they
will be brought to my attention for revision.
FORMAT
Suprageneric taxa are arranged to reflect current concepts
of taxonomic relationships, combining stratigraphie, anatomical,
shell ultrastructure and other criteria with the classic
shell morphology. A brief overview of the present status of
the systematics of the higher taxa is given below.
Bibliographic references for the supraspecific taxa are not
cited, where they are available in the Treatise on Invertebrate
Paleontology (Moore 1969), and do not require repetition,
but references to authors of names which appeared after
1969, are included. Authorities for corrections of names and
INTRODUCTION
changes in concepts or status are given, but do not appear in
the bibliography.
Genera and subgenera are arranged alphabetically. I have
avoided listing the nominate genus directly following the
family or subfamily entry as done in the 'Treatise' , as this
merely reflects chronology and is often disruptive of the
current view of natural relationships, which are constantly
changing as more information accumulates.
Each species comprises a separate entry, with the current
binomen in heavy type. The original combination and full
bibliographic reference follows for the species and its junior
synonyms, arranged chronologically, the status indicated,
where necessary, with abbreviated latin terrns. Distribution
outside the area of concern is briefly indicated. Occurrence in
the Clipperton, Cocos, or Galapagos Islands fauna is noted,
as there appear to be features distinct from the continental
shelf biota, notably the presence of a few endemic taxa and
those species with Indo-Pacific affinities. The final line of
each entry includes the geographic range to nearest degree of
latitude and the mid-point of geographical distribution. The
bathymetric range is in meters, and may differ from previously
published records as I have not cited depths based on
dead and probably displaced material. Thermal ranges are
followed by the oldest paleontological occurrence on the
American continent. Extralimital or incorrect binomina
which have become embedded in the literature are presented
in smaller type. Departures from current systematic arrangement
and proposals of replacement names are annotated by a
numbered entry appearing at the end of the catalogue section.
It is an irritant to the non-taxonomist to be faced with
changes of familiar names; however, it is unavoidable to
eventual stability and universality. All genus taxa were
checked with Neave (1939-75), and the specific names with
Sherborn (1902-33), and the useful compilation by Ruhoff
(1980) bridging the period between Sherborn and the start of
the Zoological Record. Contemporary taxonomy has largely
disgarded the typological concept of the species in favor of
emphasis on infraspecific variability. Following this I do not
use the subspecific designation, as the majority of wideranging
species are expected to yield several subspecies.
Formal taxonomie citation requires only the binomen
(genus and species), however, the original author and
publication date are usually appended. The addition of
pagination, references to illustrations, addition of the author
or editor of the work in which the description appeared,
citation of the authority for change of genus, etc, is merely
book-keeping with no formal taxonomie status. I have,
generally, followed the Anglo-American Cataloguing Rules
(Gorman & Winkler 1978) when citing authorities' names.
The prefix Du, de, von, etc is not included (Orbigny not
d' Orbigny; Blainville not Ducrotay de Blainville). Technically
this is acceptable only when the prefix follows the first
name, in other cases the name should be quoted in full
(Megerle von Milhlfeld), but as no doubt arises, and considerable
space is saved, I have followed the informal European
usage among peers (Megerle).
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