SANJ

HARVARD UNIVERSITY

Library of the

Museum of

Comparative Zoology

(ob

rf

WEST AMERICAN
CENOZOIC PHOLADIDAE
(MOLLUSCA: BIVALVIA)

MUS. COiV,r-. ^...ou
LIBRARY

^ rQ74

HARVARD
UNIVERSITY

GEORGE L.KENNEDY

SAN DIEGO

SOCIETY OF NATURAL HISTORY

MEMOIR 8

1974

WEST AMERICAN
CENOZOIC PHOLADIDAE
(MOLLUSCA: BIVALVIA)

GEORGE L. KENNEDY
UNIVERSITY OF CALIFORNIA, DAVIS

SAN DIEGO

SOCIETY OF NATURAL HISTORY

MEMOIR 8

1974

SAN DIEGO SOCIETY OF NATURAL HISTORY MEMOIRS

Memoir 8, pages 1-128

Issued June 28, 1974

Frontispiece. Fossilized wood with the wood-boring pholadid Martesia s.l. (top) and the
calcarous tubes of teredos (family Teredinidae). Collected from the Eocene Lodo
Formation on the west side of the San Joaquin Valley, Merced County, California (USGS
loc. 5712). X 1.

PUBLISHED WITH FINANCIAL AID
FROM THE

W.W. WHITNEY PUBLICATIONS ENDOWMENT

AND BY DONATIONS FROM

CENTURY CITY SCIENTIFIC CORPORATION

BERNARD D. CIRLIN

CONTENTS

INTRODUCTION 9

Material 9

Abbreviations 9

Acknowledgements 10

MORPHOLOGY 11

LIFE HISTORY AND VARIABILITY 13

Life History 13

Variability 14

ENDOLITHIC COMMUNITY 16

BURROWS 17

GEOLOGIC SIGNIFICANCE 18

GEOLOGIC RECORD 20

Summary of West American Fossil Genera 20

SYSTEMATIC PALEONTOLOGY 21

Family PHOLADIDAE 23

Subfamily PHOLADINAE 23

Genus Barnea Risso 23

Subgenus Anchomasa Leach 24

B. {A.) subtruncata (Sowerby) 24

Genus Cyrtopleura Tryon 26

Subgenus Scohinopholas Grant and Gale 26

C. (S.) costata (Linne) 26

Genus Zirfaea Gray 28

Z. dentata Gabb 29

Z. pilsbryi Lowe 31

Subfamily MARTESIINAE 36

Genus Chaceia Turner 36

C. ovoidea (Gould) 37

Genus Penitella Valenciennes 39

P. conradi Valenciennes 40

P. durhami Adegoke 43

P. fitchi Turner 44

P. gabbii (Tryon) 45

P. kamakurensis ( Yokoyama) 48

P. lorenzana (Clark) 49

P. penita (Conrad) 50

P. turnerae Evans and Fisher 54

Genus Martesia Sowerby 57

M. meganosensis Clark and Woodford 58

Subgenus Paramartesia n. subgen 59

M. (P. ) tolkieni n. sp 59

Genus Opertochasma Stephenson 60

O. turnerae (Hickman) 61

Genus Parapholas Conrad 62

P. califomica (Conrad) 62

Subfamily JOUANNETHNAE 65

Genus Nettastomella Carpenter 65

N. rostrata (Valenciennes) 66

N. japonica ( Yokoyama) 67

Genus Pholadopsis Conrad 68

P. pectinata Conrad 69

Subfamily XYLOPHAGAINAE 70

INCERTAE SEDIS 71

"Zirfaea" plana White 71

"Jouannetia" sp 72

"Martesia" sp 72

INCONCLUSIVE RECORDS 72

REGISTER OF LOCALITIES 76

LITERATURE CITED 94

PLATES 110

INTRODUCTION

The Pholadidae are a highly specialized
family of Bivalvia that have adapted to
mechanically excavating burrows in mud,
soft rock, coral, shell, and wood. The
Cenozoic fossil record of this family in
western North America is meager. And,
partly because of the previous lack of a
sound classification for the Recent species,
they have long been misinterpreted in the
fossil record.

The last major summary of the fossil
Pholadidae of North America appeared
more than seventy years ago when Dall
(1898) included the western Atlantic species
in his study of the Tertiary Mollusca of
Florida. Although fossil pholadids have been
cited frequently as occurring in Cenozoic
rocks of western North America for over a
hundred years, the literature is scattered
and work on the group has suffered because
of the lack of a general revision. This study
is an attempt to gather together available
data, and to provide an evaluation and
synthesis of the west American Cenozoic
species of Pholadidae.

The classification used herein is that of
Turner (1954, 1955), except that a new
subgenus of the genus Martesia is proposed,
and the subgenus Pholadopsis is provided
full generic rank. For the most part
subfamilial and generic descriptions follow
those of Turner (1954, 1955, 1962).

Twenty-four, valid, shallow-water spe-
cies from three subfamilies presently live on
the west coast of North America from
Panama (one may have been introduced
through the Canal) to arctic Alaska. In
addition, ten species of Xylophagainae,
mostly deeper water forms, also occur in
this region. Of the Recent shallow-water
species, only thirteen range northward from
the outer coast of central Baja California
and are included in this study. In this area,
eight species names have been proposed
previously for Cenozoic fossils, and one
species is described herein. In addition, two
species described from fossil occurrences in

Japan also occur in the northeastern Pacific
today.

MATERIAL

Because of the known effect of substrate
on the size, shape and sculpture of pholadid
shells, and because neither series nor com-
plete specimens are generally found fossil-
ized, it is often difficult to adequately define
fossil species. In order to determine ranges
of population variation and ascertain which
features are consistently independent of
external variables and therefore useful in
defining species, I studied a large number of
Recent specimens whose identifications
were known. The most important collection
of those studied was that assembled by Dr.
Ruth D. Turner at the Museum of
Comparative Zoology, Harvard University.
Other collections studied included those of
the San Diego Natural History Museum, the
Los Angeles County Museum of Natural
History, Stanford University, the California
Academy of Sciences, the University of
California Museum of Paleontology (Berke-
ley), the Academy of Natural Sciences of
Philadelphia, and the U.S. National Mu-
seum. In addition to these Recent collec-
tions, a large series of fossil specimens were
assembled for comparative study from the
collections of the aforementioned institu-
tions, as well as those at San Diego State
College, the University of California at Los
Angeles, and the U.S. Geological Survey,
Menlo Park and Washington, D.C. Other
specimens were borrowed from the Univer-
sity of Oregon (Eugene), and the University
of Washington (Seattle).

ABBREVIATIONS

The following abbreviations are used
for the museums (or collections), universi-
ties, and grid references listed below.

10

GEORGE L. KENNEDY

Catalogue numbers are indicated solely by

the abbreviation and number. Localities are

indicated by "loc." following the abbrevia-
tion and preceding the number. Type

numbers, if serially separate, are indicated

as such.

ANSP Academy of Natural Sciences of

Philadelphia, Pennsylvania.

CAS CaHfornia Academy of Sciences,

San Francisco, California.

CIT California Institute of Technol-

ogy, Pasadena, California.

CSMB California State Mining Bureau

collection, now at the California
Academy of Sciences.

HEM Humboldt Base and Meridian

(California).

HH Henry Hemphill collection, at

the California Academy of
Sciences.

LACMNH Los Angeles County Museum of
Natural History, Los Angeles,
California.

MCZ Museum of Comparative Zool-

ogy, Harvard University, Cam-
bridge, Massachusetts.

MDBM Mount Diablo Base and Merid-

ian (California and Nevada).

RM Redpath Museum, McGill Uni-

versity, Montreal, Quebec,
Canada.

SBBM San Bernardino Base and Me-

ridian (California).

SDSC San Diego State College, Cal-

ifornia.

SDSNH San Diego Society of Natural
History, California.

SU Stanford University, Stanford,

California.

UCD University of California at

Davis, California.

UCLA University of California at Los

Angeles, California.

UCMP University of California Mu-

seum of Paleontology, Berke-
ley, California.

UO University of Oregon Museum

of Natural History, Eugene,
Oregon.

USGS United States Geological Sur-

vey, Washington, D.C.

USGS-D United States Geological Sur-
vey, Denver, Colorado.

USGS-M United States Geological Sur-
vey, Menlo Park, California.

USNM National Museum of Natural

History, Washington, D.C.

UW University of Washington, Se-

attle, Washington.

WBM Willamette Base and Meridian

(Oregon and Washington).

ACKNOWLEDGMENTS

I wish to thank the following persons
who kindly responded to a myriad of
questions during the course of this study:
O.S. Adegoke, University of Ife (Ibadan
Branch), Nigeria; Kiyotaka Chinzei, Geolog-
ical Institute, University of Tokyo; J.W.
Evans, Memorial University of Newfound-
land (St. John's); J.E. Fitch, California
State Fisheries Laboratory (Terminal
Island); A.M. Keen, Stanford University;
V.S. Mallory, University of Washington
(Seattle); J.E. Merida, U.S. National
Museum; J.H. Peck. Jr., University of
California Museum of Paleontology (BerKe-
ley); R. Robertson, Academy of Natural
Sciences of Philadelphia; L.R. Saul, Univer-
sity of California at Los Angeles; J. A. Shot-
well, University of Oregon (Eugene); R.D.
Turner, Museum of Comparative Zoology;
H.E. Yokes, Tulane University; E.G.
Wilson, Los Angeles County Museum of
Natural History. Special thanks are due
Junji Itoigawa, Nagoya University, Japan,
for securing references otherwise unobtain-
able to me, providing notes on Japanese
fossil pholadids, and locating certain type
specimens in Japan. E.P. Chace of Lomita,
J.W. Evans, R.D. Turner, M.L. Webster of
Cerritos College, and E.G. Wilson have gen-
erously donated specimens of Recent and
fossil Pholadidae to the San Diego Natural
History Museum.

For permission to search their respec-
tive collections and borrow needed material,
often for extended periods, I am indebted
to: Joseph H. Peck, Jr., University of Cali-
fornia Museum of Paleontology, Berkeley;
Victor A. Zullo and Leo G. Hertlein,
Department of Geology, California Academy

WEST AMERICAN CENOZOIC PHOLADIDAE

11

of Sciences, San Francisco; Warren 0.
Addicott, U.S. Geological Survey, Menlo
Park; A. Myra Keen, Department of
Geology, Stanford University; James H.
McLean, Invertebrate Zoology Section, and
Edward C. Wilson, Invertebrate Paleontol-
ogy Section, Los Angeles County Museum
of Natural History; Ruth D. Turner,
Department of Mollusks, Museum of Com-
parative Zoology, Harvard University; R.
Tucker Abbott, Department of Mollusks,
and Horace G. Richards, Department of
Geology, Academy of Natural Sciences of
Philadelphia; Clyde F. E. Roper, Division of
Mollusks, U.S. National Museum; Wendell
P. Woodring and Druid Wilson, U.S. Geo-
logical Survey, Washington, D.C.

I am indebted to the late Edwin C. Alli-
son, Department of Geology, San Diego
State College, for supervision of the project
in its initial stages. James W. Valentine,
and Jere H. Lipps, Department of Geology,

University of Cahfornia at Davis read parts
of a final draft of the manuscript.

I am especially grateful to the San
Diego Natural History Museum for allowing
this study to be coordinated under its
auspices. Darkroom facilities were gra-
ciously provided by Dallas M. Clites, Jr.,
museum photographer, and by Eugene M.
Kennedy. Ellen J. Moore, and George E.
Radwin assisted with constructive criticism
at various stages of preparation and read
the manuscript. Arnold Ross, Curator of
Invertebrate Paleontology, has been most
helpful with numerous details, relevant
discussions, and continual encouragement.
The paper has benefited much by his critical
reading and editing of the manuscript.

Finally to Ruth D. Turner, I owe
special thanks for reading the manuscript,
and for the many kindnesses and profes-
sional courtesies shown me throughout the
course of this study.

MORPHOLOGY

As a result of the high degree of
specialization of the Pholadidae for boring
into hard substrates, and because two sub-
families (Martesiinae, Jouannetiinae) have
an unusual two-stage life history, a special
terminology exists for morphological fea-
tures not present in other bivalve groups
(except on occasion in the Teredinidae) (see
also Fig. 2). The morphological terminology
used herein follows.

APOPHYSIS (Pholadinae, Martesiinae). -
A gently curved styloid projection extend-
ing from beneath the umbo which provides
an attachment site for the foot muscles. It
may be solid or hollow, spoon-shaped or
blade-like.

BEAK (Pholadinae [some], Martesiinae,
Jouannetiinae, Xylophagainae).— As used
herein, the projected or constricted anterior
extremity on forms which are not broadly
rounded anteriorly. This is not equivalent to
the umbo.

CALLUM (Martesiinae, Jouannetiinae). —
A smooth, hemispherical portion of shell

filling the anterior pedal gape formed upon
cessation of active boring. It is calcareous,
either complete or partial, and assumes the
shape of the anterior portion of the
excavated burrow. A dorsal extension of the
callum extends between the beaks and over
the umbonal reflection to form an enclosure.

\

vm

Figure 1. Major shell regions of typical pholadids. 1,
anterior slope; 2, disc; 3, posterior slope; dm, dorsal
margin (ad, anterior dorsal; pd, posterior dorsal); am,
anterior margin; vm, ventral margin; pm, posterior
margin.

12

GEORGE L. KENNEDY

either narrow and elongate or widely
lobate, for the anterior-dorsal mantle lobe
and anterior portion of the anterior
adductor muscle.

SIPHONOPLAX (Martesiinae [some],
Jouannetiinae). — Posterior extension of the
shell for the protection of the siphons. It
may be calcareous or periostracal, paired or
present on only one valve.
UMBONAL REFLECTION (Pholadinae,
Martesiinae, Jouannetiinae, Xylophagainae).
"^ A constriction, groove, or dividing line
running from the umbo to the ventral

DEC

margin and separating the sculptured ante-
rior slope from the disc. It is manifested
internally as the UMBONAL-VENTRAL
RIDGE.

CHIMNEY (Martesiinae [some], Xylopha-
gainae [some]).— A tube built into the
siphonal end of the burrow composed of fine
particles flushed from the anterior end of
the hole during active boring, and cemented
together. It may extend anteriorly as far as
the mesoplax.

CHONDROPHORE (Pholadinae [some],
Martesiinae [some], Jouannetiinae, Xylopha-
gainae).— A modification of the hinge area
of the umbo to support the internal
ligament. The chondrophore of the right
valve is a small sweUing with a central
depresion, whereas that of the left valve is a
small shelf-like projection (Turner, 1954: 13).
CONDYLE (Pholadinae [some], Marte-
siinae, Jouannetiinae, Xylophagainae).—
The ventral knob-like point of contact situ-
ated at the junction of the ventral margin
and the sulcus. The condyle and umbo

Fig. 2. Morphologic structures of common west American
Pholadidae. From top: Nettastomella, Penitella, and
hypothetical pholadid.

META PF

MESO

A

— apophysis

ALP

— attachment lines of periostracum

AM

— anterior margin

AMS

— anterior muscle scar

AS

— anterior slope

B

— beak

C

— callum

D

— disc

DEC

— dorsal extension of callum

DPSR

— disc-posterior slope ridge

DR

— dorsal reflection of valve

MESO

— mesoplax

META

— metaplax

MSP

— muscle scar pad

P

— periostracum between valves

PF

— periostracal flaps or leaves

PL

— pallial line

PMS

— posterior muscle scar

PaS

— pallial sinus

PoS

— posterior slope

S

— siphonoplax

u

— umbo

UR

— umbonal reflection

UVR

— umbonal-ventral ridge

UVS

— umbonal-ventral sulcus

vc

— ventral condyle

VMS

— ventral muscle scar

WKST AMERICAN CENOZOIC PHOLADIDAE

13

together form a double ball joint about
which the valves can move in a rocking
motion during active boring (Lloyd, 1897:
308).

DISC (Pholadinae, Martesiinae, Jouan-
netiinae, Xylophagainae).— The central
median region of the valve between the
anterior slope (or sulcus), and the posterior
slope.

HYPOPLAX (Martesiinae [some]).- The
narrow longitudinal accessory plate situated
on the ventral margin. It covers the narrow
ventral gape.

MESOPLAX (Pholadinae [some], Marte-
siinae, Jouannetiinae [some], Xylophagai-
nae).— A transverse calcareous accessory
plate situated on the dorsal margin either
anterior or posterior to the umbo. In
actively boring animals it is situated ventral
to the adductor muscle. In those individuals

which cease active boring, a dorsal covering
is added. The plate may be in one or two
pieces, and may have lateral wings.
METAPLAX (Pholadinae [some], Marte-
siinae [some]).— Longitudinal calcareous
accessory plate situated on the dorsal
margin posterior to the umbo. It covers the
narrow dorsal gape, and should not be
confused with dorsal reflections of the valve
itself.

PROTOPLAX (Pholadinae [some]).— Re-
stricted by Turner (1954: 12) to the simple
nearly flat accessory plate situated anterior
to the umbo and resting on the anterior
adductor muscle. It may be in one or two
pieces, and is calcareous or periostracal. It
should not be confused with the dorsal
extension of the callum or the umbonal
reflection.

LIFE HISTORY AND VARIABILITY

In the Martesiinae and Jouannetiinae
there is a striking change in the appearance
of the shell at sexual maturity. In these
subfamilies boring ceases at maturity, and
the animal secretes a callum over the ante-
rior pedal gape and dorsal mantle lobe, one
or more accessory plates over the gaping
areas along the margins of the shell, and
(or) a siphonoplax at the base of the siphons.
In addition, in all genera the shell outline
as well as the nature of the ornamentation
on the anterior slope is directly affected by
the relative hardness of the substrate
penetrated and is responsible for much
variation in overall shell form within a
single species.

Because the number of species in most
genera is small, shell morphology alone is
often sufficient for species identification,
especially in restricted time-geographic
areas. In Penitella and Martesia, however,
accessory plate morphology is the most
reliable means of separating species. In
specimens from geologically older strata
(Mesozoic and early Tertiary age) too little

is known about the limits of population
variation of nominal taxa to accurately
define them. Also, earlier workers were
overly concerned with general shape or out-
line of the shell, while neglecting to com-
ment on those features which are more
reliable in the definition and recognition of
species.

It is for these reasons that I have added
the following section on general pholadid
variability so that features which might
seem important at first glance can be
recognized for what they actually represent.

LIFE HISTORY

Little is known of the reproductive and
early embryonic stages of pholadids. The
veliger stage of some species can remain in
the plankton for up to thirty days (e.g.
Martesia striata; R.D. Turner, in litt.), and
it is during this period that dispersal occurs
in the mud- and rock-boring groups. Wood-
boring species, transported in floating
wood, expand their ranges in this manner.

14

GEORGE L. KENNEDY

Several species of deep water Xylophaga do
not have pelagic larvae, but instead protect
the young in a brood pouch until the late
veliger stage, only releasing them after
metamorphosis of the juvenile shell into its
adult form (Knudsen, 1961: 200). Appar-
ently there is some substrate selection, and
metamorphosis can be delayed until a suit-
able substrate is found. Initial attachment
by byssal threads occurs in some, if not all,
species. Boring begins after metamorphosis
from the veliger stage and is concomitant
with growth. Initial penetration is probably
more of a plucking action than a true boring,
the grains being too large for rasping away,
thus explaining the paucity of rock-borers in
coarse grained sedimentary rocks. A newly
settled, and actively boring, specimen of
Penitella penita is figured by Evans (1968b:
pi. 3). Boring and growth are combined in a
re-occurring two-stage cycle (Evans and
LeMessurier, 1972: 1251) lasting in Penitella
penita about 15 days. Most growth takes
place during a 7 to 10 day period of quies-
cence and is then followed by a 5 to 8 day
period of active boring and little or no
growth.

There are two definable stages in the
ontogeny of the Martesiinae and Jouanneti-
inae, the active or boring (juvenile), and the
inactive and reproductive (adult). (The
Pholadinae and Xylophagainae remain active
borers throughout their lives and growth
does not cease.) In the first stage, the hole
is excavated until either physiological or
physical processes spontaneously inhibit
further boring. Those genera which cease
active boring at maturity subsequently
produce a callum, accessory plates, or
siphonoplax, and resorb the foot. The space
once occupied by the foot becomes filled
with the reproductively mature gonads, no
further growth occurs, and the individual
enters its reproductive stage. The ultimate
size of the adult may be directly related to
the size of the entrance diameter during the
late active period, possibly because more
food is available to animals with larger
burrow entrances (Evans, 1968b: 118).

VARIABILITY

Stenomorphism is a common phenome-
non in the Pholadidae. More larvae are able
to settle on an exposed surface than can live
within the substrate, due to the expansion
of the anterior ends of the burrows during
boring. In Martesia, particularly, there may
be extremely heavy settlement of larvae on
small pieces of floating wood, and callum-
producing adults are often only 4 mm in
length (Turner, 1954: 6). Evans (1968a: 276)
noted that in extreme crowding, when an
animal cannot bore in any direction without
breaking into a neighboring burrow, boring
is inhibited altogether. Martesia will, how-
ever, bore into teredinid tubes (Turner,
1955: 65, pi. 35).

The relationship of substrate to shell
morphology has not often been recognized
in the past, and explains the presence of a
number of synonyms in the literature. The
general outline of the valves and the nature
of the anterior sculpture depends greatly on
the hardness of the substrate in which the
pholadid is boring. Studies on Penitella
penita by Evans (1968a, 1968b, 1968d) on
these interrelationships are generally appli-
cable to other genera and species.

If the substrate is soft and easily pene-
trated, the shell will be relatively longer
than normal. Shell growth is proportional to
the size and shape of the excavation, and
since boring proceeds only at the anterior
end, obviously more rapidly in softer sedi-
ment, the shells are longer. The valves will
also be thin and the concentric ridges of the
anterior slope spaced further apart and
turned upward. If there are any imbrications
or spines on the ridges, they may be pro-
nounced. In rock-borers, the callum may
extend further anteriorly, the umbonal
reflection will be narrower, and the dorsal
extension of the callum will be raised and
not as broad or lobate as in typical
specimens. In elongate specimens (see Fig.
46), additional material may be added to the
ventral margins when the callum is formed.
In Martesia, additional shell is often added
to the posterior end, increasing overall
length by up to a third. The above situation

WEST AMERICAN CENOZOIC PHOLADIDAE

15

will occur if a typically rock-boring species
fortuitously settles in stiff mud or clay.
Crowding also will cause an elongation of
the shell without apparent increase in the
diameter of the burrow (Evans, 1968a: 276).

If, however, the developing larva set-
tles on a substrate substantially harder and
less easy to penetrate, the shell will usually
be proportionately shorter and the valves
thicker and heavier. Furthermore, the con-
centric ridges will be thicker and more
closely spaced, often so tightly that recogni-
tion of individual ridges is impossible (see
Fig. 49). Also, the adductor muscles may be
disproportionately enlarged, and the muscle
scars roughened. The umbonal reflection is
wider and, in some species, more appressed
to the anterior slope. The dorsal extension
of the callum, which is a manifestation of
the size and shape of the anterior adductor
muscle, may be low and greatly lobate ante-
riorly. Above the umbones a heavy muscle
scar pad is built up and serves for attach-
ment of the primary anterior adductor
muscle (see Figs. 43 and 50).

Boring is accomplished by mechanical
rasping with the fore edge of the last con-
centric ridge of the anterior slope on the
burrow wall. Concentric ridges behind the
leading edge apparently play no role in
boring as they show no progressive in-
crease in wear with age (Evans, 1958b: 116).
The concentric ridges in soft-rock borers are
worn little, while those boring in harder
rocks are almost smooth from wear (com-
pare Figs. 21 and 24 and Figs. 46 and 49).
Commonly, in Chaceia, Penitella, and
Parapholas, the last concentric ridge pro-
duced before the formation of the callum
shows no wear and is raised higher than
those of the anterior slope. Given two speci-
mens of equal maturity, one boring into a
soft substrate, and the other in a hard one,
the latter will produce a greater number of
concentric growth ridges in a given period
of time, but will be smaller in overall size
than the former. However, specimens
mature at a greater overall size in harder

rocks than those living in relatively soft
rocks (Evans, 1968b: 119).

In older specimens of several species,
but most notably in Parapholas califomica,
the interior of the shell may become thick-
ened with scattered deposits of aragonite or
calcite, giving the interior an irregular
appearance. When occurring along the
margins of the shell, they in effect fuse the
accessory plates to the valves. In other
genera, the apophyses seem to be the most
vulnerable spot for malformation, though
usually be resorption rather than by accre-
tion. Shell material on the inner surface of
the anterior slope may also be resorbed,
exposing the pattern of concentric ridges
normally seen only on the exterior. In
gerontic pholadids, especially in the Martesi-
inae, calcite is often deposited on the muscle
scars and pallial line, making them readily
distinguishable from the dull white aragonite
of rest of the shell (c/. Figs. 43 and 61).

In occasional specimens of Chaceia,
though only rarely in Penitella, the interior
of the callum may be structurally braced
with several high, thin struts (see Fig. 23).
Their functional significance or cause of
formation is not understood, though they
are peculiar to old and heavy shelled
specimens.

The radial arrangement of the imbrica-
tions or undulations (radial "ribs" of Turner)
on the anterior slope is quite variable and
apparently of no taxonomic importance.
They may be paired, or every second one
may be more prominent than its neighbors;
the grooves between the "ribs" may be wide
in some places and narrow in others without
any set pattern.

The shapes of the accessory plates,
formed after active boring ceases, are not
seriously affected by the nature of the sub-
strate, unless mantle tissue has somehow
been injured by boring. Accessory plate
morphology is thus usually more reliable in
species definition and recognition than
shape of the valves.

16

GEORGE L. KENNEDY

ENDOLITHIC COMMUNITY

One of the most interesting aspects of
the Pholadidae, especially the Martesiinae,
is their relationship to the substrate and the
associated faunal communities. The Mar-
tesiinae, because of their rock-boring habit,
are important in the creation of holes in the
rocky shore suitable for habitation by a
large number of marine invertebrates. For
the community inhabiting hard marine sub-
strates, KiJhnelt (1951; see Evans, 1967a:
148) proposed the term endolithic, which
includes those animals living wholly within
the rock, or endolithion.

In the absence of marine rock-borers,
the endolithic community normally will not
develop (Evans, 1967a: 149). Since the rate
of erosion is considerably higher where
rock-boring pholadids live, there is a con-
stant "exfoliation" of surface rock, due in
part to the weakening of the substrate by
the numerous burrows, and to wave action
in these habitats. This constant erosion
exposes a range of burrow sizes, from tiny
siphonal holes of complete burrows with live
animals, to broad rounded depressions left
as the only remnant of once existing
burrows. In infested rocks in Coos Bay,
Oregon, Evans (1968c: 159) estimated the
erosion rate to be about 12 mm/year. After
11 or 12 years an average burrow of 150 mm
would be reduced to a shallow bowl-shaped
depression.

In the fossil record the endolithic com-
munity is more often preserved in situ than
in detrital deposits. Barrows (1917: 970)
noted that in the presence of violent changes
in depositional conditions over a given area,
the free living fauna may readily move
away, and the sessile fauna may either be
destroyed or washed away. Further, boring
forms trapped in the rock would thus con-
stitute the only relics of the former fauna
and would be indicative of the past
environment.

A large variety of animals inhabit
vacant pholadid burrows. Evans (1967a: 150)
listed thirty species of marine invertebrates
from the Coos Bay region of Oregon, includ-
ing coelenterates, annelid worms, sipun-

culids, crabs, shrimp, chordates, and mol-
lusks other than pholadids. Sediment free
burrows are often internally encrusted by
bryozoa, barnacles, and various algae. In
protected localities the burrows are likely to
become filled with mud and finer sediments,
while those on the open coast are not
usually filled, or filled with coarser sedi-
ment. These protected microhabitats are
thus ideal for the settlement of small mud
and sand living invertebrates, as well as the
common bivalve nestlers. Some of the mol-
lusks found by Evans in these microhabitats
were Trimusculus reticulatus (Sowerby,
1835), Irus lamellifer (Conrad, 1837),
Macoma nasuta (Conrad, 1837), Entodesma
saxicola (Baird, 1863), Saxicava sp., Kellia
sub orbicularis (Montagu, 1904), and Adula
califomiensis (Philippi, 1847). Mollusks
found by Evans and also found by Addicott
(1963b: 144) in pholadid burrows on a
Pleistocene terrace at Point Aiio Nuevo,
California, include Crepidula nummaria
Gould, 1846, Tresus nuttallii (Conr&di, 1837),
Petricola carditoides Conrad, 1837, and
Protothaca staminea (Conrad, 1837) [P. s.
var. ruderata (Deshayes, 1853) as fossil].

The presence of more than one nestler
per pholadid burrow is not unusual, and
Chace (1942: 42) reported the occurrence of
six bivalves from within a single dead Para-
pholas californica found in a shale block
thrown onto Del Monte Beach, near Monte-
rey. The largest of these nestlers, a Pro-
tothaca staminea, measured 57 mm in
length, while four others ranged from 20 to
27 mm in length. A single Irus lamellifer
was 42 mm long.

In Coos Bay, silt-filled burrows are
most commonly inhabited by the terebellid
worm Thelepus sp. and its commensal scale
worm, Halosydna brevisetosa Kinberg
(Evans, 1967a: 149). Thelepus seems to
extract CaC03 from the pholadid shell,
using at least part for its own parchment
burrow, while gradually dissolving the
pholadid shell completely.

While pholadid burrows may provide
excellent habitats for small bivalve nestlers,

WEST AMERICAN CENOZOIC PHOLADIDAE

17

the young of larger species also occur here,
and subsequent growth often finds these
individuals greatly restricted within the
confines of the burrow, resulting in extreme
shell deformation or death. Addicott (1963b)
reported a specimen of Tresus nuttallii in
the Pleistocene of Point Aiio Nuevo, Cali-
fornia, which was oriented in the wrong
direction, and had become quite misshapen,
the siphons protruding through another, but
intersecting pholadid burrow. Three ex-
amples from the Pleistocene Palos Verdes

Sand of Newport Beach, California also
illustrate such deformation: Anomia peru-
viana d'Orbigny (Fig. 95) which began
growing in a truncated burrow and was
quite restricted until reaching the surface
and spreading out; Chama pellucida Sower-
by (Fig. 96) which abandoned its normal
growth pattern and thereafter grew straight
up; and Ostrea lurida Carpenter (Fig. 97)
which was forced to assume the shape of the
pholadid burrow it was Hving in.

BURROWS

The Pholadidae are not the only bi-
valves which bore into hard substrates.
Sand- and mud-filled burrows, or "sand-
pipes", of several other bivalve groups may
be confused with those of the pholadids.
Within the family itself, members of the
Pholadinae are mostly mud- or soft sedi-
ment-borers, and their burrows are rarely
preserved in the fossil record. Most pre-
served burrows belong to the Martesiinae,
though a few may be assigned to the Jouan-
netiinae. Of those which are preserved,
excluding variability, the general shape is
that of an inverted ice cream cone, with a
large bulbous anterior end that tapers poste-
riorly to the siphonal opening. This conical
shape results from mechanical scraping by
the valves only at the rounded anterior end
of the burrow. Burrows of Jouannetiinae
and most Martesiinae are about one to two
times the length of the shell. Burrows of
Xylophagainae are five to ten times the
length of the shell, and can usually be
separated from those of teredinids, which
have long worm-like burrows (Turner,
1969: 704).

Crowding often affects the shape of the
burrow, as more pholadids can settle on the
substrate surface than can live in the rock
or wood below (Evans, 1968a: 276). Burrows
in uncrowded conditions are relatively
straight, while those in crowded conditions
are often twisted (Evans, 1968a: 276; see

also Fig. 100). Apparently pholadids can
detect boring activity in neighboring bur-
rows and usually avoid these other individ-
uals. This may be accomplished by changing
direction of boring, by elongating the
burrow without increasing its relative dia-
meter, or by cessation of boring altoghter.
Martesia will bore through teredinid tubes,
though the reverse does not hold true
(Turner, 1955: pi. 35). Figure 52 shows a
specimen of Penitella penita which was
bored into while alive and subsequently
repaired its shell.

Erosion of the substrate is also respon-
sible for shorter burrows. Evans (1968c:
159) showed that substrate erosion is sub-
stantially increased in areas with a high
pholadid density. As the tops of the burrows
are truncated, making the burrows shorter,
the diameter of the siphonal opening is in-
creased, and the animal within is more
susceptible to predation. In soft rock the
siphons may also enlarge the entrance dia-
meter of the burrow by several miUimeters
(Evans, 1968a: 276), which is more apparent
in larger individuals or species.

Where the substrate is relatively soft,
grooves left by the mechanical rasping of
the valves are preserved in the burrow wall,
and molds of these are preserved as
ornamentation on some "sand-pipes" (Fig.
103; see also Itoigawa, 1963: pi. 3, Fig.
5-6, 8).

18

GEORGE L. KENNEDY

"Sand-pipes" found in rock are difficult
to assign to a specific genus without first
exposing the valves inside. The burrows of
Martesiinae are similar in appearance.
Those burrows found in shell may belong to
gastrochaenids, to Penitella, or to Diplo-
thyra only because shell may be inhabited
by species of these genera. The burrows of
species of Penitella are so variable that
specific classification by burrows per se is
impossible. The burrows of large Chaceia
ovoidea may reach a length of 40 to 50 cm,
and do not taper rapidly. The burrows of
Jouannetiinae usually have more bulbous
anterior ends than those of Martesiinae (c/.
Turner, 1969: Fig. E191). Evans (1967b: pi.
17) figures Recent burrows of Nettastomella
rostrata and P. penita for a comparison of
general shape. Fossil burrows of Penitella
are also figured by Adegoke (1966: pi. 21;
1967: fig. 17, 21-22, 25-26). Burrows figured
by MacNeil (1957: pi. 12, fig. 1; USNM
561882) as possibly belonging to Martesia
were made by teredinids. Rock- and wood-

boring bivalves and their associated burrows
from the Miocene Mizunami Group of
central Japan have been studied by Itoigawa
(1963).

The burrows of rock-boring mytilids,
such as Lithophaga, are readily distinguish-
able from those of pholadids by their verti-
cally constant cross sectional area in
relation to length, and to their bilateral
symmetry at the siphonal end. They are
usually lined internally with a calcareous
incrustation. Furthermore, because mytilid
borings are formed partly by dissolution
rather than a rotational mechanical process,
their burrows may tend to be bilaterally
symmetrical and non-circular in cross
section. Pholadid burrows are circular in
cross section. Burrows of Gastrochaenidae,
which also bore into soft rock, coral, and
other shell, are less easily separated from
small pholadid burrows, and extraction and
examination of the valves within is the only
rehable method of distinguishing between
the two families.

GEOLOGIC SIGNIFICANCE

The geologic significance of pholadids
has generally been overlooked by field
geologists, even though these organisms can
be simple and useful tools in stratigraphical
and in paleoecological studies.

Most genera of Pholadidae, exclusive of
the Xylophagainae, are inhabitants of the
intertidal or high inner sublittoral zones. As
shallow water indicators, they can be used
for postulating ancient shorelines, although
not with the precision indicated by the
presence of some mytilids.

In discussions on the paleoecology of
the Pholadidae, the family should be divided
into three general categories, the mud- or
soft sediment-borers (generally the Phola-
dinae), the rock-borers (generally the Mar-
tesiinae and Jouannetiinae), and the wood-
borers (generally Martesia-Mke forms, and
the Xylophagainae). There are exceptions to
each of these however. For instance in the

Pholadinae, the genus Zirfaea will bore into
soft rock as well as wood, and Pholas
dactylus Linne, 1758, has been known to
bore into gneiss (MCZ 197105).

The preferred substrates of the first
group are sand, mud, peat, clay, and sedi-
ments stiffened by settling and compaction
rather than by subsequent induration. Often
these unconsolidated sediments are being
actually deposited, so the pholadid popula-
tions would be geologically the same age as
the sediments they were inhabiting. In such
instances, the resulting filling of the burrow
after death of the animal would be indistin-
guishable from the substrate itself. Collapse
of the burrow could cause the internal filling
of the burrow to be lithologically identical
with the substrate, and would indicate soft
sediment.

Since the mud-borers live in habitats
which are generally not narrowly restricted

WEST AMERICAN CENOZOIC PHOLADIDAE

19

in size, as compared to isolated outcrops of
harder rock, or pieces of wood, it would be
expected that fossil exposures would yield
fewer specimens per locality, but that there
would be a greater number of productive
outcrops. This is especially true in the
Miocene deposits of California where Zirfaea
dentata is quite common and the rock-boring
Penitella (subfamily Martesiinae) is rare in
comparison.

If a fossil pholadid burrow is filled with
matrix that is identical to the surrounding
strata, it may be assumed that deposition
was contemporaneous with the boring
activity of the bivalve, that it occurred in a
low energy shallow water environment, that
the substrate was non-indurated, and that
the surrounding matrix is geologically the
same age as the bivalve.

Of the rock-boring species, the subfamilies
Martesiinae (except Martesia, Lignopholas
and Opertochasma) and Jouannetiinae pre-
sent a somewhat different picture, though
the dividing line between very soft rock and
very stiff mud is not well delimited. Most
species in this group prefer harder and
more indurated substrates than do the
Pholadinae. This therefore precludes most
of the substrates available to the mud-
borers, but leaves isolated exposures of
harder rock which are usually found only
intertidally on the open coast or in sub-
marine canyons. If the rock surface can be
kept clean of finer sediments by currents,
rock-borers will inhabit deeper water, such
as the pholadids found boring into serpen-
tine between 60 and 100 meters at the
mouth of San Francisco Bay (Barrows,
1917: 970).

Because these species necessarily in-
habit rock surfaces, their occurrence is
virtually restricted to a single non-deposi-
tional plane, and do not range throughout a
sedimentary sequence as could the mud-
boring species. This is in part responsible
for the spotty fossil record of the rock-
borers. The presence of isolated outcrops of
rock will often result in heavy concentra-
tions of pholadids in small areas. Though
their actual occurrences in situ are few in
the fossil record, concentrations are locally

greater than that recorded for mud-boring
species.

Almost any geologically older unit pro-
vides an excellent habitat, and for this
reason, rock-boring pholadids, when found,
almost always indicate a considerable time
differential or unconformable relationship
with the surrounding substrata. When
overlying strata are deposited, the lithology
above is invariably different from that
below and often is readily distinguishable.
Because sedimentation is slight in the pre-
ferred habitats, burrows may not be im-
mediately filled, or if filled before complete
inundation by another unit, it is generally
with coarser grained sediments.

In summary, the rock-boring pholadids
have burrows filled with sediment different
from that of the surrounding substrata, are
indicative of an unconformable contact, and
are geologically the same age as the over-
lying stratigraphic unit.

Fossil wood-boring pholadids are much
rarer than either of the two above mentioned
groups. The most significant reason is that
suitable habitats, such as floating or water-
logged wood, are much rarer than mud flats
or outcrops of rock, and may be more
widely distributed in deeper water sedi-
ments. They are seldom found in shallow
water deposits or normal molluscan death
assemblages. Pieces of floating wood, after
becoming waterlogged, may settle in deep
water. The chance that an isolated piece of
fossilized wood containing pholadids will be
found is small. Moreover wood, unlike rock
and mud, will often decompose and free the
valves thereby allowing for further dis-
persal. The pholadids (and teredinids, if
present) would be geologically the same age
as the sediments in which they had settled.
The piece of wood would be analogous to the
hard, but geologically older, substrata
inhabited by the rock-borers.

Another aspect in which pholadids are
useful as paleoecologic indicators is in deter-
mining the relative hardness of fossil sub-
strates. Because substrate hardness is
reflected in the sculpture of the anterior
slope (see section on Variability; also Evans,
1970), the relative hardness of a fossil sub-

20

GEORGE L. KENNEDY

strate at the time of boring, and probably of
subsequent deposition of overlying beds,
can be estimated by comparing the fossils to
Recent specimens taken from rocks of
known hardness and rated on any arbitrary
scale. Evans (1968a) has described one
method for determining relative hardness
and figures examples of Penitella penita
from Coos Bay, Oregon. Variation between
and within populations of pholadids prevent
their use in determining minute substrate
differences, though differences of a certain
magnitude are easily detected.

Barrows (1917: 970) suggested that the
presence of pholadids in burrows, as the
sole remnant of a fossil fauna, may offer the

only clue to the age of the formations in-
volved. Unfortunately, too little is known
about paleozoogeography and geologic
ranges of fossil pholadids before the Neogene
and their value as age indicators is only
speculative at present. The presence of
burrows of rock-boring Pholadidae can pin-
point the exact stratigraphic position of a
suspected disconformity, although the time
differential cannot be accurately determined.
Pholadids are useful in various phases
of stratigraphic and paleoecologic work, but
nevertheless have their limitations. Where
possible, geologic conclusions based on
these borers should be confirmed by other
lines of evidence.

GEOLOGIC RECORD

The Pholadidae have left a poor fossil
record. In western North America they are
common only in Pliocene and Pleistocene
strata. Although they supposedly arose in
the Jurassic, or questionably even in the
Carboniferous (Turner, 1969: 706), the
oldest known species on the Pacific slope of
North America are Cretaceous in age. Of
the 28 genera recognized by Turner (1969),
nine are known only from their fossil
records; five from the Cretaceous, one from
the Cretaceous to the Oligocene, and three
from the Eocene. The remaining 19 genera
all have living representatives and most
have at least short fossil records. The total
number of genera may be small, as fossil
pholadids have not received as much atten-
tion in some parts of the world as they have
on the North American and European
continents.

SUMMARY OF WEST AMERICAN
FOSSIL GENERA

I have been able to document the pres-
ence of only three genera in the Cretaceous
of the Pacific coast, Opertochasma (repre-
sented by Gabb's Martesia clausa, and other
occurrences in the Sacramento Valley),
Tumus (Gabb's T. plenus, and other occur-

rences in the Sacramento Valley), and
Xylophagella (from an occurrence in San
Diego). Xylophagella and Tumus are not
known in younger rocks, but Opertochasma
has been found in Paleocene strata in Cali-
fornia and Oligocene rocks in Oregon. It is
probably this genus that has been incorrectly
identified from Cretaceous strata as Mar-
tesia and Parapholas. Paleogene pholadid
records are extremely rare, but include the
first substantiated record of Martesia. Also
known are two (or three) forms which can
not now be placed in any known pholadid
genus. Unfortunately they are poorly pre-
served and their systematic postion must
remain unclear.

The first occurrence of Penitella is in
the Oligocene of California. It is, however,
almost unknown in the Miocene, and the
record for Penitella through this epoch is so
poor that no evolutionary lineages can be
traced. Penitella is quite common in Pliocene
and Pleistocene units, both in numbers of
species as well as specimens. Although the
fossil record is incomplete, Ramsetia, from
the Cretaceous of Texas, is similar to Phola-
didea, which has no fossil record on this
coast, and Penitella, and could possibly have
given rise to both genera. Ramsetia is still
inadequately defined however.

WEST AMERICAN CENOZOIC PHOLADIDAE

21

The genus Cyrtopleura has a good fossil
record from the Miocene onward in the
eastern and Gulf coastal states, but is known
only from the MioceneC?) of northwestern
Washington and the Pliocene of the Gulf of
California trough. The mud-boring genus
Zirfaea is common in the Miocene of Cali-
fornia, but no ancestral form is known. It
can be shown, however, that the modern
Zirfaea is directly related to this Miocene
species. A single specimen from the upper
Miocene of Oregon appears to represent a
link between Zirfaea, and the Pliocene to
Recent Chaceia. Japanese species of Zirfaea
are characterized by a different type of
sculpture, and probably represent a different
lineage.

In the Pliocene, Barnea {Anchomasa)(7) ,
Chaceia, Parapholas, Nettastomella, and
Pholadopsis make their first appearance on
the west coast. Pholadopsis has a longer
geologic record in other parts of the world
(Turner, 1969: 720), and species of Para-
pholas are known from Miocene and possibly
Oligocene rocks in Japan. The Cretaceous to
Recent range (of authors) for Parapholas
can not be documented.

The following taxa have representatives
living in the tropical eastern Pacific today,
but so far are unknown in the fossil record:
Cyrtopleura s.s., Thovajia, Hatasia, Diplo-
thyra, Particoma, Jouannetia, Xylophaga,
and Xyloredo. This is probably due to the
sparsity of late Cenozoic fossil deposits in
the tropical eastern Pacific rather than to
their real absence in the fossil record.
Species of these genera are described and
figured by Turner (1954, 1955, 1972), and
Knudson (1961).

The geologic ranges of west American
Pholadidae are listed under each species in
the systematic section, as well as detailed
records of all known occurrences in western
North America. Geologic ranges of pholadid
genera are given in Turner (1969). Many of
these do not refer to west American species
or occurrences and therefore differ from the
ranges of those on this coast. Some of
Turner's generic ranges must also be re-
vised, as well as the geologic ranges of most
of the species treated herein. Table 1 shows
generic ranges as given by Turner compared
with generic ranges documented by occur-
rences only from the eastern Pacific.

SYSTEMATIC PALEONTOLOGY

The family is divided into four sub-
families, the Pholadinae, Martesiinae,
Jouannetiinae, and Xylophagainae. Under
each, I include a definition of the subfamily,
the type genus, and a list of taxa found in
the next lowest taxon. Each genus contains
a brief synonomy, a definition of the genus,
and how it differs from others in the same
subfamily, the type species and its designa-
tor, and a list of taxa included within the
genus. Subgenera are arranged in the same
format. Under each species I have included
a synonomy which contains 1) only major
objective synonyms, or references of impor-
tance in defining ecological or distributional
data, and 2) an exhaustive list of references
to all known fossil occurrences of this
species. These latter references are based

almost entirely on my personal examination
of the specimens utilized by the original
authors, and are at least internally consis-
tant. Following this is a diagnosis of the
species (within the genus) and a complete
description. The original description of all
nominal species described as fossils are also
included, if applicable. This in turn is
followed by pertinent data on any type
specimens and their depositories, the type
locality, and the presently known modern
distribution of the species.

The Geologic Record is that documented
by actual specimens, and is a list of fossil
localities with their references (whether by
locality number, published account, or both).
These are arranged by epoch, and within
each, from north to south.

22

GEORGE L. KENNEDY

TABLE 1
Geologic ranges of eastern Pacific fossil pholadid genera, taken from Turner (1969; worldwide records,
solid lines), and from eastern Pacific fossil records (documented herein, dotted lines). (Periods and
epochs not subdivided.)

Carb.

Tri.

Jur.

Ore.

Paleo.

Eoc.

Oligo.

Mio.

Plio.

Pleist.

Recent

Age

genus

•fee-.
Si

S.S.

Barnea (Anchomasaj "^

Cyrtopleura s.s.

C. (Scobinopholas)

Pholas (Thovana)

Zirfaea

Chaceia

Penitella

Pholadidea (Hatasia)

Martesia s.s.

M. (Particoma)

M. (Paramartesia)

Diplothyra

Opertochasma

Parapholas

Nettastomella

Pholadopsis

Jouannetia

► <

<

QC
<

<

=3
O

Xylophaga
Xyloredo

Xylophagella

Turnus

^ ^

<
► <

>

X

I- cc

WEST AMERICAN CENOZOIC PHOLADIDAE

23

Phylum MOLLUSCA

Class BIVALVIA Linne, 1758

Subclass HETERODONTA Neumayr, 1884

Order MYOIDA Stoliczka, 1870

Suborder PHOLAXDINA Adams and
Adams, 1858

Superfamily PHOLADACEA
Lamarck, 1809

Family PHOLADIDAE Lamarck, 1809

A description of the family was given
by Turner (1954: 15; 1969: 706). Closely
allied to the Teredinidae, the Pholadidae
possess several structures not present in
other bivalve groups, including various
accessory plates, internal apophysis, callum,
siphonoplax, siphonal tube, and chimney.
No single genus possesses all these features
however. Anatomical comparisons of phola-
dids with a teredinid and a typical venerid
are given in Turner (1966b: 20, fig. 5).
Teredinids lack most pholadid features, but
possess apophyses, pallets to plug the
siphonal entrance, and a large soft body
incapable of even slight retraction within
the shell. Teredinids also secrete a calcare-
ous lining to their burrow, an extremely
rare feature in the Pholadidae (Xyloredo).
TYPE GENUS.- Pholas Linne, 1758.
TAXA INCLUDED.— The family contains
the subfamiHes Pholadinae, Martesiinae,
Jouannetiinae, and Xylophagainae. Genera
are listed under each subfamily. Generic
synonomies are given in Turner (1969), and
a list of most of the known genus-level taxa
is included in Yokes (1967: 326-330).

Subfamily PHOLADINAE Lamarck, 1809

DEFINITION.- Shell beaked or broadly
rounded anteriorly, not closed by a callum
in the adult stage. Valves not divided by an
umbonal-ventral sulcus, except in the
genera Zirfaea and Zirlona (New Zealand
Tertiary). All genera possess a protoplax
and (or) a mesoplax (a metaplax is also
present in Pholas), and all lack a callum,
hypoplax, and siphonoplax. The foot is well
developed and does not atrophy in the adult

stage. Animal incapable of complete retrac-
tion within the shell.
TYPE GENUS.- Pholas Linne, 1758.
TAXA INCLUDED.— Seven genera and
seven subgenera (three nominate) are
recognized (Turner, 1969) in the Pholadinae,
as follows: Pholas s.s. Linne, 1758, Mono-
thyra Tryon, 1862a, and Thovana Gray,
1847; Bamea s.s. Risso, 1826 and Ancho-
masa Leach, 1852; Cyrtopleura s.s. Tryon,
1862a and Scobinopholas Grant & Gale,
1931; Clavipholas Conrad, 1868; Talona
Gray, 1840; Zirfaea Gray, 1840; and Zirlona
Finlay, 1930.

Pholas s.s. (eastern Atlantic), Mono-
thyra (Indo-Pacific), Bamea s.s. (eastern
Atlantic), Talona (west Africa), and Zirlona
(New Zealand) are not represented in the
western hemisphere. Clavipholas Conrad,
1868, was described from the upper
Cretaceous of New Jersey. Cyrtopleura s.s.
is represented by a single species in the
eastern Pacific and Scobinopholas by two
living species in the western Atlantic, and
fossil occurrences on both the east and west
coasts. Only Anchomasa, Thovana, and
Zirfaea are found living today in both the
eastern Pacific and the western Atlantic.

Genus Barnea Risso, 1826

Bamea Leach [MS] Risso, 1826:376. Turner, 1954:19.

DEFINITION.— Shell more or less elliptical
in outline, beaked or broadly rounded
anteriorly. Only accessory plate a calcareous
lanceolate protoplax. Umbonal reflection
simple, barely reflected anteriorly, closely
appressed to or raised slightly above
surface of umbo posteriorly. Pedal gape
either a narrow slit in anteriorly rounded
forms {Bamea s.s.), or broadly oval in
beaked species (Anchomasa).

Bamea differs from other genera in the
Pholadinae by having only a single acces-
sory plate, the lanceolate protoplax. The
umbonal reflection is not septate, as in
Pholas, nor are the valves divided by an
umbonal-ventral sulcus, as in Zirfaea.
Cyrtopleura has a complicated socket
arrangement in the umbonal region (see
Fig. 12).

24

GEORGE L. KENNEDY

TYPE SPECIES.— Bamea spinosa Risso,

1826 {=Bamea [B.] Candida [Linne, 1758]),

by original monotypy.

TAX A INCLUDED.— The genus contains

two subgenera, Bamea s.s. and Anchomasa.

Bamea s.s. does not occur in the western

hemisphere.

Subgenus Anchomasa Leach, 1852

Anchomasa Leach, 1852:253. Turner, 1954:22.

DEFINITION.- Shell beaked anteriorly,
rounded to truncate posteriorly with a
moderate to large posterior gape. Pedal
gape large, oval, and extending about
one-third of shell length posteriorly. Um-
bonal reflection simply, usually closely
appressed over umbo, raised anteriorly and
barely reflected at beaks.

Anchomasa differs from Bamea s. s. by
gaping widely anteriorly, and sometimes
posteriorly, and by being beaked. Bamea
s.s. is rounded anteriorly, and has slit-like
gapes.

TYPE SPECIES. — Anchomasa pennantiana
Leach, 1852 (=Bamea [A.] parva [Pennant,
1777]), by original monotypy.
TAXA INCLUDED.— American species of
Anchomasa are B. subtruncata from the
eastern Pacific, B. truncata (Say, 1822) from
the eastern and western Atlantic, and B.
lamellosa (d'Orbigny, 1846) from the east
coast of South America. The type species is
from western European waters.

Bamea (Anchomasa) subtruncata

(Sowerby. 1834)

Figures 3-7

Pholas subtruncata Sowerby, 1834:69.

P. \holas\ spathulata Deshayes, 1843:1, pi. 79.

Pholas Pacifica Stearns, 1871:1.

B. [amea] [Cyrtopleura] spathulata: Lamy, 1925:89.

Bamea pacifica: Cook and Clark, 1943:17. Fitch, 1953:94,
fig. 60. Kanakoff and Emerson, 1959:22, in part
(Bamea subtruncata, in part Zirfaea pilsbryi). Valen-
tine, 1961:377.

Bamea {Anchomasa] subtruncata: Turner, 1954:31, pi. 8
(fig. 1-3), 14-16.

Zirfaea pilsbryi: Kanakoff and Emerson, 1959:25, in part
(Zirfaea pilsbryi, in part Bamea stibtruncata) . Chace,
1966:170, in part (Zirfaea pilsbryi, in part Bamea sub-
truncata and Chaceia ovoidea).

DIAGNOSIS.— Shell beaked anteriorly,
broadly rounded to truncate posteriorly, not
divided by umbonal-ventral sulcus. Sculp-
ture more prominent anteriorly, absent on
posterior slope. Umbonal reflection sepa-
rated from anterior slope by narrow V-
shaped furrow. Only accessory plate a
narrow lanceolate protoplax.
DESCRIPTION.- Valves thin, light in
structure, medium in size, reaching approxi-
mately 9 cm in length and 3.5 cm in height.
Shell beaked anteriorly, broadly rounded to
truncate posteriorly, gaping both anteriorly
and posteriorly throughout life. Valves not
divided by umbonal-ventral sulcus. Anterior
slope and disc regions sculptured with low,
thin, usually widely spaced, concentric
ridges. Ridges laminated and scalloped
anteriorly, weaker on disc, absent on
posterior slope except as growth Hnes.
Radial sculpture formed by aligned imbrica-
tions of concentric lamellae, stronger on
anterior slope, absent on posterior slope.

Umbonal reflections free or barely
appressed posteriorly, narrowing abruptly,
barely reflected anteriorly. Reflected area
separated from anterior slope by narrow
V-shaped furrow, which internally exists as
narrow ridge extending to beaks.

Protoplax (Fig. 6) only accessory plate,
situated above and anterior to umbones,
covers anterior dorsal gape, lanceolate,
usually rather broad and truncate posteri-
orly, acuminate anteriorly, sculptured with
distinct growth lines and posterior nucleus.

Muscle scars and pallial line faint.
Pallial sinus broad, extending anteriorly Vs
to V2 length of shell. Chondrophore present
on knob-like umbo. Apophyses long, narrow
for entire length, curved inwardly, ventrally
and somewhat posteriorly directed (nearly
parallel with external radial sculpture).

Periostracum thin. Siphons incapable of
complete retraction within shell. Foot not
atrophyed in adult.

HOLOTYPE.— Oi Pholas subtruncata Sow-
erby, is lost (Turner, 1954: 33). Insulam
Platae, Colombiae Occidentalis (=Isla la
Plata, Ecuador). Recent.
HOLOTYPE.— Of Pholas spathulata Des-
hayes, according to Lamy (1925: 89) is in the

WEST AMERICAN CENOZOIC PHOLADIDAE

25

Museum National d'Histoire Naturelle in
Paris, France. "Seas of Chile" is given by
Deshayes (1834), though Lamy notes that
the single type is from Payta, Peru, which
has subsequently been designated the type
locality by Turner (1954: 33). Recent.
LECTOTYPE.— Oi Pholas pacifica Stearns,
USNM 74717, designated by Turner (1954:
33). PARALECTOTYPES.- MCZ 187260
(2 specimens), MCZ 187262 (14 specimens),
CAS 10085-10088. Alameda, San Franciso
Bay, California, ". . . common in sandy mud
between tide marks" (Stearns, 1871: 1).
Collected by "Messrs. Harford, Hemphill,
Drs. Kellogg and W. P. Gibbons." Recent.
DISTRIBUTION.— Recent; Newport, Ore-
gon (46° 28.5' N. lat.; Turner, 1954: 34)
south, including entire Gulf of California, to
Atacama Province, Chile (ca. 26-29° S. lat.;
Gigoux, 1934: 285 {fide Turner]).
GEOLOGIC RECORD.- Pliocene?, Pleisto-
cene to Recent.

Pliocene or Pleistocene: Dredged from
Oakland Creek, SDSNH loc. 2575.

Pleistocene: Cheviot Vista Place, Palms,
Los Angeles, LACMNH loc. 426, Vermont
Avenue and Sepulveda Blvd., north of San
Pedro (Cook and Clark 1943: 17), LACMNH
loc. 147. Below Nob Hill, San Pedro,
LACMNH loc. 300. Deadman Island, San
Pedro, LACMNH loc. 2. San Pedro Sand, in
San Pedro, at high school at 15th and
Leland Streets, SDSNH loc. 2138 [=L-2138]
(Chace, 1966: 169; as Zirfaea pilsbryi, in
part), on Harbor Boulevard, opposite old
San Pedro Lumber Co., USGS loc. 12628.
Palos Verdes Sand, old Bixby Slough,
Harbor City, LACMNH loc. 229, near
Harbor Boulevard, UCLA loc. 3600 (Valen-
tine, 1961: 377), on Harbor Boulevard,
opposite old San Pedro Lumber Co., UCMP
loc. B-469, Cherry Avenue in Signal Hill,
USGS loc. 12630, on east bluff above Upper
Newport Bay, LACMNH loc. 66-2 (Kanakoff
and Emerson, 1959: 22), LACMNH Iocs.
66-10 and 136, SDSC loc. 533.
DISCUSSION. — Bamea subtruncata typi-
cally Hves in heavy muds of bays and
estuaries and in other low energy environ-
ments. Fitch (1953: 94) reported them living
at depths of ten inches or more and in

"colonies" of up to twenty individuals.
Generally, the sculpture is sparse, and the
concentric ridges are rather distantly
spaced. Occasional specimens will bore into
soft rock or waterlogged wood, but these
are usually somewhat stunted, have more
pronounced beaks, and a rounded and
reduced posterior slope (Turner, 1954: 34).

Because of its preference for muds in
protected environments, the valves are
usually thin and fragile. This severely limits
preservation in detrital deposits (such as
predominate in the Pleistocene of California)
to heavier shelled specimens, and could
explain the poor fossil record for this
species. Though its appearance in fossil
deposits has only been recorded twice
previously, it occurs not uncommonly in the
Pleistocene San Pedro Sand and Palos
Verdes Sand of San Pedro and Newport
Beach. One locality in the San Francisco
Bay area has yielded dredged material
which appears fossiHzed, though no definite
age assignment can be given at this time.

Fossil specimens boring in soft rock are
known from the late Pleistocene Palos
Verdes Sand on the east bluff above Upper
Newport Bay, California, where they occur
with Chaceia ovoidea, Penitella fitchi, P.
penita, and Nettastomella rostrata. The
sculpture of B. subtruncata is typical of
mud-boring pholadids in hard substrates
(see Fig. 3-4). Chaceia ovoidea also was
adversely affected by the hard substrate,
though the Penitella and Nettastomella
were not.

Bamea truncata (Say, 1822) of the
western Atlantic is most closely related to
B. subtruncata, and differs from the eastern
Pacific species by its generally smaller size
and shorter posterior dorsal margin. The
protoplax is also wider in proportion to its
length. It is quite probable these two
species are derived from a common ances-
tor, and diverged from each other some
time in the early Neogene.

26

GEORGE L. KENNEDY

Genus Cyrtopleura Try on, 1862

Cyrtopleura Tryon. 1862a:201. Turner, 1954:34.

DEFINITION.— Shells essentially elliptical
in outline, rounded or beaked anteriorly,
not divided by umbonal-ventral sulcus.
Pedal gape either a narrow slit in anteriorly
rounded forms (Scobinopholas) , or broadly
oval in beaked forms (Cyrtopleura s.s.).
Radial and concentric sculpture especially
prominent over anterior slope and disc.
Protoplax entirely periostracal or slightly
impregnated with aragonite. Mesoplax
transverse, in one or two pieces, calcareous,
solid. Umbonal reflection simple, barely
reflected anteriorly, folded into complicated
socket arrangement posteriorly, not septate.
Cyrtopleura differs from Thovana by
possessing umbonal sockets and a simple,
non-septate, umbonal reflection. Bamea has
a single acuminate protoplax, is less
prominently sculptured, and lacks the
umbonal sockets.

TYPE SPECIES.- Ph.[olas] crudfera,
Sow. [erby] (=Cyrtopleura [C] cruciger
[Sowerby, 1834]), by subsequent designa-
tion of Stoliczka (1871: xv).
TAXA INCLUDED.— The genus is divided
into Cyrtopleura s.s. and Scobinopholas.
The nominate subgenus contains only C.
cruciger (Sowerhy , 1834) which ranges from
Guaymas, Sonora, Mexico, to the Gulf of
Guayaquil, Ecuador. It has never been
reported in the fossil record. Scobinopholas
occurs today along the Atlantic coasts of
North and South America, and in late
Cenozoic deposits of both eastern and
western North America.

Subgenus Scobinopholas Grant and
Gale, 1931

Scobina Bayle, 1880:242 [not Scobirm Lepeletier, 1825

=Hymenoptera].
Scobinopholas Grant and Gale, 1931:431 [new section

name]. Turner, 1954:35.

DEFINITION.- Shell rounded at both
ends, pedal gape long, narrow, slit-like.
Radial and concentric sculpture prominent
over anterior slope and disc. Protoplax
triangular to T-shaped, thin, largely perio-
stracal. Mesoplax heavy, transverse, calcar-

eous, in one or two pieces. Umbonal re-
flection appressed to posterior portion of
umbo, raised abruptly, narrow, barely
reflected anteriorly. Combination of folds in
dorsal margin, umbonal reflection, muscle
scar pad, and dorsal end of chondrophore
forms complicated socket structure in um-
bonal region. Apophyses large, broad, more
or less spoon-shaped, solid or hollow.

Scobinopholas differs from the nomi-
nate subgenus by its rounded anterior, and
slit-like pedal gape. Cyrtopleura s.s. is
somewhat beaked anteriorly, has an oval
pedal gape, and less pronounced sculpture
and umbonal socket structure.
TYPE SPECIES.— Pholas costatus Lin-
naeus, by original designation of Grant and
Gale (1931: 431).

TAXA INCLUDED.- The subgenus in-
cludes C. costata, from the western Atlantic
of North and South America and the
Neogene of both eastern and western North
America, C. lanceolata (Orbigny, 1846) from
the Atlantic coast of South America, and C.
arcuata (Conrad, 1841), from the Miocene of
the eastern United States.
DISCUSSION.— Fossil specimens referable
to Scobinopholas are extremely rare on the
Pacific slope, the best known occurrence
being in the Pliocene of Imperial Co.,
California. The only other record consists of
two partial specimens in the U.S. National
Museum (USNM 5913) collected by J. G.
Swan from supposedly Miocene strata at
"Neeah Bay, Pugets Sound, Oregon"
[= Washington]. The more complete of the
two specimens is figured (Fig. 11-12).

Cyrtopleura (Scobinopholas) costata
(Linne, 1758)
Figures 8-10

[Pholas] costatus Linne, 1758:669. Gmelin, 1791:3215.
not Pholas costata: Tuomey and Holmes, 1857:102, pi.

24 fig. 4 {=Cyrtopleura arcuata (Conrad, 1841); fide

Dall, 1898).
Pholas costata: Holmes, 1860:58, pi. 9, fig. 1, la. Plum-

mer, in Sellards, Adkins, and Plummer, 1932:794.
C. \apulus] Shreevei Conr^d. 1869:105, pi. 13, fig. 3, 3a

(apophysis only; fide Turner, 1954).
Pholas {Bamea) costata: Dall, 1889:274.
Bamea {Scobina] costata: Dall, 1898:816. Clark, 1906:

192, pi. 52. Mansfield, 1928:130, 131, 140.

WEST AMERICAN CENOZOIC PHOLADIDAE

27

Bamea costata: Pugh, 1905:36, 46, 53, 54. Hanna, 1926:
462, pi. 28, fig. 5 6. Richards, 1962:71, pi. 13, fig. 9.

Pholas iaff.) crucigera: Arnold, 1906:22.

Phulas, sp.: Kew, 1914:46. Vaughan, 1917:367.

Pholas [Bamea) costatus: Grant and Gale, 1931:431.

Bamea (Scobinopholas) fo^?a<a:| Turner, 1954:35, pi. 17
(fig. 4-5). 18. DuBar, 1958:182, fig. 14, 34; pi. 9, fig. 2.

DIAGNOSIS.- Shell oval in outline,
rounded anteriorly and posteriorly, not
beaked. Radial sculpture strong, extending
over entire shell. Interior of shell regularly
pitted. Umbonal reflection appressed to
posterior portion of umbo, raised abruptly,
narrowed and barely reflected anteriorly.
Complicated umbonal socket structure
formed by folds in dorsal margin, umbonal
reflection, muscle scar pad, and dorsal end
of chondrophore. Protoplax deltoid in
outline, largely periostracal. Mesoplax T-
shaped, transverse, in one piece, calcareous.
Apophyses large, broadly spoon-shaped,
hollow at upper end.

DESCRIPTION.- Shell oval in outline,
large, approaching 19 cm in length and 7.5
cm in height, light in structure, gibbose,
rounded anteriorly and posteriorly. Pedal
gape long, narrow. Sculpture of relatively
weak concentric ridges interspersed with
many fine growth lines, and more pro-
nounced radial "ribs" formed in part by
scalloping of the concentric ridges. "Ribs"
strong on anterior and posterior slopes,
slightly reduced over disc due to differential
wear.

Umbones located anteriorly. Umbonal
reflection appressed to posterior portion of
umbo, abruptly raised, forms part of area of
attachment of anterior adductor muscle,
then narrows and is barely reflected
anteriorly. Combination of folds in dorsal
margin, umbonal reflection, muscle scar
pad, and dorsal end of chondrophore form
complicated socket structure in umbonal
region. Mesoplax in one piece, transverse,
more or less T-shaped in outline, solid,
calcareous, positioned by umbonal sockets.
Protoplax large, thin, deltoid in outline,
pointed and grooved anteriorly, broad and
occasionally slightly lobate posteriorly,
largely periostracal, occasionaly impreg-
nated with small amounts of aragonite in
larger specimens (Turner, 1954: 36), nucleus

centrally located.

External sculpture reflected internally
due to thinness of shell, which consists of
prominent, regular pits and furrows. Pallial
sinus short, extends anteriorly Vs length of
shell. Pallial hne and muscle scars not calci-
fied, barely visible. Occasional specimens
have a ventrally protruding ledge below the
posterior adductor muscle scar which pro-
vides a greater area of attachment for the
muscle (Turner, 1954: 36). Apophyses
short, broadly spoon-shaped and widened
ventrally, hollow dorsally, extending paral-
lel to radial sculpture of shell.

Periostracum thin, deciduous. Foot
elliptical in outline, truncate, not resorbed
in adult. Siphons not capable of complete
retraction within shell. Soft-part anatomy
given by Dall (1889).

LECTOTYPE.— Of Cyrtopleura costata
(Linne), disposition unknown, designated by
Turner (1954: 36) as specimen figured by
Gualtieri (1742: pi. 105, fig. G). In rocks in
southern Europe (Linne, 1758: 669), cor-
rected by Gmelin (1791: 3215) to "mari
americano", and subsequently restricted to
Charleston, South CaroHna by Turner (1954:
36). Recent.

HOLOTYPE.— Of Capulus shreevei Con-
rad, disposition unknown. It is not in the
Academy of Natural Sciences in Philadel-
phia. Long Island, S. CaroHna, collected by
Lizzie Shreeve. Recent.
DISTRIBUTION.— Recent; Fall River,
Massachusetts (41° 42' N. lat.) south to Rio
de Janeiro, Brazil (22° 54' S. lat.; Turner,
1954: 38).
GEOLOGIC RECORD. -Pliocene to Recent.

West Coast Pliocene: Imperial Forma-
tion, unknown locality, "UC loc. 51" [ =
W.S.W. Kew loc. no.]. Coyote Mountain,
CAS loc. 701 (both Hanna, 1926: 462),
SDSNH loc. 2532, 3 miles east of Carrizo
Stage Station, SDSNH loc. 0051, Carrizo
Creek, USGS loc. 3857, Barrett's Oil Well,
20 miles north of Mexican border, USGS
loc. 3921, one mile south of Alverson
Canyon, USGS loc. 6847 (Hanna, 1926: 462),
south of Yuha Buttes, in Baja California,
Mexico, SDSC loc. 350.

28

GEORGE L. KENNEDY

East Coast Pliocene and Pleistocene:

From Massachusetts (Dall, 1898: 816) to
Texas (Plummer, in Sellards, Adkins, and
Plummer, 1932: 794).

DISCUSSION.— Cyrtopleura costata is the
most commonly found fossil pholadid in the
Pliocene and Pleistocene formations of the
Atlantic and Gulf coastal states.

The fossil occurrence of this species in-
the eastern Pacific is unusual, though in the
Imperial Formation where it is found, there
are a number of Atlantic taxa present. None
of the specimens here asigned to C. costata
are well preserved and all are small
compared to large living specimens from the
east coast. Arnold's (1906: 22) reference to
"Pholas (aff.) crucigera Sowerby" is prob-
ably based on specimens of C. costata.
Hanna (1926: 462) remarked that "regarding
the identification of the species with the
common east coast species, it should be said
that they correspond exactly in shape,
number of ribs, and form of sculpturing on
the inside of the shells." Hanna did not com-
pare his specimens with C. arcuata, how-
ever, and I have not seen a series of this
latter species. According to Dall (1898: 816)
C. costata differs from the Miocene C.
arcuata by its uniformly thinner texture,
which results in a punctate pattern on the
interior of the valves, its larger size, and
the different proportions of the umbonal
reflection. Further, Cyrtopleura arcuata is
smaller, has a longer umbonal reflection, is
usually more solid and thick, and has more
numerous and finer radial "ribs."

According to Turner (1954: 37) C.
costata typically lives in sandy mud at, and
just below, low water mark in protected
areas, or well below the tide line on exposed
outer beaches. Further, they can burrow to
a depth of two feet or more and are capable
of moving up and down in their burrows at
will, often extending their siphons a short
distance out of the burrow.

Cyrtopleura (C.) cruciger (Sowerby) of
the eastern Pacific (Guaymas, Sonbra,
Mexico and south) differs from C. costata by
being smaller, somewhat beaked anteriorly,
and having less pronounced sculpture. The
inside of the shell is not sculptured with

little pits, as is that of C. costata. To my
knowledge it is unknown as a fossil.

Genus Zirfaea Gray, 1842

Zirfaea Leach [MS] Gray, 1840:150 \nomen nudum].

Gray, 1842:76. Gray, 1847:188. Turner, 1954:54.
Thurlosia Leach [MS] Callow and Reeve, 1845:3.
Zirphaea Leach, 18,52:250, 252.
Zirphoea [error {ov Zirphaea]: Cooper, 1888:270. Ashley,

1895:328.
Zirphaaea [error for Zirphaea]: Anderson, 1908:19.
Zirphea [error for Zirphaea]: Smith, 1912:174.

DEFINITION.— Shell cylindrical to oval in
outline, beaked anteriorly, rounded to
truncate posteriorly, widely gaping both
anteriorly and posteriorly. Not closed by
callum in adult. American species sculptured
with overlapping concentric ridges with
pointed imbrications. Sulcus weak. Meso-
plax only accessory plate, small, more or
less V-shaped, situated posterior to um-
bones. Apophyses solid, strongly curved,
broadened, often spoon-shaped ventrally.

Zirfaea differs from other pholadine
genera by its transverse V-shaped meso-
plax, the presence of an umbonal-ventral
sulcus, and the characteristic overlapping
concentric ridges. In Chaceia a callum is
produced in the adult, and the concentric
ridges are upturned and more undulate.
TYPE SPECIES.— P/iotos crispata Linne (=
Mya crispata Linne, 1758), by subsequent
designation of Gray (1847: 188).
TAXA INCLUDED.— The American spe-
cies are: Z. crispata (Linne, 1758) from the
western Atlantic and Europe, Z. pilsbryi
Lowe from the eastern Pacific, and Z.
dentata Gabb from the Miocene of California.
DISCUSSION.— There are two separate
Zirfaea lineages, a Japanese, and an
American. The American stock contains
species characterized by an anterior slope
sculptured with overlapping concentric
ridges with imbricated "spines." Zirfaea sp.
of Masuda and Noda (1969: 133, pi. 14, fig.
5-6) from the lower Pliocene of Japan also
belongs to this group. The Japanese stock,
characterized by an anterior slope sculp-
tured with upturned and undulate concentric
ridges (similar to those of Chaceia ovoidea),
includes the nominal species Z. suhconstricta

WEST AMERICAN CENOZOIC PHOLADIDAE

29

(Yokoyama, 1924) (at least Pleistocene to
Recent), Z. hataii Masuda and Noda, 1969
(lower Pliocene; probably a thick shelled Z.
subconstricta),' and Z. subconstricta kotorai
Otuka, 1934 (Miocene).

Zirfaea dentata Gabb, 1866
Figures 13-15

Z. [irphaea] dentata Gabb, 1866:18, pi. 3, fig. 31, 31a

[plate issued 1869].
Zirphoea \sic\ dentata: Cooper, 1888:270, in part (Zirfaea

dentata, in part. Z. pilsbryi).
Zirphoea [sic] gabbi: Cooper, 1888:270, in part {Zirfaea

pilsbryi, in part Z. dentata).
Zirphaea dentata: Merriam, 1895:3rd p. Anderson, 1905:

176, 177. Osmont, 1905:96. Anderson, 1908:23. Arnold,

1909 [19101:17, 21, 26[?1, 27. pi. 7 fig. 5. Arnold and

Anderson, 1910:85. 86, 94, 110[?], Ill, pi. 29, fig. 5.

Clark, 1912:57. Smith, 1912:174. Clark, 1915: facing

400, 404, facing 408, 421, 426, pi. 63, fig. 1-2. Nomland,

1917b:299. Trask, 1922:142, 144. Clark, [1929]:23, pi.

25, fig. 5 [Zirphea on plate]. Stewart, 1930:7. Keen

and Bentson, 1944:122. Stewart, 1946:99, 100, table 2.

Weaver, 1953:68. Hall, 1958:25. Hall, 1960:292, 295.
? Zirphaea sp.: Turner, 1898:494. Watts, 1900 [1901]:219.

Anderson, 1905:172. Arnold, 1906:24. Weaver, 1909:

263. Loel and Corey, 1932:71.
? Zirphaaea [sic] sp.: Anderson, 1908:19.
Zirphaea dentata Conrad [sic]: Smith, 1912:67.
Zirphea [sic] gabbi: Smith, 1912:174, in part (Zirfaea

pilsbryi, in part Z. dentata).
?not Zirphaea dentata: Smith, 1919:147 (Pliocene).
?not Zirphea [sic] dentata: Smith, 1919:148 (Pliocene).
Zirphea [sic] dentata: Smith, 1919:160.
? Zirfaea, cf. dentata: Nomland, 1916:203.
Zirphaea, aff. crispata: Nomland, 1917b:301.
Pholas (Zirfaea) dentatus: Grant and Gale, 1931:433.

Soper, 1938:168.
? Zirfaea sp.: Loel and Corey, 1932:66, 76. Addicott,

1966b:646. Adegoke, 1969:40.
? Zirfaea n. sp.: Loel and Corey, 1932:130, and, 148, 234

[both as n. sp.?].
Zirfaea dentata: Loel and Corey, 1932:148, 171. Adegoke,

1969:154, "fig." 6A.
Zirfaea cf. Z. dentata: Woodring, Stewart, and Richards,

1940 [1941]:143.
Zirfaea pilsbryi: Durham and Addicott, 1965:14, ? in part

(Zirfaea dentata; ? in part Z. pilsbryi [no specimens

seen]).

DIAGNOSIS.- Shell beaked anteriorly,
broadly rounded posteriorly, gaping widely
at both ends. Concentric ridges on anterior
slope imbricate, bend sharply and lose
imbrications opposite anterior-most contact
of valves on ventral margin, exist as low
rounded ridges which parallel sculpture of
posterior ventral margin, exist only as
growth lines posterior to sulcus. Sulcus

intersects ventral margin half the distance
along line of contact of valves. Muscle scar
pad on umbonal reflection large, heavy,
extends two thirds distance to beaks.
ORIGINAL DESCRIPTION.- Shell large,
subcylindrical, thin; ends broadly gaping;
beaks [=umbones] anterior to the middle;
covered by the dorsal plate [=umbonal re-
flection]; posterior dorsal margin of valves
thin and sharply reflexed. Surface of ante-
rior third of shell marked by serrated,
squamose plates, as in Z. crispata; a faint
line or rib passes between the middle and
posterior third of the width, from the beaks
[=umbones] obliquely down to the base;
dorsal plate [=umbonal reflection] heavy,
compressed, and divided into two concave
surfaces by a sharp, angular ridge, com-
mencing at the posterior end, and running
forwards, slightly curved, ending in a tooth
at a point about a third of the length of the
plate from the anterior extremity.
SUPPLEMENTARY DESCRIPTION.—
Shell large, long, cylindrical for diameter,
reaching 14 cm in length. Siphonal and
pedal gapes wide. Valves divided by weak
umbonal-ventral sulcus, intersecting ventral
margin near its midpoint. Anterior portion
often larger than posterior, sculptured with
heavy, knobby, or imbricate, occasionally
spinose, concentric ridges, and radial
pattern created by aligned imbrications.
Concentric ridges of anterior slope bend
sharply, lose imbrications opposite foremost
point of contact of valves, then run
posteriorly, parallel to sculpture of posterior
ventral margin, as low rounded ridges,
vanish at sulcus, then existing only as
growth lines.

Umbonal reflection heavy, longitudi-
nally symmetrical, appressed for much of
length. (That of Z. pilsbryi is lighter, wider
above the umbonal region, and usually not
appressed except over the umbo.) Muscle
scar pad large, part of umbonal reflection,
commonly extends nearly two thirds dis-
tance to beaks.

Umbonal-ventral ridge low, prominent,
occasionally ornamented with little bumps,
corresponding to intersection of sulcus with
concentric ridges on exterior of shell.

30

GEORGE L. KENNEDY

Muscle scars, pallial line and sinus, and
apophysis unknown. Mesoplax unknown,
probably similar to that of Z. pilsbryi.
HOLOTYPE.— Of Zirphaea dentata Gabb,
once in the University of California Museum
of Paleontology (Merriam, 1895: 3rd p.), it
appears now to be lost (Stewart, 1930: 7).
(See also Discussion remarks.) Pliocene
beds at the east end of Kirker's Pass,
Contra Costa Co., California (Gabb, 1866:
18). Grant and Gale (1931: 433) however
suggest an age of 'possibly Miocene.'
GEOLOGIC RECORD.— Miocene to lower
Pliocene.

Miocene: Lake County, USGS loc. 93.
Martinez, USGS loc. 104. East end of
Kirker's Pass (Gabb, 1866: 18; type
locality). Briones Sandstone, east, and west
limbs of the Pacheco Syncline, UW Iocs.
3415 and 3414 (both Weaver, 1953: 68),
northeast side of Shell Ridge, UCMP loc.
305. San Pablo Group, east of Riggs Canyon
north of Tassajara, UCMP loc. 492 (Clark,
1915: facing 408), south of Rodeo, UCMP
loc. 1600, near Tormey, UCMP loc. 1607,
south of Pittsburg, UCMP loc. 1891.
Temblor Formation, near Cantua Creek,
UCMP loc. B-8609, 4.5 miles southeast of
Ciervo Mountain, USGS loc. 5802. Santa
Margarita Formation, Big Blue Hills, USGS
loc. 5828, Cantua Creek, USGS loc. 5829,
near Domengine Creek, UCMP loc. A-9731.
Vaqueros Formation, in the Oil City-Oilfields
region, UCMP Iocs. 2300, 2309, and 2313,
USGS Iocs. 4633, and 4803 (both Arnold,
1909 [1910]: 17; and Arnold and Anderson,
1910: 85, 86). Temblor Formation, in the Oil
City-Oilfields region, UCMP Iocs. B-7085,
B-7086, D-115, D-116, D-1072, D-1073,
D-1076, and D-1078 (all Adegoke, 1969:
154), CAS Iocs. 2087, 2088, and 28485,
UCMP Iocs. A-1306, and A-3345. Santa
Margarita Formation, northwest of San
Joaquin Valley Coal Mine, USGS loc. 4632
(Arnold, 1909 [1910]: 21; and Arnold and
Anderson, 1910: 94). Vaqueros Formation,
Sulphur Spring Canyon below Garza Creek,
USGS loc. 4625, west of Big Tar Canyon,
USGS loc. 4627 (both Arnold, 1909 [1910]:
17; and Arnold and Anderson, 1910: 85).
Temblor Formation, vicinity of Reef Ridge,

UCMP Iocs. B-6518 and D-1059 (both
Adegoke, 1969: 154), near Garza Creek,
UCMP loc. B-6511 (Adegoke, 1969: 154),
UCMP loc. A-7583, east of Big Tar Canyon,
UCMP Iocs. A-9739, and D-1048 (both
Adegoke, 1969: 154), UCMP loc. A-9742,
south of Big Tar Canyon, UCMP loc.
B-4339, west of Little Avenal Creek, UCMP
loc. D-1066 (Adegoke, 1969: 154), Reef
Ridge northwest of Garza Peak, USGS loc.
14397, near Betram Creek, USGS loc.
14408, Arroyo Pinoso, USGS loc. 14409, and
west side of Zapato Canyon, USGS loc.
14410 (all USGS Iocs. Stewart, 1946: table
2). Escudo Formation, south side of Escudo
Mountain, USGS-M loc. 3779 (cf.). ?Va-
queros Formation, Neason's Flat in the
Pleito Hills, UCMP loc. 7180. Bacon Hills,
USGS loc. 18740. West of El Tranquillon
Peak, CAS loc. 27871A. Temblor Formation,
Santa Rosa Island, CAS loc. 1154 (? Loel
and Corey, 1932: 66). Vaqueros Formation,
Santa Clara Valley west of mouth of Wiley
Canyon, UCMP loc. A-252, and Santa
Monica Mountains west of Ensenal Canyon,
UCMP loc. A-551 (both Loel and Corey,
1932: 66, 76). Temblor Formation, upper
Malibu Canyon, UCMP loc. A-557. Topanga
Formation, two miles south of Calabasas,
LACMNH loc. 2905, Dry Canyon, UCLA
loc. L-167 (Soper, 1938: 168), Old Topanga
Canyon, LACMNH Iocs. 32 and 317-J,
USGS loc. 18732, ridge north of Mesa Peak
in Santa Monica Mountains, USGS-M loc.
1071. Southwest of Irvine Lake Reservoir,
USGS loc. 18459.

Pliocene: Jacalitos Formation, Coalinga
area, on ridge south of Garcas Creek, USGS
loc. 4745 (Arnold, 1909 [1910]: 26; and
Arnold and Anderson, 1910: 110. [ = Zirfaea
sp. indet.]), on or near Jacalitos Creek
(Nomland, 1916: 203). Etchegoin Formation
[Jacalitos "stage," faunizone E, zonule 8],
near Shell Oil well 155-15, Domengine
Ranch quad., UCMP loc. B-6534 (Adegoke,
1969: 154). Pancho Rico Formation, east of
Peachtree Valley, UCMP loc. A-3241, south
side of Pancho Rico Creek, USGS-M loc.
1966 [?], and north side of Powell Canyon,
USGS-M loc. 979 [?] (all Durham and Addi-
cott, 1965: 14; as Zirfaea pilsbryi; no

WEST AMERICAN CENOZOIC PHOLADIDAE

31

specimens seen for last two localities).
DISCUSSION.— Zirfaea dentata was the
first extinct species of Pholadidae described
from Cenozoic deposits of the Pacific slope.
It is restricted to the Miocene and
lowermost Pliocene of California, where it is
often locally abundant.

The holotype of Z. dentata Gabb was
reported to be in the University of
California Museum of Paleontology by
Merriam (1895), but missing by Stewart
(1930: 7). A specimen in the UCMP collec-
tions, no. 31180, matches Gabb's original
figure (1869: pi. 3, fig. 31), but is a mirror
image. If the figure was not reversed, the
type is probably lost. No other specimens
matching the figure could be found in the
Miocene collections in the University of
California Museum of Paleontology.

Zirfaea dentata can be recognized by its
sculpture on the anterior slope, which
distinguishes it from its Pliocene to Recent
descendent, Z. pilsbryi. The imbricated con-
centric ridges of dentata bend sharply at the
central part of the anterior slope, lose their
imbrications, and then (still anterior to the
sulcus) run parallel to the sculpture of the
posterior ventral margin. The sulcus itself
intersects the ventral margin one half way
along the line of contact of the valves, thus
differing from pilsbryi in which the sulcus
intersects the margin near the anterior
point of contact. Though not well shown on
the figures, this feature is distinct on fossil
specimens.

Zirfaea dentata is conspicuously absent
in strata outside of central and southern
California. It is not known to occur in the
Miocene of Oregon or Washington, though
suitable habitats existed. Since Z. pilsbryi
occurs today on the Arctic coast of Alaska,
the slightly colder waters of the northwest
coast was probably not the limiting factor.
Zirfaea dentata is especially common in the
Coalinga-Kettleman Hills region of the
western San Joaquin Valley. The southern-
most occurrence of the species is in Orange
County, southwest of Irvine Lake reservoir.

Zirfaea dentata has often been charac-
terized as a typically Miocene species,
though it also ranges into the lowermost

Pliocene (Jacalitos "stage" of authors). Both
Arnold (1909 [1910]: 26) and Arnold and
Anderson (1910: 110) reported Z. dentata
from the Jacalitos Formation near Coalinga
(USGS loc. 4745), but the specimen cannot
be identified to species. More recently,
Durham and Addicott (1965: 14) cited speci-
mens, as Z. pilsbryi, from the lower
Pliocene (Jacalitos "stage") Pancho Rico
Formation in the Salinas Valley. Specimens
from only one locality of three could be
located, and these were representative Z.
dentata. They were originally catalogued as
Miocene, Santa Margarita Formation, from
UCMP loc. A-3241. Adegoke (1969: 154) also
cited one lot of specimens, of good Z.
dentata, from the Pliocene Etchegoin For-
mation from the Coalinga region (UCMP loc.
B-6534). These are from his lowest Pliocene
faunizone E, zonule 8, equivalent to the
Jacalitos "stage" of authors. This faunizone
is transitory, and includes strata with the
highest occurrences of some Miocene spe-
cies, as well as the lowest occurrences of
several Pliocene species. The name Jacalitos
was dropped because it could not be
properly distinguished on a purely lithologic
basis from the Etchegoin (Adegoke, 1969:
26-27). Unfortunately, this is likely to cause
confusion with those who associate the
Etchegoin Formation with Middle Pliocene,
or Etchegoin "stage" of past authors.

Zirfaea pilsbryi Lowe, 1931
Figures 16-18, 19

Z. [irphaea] Gabbii: Gabb, 1869:52, 88, in part; not pi.

15, fig. 10 (Penitella gabbii, in part Zirfaea pilsbryi

and Chaceia ovoidea [pi. 15, fig. 10].
Zirpkoea [sic] dentata: Cooper, 1888:270, in part {Zirfaea

dentata, in part Z. pilsbryi).
Zirpkoea [sic] gabbi: Cooper, 1888:270, in part {Zirfaea

pilsbryi, in part Z. dentata).
Zirpkoea [sic] crispata: Orcutt, 1889:71. Osmont, 1905:95.
Zirphaea crispata: Diller, 1896:482. Newcombe, 1914:109.

Nomland, 1917a: facing 230. Wagner, 1959:37, 38, 40.
Zirpkaea orispata [sic]: Watts, 1900 |1901]:224.
Zirphaea gabbi: Arnold, 1903:23, 25, 27, 31, 38. Arnold,

1906:27, 34. Arnold, 1908:354, 355. Arnold, 1909

[1910]:35, 39. Arnold and Anderson, 1910:129, 132.

Martin, 1916:243, 245. Smith, 1919:143, 144. Waterfall,

1929: facing 78. Crickmay, 1924:631. Natland, 1957:

facing 548. Glen, 1959:158. Faustman, 1964:105.
Zirphaea gabbii: Arnold, 1903:184. Martin, 1916:229, 255.
not? Zirpkea [sic] gabbi: Smith, 1912:174 {l=Zirfaea

dentata).

32

GEORGE L. KENNEDY

? Zirphaea, species: Gester, 1917:224.

Zirphea [sic] gabbi: Smith, 1919:145.

Zirfaea gabbi: Orcutt, 1921:24. Jordan, 1926:245 (of
"Dal!" [=Orcuttl, 1921). Manger, 1934:283, 293. Wag-
ner, 1959:40. Valentine, 1960b:19. Adegoke, 1969:154,
"fig." 6A.

? Zirphaea sp.: Santillan and Barrera, 1930:26.

Zirfaea gabbi?: Hoots, 1931:122.

Zirfaea pilsbryi Lowe, 1931:53, pi. 3, fig. 1-2. Willett,
1937 [19381:106, in part (Z. pilsbryi, in part large
Penitella). Putnam, 1942:699. Wilson, 1943:246. Burch,
1947:9. Emerson, 1951:89, pi. 31. Fitch, 1953:95, fig.
61. Emerson and Addicott, 1953:434, 441. Turner,
1954:58, pi. 30 (fig. 4-9), 31-34. Valentine, 1956:196, in
part (Z. pilsbryi, in part Chaceia ovoidea). Valentine,
1957:297. Emerson and Addicott, 1958:8. Addicott and
Emerson, 1959:17. Valentine, 1959:54. Kanakoff and
Emerson, 1959:25, in part (Z. pilsbryi, in part Bamea
subtruncata) . Emerson and Chace, 1959:338. Emerson,
1960:5. Valentine, 1961:357. Addicott, 1964a:658.
Addicott, 1966a:4, pi. 4, fig. 18. Chace, 1966:170, in
part (Zirfaea pilsbryi, in part Bamea subtruncata and
Chaceia ovoidea). Thompson, 1967 MS:22. McLean,
1969:90, fig. 53.2. Wright, 1972:691. Kennedy,
1973:122.

Phokis (Zirfaea) gabbi: Grant and Gale, 1931:432, pi. 24,
fig. 2. Wilson, 1966:108.

Pholas pilsbryi: Willett, 1937:391.

Zirfaea gabbi var.: Woodring, Stewart, and Richards,
1940 [1941]:33, 68, opposite 78, 96.

Zirfaea gabbii var.: Woodring, Stewart, and Richards,
1940 [19411: opposite 35.

Zirfaea cf. Z. gabbi: Woodring, Stewart, and Richards,
1940 [19411:54.

Zirfaea sp.: Woodring, Stewart, and Richards, 1940
[19411: opposite 67, 70.

Pholas gabbi: Belong, 1941:242, facing 244.

Zirfea [sic] gabbi: Cook and Clark, 1943:17.

Zirfaea pilsbryi (Tryon) [sic]: Bruff, 1946:233.

Zirfaea cf. Z. pilsbryi: Woodring and Bramlette, 1950
[19511: facing 49. Hertlein and Grant, 1972:331.

not Zirfaea? sp.: Valentine, 1958:691 (^Chaceia ovoidea?).

Pholas (Zirfaea) cf. P. (Z.) gabbi: Glen. 1959:157, 177.

Pholas (Z.) gabbi: Glen, 1959:160.

? Zirphaea aff. gabbi: Hall, 1960:295.

Pholadidea penita: Valentine, 1961:370, in part (Penitella
penita, in part Zirfaea pilsbryi and Chaceia ovoidea).

not Zirfaea? cf. Z. pilsbryi: Valentine, 1961:376 (^Chaceia
ovoidea).

not Zirfaea pilsbryi: Addicott, 1963a:344 (^Penitella
tumerae). Durham and Addicott, 1965:14, in part ?
(Zirfaea dentata: ? in part Z. pilsbryi [no specimens
seenl).

Parapholas califomica: Vedder and Norris, 1963:46, 50,
in part (P. califomica, in part Zirfaea pilsbryi and
Chaceia ovoidea).

Penitella gabbi: Adegoke, 1967:16, in part (Penitella
gabbii, in part Zirfaea pilsbryi [all fossil referencesl).

Zirfaea gabbi (Tryon) femii Adegoke, 1967:17 (nomen
nudum). Adegoke, 1969:154, "fig." 6A; pi. 9, fig. 2, 8,
11-12; pi. 10, fig. 3, 5-6, 13.

Zirfaea? species: Addicott, 1969:63, 74, pi. 2, fig. 9.

? Zirfaea sp.: Masuda and Noda, 1969:133, pi. 14, fig. 5-6
[Pliocene of Japanl.

Zirfae [sic] pilsbryi: Human, 1972:9.

DIAGNOSIS.— Sculpture on anterior slope
not parallel to the ventral margin posterior
to the sulcus. Shell beaked anteriorly,
broadly rounded to truncate posteriorly,
gaping widely at both ends. Valves usually
in contact on the ventral margin only
posterior to the sulcus. Apophyses spoon-
shaped.

DESCRIPTION.- Shell reaching 14 cm in
length and 10 cm in height, beaked anteri-
orly, broadly rounded or truncate posteri-
orly. Pedal and siphonal ends widely gaping
throughout life. Valves in contact only at
umbones and ventral margin posterior to
sulcus.

Anterior slope sculptured with moder-
ately spaced, laminate, often spinose,
imbricate, concentric ridges, and weak
radial pattern imparted by the radial
alignment of imbrications on the concentric
ridges. In heavy-shelled specimens, concen-
tric ridges are closely spaced, more
undulate and up-turned, giving the appear-
ance of thickness. Shell divided by weak
umbonal-ventral sulcus, more conspicuous
in juvenile specimens, almost disappearing
near the ventral margin in older specimens.
Disc and posterior slope ornamented only
with concentric growth lines.

Umbonal reflections only appressed to
anterior slope near umbones, becoming
narrower and less appressed anteriorly. The
reflection is always worn at the point of
contact of the valves. Mesoplax only
accessory plate, transverse, small for size of
valves, more or less triangular in outline,
commonly with a well-developed basal
flange (Turner, 1954: 60), situated posterior
to umbones.

Pallial line well-marked, muscle scars
indistinct. Ventral muscle scar barely
differentiated from widened, often calcified
pallial line. It is quite different from the
ventral muscle scar of Chaceia ovoidea.
Pallial sinus broad, deep, extending anteri-
orly about one-half the length of the shell.
Umbonal-ventral ridge distinct, beaded in
juveniles, lacking entirely in older speci-
mens. Apophyses large, strong, curved, and
moderately to strongly spoon-shaped.

WEST AMERICAN CENOZOIC PHOLADIDAE

33

Periostracum thin, usually persistent
on posterior slope. Siphons large, incapable
of retraction within shell. Foot truncate and
nearly circular in outline.
HOLOTYPE.— Of Zirfaea pilsbryi Lowe,
ANSP 50809. PARATYPES: Once in the
Lowe collection (Lowe, 1931: 53), and
thought to be in the San Diego Natural
History Museum (Turner, 1954: 60), they
are not recognizable as such, if at all
present (cf. Wilson and Kennedy, 1967). A
search was made for them and tHhey were
not found. Bolinas, California, collected by
Henry Hemphill. Recent.
HOLOTYPE.— Of Zirfaea gabbi femii
Adegoke, UCMP 36795. PARATYPES:
UCMP 36796-36798. South slope of hill, in
sec. 22. T. 22 S., R. 16 E., MDBM, Kings
County, California, UCMP loc. B-6538.
Collected ? by 0. S. Adegoke, 1963.
Pliocene, Etchegoin Formation.
DISTRIBUTION.- Recent; Point Lay,
Arctic coast of Alaska (69° 44' N. lat.;
USGS-M loc. 2069 [fragment] to Magdalena
Bay, Baja California, Mexico (ca. 24° 30' N.
lat.; SDSNH 50645 [beachworn]).
GEOLOGIC RECORD. — Pliocene to Recent.

Pliocene: Merced Formation, three-
fourths of a mile southeast of Mussel Rock,
UCMP loc. 1722 (Martin, 1916: 229; cf.).
Moss Beach, UCMP loc. B-4793 (Glen, 1959:
157), northwest corner of Santa Clara Co.,
UCMP loc. B-8348. MercedC?) Formation,
Arastradero Road, city of Los Altos Hills,
USGS-M loc. 1715 (Addicott, 1969: 61, 63,
74; as Zirfaea? species). Purisima Forma-
tion, sea cliffs south of Halfmoon Bay
(Martin, 1916: 243), west of Sargent on
north side of Pescadero Creek, UCMP loc.
1905 (Martin, 1916: 245), Santa Cruz quad-
rangle (Arnold, 1906: 27; and Arnold, 1908:
354). ?Paso Robles Formation, northwest of
Jolon, UCMP loc. B-4928. Etchegoin Forma-
tion, east side of San Benito River southeast
of San Benito, USGS loc. 18558 (cf.),
Gabilan Range, NNW of Pinnacles, UCMP
loc. B-2178, northeast side of Bitterwater
Valley, LACMNH loc. 1204, hills northeast
of Priest Valley, UCMP loc. 3016 (Nomland,
1917a: facing 230), near Jacalitos Creek,
UCMP Iocs. 2668 (cf.) and A-650, northwest

of Zapato Creek, USGS loc. 4710, and near
Henry Spring, SSW of Coalinga, USGS loc.
4758 (both Arnold, 1909 [1910]: 35, 39; and
Arnold and Anderson, 1910: 129, 132). San
Joaquin Formation, Coalinga region, CAS
loc. 509, west of Oilfields, UCMP loc.
D-1203 (Adegoke, 1969: "fig." 6A), south-
west slope of Kreyenhagen Hills, UCMP
Iocs. B-6537 and B-6538 (both Adegoke,
1969: 155; as Zirfaea gabbi femii). Etchegoin
Formation, North Dome of Kettleman Hills
(all [USGS Iocs.] Woodring, Stewart, and
Richards, 1940 [1941]), on ridge north of El
Chichon, USGS loc. 12421 (p. 68), southwest
of Discovery Ridge, USGS loc. 12818 (opp.
p. 67), east slope of La Tusa, USGS loc.
14119 (p. 70), La Cuesta, UCMP loc.
A-9738, southeast slope of El Serrijon,
USGS loc. 12424 (p. 68), west side of La
Paredes, USGS loc. 14113 (p. 70), on branch
of Arroyo Doblegado southeast of Las
Paredes, USGS loc. 12426 (p. 70). and on
Arroyo Murado southeast of La Clavija,
USGS loc. 14122 (p. 70). Cascajo Conglom-
erate member of San Joaquin Formation (all
Woodring. Stewart, and Richards 1940
[1941]: 54), North Dome of Kettleman Hills,
on south slope of Cerro Ultimo, USGS loc.
14087. South Dome, at El Arco. USGS loc.
12653. north of Oyster Hill, USGS Iocs.
12657. 12793, and 12794, west of Oyster
Hill. USGS loc. 12656, ESE of Oyster Hill,
USGS loc. 12660. Cascajo Hill, USGS loc.
12645. San Joaquin Formation, Kettleman
Hills, UCMP loc. B-7727, on North Dome,
ridge above fork of Arroyo Murado, UCMP
loc. B-8589, near El Rascador, UCMP loc.
D-330, along west branch of Arroyo Hondo,
USGS loc. 12336, and (all Woodring,
Stewart, and Richards, 1940 [1941]) Arroyo
del Camino, USGS Iocs. 12372 (p. 33) and
12370a (opp. p. 35), Arroyo Somero, USGS
loc. 12373 (opp. p. 35). Northeast flank of
Caliente Mountain, USGS loc. 12956. Etche-
goin Formation, from oil well near McFar-
land. SDSNH 00201 (Grant and Gale. 1931:
433). Graciosa Member of Careaga Sand-
stone, north slope of Casmalia Hills, north-
west of Schuman's Siding, USGS loc. 14609
(Woodring, Stewart and Richards, 1940
[1941]: facing 49). Sisquoc Formation,

34

GEORGE L. KENNEDY

Pennsylvania asphalt mine southeast of
Orcutt, USGS loc. 4472 (cf.). "Pico" Forma-
tion, south of Santa Paula on south side of
South Mountain, UCMP loc. 7098 (Water-
fall, 1929: facing 78). San Diego Formation,
southwest of Goat Canyon, LACMNH loc.
305 (Hertlein and Grant, 1972: 331).

Pliocene or Pleistocene: Cujije [?]
Arroyo, San Antonio Rancho, Baja Califor-
nia, Mexico, USGS loc. 9156.

Pleistocene: Near Cook Street, between
Spring Ridge and Protestant Orphanage,
Victoria, British Columbia (Newcombe,
1914: 109 ; as Zirphaea crispata). Saanich
Formation, Bay Street and Cedar Hill Road,
Victoria, British Columbia (Wagner, 1959:
38). Hinton Point, Yaquina Bay, LACMNH
loc. 3952, USGS-M loc. 4622. North of jetty,
Yaquina Bay State Park, Oregon, USGS-M
loc. 3026. Cliff near "Newport Point,"
Oregon (Diller, 1896: 482; as Zirphaea
crispata). Cape Blanco, Oregon, UCMP loc.
A-8712 (Addicott, 1964a: 658), and .5 miles
southeast, CAS loc. 20 (aff.). Crannell Road
and Highway 101 south of Trinidad,
LACMNH loc. 3936. Point Ano Nuevo,
USGS-M Iocs. 1690 (aff.) and 2147 (both
Addicott, 1966a: 4), SDSNH loc. 2670 (aff.).
Southeast of Lions Head, USGS loc. 15052.
Isla Vista, near Goleta (Wright, 1972: 691;
Z. p. and Z. sp. aff. Z. p.), LACMNH Iocs.
416 and 2694. West of Goleta Point, SDSNH
loc. 0040. Santa Barbara (Cooper, 1888:
270). Near Ventura, on ridge between
Javon and Madranio Canyons (Putnam,
1942: 299). Potrero Canyon, Pacific Pali-
sades (Hoots, 1931: 122), UCLA loc. 3225
(Valentine, 1956: 196; in part). Cheviot
Vista Place, Palms, Los Angeles, LACMNH
loc. 426. Palos Verdes Sand, Lincoln
Avenue, near Venice, LACMNH 59 (Willett,
1937: 391). Undifferentiated Pleistocene at
San Pedro (Gabb, 1869: 52, 88), LACMNH
loc. 1, SDSC loc. 736, UCMP loc. 2112,
Deadman Island, LACMNH loc. 17, San
Pedro RR cut, SDSNH loc. 1899, new San
Pedro lumberyard, SDSC loc. 648, SDSNH
loc. 1960, Wilmington and San Pedro Road,
USGS loc. 12141 (cf.). First Street and [old]
Harbor Boulevard, UCMP loc. A-218, "San
Pedro Bluffs" at Second and Beacon Streets,

UCMP loc. D-1627. San Pedro Sand, in San
Pedro, at Nob Hill, LACMNH loc. 300,
Pacific Avenue, LACMNH loc. 131, Third
and Mesa Streets, LACMNH loc. 98, corner
of Bonita Street and Pacific Avenue, ANSP
|no locality number], high school at 15th and
Leland Streets, SDSNH loc. 2138 [= L-2138]
(Chace, 1966: 170; in part), LACMNH loc.
2687, Peck Park, USGS loc. 13125. Palos
Verdes Sand, in San Pedro, CAS loc. 91,
south of Union Oil refinery in Harbor
District Sanitation yard, LACMNH Iocs. 427
and 1210, opposite San Pedro Lumber
Company, UCMP loc. B-469, Pacific Avenue
and Hards Street, LACMNH loc. 440,
Pacific Avenue and Bonita Street, USGS
loc. 12132, Second and Mesa Streets, UCMP
loc. D-390, Third and Mesa Streets, SDSNH
loc. 2660, USGS loc. 13779, Palos Verdes
Avenue between Eighth and Ninth Streets,
UCLA loc. 3440 (Valentine, 1961: 370; as
Pholadidea penita, in part). Third Street
and Palos Verdes Avenue, USGS loc. 12134,
Deadman Island (Crickmay, 1929: 631), old
Crawfish George's, and San Pedro Bluff
(last three Arnold, 1903: 23, 25, 27), 22nd
and Mesa Streets, USGS loc. 12138, outfall
sewer at Lomita and Main Streets in
Wilmington, LACMNH loc. 77, Cherry
Avenue in Long Beach, LACMNH loc. 424,
Cherry Avenue in Signal Hill, USGS loc.
12630, USGS-M loc. 2011, Raymond Avenue
in Signal Hill, CIT loc. 1348 (Delong, 1941:
facing 244), Signal Hill, UCMP Iocs. A-221
and A-1483, Los Cerritos Hill [= Signal Hill]
(Arnold, 1903: 31), Huntington Beach mesa,
UCLA loc. 3657 (Valentine, 1957: 297), west
facing bluff of Santa Ana River channel,
UCMP loc. A-3129, west bluff of Upper
Newport Bay, UCMP loc. A-3101 (both
Bruff, 1946: 233), west bluff of "middle"
Newport Bay, LACMNH loc. 68-A, and east
bluff of Upper Newport Bay, LACMNH loc.
66-2 (both Kanakoff and Emerson, 1959: 25;
in part), LACMNH loc. 136, SDSC Iocs. 531,
532, 534, and 535, CAS loc. 38432, USGS-M
loc. 1722, Newport Beach, ANSP [no
locality number]. Corona del Mar (Human,
1972: 9). Capistrano Beach, LACMNH loc.
58 (Willett, 1937 [1938]: 106; in part). San
Nicolas Island, USGS loc. 21664 (Vedder

WEST AMERICAN CENOZOIC PHOLADIDAE

35

and Norris, 1963: 46; as Parapholos
califomica, in part). Torrey Pines Beach
State Park. UCLA loc. 2410. Lindavista
Formation, east of Murphy Canyon, San
Diego, SDSNH loc. 0325 (Kennedy, 1973:
122). Bay Point Formation, Tecolote Can-
yon, San Diego (Kanakoff, in Emerson and
Chace, 1959: 338), Glorietta Bay, Coronado,
SDSC loc. 71 or 118 (Thompson, 1967 MS:
22), LACMNH loc. 2658. Coronado Beach,
SDSNH loc. 2528, CAS (HH 12008). Two
miles south of Ocean Beach, San Diego
(Orcutt, 1889: 71). Border locality in south-
western San Diego County, UCMP Iocs.
A-9003, A-9004, A-9005, and A-9006 (all
Emerson and Addicott, 1953: 434, 441),
UCLA loc. 3175 (Valentine, 1961: 357),
LACMNH loc. 4556, SDSNH loc. 0120. In
Baja California, Mexico, at Rosarito Beach,
UCLA loc. 2720 (Valentine, 1957: 297);
Punta San Jose (Emerson, 1960: 5); Punta
Cabras and vicinity, UCMP Iocs. A-9589
("?"), A-9587, A-9713, and A-9917 (all
Addicott and Emerson, 1959: 17); San
Quintin (Orcutt, 1921: 24; Manger, 1934:
283), uses Iocs. 7498, 7499, and 11729;
immediately east of Punta Baja, UCMP Iocs.
A-9590 and A-9591 (both Emerson and
Addicott, 1958: 8); Bahia San Bartolome
1= Bahi'a Tortolo], UCMP Iocs. B-3027 and
B-3050; near San Juanica and Punta
Pequeiia, LACMNH loc. 2719.
DISCUSSION.— Zirfaea pilsbryi was long
known under the trivial name gabbi.
Though actually a Penitella, gabbii was
construed to be the living west coast Zirfaea
until Lowe described it as Z. pilsbryi in
1931. Unfortunately Lowe's description was
published too late to be included in Grant
and Gale's (1931) "Catalogue of the marine
Pliocene and Pleistocene Mollusca of Califor-
nia," and thus the older name remained in
common use in paleontological literature.
Zirfaea pilsbryi is readily distinguished
from other Pholadinae by its umbonal-
ventral sulcus. It can be separated from Z.
dentata, a Miocene to lowermost Pliocene
species, by the sculpture on the anterior
slope, which does not parallel that of the
posterior slope, and the umbonal-ventral
sulcus, which intersects the ventral margin

near the anterior-most point of contact of
the valves, rather than near the midpoint as
in Z. dentata.

Zirfaea gabbi femii described by Ade-
goke (1969: 154) from the Pliocene San
Joaquin Formation is only a young Z.
pilsbryi. Many specimens utilized by Ade-
goke (from UCMP Iocs. B-6537, B-6538, and
D-1203) in his description were not given
type designations.

Typically a soft-sediment borer, Z.
pilsbryi inhabits heavy muds, clay, or soft
rock, in bays, estuaries, and other low
energy environments, though it may also
bore into soft rock on the open coast (Fitch,
1953: 95). Burrows in mud may reach a
depth of 40 cm (Fitch, 1953: 95). Emerson
(1951: 89, pi. 31) reported Z. pilsbryi in
waterlogged wood, though the occurrence
seems to be fortuitous.

Zirfaea pilsbryi is the most common
fossil pholadid on the Pacific slope of North
America and is well known from detrital
Pleistocene deposits of California and
northern Baja California. Known Pleisto-
cene occurrences in situ are uncommon,
though it has been found at Point Aiio
Nuevo (Addicott, 1966a: 3), in the low late
Pleistocene terrace near Goleta, both places
associated with Penitella turnerae, at the
border locality of Emerson and Addicott
(1953), and on the terrace platform at Punta
San Jose, Baja California (Emerson, 1960:
5). The few occurrences of paired valves in
the Pleistocene are due to the soft nature of
the preferred habitat, which does not well
withstand erosive action.

Except for a locality of questionable age
in Baja California, Z. pilsbryi is known from
Pliocene deposits only in California, com-
monly with both valves together. Masuda
and Noda (1969: 133, pi. 14, fig. 5-6)
however have cited incomplete specimens of
Zirfaea sp. from the early Pliocene Tatsuno-
kuchi Formation near Sendai, Japan, which
in all respects are identical to living Z.
pilsbryi, and unlike Z. subconstricta of
Japan or Z. dentata of the California
Miocene.

A variant of Z. pilsbryi, cited through-
out as Zirfaea sp. aff. Z. pilsbryi (see Fig.

36

GEORGE L. KENNEDY

19), also occurs in the Pleistocene of
northern California and Oregon. The type of
anterior sculpture does not closely resemble
that of the nominal species, but is more like
that of Chaceia ovoidea, with separated
undulating concentric ridges. More work
needs to be done on this form, which is also
known from living specimens (e.g., Buhne
Point in Humboldt Bay, MCZ 195915).

Subfamily MARTESIINAE Grant
and Gale, 1931

DEFINITION.— Shell beaked and gjaping
anteriorly in the young stage, closed in the
adult by a callum, a dorsal extension of
which usually encloses the anterior adductor
muscle. Number of accessory plates vari-
able, but always possessing a mesoplax and
lacking a protoplax. Apophyses always
present. Valves divided into two regions by
an umbonal-ventral sulcus, and into three
regions in some genera. Foot well-developed
in the young stage, atrophied in the adult.
Siphons capable of complete retraction
within the shell except in the genus
Chaceia.

TYPE GENUS.— Martesia Sowerby, 1824.
TAXA INCLUDED.— Fourteen genera and
four subgenera are recognized (Turner,
1969) in the Martesiinae, as follows:
Aspidopholas Fischer, 1887, Chaceia Tur-
ner, 1955, Diplothyra Tryon, 1862b, Eutylus
Vincent, 1891, Goniochasma Meek, 1864,
Heteropholas Fischer, 1887, Lignopholas
Turner, 1956, Martesia s.s. Sowerby, 1824,
and Particoma Bartsch & Rehder, 1945,
Opertochasma Stephenson, 1952, Para-
pholas Conrad, 1848, Penitella Valenci-
ennes, 1846, Pholadidea s.s. Turton, 1819
and Hatasia Gray, 1851, Ramsetia Stephen-
son, 1941, and Xylophomya Whitfield, 1902.
Olsson (1961) considers Hatasia to be of full
generic rank. A new subgenus of Martesia,
Paramartesia is described later in this
paper.

The type species of Aspidopholas,
Eutylus, Goniochasma, Heteropholas, Oper-
tochasma, Paramartesia, Ramsetia, and
Xylophomya are fossils. The genera occur-
ring today in the eastern Pacific are

Chaceia, Diplothyra, Martesia s.s. (and ?
Particoma), Parapholas, Penitella, and Ha-
tasia. Opertochasma and Paramartesia are
known from fossils in the same region.

Genus Chaceia Turner, 1955

ChaceiaTurner, 1954:3, 16, 17; [nomen nudum]. Turner,

1955:66.
not Chaceia (?): Adegoke, 1966:233 {=PeniteUa).

DEFINITION.— Shell oval, moderate to
large in size, widely gaping anteriorly and
posteriorly in young stage. Pedal gape only
partially closed by callum in adult, siphonal
gape remaining wide. Umbonal-ventral
sulcus pronounced. Valves in contact only at
umbones and ventral condyles. Dorsal
extension of calum extends from beaks to
umbones. Mesoplax only accessory plate,
transverse, single, small and V-shaped in
juvenile, covered and U-shaped in adult.
Siphons incapable of complete retraction
within shell.

The genus Chaceia differs from other
morphologically similar genera by gaping
widely at both ends of the shell, and by
possessing only a partial callum.
TYPE SPECIES.— Pholas ovoidea Gould,
by original designation of Turner (1955: 66).
TAXA INCLUDED.- The genus only
includes Chaceia ovoidea from the eastern
Pacific. "Pholadidea (Penitella) chishimana
Habe, 1955," of Japan, may possibly belong
to either Chaceia or Zirfaea rather than to
Penitella.

DISCUSSION.— The genus Chaceia was
proposed for Pholas ovoidea Gould, a
species not easily accommodated in either
Pholadidea in its revised and restricted
sense, or in Penitella. It is most closely
related to Zirfaea (subfamily Pholadinae)
and there is little doubt that it did not
evolve from this latter genus sometime in
the early Neogene. A single specimen of
'! Zirfaea sp. collected from the basal portion
of the Miocene Montesano Formation of
Canyon River, Washington (USGS-M loc.
3073), may represent an ancestral Chaceia.
The poorly preserved specimen has a short
anterior dorsal margin similar to C. ovoidea,
and an anterior slope quite unlike that of
Zirfaea dentata. Additional specimens are

WEST AMERICAN CENOZOIC PHOLADIDAE

37

needed before its systematic position can be
clarified.

Chaceia is definitely known only from
the Pliocene to Recent. Siliceous mud filled
burrows from the late Miocene Pismo
Formation of San Luis Obispo Co., Califor-
nia, questionably attributed to Chaceia by
Adegoke (1966) belong to Penitella. One
specimen (UCMP 32523) possesses a com-
plete callum (see Adegoke, 1966: pi. 21,
fig. 1) and others resemble Penitella in size
and anterior slope sculpture, though these
are not diagnostic features. Evans (1967b)
has refuted the generic assignment of
Adegoke's specimens to Chaceia (?) on the
basis of shell morphology and burrow shape.
See also Discussion under Nettastomella
rostrata.

Chaceia ovoidea (Gould, 1851)
Figures 20-27, 103

Pholas ovoidea Gould, 1851:87. Gould, 1853:388, pi. 15,

fig. lac. Johnson, 1964:121.
Z.lirphaea] Gabbii: Gabb, 1869:52, pi. 15, fig. 10, in part

(Penitella gabbii, in part Chaceia ovoidea (pi. 15, fig.

10], and Zirfaea pilsbryi).
not? Pholadidea ovoidea: Dall, 1878a:ll. Dall, 1878b:28.

Cooper, 1888:259. Arnold, 1909 [19101:39. Arnold and

Anderson, 1910:132. Smith, 1912:174, 182. Burch and

Burch, 1943:9. Clark, 1943:4. Burch, 1947:9.
not? Pholadidea (aff.) ovoidea: Watts, 1900 [1901]:224

(? Penitella penita) .
not Pholadidea ovoidea Conrad [sic]: Arnold, 1907:423,

pi. 55, fig. lab (=Penitella tumerae). Arnold and

Anderson. 1907:59, pi. 22 fig. lab {-Penitella gabbii,

P. penita, and P. tumerae [pi. 22, fig. lab]).
Pholadidea [Pholadidea] ovoidea: Grant and Gale, 1931:

434, in part {Chaceia ovoidea, in part Zirfaea pilsbryi

and Penitella spp.).
not Pholadidea ovoidea (Gould), short var.: Woodring,

Stewart, and Richards, 1940 [1941]: facing 78, pi. 14,

fig. 6 {^Pholadopsis pectitiata).
Pholadidea ovoidea: Fitch, 1953:93, fig. 59. Kanakoff and

Emerson, 1959:24, in part {Chaceia ovoidea, in part

Penitella penita).
Chaceia ovoidea: Turner, 1955:66, pi. 36-38, 39 (fig. 1-3).

McLean, 1969:91, fig. 53.3.
Zirfaea pilsbryi: Valentine, 1956:196, in part {Zirfaea

pilsbryi, in part Chaceia ovoidea). Chace, 1966:170, in

part {Zifaea pilsbryi, in part Bamea suhtruncata and

Chaceia ovoidea).
Pholadidea! sp.: Valentine, 1960a:163, in part {Penitella

sp. and Chaceia ovoidea). Valentine, 1962:95.
Pholadidea penita: Valentine, 1961:370, in part (Penitella

penita, in part Zirfaea pilsbryi and Chaceia ovoidea).
Zirfaea'! cf. Z. pilsbryi: Valentine, 1961:376.
Paraphokis califomica: Vedder and Norris, 1963:46, .50,

in part (P. califomica, in part Zirfaea pilsbryi and

Chaceia ovoidea).
not Chaceia ovoidea: Addicott, 1964b: 147 (^Penitella sp.

ef. P. conradi). Wright, 1972:691 (=Penitella gabbii).
not ChaceiaC!) sp. indet.: Adegoke, 1966:234 (=Penitella
sp. indet.).

DIAGNOSIS. — Shell large, widely gaping
anteriorly and posteriorly. Valves in contact
only at umbones and ventral condyles.
Callum only partial, infolded between
beaks, not protruding anteriorly. Apophy-
ses often channeled, not spoon-shaped.
Mesoplax broadly V-shaped (like that of
Zirfaea), or in old specimens, covered
dorsally and widely U-shaped.
DESCRIPTION.- Shell reaching approxi-
mately 12 cm in length, 8 cm in height,
broadly oval in outline, inflated, usually
light in structure. Immature specimens
strongly beaked anteriorly, pedal gape
nearly circular, posterior broadly rounded,
widely gaping, closed by partial callum in
adult.

Anterior slope sculptured with moder-
ately to tightly spaced, up-turned, undulate
concentric ridges, supplemented by radial
pattern formed by alignment of undulations
of these ridges. Umbonal-ventral sulcus
prominent, variable in width. Disc and
posterior slope ornamented with distinct,
low rounded concentric ridges (more re-
duced posteriorly), which are extensions of
ridges of anterior slope.

Umbonal reflections broad, closely
appressed over umbones and upper part of
anterior slope, immediately narrowing ante-
riorly, barely reflected and free at beaks.
Callum only partial, sculptured with fine
concentric growth lines, and with radial
depressions near the anterior margin in
heavy shelled specimens. Callum extends
dorsally, flush or posterior (but never
anterior) to tips of beaks, forms a narrow
dorsal extension of callum on umbonal
reflection.

Umbonal-ventral ridge pronounced, or-
namented with beads in thin-shelled speci-
mens. Muscle scars usually not apparent,
but often heavily calcified in older speci-
mens. Ventral muscle scar distinctive,
short, high, extends antero-dorsally for

38

GEORGE L. KENNEDY

short distance. Pallial sinus deep, extends
beyond umbonal-ventral ridge. Apophyses
narrow, often channeled, but not large or
broadened ventrally, extend from beneath
umbones nearly parallel to umbonal-ventral
ridge.

Periostracum thin, persistent. Siphons
very large, not capable of retraction within
shell. Foot large, broadly oval in outline and
truncate, atrophied in adult (Turner, 1955:
69).

HOLOTYPE.— Of Pholas ovoidea Gould,
according to Johnson (1964: 121) is missing.
Monterey, California, collected by Major
William Rich. Recent.

DISTRIBUTION.— Recent; Santa Cruz,
Santa Cruz Co., California (37° N. lat.) to
Bahia San Bartolome [= Bahia Tortolo], Baja
California, Mexico (27° 39' N. lat.; Fitch,
1953: 93).
GEOLOGIC RECORD.— Pliocene to Recent.

Pliocene: One mile southegM of Oil
City, Fresno Co., CAS loc. 28485^ee text].

Pleistocene: San Nicolas Island, USGS
loc. 21664 (Vedder and Norris, 1963: 46; as
Parapholas californica, in part), SDSNH loc.
0702. Potrero Canyon, Pacific Palisades,
UCLA loc. 3225 (Valentine, 1956: 196; as
Zirfaea pilsbryi, in part). Fourth terrace.
Fort MacArthur Upper Reservation, San
Pedro, UCLA loc. 4243 (Valentine, 1962: 95;
as Pholadidea? sp.). Seventh terrace, Palos
Verdes Hills, LACMNH loc. 1307. San
Pedro Sand, at high school at 15th and
Leland Streets, San Pedro, SDSNH loc.
2138 [= L-2138] (Chace, 1966: 169; as Zirfaea
pilsbryi, in part). Palos Verdes Sand,
Western Avenue, San Pedro, UCLA loc.
3602 (Valentine, 1961: 376; as Zirfaea? cf. Z.
pilsbryi), near Palos Verdes Avenue be-
tween Eighth and Ninth Streets, UCLA loc.
3440 (Valentine, 1961: 370; as Pholadidea
penita, in part), Los Angeles Harbor
District sanitation yard, San Pedro,
LACMNH loc. 1210, on west bluff of
"middle" Newport Bay, LACMNH loc. 68-A
(Kanakoff and Emerson, 1959: 24 [specirriens
not seen]), on east bluff above Upper New-
port Bay, LACMNH loc. 66-2 (Kanakoff and
Emerson, 1959: 24; in pari Penitella penita),
LACMNH Iocs. 66-10 and 136, SDSC Iocs.

533 and 537. Torrey Pines Beach State
Park, UCLA Iocs. 3457 (in part) and 3458 (in
part) (both Valentine, 1960a: 163; as
Pholadidea? sp.). On west side of Point
Loma, SDSNH loc. 2631. Bahia Tortolo,
Baja California, Mexico, UCMP loc. B-3007.
DISCUSSION.— Chaceia ovoidea has never
been properly interpreted in paleontological
literature. Over a hundred years ago Gabb
(1869: 52, pi. 15, fig. 10) figured a Recent
juvenile specimen of C. ovoidea under the
name Zirphaea gabbi in his "Palaeontology
of California." In reality Gabb's reference
included three species (in three genera); the
name and unique type refer to Penitella
gabbii, the figure to C. ovoidea, and the
fossil record of large valves in the San
Pedro Pleistocene to Zirfaea pilsbryi. Grant
and Gale (1931: 434) placed Gabb's whole
citation under their Pholadidea ovoidea
because of the figure. Adegoke (1966: 235)
called attention to Grant and Gale's "error"
and placed the reference in his over-
inclusive "P. [enitella] gabbii."

Many authors (see synonomy) have re-
peatedly cited specimens of Penitella gabbii
and P. tumerae together as ''Pholadidea
ovoidea." In addition, Woodring, Stewart,
and Richards (1940 [1941]: facing 78) have
cited and figured the very ovoid and globose
Pholadopsis from the Kettleman Hills of
California as a short variety of Pholadidea
ovoidea. Most recently Addicott (1946b:
147) cited a specimen of Penitella sp. cf. P.
conradi as C. ovoidea.

Chaceia ovoidea can be recognized by
its large size, broad pedal and siphonal
gapes, partial and non-protruding callum,
small V-shaped mesoplax, and narrow
dorsal extension of the callum. Confusion
may occur in identification between juvenile
and (or) fragmentary C. ovoidea and old,
heavy shelled Zirfaea pilsbryi (subfamily
Pholadinae). Although there are no good
criteria for separating fragmented speci-
mens, the nature of the concentric ridges of
the anterior slope, the more prominent
umbonal-ventral sulcus, and the umbonal
reflection of C. ovoidea may be useful. The
ventral muscle scar of C. ovoidea (see Fig.
23) is distinctly different from that of Z.

WEST AMERICAN CENOZOIC PHOLADIDAE

39

pilsbryi, which is not well distinguished
from the pallial line.

Though individuals of C. ovoidea have
been known to bore into waterlogged wood
(MCZ 251345), the species is usually found
boring into clay, shale, sandstone, or other
soft rock on the open coast to a depth of
twenty inches, the burrows tapering to an
inch in diameter at the surface (Fitch, 1953:
93). Specimens of this species normally do
not cease boring and produce a callum until
they are 70-90 mm in length and 40-50 mm
in height, but may reach 120 mm in longi-
tude and 82 mm in altitude (USNM 612116).

The fossil record of C. ovoidea is rather
meager. In the Pleistocene, the species is
most abundant in the Palos Verdes Sand of
Upper Newport Bay, in Orange Co., where
many articulated specimens have been
found. The only known specimen with a
preserved mesoplax (a juvenile) came from
this region (SDSC loc. 533).

Only one known specimen has been
found in rocks which might be Pliocene in
age. The specimen (see Fig. 103) was
associated with several Zirfaea dentata and
supposedly was from the same general Mio-
cene locality (CAS loc. 28485). The matrix
and type of preservation are so entirely
different however, there can be no doubt
they were collected at another locality, the
Chaceia most probably coming from nearby
Pliocene strata.

Genus Penitella Valenciennes, 1846

Penitella Valenciennes, in du Petit-Thouars, 1846: pi. 24,
legend [no description]. Turner, 1955:70. Adegoke,
1967:9.

Navea Gray, 1851:385.

DEFINITION.- Shell oval in outline, dis-
tinctly divided by umbonal-ventral sulcus,
small to large, reaching 12 cm in length.
Anterior beaked, widely gaping in young
stage, closed by partial or complete callum
in adult; posterior rounded to truncate, and
closed. Umbonal reflection usually ap-
pressed to anterior slope, but may be free
anterior to umbones. Mesoplax only acces-
sory plate, transverse, situated posterior to
umbones, circular or V-shaped in juvenile,
covered dorsally in adult. Siphonoplax

noncalcareous, presence variable. Siphons
capable of complete retraction within shell.
Penitella differs from other genera in
the Martesiinae by its single accessory
plate, a dorsally covered mesoplax situated
posterior to the umbones. The umbonal
reflection is generally appressed to the
anterior slope, and the dorsal extension of
the callum extends from thhe beaks to the
umbones. The mesoplax of Pholadidea is
longitudinally divided into two pieces.
Chaceia is larger, has a partial callum, non-
retractable siphons, and a wide posterior
gape.

TYPE SPECIES.— P.[enitella] conradi
Valenciennes, by subsequent designation of
Grant and Gale (1931: 433).
TAXA INCLUDED.— There are at least
eight species from the eastern Pacific alone,
two of which are known only from their
fossil records (P. lorenzana and P. durhami).
Penitella conradi, P. fitchi, P. gabbii, P.
penita, and P. tumerae are all found both
living and as fossils. Penitella kotakae
(Kanno and Matsuno, 1960) is known from
the upper Oligocene of Japan, and P.
kamakurensis (Yokoyama, 1922) from both
Pleistocene and Recent faunas of Japan and
Alaska. Pholadidea (Penitella) chishimana
Habe, 1955, also of Japan, may belong to
Zirfaea or Chaceia rather than to Penitella.
DISCUSSION.— The genus Penitella, as is
true of most Martesiinae, characteristically
bores into finer grained soft rock, shales,
and mudstones (all in various stages of
induration), usually on the open coast or in
situations where the burrow entrance will
not be occluded by sedimentation. Because
of this habitat preference, species of
Penitella are geologically younger than the
rocks in which they inhabit, and are found
in situ in outcrops or in cobbles in detrital
deposits. Representatives of this genus are
probably responsible for most of the mud
filled burrows found in Neogene formations
on the Pacific slope.

The genera Penitella and Zirfaea (sub-
family Pholadinae) constitute the bulk of
known fossil pholadid specimens in the west
coast Cenozoic. Whereas there are only two
species of Zirfaea, there are at least eight

40

GEORGE L. KENNEDY

species of Penitella in North America,
ranging from the Oligocene to the present.
Because specific differences are minor, and
there were misunderstandings about the
genus for many years, the number of
species was considered small. Consequently
the trivial name penita was often used indis-
criminately for any fossil Penitella. When
Turner (1955) monographed the genus, it
was then possible to clear up the many
years of accumulated mis-citations in the
paleontologic literature, a task not accom-
plished by Adegoke (1967) in his brief
review of the fossil and Recent species of
Penitella.

The "sudden occurrence" in the OUgo-
cene of California of two species of Penitella
leaves no doubt that the group is older than
middle Oligocene. Though Eocene records of
Penitella are unknown, this may be due to
the thicker sections of continuous deposi-
tion, which would not provide suitable
substrates. Miocene occurrences of Penitella
are so rare, and specimens so poorly pre-
served, that tracing specific lineages from
the Oligocene to the Pliocene is difficult.

It has not be possible to identify to
species a fair number of specimens of
Penitella, and although they are not listed
here for reasons of brevity, they may be
found in the Register of Localities.

Penitella conradi Valenciennes, 1846
Figures 41-45

Penitella conradi Valenciennes, in du Petit-Thouars,
1846: pi. 24, fig. 1, lab (no description]. Lamy, 1921:
179. Turner, 1955:75, pi. 43-46. Adegoke, 1967:15.
Meredith, 1968:281, pi. 42. McLean, 1969:92, fig. 53.7.
Smith, 1969:869 et seq. Hertlein and Grant, 1972:332,
pi. 57, fig. 5, 13.

N.[avea] subglobosa Gray, 1851:385.

P.[enitella] parva Tryon, 1965:39, pi. 2, fig. 4-5.

P.[enitella] conradi: Grant and Gale, 1931:433 [in text].

Pholadidea (Pholadidea) penita: Willett, 1937:391.

Pholadidea parva: Willett, 1937 [1938]:106.

not? Naveal cf. A^. subglobosa: Valentine, 1960a: 163
{^Penitella sp. indet.).

Penitella penita: Vedder and Norris, 1963:46, 50, in part
(P. penita, in part P. conradi and P. gabbii). Wright,
1972:691, in part (P. tumerae and P. sp. cf. P. conradi).

Chaceia ovoidea: Addicott, 1964b: 147 (Penitella sp. cf.
P. conradi).

DIAGNOSIS.— Small, globose Penitella.
Umbonal reflections broad, closely ap-
pressed their entire length. Dorsal exten-
sion of callum anteriorly lobate. Mesoplax
semicircular in outline, broadly rounded or
truncate posteriorly, bluntly pointed ante-
riorly, lacking any lateral wings. Posterior
muscle scar roughened. Siphonoplax heavy,
lined with aragonitic or calcitic granules.
Small deformed specimens found in abalones
{Haliotis).

DESCRIPTION.- Shell generally globose,
oval in outline, small, reaching about 3 cm
in length and 2 cm in height. Beaked, widely
gaping anteriorly in young specimens,
closed by complete callum in adult; rounded
and closed posteriorly. Anterior slope about
one third size of combined disc and posterior
slope, sculptured with very fine, tightly-
spaced, upturned, undulate concentric ridges
and weak supplementary radial pattern
expressed mainly by alignment of concentric
undulations. Umbonal-ventral sulcus prom-
inent, not incised. Disc and posterior slope
sculptured with concentric growth lines.

Umbonal reflection wide, closely ap-
pressed its entire length. Callum heavy (in
Haliotis) or thin and light (in shale), extends
dorsally anterior to beaks. Dorsal extension
of callum low, anteriorly lobate.

Mesoplax only accessory plate, thin,
nearly flat, more or less semicircular in
outline in young specimens (Turner, 1955:
76), covered dorsally in adult, posteriorly
broadly rounded to truncate, anteriorly
bluntly pointed, lacking any lateral wings.

Umbonal-ventral ridge barely visible.
Muscle scars large, pronounced, usually
roughened. Muscle scar pad large, semicir-
cular, present immediately above umbo on
umbonal reflection. Pallial sinus broad,
deep, extends anteriorly beyond umbonal-
ventral ridge. Apophyses very narrow,
fragile, often broken in fossil specimens,
occasionally rather deformed and irregular
when boring in Haliotis.

Siphonoplax lined internally with white
calcareous granules. Periostracum persist-
ent, heavy on posterior slope. Siphons
capable of complete retraction within the
shell. Foot large, nearly circular in outline,

WEST AMERICAN CENOZOIC PHOLADIDAE

41

truncate, in young specimens, atrophied in
adult (Turner, 1955: 73).
TYPES.— Of Penitella conradi Valenci-
ennes, are in the Museum National d'His-
toire Naturelle in Paris (Lamy, 1921: 179).
Monterey, California, is on the type label,
though no locality was published by Valen-
ciennes (Lamy, 1921: 179). Recent.
LECTOTYPE.- OiNavea subglobosa Gray,
selected by R.D. Turner and to be published
at a later date, is in the British Museum
(Natural History). California, in a hole in a
shell. Recent.

LECTOTYPE.- Of Penitella parva Tryon,
ANSP 50999, designated by Turner (1955:
78). PARALECTOTYPES: ANSP 136741
(six valves). Lower California, from a
Haliotis. Collected by Wesley Newcomb.
Recent.

DISTRIBUTION.— Recent; Canon Beach,
Clatsop Co., Oregon (45° 53' N. lat.; Mere-
dith, 1968: 281) south at least as far as
Bahia San Bartolome [= Bahia Tortolo], Baja
California, Mexico (27° 39' N. lat.; Turner,
1955: 79).

GEOLOGIC RECORD.- ?Miocene, Plio-
cene to Recent.

Miocene: East side of El Toro Valley,
southwest of Salinas, UCMP loc. A-2549.
?Monterey Formation, near end of road
leading north from Klondike Canyon (north
off of Carmel Valley), UCMP loc. A-2550
(cf.).

Pliocene: Saugus Formation, south of
Piru, CAS loc. 90 (cf.). Fernando Formation,
Crocker Citizens Plaza excavation at Sixth
and Hope, LACMNH loc. 466, ARCO Plaza
excavation at Sixth and Flower, both down-
town Los Angeles, LACMNH loc. 1219, on
the east bluff above Upper Newport Bay,
LACMNH loc. 471. San Diego Formation, in
San Diego, at Arroyo Drive, SDSNH loc.
2454, quarry at end of Arroyo Drive,
LACMNH loc. 107, Laural Canyon, SDSNH
loc. 2455, northeast corner of Upas and
India Streets, SDSNH loc. 2529 (cf.), on hill
between Goat Canyon and U.S. -Mexican
border, LACMNH Iocs. 305 (in shell) and
305C (both Hertlein and Grant, 1972: 332).

Pleistocene: Isla Vista near Goleta,
USGS-M (cf.) (Wright, 1972: 691; as
Penitella penita, in part). Lincoln Avenue,

northeast of Playa del Rey, LACMNH loc.
59 (Willett, 1937: 391; as Pholadidea
penita). Point Dume terrace, near Escon-
dido Beach, USGS-M loc. 1710 (cf.) (Addi-
cott, 1964b: 147; as Chaceia ovoidea).
Lomita Marl, San Pedro, northeast corner
of Coralmount Drive and Park Western
Drive, LACMNH loc. 435, SDSNH loc.
2669, fourth ravine west of Hawthorne
Avenue on north border of Palos Verdes
Hills. USGS loc. 12259. Undifferentiated
formations on Palos Verdes Peninsula, on
second terrace, immediately east of Flat-
rock Point, USGS loc. 12192, below Nob
Hill. LACMNH loc. 300 (cf.). Third and
Mesa Streets, LCAMNH loc. 98, Eighth and
Palos Verdes Streets, LACMNH loc. 226.
Palos Verdes Sand, on Deadman Island
(zone 7 of Arnold), CAS loc. 1479. Calle
Fortuna, Capistrano Beach, LACMNH loc.
58 (Willett, 1937 [1938]: 106). San Nicolas
Island. USGS Iocs. 21653 and 21655 (Vedder
and Norris, 1963: 46; as Penitella penita, in
part).

DISCUSSION. — Penitella conradi was long
known under the names Penitella parva and
Navea subglobosa. Active boring specimens
without a callum and covered in the mantle
cavity of an abalone with patches of black
conchin (= conchiolin) were cited as N.
subglobosa, while those adults which had
produced the callum and siphonoplax, and
were thereafter covered with nacre in the
inside of the Haliotis, were called P. parva.
The affinities of these were recognized by
Turner (1955) and were synonomized. When
the active boring pholadid breaches the
nacreous layer in the mantle cavity of the
abalone, the abalone begins depositing a
heavy layer of conchin over the active irrita-
tion, keeping pace with boring, but nacre is
not deposited over the active animal. This
continues until the pholadid has ceased
boring and produces a callum and siphono-
plax, at which time the no longer active
irritation can be covered over with the
nacreous layer. Smith (1969: 869) believes
the boring process in P. conradi is mainly
through dissolution, but whether the effect
is on the organic matrix or the crystals
themselves is still unknown. This may be
the key to discovering why nacre is not

42

GEORGE L. KENNEDY

deposited over an active borer. Smith
further notes that "mechanical abrasion
helps remove loosened crystals and/or
organic matrix."

Penitella conradi is also known to bore
into other marine mollusks (Mytilus califor-
iduas Conrad, Astraea sp., Pododesmus
sp.), as well as the abalones Haliotis fulgens
Philippi, H. rufescens Sowerby, and H.
sorenseni Bartsch (Turner, 1955: 79; Mere-
dith, 1968: 281), H. cracherodii (SDSNH
53172), and the hybrid H. kamtschatkana
assimilis x H. sorenseni (cf. Owen, McLean,
and Meyer, 1971: fig. 17, upper right).
Abalone borers are often deformed (see
Turner, 1955: pi. 44-45; McLean, 1969: fig.
53.7) and have large adductor muscles, a
roughened posterior muscle scar, and a dis-
proportionately large mesoplax and dorsal
extension of the callum Specimens boring
into soft rock are often perfectly formed,
though uncommon. In the fossil record a
reverse situation exists and only a single
valve is known from a fragment of unidenti-
fied shell material, the remainder coming
from soft rock in situ, or from detrital
deposits.

Recent specimens of P. conradi boring
into shale or soft rock are easily separated
from the quite similar P. penita, and other
species of Periitella. The semicircular meso-
plax of P. conradi plus the granular and cup-
shaped siphonoplax are sufficient for posi-
tive identification. Penitella penita has a
posteriorly pointed mesoplax and a perio-
stracal siphonoplax. In detrital fossil speci-
mens however, these are lost or typically
not preserved and identification is more
difficult. Fossil occurrences of the meso-
plax are uncommon, and I have seen but a
single siphonoplax preserved (from
LACMNH loc. 435).

Fossil specimens boring into shale are
often mistaken for short ovoid forms of P.
penita. The more difficult the substrate is to
penetrate, the greater is the similarity of P.
penita to P. conradi. Both the overall shell
outline and nature of the anterior ornamen-
tation are extremely similar. In P. conradi
however, the posterior muscle scar is
usually more deeply impressed and quite

roughened, while a muscle scar pad is often
produced above each umbo. Further, the
posterior dorsal margin is humped, the
beaks are slightly blunter, the beak to umbo
distance is usually shorter, and the apophy-
ses thinner and more fragile in P. conradi
than in P. penita.

The fossil record of P. conradi is more
extensive than previously realized, ranging
back into the Miocene with two occurrences
in the Salinas-Carmel Valley area east of
Monterey. Both lots were collected in 1936
and exact age or formational assignments
are not known. One locality was question-
ably assigned to the Monterey Formation,
but may only have been boring into that
formation, and thus would be geologically
younger. Considering the habitat preference
of P. conradi, i.e., shell and harder
substrates, it is doubtful that the animals
were living at the time of deposition, but
more probably that they lived some time
after the underlying formation had consoli-
dated into a more indurated substrate.

The greatest abundance of Pliocene P.
conradi is in the San Diego Formation on
Arroyo Drive in the city of San Diego.
Identified from the shape of the mesoplax,
many are short and globose, though some
seem almost too elongate and would not
have been assigned to conradi without the
accessory plate, which eliminates assign-
ment to any other known species.

Of Pleistocene occurrences, the speci-
mens collected from the Lomita Marl in San
Pedro (LACMNH loc. 435, SDSNH loc.
2669) are remarkedly well preserved; one
specimen still had its calcareously lined
siphonoplax intact. This locality is the
richest Pleistocene locality for P. conradi.
The Pleistocene specimen cited by Valentine
(1960: 163) as Naveai' cf. N. subglobosa may
possibly be P. penita, but it is too small and
poorly preserved for positive identification.
The specimen was collected from Torrey
Pines Beach State Park in San Diego Co.
(UCLA loc. 2410, not UCLA loc. 3457 as
cited).

WEST AMERICAN CENOZOIC PHOLADIDAE

43

Penitella durhami Adegoke, 1967
Figures 33-35

Pholadidea {Penitella) lorenzana: Weaver, 1953:60.
Penitella durhami Adegoke, 1967:12, fig. 12, 16-17, 20-26.

DIAGNOSIS.— Valves well inflated. Um-
bonal reflection only loosely appressed ante-
riorly, free at beak. Galium not extending
beyond beaks. Mesoplax unknown.
ORIGINAL DESCRIPTION.- Shell small
to large, with elongate oval outline;
immature specimens gaping wide anteriorly
and posteriorly; umbonal-ventral sulcus
conspicuously depressed, flanked by two
narrow but prominently elevated ridges
which are further delineated from the rest
of shell by shallow broad depressions;
umbonal-ventral sulcus divides valves into
two distinct and very unequal parts;
anterior portion small, about half length of
posterior portion, remarkably robust, in-
flated, and rounded, with subcircular
cross-sectional outline; sharp ventral con-
cave flexure coincides with ventral portion
of umbonal-ventral sulcus, further delimit-
ing rounded anterior from the less high,
laterally compressed posterior; protoplax
1= dorsal extension of callum] strongly
developed, separated from beak and
callum by narrow, depressed umbonal
reflection; callum well developed, protrudes
beyond beaks, closes pedal gape in adults;
anterior slope ornamented by numerous
wavy concentric ridges with poorly defined,
radially arranged spines; posterior region of
shell longer than anterior region, flattened
laterally, not as high as anterior region;
posterior dorsal margin prominently ridged,
and convex; posterior ventral margin
keeled, markedly concave; posterior slope
and disc ornamented by wide concentric ribs
with narrow interspaces; posterior extrem-
ity sharply truncated, with wide subcircular
siphonal gape.

SUPPLEMENTARY DESCRIPTION.—
Shell robust, well inflated, small to large,
reaching 7 cm in length and 3 cm in height,
producing a callum in the adult stage. The
valves may be widely gaping posteriorly
(Adegoke), but I have not seen any

specimens with the posterior slope complete.
Immature specimens very strongly beaked,
the anterior margin being strongly angulate.

Anterior slope sculptured with moder-
ately spaced undulate, upturned, concentric
ridges, not spinose. Umbonal-ventral sulcus
distinct. Disc and posterior slope orna-
mented with conspicuous smooth rounded
concentric ridges which are extensions of
the ridges of the anterior slope.

Umbonal reflection appressed near
umbo, looser anteriorly, free at beaks,
widest just posterior to widest point of
dorsal extension of callum (= "protoplax" of
Adegoke), appears only where the two do
not overlap. The callum does not extend
anterior to the beaks, though it may be
flush with them. A simlar situation exists in
P. gabbii and any protrusion is less than a
fraction of a mm. Normal callum almost
hemispherical, occasionally so reduced as to
be almost recessed.

Mesoplax only accessory plate, so
poorly preserved on available specimens
that little can be said of it. Apophyses,
pallial sinus, and pallial line unknown.
Posterior muscle scar symmetrically oval in
outline. Umbonal-ventral ridge beaded,
quite distinct, flanked by sUght depressions.
HOLOTYPE.— Of Penitella durhami. Ade-
goke, UGMP 30108. PARATYPES: UGMP
30102-30105, 30108. 32493-32497. 32503-
32508. East limb of Pacheco Syncline, in
road cut on California State Highway 4,
Contra Costa Co.. California. UGMP loc.
A-4296 (here corrected). Collected by Univ.
Calif. Paleontology 103 class, 1947, J.H.
Peck and J.W. Durham, 1951, and O.S.
Adegoke, 1966. Late Oligocene, basal San
Ramon Formation.
GEOLOGIC RECORD.- Oligocene.

Oligocene: Along California State High-
way 4 (= Arnold Industrial Highway) on the
east limb of the Pacheco Syncline, UW loc.
1238 (Weaver, 1953: 60; as Pholadidea
lorenzana [specimens not seen]), UGMP loc.
A-7762 (Adegoke, 1967: 13), UGMP loc.
A-4296 (holotype collected here).
DISCUSSION.- Penitella durhami was the
second Oligocene Penitella to be described
from California. Based on poorly preserved

44

GEORGE L. KENNEDY

specimens, it is difficult to characterize,
though it probably is distinct. The most
useful distinguishing character, the meso-
plax, cannot be adequately described from
the available material. Penitella durhami
can be separated from the other Oligocene
species, P. lorenzana, by its more robust
shape and the callum which does not
protrude anterior to the beaks.

At the type locality on the east limb of
the Pacheco Syncline, the basal San Ramon
Formation (Oligocene) is disconformable
with the uppermost Pereira Shale Member
of the Eocene Alhambra Formation (Weaver,
1953: 50). At this locality P. durhami is
associated with Platyodon pecki Adegoke,
1967, and both are found boring into the
underlying Eocene strata.

The holtype of P. durhami was
collected from UCMP loc. A-4296, not
UCMP loc. A-7762 as cited by Adegoke
(1967: 13), and is here designated the type
locality. The two localities are supposed to
be equivalent however. Several of the
"paratype" specimens, UCMP 32503-32508
are only mud filled burrows and specific
determinations are not possible. Other
specimens from UCMP loc. A-4296 are
better preserved than much of the type
material, and were available to Adegoke
(the holotype was selected from this lot),
but were not cited. Much of the supplemen-
tary description herein is based on these
specimens.

Penitella fitchi Turner, 1955
Figures 55-59

Penitella fitchi Turner, 1955:71, pi. 40-42. Adegoke,

1967:15.
Pholad sp.?: Chace, 1956:178.
Pholadidea penita Carpenter [sic\: Chace, 1966:170, in

part (Penitella penita, in part P. fitchi).

DIAGNOSIS.— Anterior-dorsal margin
short, dorsally convex, giving beaks a blunt
appearance. Mesoplax large, subcircular,
broader than long, with or without primary
lateral wings. Umbonal reflection longitudi-
nally symmetrical, tightly appressed for
entire length. Callum only partial, extends
dorsally anterior to beaks. Siphonoplax

composed of numerous periostracal leaves.
DESCRIPTION.— Shell oval in outline,
solid in structure, moderate in size,
reaching about 6 cm in length and 3.5 cm in
height. Beaked and widely gaping anteriorly
in young specimens, closed by partial callum
in adult, rounded and closed posteriorly.
Anterior slope small, about one third size of
combined disc and posterior slope, tapering
to point on ventral margin, sculptured by
very close-set, upturned, undulate concen-
tric ridges, and by secondary radial pattern
formed by alignment of the undulations.
Umbonal-ventral sulcus pronounced. Poste-
rior slope broadly rounded in young
specimens, proportionately longer and more
tapered in adult, sculptured with fine
growth lines. Umbones located near ante-
rior third of shell. Dorsal margin just
posterior to umbones "humped" in adults.
Umbonal reflection longitudinally sym-
metrical, tightly appressed for entire
length. Callum partial (see Turner, 1955: pi.
40, fig. 1), rather heavy, solid, extends
dorsally anterior to beaks, sculptured with
growth lines and slight indication of forward
extension of radial sculpture of anterior
slope.

Mesoplax only accessory plate, broad,
thin, nearly flat, rounded posteriorly in
young specimens (Turner, 1955: 72), large,
heavy, subcircular to nearly laterally ellip-
soidal in outline, bluntly pointed anteriorly,
covered dorsally in adult. Lateral wings,
when present, fragile, only remnant exten-
sions of juvenile mesoplax. Mesoplax figured
by Turner (1955: pi. 40, fig. 2, and pi. 42).
Umbonal-ventral ridge broad, smooth.
Muscle scars large, pronounced, roughened
in adult. Pallial sinus broad, deep, extends
anteriorly beyond umbonal-ventral ridge.
Apophyses solid, expanded, very blade-like
ventrally, extend in direction anterior to
umbonal-ventral ridge.

Periostracum thin and deciduous. Si-
phonoplax periostracal, composed of numer-
ous leaf-like layers. Siphons capable of
complete retraction within shell. Foot large,
nearly circular in outline, truncate in young
specimens, atrophied in the adult (Turner,
1955: 73).
HOLOTYPE.- Of Penitella fitchi Turner,

WEST AMERICAN CENOZOIC PHOLADIDAE

45

MCZ 189413. PARATYPES: MCZ 189414
(15 specimens), MCZ 189741 (11 specimens),
USNM 701539 (3 specimens), ANSP 191715
(2 specimens), LACMNH 1444 (2 specimens),
SDSNH types 4183 and 4184, SU 10059 (2
specimens). Berry collection (? part of SU
10059). North side of Bahia San Bartolome,
Baja California, Mexico, in sedimentary
rocks. Holotype and paratypes collected by
J.E. Fitch, November 21, 1952; paratypes
by E. Dwyer and D.C. Joseph, January 6,
1954. Recent.

DISTRIBUTION.— Recent; Redondo Beach,
Los Angeles Co., California (33° 15.4' N.
lat.; LACMNH A.2777) south to Punta
Pequefia, Baja California, Mexico (26° 14' N.
lat.; LACMNH 71-181).
GEOLOGIC RECORD.- Pleistocene to
Recent.

Pleistocene: San Pedro Sand, at high
school at 15th and Leland Streets, San
Pedro, SDSNH loc. 2138 [= L-2138] (Chace,
1966: 170; as Pholadidea penita, in part).
Palos Verdes Sand, on east bluff above
Upper Newport Bay, SDSC loc. 537,
SDSNH loc. 2561. In hills opposite south-
west corner of Turtle Bay, Baja California,
Mexico, SDSNH loc. 0624 (Chace, 1956: 178;
as Pholad sp.?).

DISCUSSION.— Recent specimens of Peni-
telkb fitchi are rare in collections and are
restricted to the Californian and Surian
(overlap area of the Californian and
Panamic) Provinces of the eastern Pacific.
Though it has been found in greatest
abundance at the type locality, Bahia San
Bartolome, the waters of this bay are
known to be cool and near the temperature
of those in southern California (E.C. Allison,
pers. comm.). Other occurrences are few,
but specimens are known from Redondo
Beach (LACMNH A.2777), San Diego
(USNM 111401), La Jolla (author's collec-
tion), and from Baja California near Isla San
Geronimo (LACMNH 71-91), San Cristobal
Bay (LACMNH 71-172), and at Punta
Pequefia (LACMNH 71-181).

At the type locality, J.E. Fitch
(Turner, 1955: 74) found P. fitchi associated
with equal numbers of P. penita and
Chaceia ovoidea. The dead specimen col-

lected from La Jolla was found intertidally
in a large mudstone cobble with P. gabbii,
P. penita, Nettastomella rostrata, and
Lithophaga plumula (Hanley, 1843).

Penitella fitchi is even rarer in the
fossil record, and is known from only three
localities in the Pleistocene and not at all in
the Pliocene. Several specimens of P. fitchi
are known from the late Pleistocene Palos
Verdes Sand on the east bluff above Upper
Newport Bay, California. One, a juvenile
collected in loose sandy-shelly detrital
material, has both valves present, and is in
perfect condition. Another, represented by
fragments of both valves of an adult, was
collected in situ, and associated with
relatively large numbers of Chaceia ovoidea
and Nettastomella rostrata, and lesser
numbers of P. penita and Barnea subtrun-
cata. Penitella fitchi also occurs in the
Pleistocene deposits of San Pedro, and
Turtle Bay, Baja California.

Penitella fitchi is not closely related to
any west American Penitella, though in
some respects it appears similar to P.
conradi. Both have a rounded mesoplax,
roughened muscle scars, and a little hump
on the posterior-dorsal margin in the adult.
Penitella fitchi however has a partial
callum, very blade-like apophyses, and a
shorter convex anterior-dorsal margin,
which gives the beaks a blunt, rounded
appearance.

Penitella gabbii (Tryon, 1863)
Figures 36-40

Zirphaea Gabbii Tryon. 1863:144, pi. 1, fig. 1.

Z. [irphaea] Gabbii: Gabb, 1869:52, 88, in part; not pi.
15, fig. 10 (Penitella gabbii, in part Zirfaea pilsbryi,
and Chaceia ovoidea [pi. 15, fig. 10]).

Pholadidea ovoidea Conrad [sic]: Arnold, 1907:423, in
part; not pi. 55, fig. lab {Penitella gabbii, P. penita,
and P. tumerae [fig. la-b]). Arnold and Anderson,
1907:59, in part; not pi. 22, fig. lab (ibid). (Author
on plates is Gould.]

not Pholas (Zirfaea) gabbi: Grant and Gale, 1931:433, pi.
24, fig. 2. Wilson, 1966:108. (Both =Zirfaea pilsbryi).

Pholadidea penita: Bruff, 1946:232, in part (Penitella
penita. in part P. gabbii). Woodring and Bramlette,
1950 [1951]: facing 34, 41, facing 48, 66, 91, in part;
not p. 54, pi. 8, fig. 6, nor pi. 14, fig. 3 (Penitella
penita, in part P. gabbii, and P. tumerae [figures]).

Peyiitella gabbi: Turner, 1955:85, pi. 52-54. Turner, 1962:
306. Adegoke, 1967:16, in part (Penitella gabbii [Re-

46

GEORGE L. KENNEDY

cent], in part Zirfaea pilsbryi [all fossil references]).
Penitella penita: Vedder and Norris, 1963:46, 50, in part

(Penitella penita, in part P. conradi and P. gabhii).
not Zirfaea gabbi (Tryonl/emiV Adegoke, 1967:17 {nomen

nudum, introduced manuscript name). Adegoke, 1969:

154, "fig." 6A, pi. 9, fig. 2, 8, 11-12; pi. 10, fig. 3, 5-6,

13. {Both = Zirfaea pilsbryi).
Chaceia ovoidea: Wright, 1972:691.

DIAGNOSIS.— Galium not protruding be-
yond beaks. Umbonal reflections narrow,
lightly appressed over umbones, free
anteriorly. Mesoplax with blunt, ventrally
directed point and broad lateral wings
posteriorly. Periostracum not present inside
siphonal opening. Siphonoplax lacking.
DESGRIPTION.- Shell oval in outline, solid
in structure, reaching 10 cm in length and 5
cm in height (Turner, 1962: 306) (though
rarely even one-half these dimensions).
Immature specimens beaked, widely gaping
anteriorly, closed by complete callum in
adult; rounded and closed posteriorly.
Anterior slope sculptured by close-set,
upturned, undulating, concentric ridges,
and radial "ribs" formed by aligned undula-
tions of the ridges. Umbonal-ventral sulcus
prominent. Disc and posterior slope sculp-
tured with concentric growth lines and
obscure, low, rounded ridges. Umbones
prominent, located near anterior third of
shell.

Umbonal reflection narrow, lightly
appressed over umbo, free centrally and
anteriorly. Galium sculptured by weak
radial ribs (foreward extensions of radial
sculpture of anterior slope), does not
protrude anterior to beaks. Dorsal extension
of callum narrow, not lobate.

Mesoplax transverse, situated posterior
to umbones, truncate or pointed anteriorly,
rounded posteriorly with a blunt, ventrally
directed point, and with two wide lateral
wings posteriorly.

Umbonal-ventral ridge low, prominent,
terminating ventrally in small circular
condyle in active boring specimens, but
inconspicuous in adult. Muscle scars visible,
not roughened. Ventral muscle scar long,
narrow, overlaps umbonal-ventral ridge.
Posterior muscle scar elongate-oval in
outline. Pallial sinus broad, extends beyond
umbonal-ventral ridge, sometimes to ante-

rior margin. Apophyses flattened, not
blade-like, rotated 1/8 turn from long axis
of shell, wider ventrally, protruding at
angle slightly anterior to that of umbonal
ridge.

Periostracum moderately heavy, per-
sistent (Turner, 1955: 86), exists inside shell
at siphonal opening only as narrow marginal
band. Siphons capable of complete retrac-
tion within shell. Foot in young specimens
nearly circular in outline, truncate (Turner,
19.55: 86), atrophied in the adult.
HOLOTYPE.- Of Zirphaea gabbii Tryon,
ANSP 51085. Tryon (1863: 144) cites "?coast
of Japan," but according to Gabb (1869: 53),
Tryon believed it to be a Galifornia shell.
Turner (1955: 87) has subsequently re-
stricted the type locality to Monterey,
Galifornia. Recent.

DISTRIBUTION.- Recent; Drier Bay,
Knight Island, Prince William Sound,
Alaska (60° 18.5' N. lat.; Turner, 1955: 88),
south to Sacramento Reef, just south of Isla
San Geronimo, Baja California (29° 43.7' N.
lat.; LAGMNH 71-91).
GEOLOGIG RECORD.- Pliocene to Recent.

Pliocene: Etchegoin Formation, east of
Priest Valley in Hans Grieve Canyon, USGS
loc. 9393. Foxen Mudstone, at Waldorf
asphalt mine, 3 miles SSE of Guadalupe,
USGS loc. 4473 (Arnold, 1907: 423; Arnold
and Anderson, 1907: 59; both as Pholadidea
ovoidea, in part), and USGS loc. 14879 (both
localities, Woodring and Bramlette, 1950
[1951]: 41; as Pholadidea penita, in part),
CAS loc. 76, USGS loc. 23621. Graciosa
Member of Careaga Sandstone, Howard
Canyon, Solomon Hills, USGS loc. 14722
(Woodring and Bramlette, 1950 [1951]:
facing 48; ibid.). Cebada Member of Careaga
Sandstone, on Graciosa Ridge, 3.7 miles
•southeast of Orcutt, USGS loc. 14648
(Woodring and Bramlette, 1950 [1951]:
facing 48; ibid.), at Fugler Point asphalt
mine, one mile NNE of Garey, USGS loc.
4475 (Arnold and Anderson, 1907: 59; as
Pholadidea ovoidea, in part). Sisquoc For-
mation, at the Pennsylvania asphalt mine,
3V2 miles southeast of Orcutt, USGS loc.
4472 (Arnold and Anderson, 1907: 59; ibid.),
NTU asphalt mine, NNW of Casmalia,

WEST AMERICAN CENOZOIC PHOLADIDAE

47

UCMP loc. D-2845 (cf.).

Pleistocene: North side of Fivemile
Point near Bandon, Oregon, LACMNH loc.
3950. Isla Vista, near Santa Barbara
(Wright, 1972: 691; as Chaceia ovoidea).
Palos Verdes Sand, on north side of
Newport Bay proper, opposite Lido Isle,
UCMP loc. A-3132 (Bruff, 1946: 232; as
Pholadidea penita, in part). San Nicolas
Island, uses loc. 21655 (Vedder and
Norris, 1963: 46; as Penitella penita, in
part). Rosarito Beach, Baja California,

Mexico, SDSNH loc. 2531.
DISCUSSION.— The description of P.
gabbii was based on a unique battered
specimen without a callum sent to Tryon by
W.M. Gabb, who noted (1869: 52-53) that he
obtained it from Japan with a collection of
miscellaneous shells, though Tryon himself
believed it to be a California shell. Further
confusion about the species was perpetrated
by Gabb (1866-1869) who, in his treatise on
the paleontology of Cahfornia, actually
included three separate species in his
discussion of P. gabbii. In the citation, the
unique specimen (holotype) referred to is
Penitella gabbii, the figure is of a juvenile
Chaceia ovoidea, and the fossil reference to
large valves in the San Pedro Pleistocene
can only be Zirfaea pilsbryi. Both Tryon and
Gabb thought gabbii was a Zirfaea, which
led to subsequent common usage of the
name for the west coast species of Zirfaea.
Over sixty years passed before Lowe (1931:
52) recognized the type of gabbii as a Peni-
tella, and described Z. pilsbryi. Lowe how-
ever put gabbii in synonomy with Penitella
penita concamerata (Deshayes), itself a
synonym of P. penita. The validity of P.
gabbii (Tryon) was generally not accepted
until recognized by Turner (1955: 85).

Penitella gabbii is not easily confused
with other species of Penitella, and may be
readily identified by its narrow and
anteriorly free umbonal reflection, the
callum which does not extend beyond the
tips of the beaks, and the characteristic
mesoplax (see Fig. 37-38). The apophyses
are also flattened, gently curving, and are
unlike the stouter, weakly blade-like apoph-
yses of P. penita.

Penitella gabbii lives in the same
substrates as P. penita, i.e., in "soft" rock
on the open coast. At Coos Bay it is found in
abundance closely associated with P. penita
and P. tumerae, which has led some
workers to believe that together with P.
penita, it is responsible for the existence of
the "hybrid" P. tumerae. Without further
evidence this is not accepted, although
there are some suspicious records of these
species occurring together.

The geologic record of this species has
long been confused. With the specific name
gabbii "occupied" by a Zirfaea, there can be
little wonder that workers had to find other
names for this Penitella, and both penita
and ovoidea [= Chaceia] have been used.
This latter name, thought incorrect, is
appropriate because of the usual perfectly
ovoid shape of P. gabbii s callum filled
anterior.

Although Adegoke (1967: 16) was
correct in citing the geologic range of P.
gabbii as Pliocene to Recent, his conclusion
was based on two Pliocene records of
''Zirfaea gabbi" {= Zirfaea pilsbryi Lowe) and
not on the true Penitella. Zirfaea gabbi
(Tryon) femii Adegoke, introduced as "a
small variety of P. [enitella] gabbi," is also
Zirfaea pilsbryi. Penitella gabbii is abundant
as a fossil only in the asphalt mines in the
Pliocene Foxen Mudstone, Cebada Member
of the Careaga Sandstone, and in the
Sisquoc Formation, all exposed in the Santa
Maria district of California. Here P. gabbii
and equal numbers of P. tumerae are
commonly found in situ, with accessory
plates preserved, and together have been
variously reported under the specific names
ovoidea and penita. It is unusual that P.
gabbii is not better represented in the
Pleistocene of California, especially in the
San Pedro region. The only known Pleisto-
cene occurrences are from Isla Vista, the
Palos Verdes Sand of Newport Beach, San
Nicolas Island, and Rosarito Beach in north-
western Baja Cahfornia, Mexico.

48

GEORGE L. KENNEDY

Penitella kamakurensis (Yokoyama, 1922)
Figure 60

Jouannetm kamakurensis Yokoyama, 1922:120, pi. 6,

fig. 10. Hanzawa, Asano, and Takai, 1961:247.
"Jouannetia" kamakurensis: Sieverts, 1933:292.
Pholadidea penita: MacNeil, in MacNeil, Mertie, and

Pilsbry, 1943: 73, 75, 76, 94, pi. 16, fig. 4-6. Hopkins,

1967:66, 78. McCulloch, 1967:108.
Ph.[okididea] (P.[eniteUa]) kamakurensis: Habe, 1952:

243, fig. 665-666.
Pholadidea (Penitella) kamakurensis: Taki and Oyama,

1954: pi. 26, fig. 10. Taki and Habe, 1955:11, pi. 2, fig.

14-15. Kira, 1965:183, pi. 63, fig. 18. Masuda and

Matsushima, 1969: pi. 4, fig. 3.
P.[holadidea] (P.[enitella]) kamakurensis: Habe, 1955:

24 |in text], pi. 7, fig. 5-6.
Pholadidea kamakurensis: Itoigawa, 1963:110 [in text],

pi. 3, fig. 3.

DIAGNOSIS.— Anterior dorsal margin
short for genus. Umbonal reflection narrow,
not appressed anteriorly. Mesoplax longi-
tudinally ellipsoidal to rectangular, bluntly
pointed posteriorly, with small lateral
wings. Galium complete, flush with tips of
beaks, does not protrude beyond. Posterior
dorsal margin humped in adult.
ORIGINAL DESCRIPTION.- Shell small,
roughly four-sided in outHne, with surface
divided into two parts by a mesial groove.
The anterior half is very convex with the
dorsal margin very short and slightly
concave, and the ventral margin steeply
ascending, almost twice as long as the
dorsal, and at first straight, but excavated
near the upper end, so that the front border
of the shell becomes pointed, though blunt
at apex. The sculpture consists of concentric
and radiating riblets. The radiating riblets
are unequal, rather distant, about ten in
number, alternately large and small in the
middle portion of the surface and quite
absent in a small space immediately
bordering the mesial groove. The concentric
riblets are close, rounded and going over
the radiating ones, giving them a crenate
appearance. The margin is also crenate. The
dorsal margin of the posterior half of the
shell is double the length of that of the
anterior half, scarcely convex, sloping, the
meeting point with the ascending, somewhat
undulatory ventral margin being subtrun-
cate. Margin smooth.

LECTOTYPE. — Oi Jouannetia kamakuren-
sis Yokoyama, is in the Geological Institute,
University of Tokyo, no. CM 21154, here
designated. PARALECTOTYPE: In the
Institute, no. CM 21155. The lectotype, a
"living shell [was] picked up on the coast of
Kamakura" (Yokoyama, 1922: 120) on
Sagami Bay, Island of Honshu, Japan, here
designated the type locality. Recent.
DISTRIBUTION.- Recent; Island of Kyu-
shu, Japan (ca. 31-34° N. lat.; Kira, 1965:
183), north into the Gulf of Alaska
(Middleton Island, 59° 27' N. lat.; USGS-M
loc. 3852).

GEOLOGIC RECORD.- Pleistocene to
Recent.

Pleistocene: Upper Musashino [? = Na-
rita Formation] Formation, Shito, Chiba
Pref., Honshu, Japan (Yokoyama, 1922:
120). Second beach, Peluk Creek, near
Nome, Alaska, USGS loc. 3752 (MacNeil, in
MacNeil, Mertie, and Pilsbry, 1943: 94; as
Pholadidea penita) , USGS loc. 3751. Yakatat
Bay, Gulf of Alaska, USGS loc. 15864.
DISCUSSION. — Penitella kamakurensis
has not previously been reported, either
living or fossil, outside of Japan. The
species however occurs at least as far north
as the Gulf of Alaska (Chirikof Island and
Middleton Island). Pleistocene specimens
also are known from Alaska in the Second
Beach deposits near Nome, and in the
vicinity of Yakatat Bay, Gulf of Alaska.

The type specimens of Jouannetia
kamakurensis are now in the Geological
Institute of the University of Tokyo. Unfor-
tunately, Yokoyama did not indicate either
a type specimen nor a type locality. The
single specimen figured by Yokoyama (1922:
pi. 6, fig. 10; see Taki and Oyama, 1954: pi.
26, fig. 10), said to be the Pleistocene
specimen from Shito, is actually the Recent
one from the coast of Kamakura (K. Chinzei,
in litt.). This specimen (CM 21154) is
designated the lectotype, and the Pleisto-
cene specimen (CM 21155) is designated a
paralectotype. The "Holotype" listings in
Taki and Oyama (1954: facing pi. 26) and in
Hanzawa, Asano, and Takai (1961: 247) are
confusing because of Yokoyama's error in
his original plate description, and are con-
sidered invalid.

WEST AMERICAN CENOZOIC PHOLADIDAE

49

Penitella lorenzana (Clark, 1925)
Figures 28-32

Pholadidea aff. penita: Clark, 1918:162.

PhoJadidea (Penitella) lorenzaiia Clark, 1925:107, pi. 18,

fig. 5 [holotype], 6 [paratype]. Keen and Bentson,

1944:98.
Pholadidae lorenzana: Clark, 1925:107 (text),
not Pholadidea {Penitella) lorenzana: Weaver, 1953:60

{=Penitella durhami).
Penitella aff. P. penita: Addicott, 1966b:646.
Penitella lorenzana: Adegoke, 1967:11, fig. 14, 27.

DIAGNOSIS.— Shell narrow, flattened,
somewhat spindle-shaped. Posterior ex-
tremity subacutely pointed, closed. Galium
prominently protruded beyond beaks. Um-
bonal reflection narrow, free anteriorly.
Mesoplax more or less rectangular, bluntly
flattened posteriorly with lateral wings.
ORIGINAL DESCRIPTION.- Shell elon-
gate subovate; beaks [= umbones] in anterior
third of shell, each covered by a callus
which stands out very prominently on
anterior dorsal edge. Anterior portion of
shell separated from posterior portion by a
fairly deep transverse furrow, between
beaks [= umbones] and above the middle of
ventral edge. Anterior end bluntly pointed.
On specimens at hand, siphonal gap
[= anterior pedal gape] is filled by a callus
plate; posterior end subacutely rounded, not
gapping, as on shells belonging to the
Recent species, P. penita Conrad. Surface of
shell anterior to transverse furrow covered
by concentric spinose wavy lamellae; the
spines of the different lamellae are in line,
and so give the effect of a number of fairly
distinct radiating lines crossing the wavy
lamellae. Surface of shell posterior to trans-
verse lamellae smooth, except for somewhat
irregular, fairly heavy incremental lines; a
rather narrow, elongate quadrate metaplax
[= mesoplax] with upper surface rather
strongly concave, hinge plate not exposed.
SUPPLEMENTARY DESCRIPTION. -
Shell narrow, laterally compressed, some-
what spindle-shaped, small to medium in
size, reaching 6.5 cm in length, and 2 cm in
height. Anterior gaping in juvenile, closed
by callum in adult. Galium complete,
protrudes prominently beyond beaks. Pos-
terior compressed, conspicuously closed in

both young and adult stages. Anterior slope
sculptured with narrow low, slightly undu-
late concentric ridges with an inconspicuous
radial pattern. Umbonal-ventral sulcus nar-
row, distinct. Disc and posterior slope
ornamented with indistinct concentric
ridges.

Umbonal reflections appressed above
umbones, loose, free anteriorly. Callum
thin, protruding anterior to beaks, sculp-
tured with prominent concentric growth
lines. Dorsal extension of callum longitudi-
nally symmetrical, reasonably narrow, not
lobate.

Mesoplax [= metaplax of Clark] only
accessory plate, situated posterior to um-
bones, quadrate, posteriorly truncate, medi-
anly and centrally constricted, and with
posterior lateral wings.

On specimens from CAS loc. 36499 the
posterior muscle scar is nearly circular in
outline, and is situated high near the dorsal
margin at the posterior end of the shell.
Periostracum attachment scars extend only
a short distance within the siphonal end of
the valves.

HOLOTYPE.— Of Pholadidea {Penitella)
lorenzana Clark, UGMP 30323 (not 30612, as
cited by Clark, 1925: 107). A cast is in the
California Academy of Sciences, no. 6253
(Keen and Bentson, 1944: 98). PARATYPE:
UGMP 33491. Collected from UGMP loc.
1131, one half mile southwest of the town of
Walnut Creek, in creek bed about 100 yards
east of the Oakley-Antioch Bridge, Contra
Costa Co., California. 37° 53' 07" N. lat.,
122° 04' 08" W. long. Oligocene, basal San
Lorenzo [= San Ramon] Formation.
GEOLOGIC RECORD.- Oligocene to
Miocene.

Oligocene: San Ramon Formation,
southwest of town of Walnut Creek, UGMP
loc. 1131 (type locality; Clark, 1918: 162;
and Clark, 1925: 107), and in large highway
cut at Carquinez, CAS loc. 36499.

Miocene: Basal Montesano Formation,
Canyon River, Washington, USGS-M Iocs.
3117 and 1542 (both Addicott, 1966b: 646; as
Penitella aff. P. penita). "Monterey Forma-
tion," near Crockett, UGMP loc. D-599 (cf.).
DISCUSSION.— Penitella lorenzana, a

50

GEORGE L. KENNEDY

little known Oligocene to Miocene species,
has not been reported since its initial
discovery. The specimens which Clark
(1925) used in his description are probably
those which he had cited seven years earlier
as Pholadidea aff. penita Conrad from the
same locality (Clark, 1918: 162). At that
time he noted that it was probably new, but
declined to describe it due to the poor
preservation of the specimens.

At the type locality, P. lorenzana was
associated with the following mollusks
(Clark, 1925: 107; Adegoke, 1967: 11): Acila
muta (Clark), Anomia inconspicua Clark,
Antigona mathewsonii (Gabb), Anadara
(Anadara) mediaimpressa (Clark), Glycym-
eris tenuimbricata Clark, Mytilus mathew-
sonii Gabb, Yoldia cooperi supramonterey-
ensis Arnold, Bruclarkia gravida (Gabb),
and Molopophorus hiplicatus Gabb. The two
specimens of P. lorenzana collected by Clark
were boring from the basal Oligocene beds
"into beds that were presumably Tejon
[Eocene], though no Tejon fossils were
found at this locality [UCMP loc. 1131]"
(Clark, 1918: 162). The thinness of the
valves and the elongate shape indicate the
substrate must have been relatively soft at
the time of penetration by P. lorenzana.

Penitella lorenzana is presently known
only from the Oligocene, and possibly
Miocene, of central California, and the
Miocene of Washington. Four specimens
from CAS loc. 36499 from the San Ramon
Formation at Carquinez resemble P. loren-
zana in all respects, unless there are
differences in the mesoplax, which is
imperfectly preserved on the type speci-
mens. The mesoplax of at least one of these
specimens appears different from the rest,
but too little is known of the species to
validate any differences. Specimens from
the Miocene "Monterey Formation" near
Crockett (UCMP loc. D-599) are internal
molds and are only questionably assigned to
P. lorenzana on the basis of outline and the
prominently protruded callum. The speci-
mens cited by Addicott (1966b: 646) as
Penitella aff. penita- from the Miocene
Montesano Formation, Canyon River, Wash-
ington (USGS-M Iocs. 3117 and 1542) very

closely match the type specimens of P.
lorenzana.

Penitella lorenzana is easily separated
from the only other Oligocene Penitella, P.
durhami Adegoke, by the callum which
protrudes anterior to the beaks.

Penitella penita (Conrad, 1837)
Figures 46-54

P.[holas\ penita Conrad, 1837: 237, pi. 18, fig. 7.

Pholas concamerata Deshayes, 1839: 357.

Penitella speloeum Conrad, 1855: 7 {nomen nudum).
Blake, 1856: 55. Blake, 1857: 186.

P.[enitella] speloeum Conrad, 1855: 16.

Penitella spelaeum: "Conrad," 1856: 270.

Penitella spelaea: Conrad, 1857: 319. Carpenter, 1864:
590. Schuchert, 1905: 492.

P.[enitella] speloea: Conrad, 1857: 326, pi. 5, fig. 43,
43ab.

P.lenitella] curvata Tryon, 1865:40, pi. 2, fig. 6-8.

P. [enitella] penita: Gabb, 1869: 88, in part {P. penita, in
part P. tumerae).

Pholadidea penita: Cooper, 1888: 259, in part {Penitella
penita, in part P. tumerae). Bowers, 1890: 408.
Arnold, 1903: 15, 23, 25, 27, 31, 37. Arnold, 1906: 31,
34. Moody, 1916: 45. Jordan, 1924: 154. Oldroyd, 1925:
8. Crickmay, 1929: 631. Willett. 1937 [1938]: 106.
Putnam, 1942: 699. Weaver, 1942 (1943): 265, in part
(Penitella penita, in part P. tumerae). Bruff, 1946:
232, in part [Penitella penita, in part P. gabbii). Burch,
1947: 9. Woodring and Bramlette, 1950 [1951): 54, 91,
in part; not pi. 8, fig. 6, nor pi. 14, fig. 3 (Penitella
penita, in part P. gabbii, and P. tumerae [figures]).
Valentine, 1957: 297, in part (Penitella penita, in part
Parapholas califomica). Valentine, 1958:691, in part.
Valentine, 1960a: 163. Orr, 1960: 1117. Valentine,
1961: 407; 370, in part (Penitella penita, in part ZiV/aea
pilsbryi and Chaceia ovoidea). Valentine and Meade,
1961: 19: 10, in part (Penitella sp. cf. P. penita, Para-
pholas califomica and Nettastomella rostrata). Orr,
1968: 22.

IPholadidea (aff.) ovoidea: Watts, 1900 [1901]: 224.

Pholadidea (Penitella) penita: Arnold, 1903: 184.

Pholadidea ovoidea Conrad \sic]: Arnold and Anderson,
1907: 59, in part; not pi. 22, fig. lab (Penitella penita,
P. gabbii, and P. tumerae [fig. lab]) [author on plate
is Gouldl.

? Pholadidea cf. penita: Eldridge, 1907: 27.

not? Pholadidea penita: Arnold, 1908: 355 (7=Penitella
tumerae). Soper, 1938: 168 (Miocene). Weaver, 1945:
56 ('?=Pe7iitella tumerae). Woodring and Bramlette,
1950 [1951]: facing p. 49 (specimens not seen, likely
Penitella gabbii and/or P. tumerae).

not Pholadidea penita: Dall, 1909: 134. Howe, 1922: fac-
ing 92. (Both =Penitella tumerae). Hertlein and Crick-
may, 1925: 274. MacNeil, in MacNeil, Mertie, and Pils-
bry, 1943: 75, 94, pi. 16, fig. 4-6 (=Penitella kamakur-
ensis). Hopkins, 1967: 66, 78. McCuUoch, 1967: 108.
(Boih=Penitella kamakureiisis).

Pholadidea sagitta (Stearns Ms) Dall, 1916b: 417.

not Pholadidea aff. penita: Clark, 1918: 162 (=PeniteUa

WEST AMERICAN CENOZOIC PHOLADIDAE

51

lorenzana) .

Pholadidea penita ?: Hoots, 1931: 120.

Pholadidea {Pholadidea) penita: Grant and Gale, 1931:
434, in part; not pi. 24, fig. lab (Penitella penita. in
part P. conradi, and P. tumerae (figures]). Soper and
Grant, 1932: 1060.

not Pholadidea (Pholadidea) penita: Willett, 1937: 391
(=Pejiitella conradi). Wilson, 1966: 108 {=Penitella
tumerae).

Pholadidae \sic] penita: Upson, 1951: 430.

Penitella pe7iita: Fitch, 1953: 97, fig. 63. Turner, 1954:
pi. 5. Turner, 19.55: 80, pi. 47-51. Emerson, 1960: 5.
Vedder and Norris, 1963: 46, 50, in part {P. penita. P.
conradi, and P. gabbii). Evans, 1967a: 148. Adegoke,
1967: 17, fig. 11. Evans, 1968a: 271. Evans, 1968b:
111, pi. 1-4. Evans, 1968c: 1.56. Evans, 1968d: 619,
fig. 2. 4-5. Zullo, 1969: 3.50, fig. 4. Human, 1972: 9.
Bishop and Bishop, 1972: 6. Hertlein and Grant, 1972:
333, in part: pi. 56, fig. 8-9, 16; pi. 57, fig. 1-2 (P.
penita. not Miocene record).

Pholadidea ovoidea: Kanakoff and Emerson, 1959: 24, in
part (Chaceia ovoidea. in part Penitella penita).

Pholadidea:! sp.: Valentine, 1961: 360.

not Pholadidea cf. P. penita: Valentine, 1961: 389 {Peni-
tella tumerae and Parapholas calif omica) .

Pholadidea penita Carpenter |s('cl: Chace, 1966: 170, in
part {Penitella. penita. in part P. fitchi).

not Penitella penita: Addicott, 1966a: 4, pi. 4, fig. 1 (=P.
tumerae). Bradley and Addicott, 1968: 1204 { = P. tur-
nerae). Wright, 1972: 691 {=P. tumerae and P.
conradi).

not Penitella aff. P. penita: Addicott, 1966b: 646 (=P.
lorenzana).

Pholas penita: Keen, 1966: 171.

DIAGNOSIS.— Mesoplax sharply pointed
posteriorly with anteriorly swept-back
wings. Umbonal reflection wide, appressed
entire length. Dorsal extension of callum
low, often lobate. Posterior dorsal margin
not "humped." Apophyses short, solid,
thick, weakly blade-like.
DESCRIPTION.- Shell oval in outline,
solid in structure, medium to large in size,
reaching 9.5 cm in length, and 5 cm in
height. Anteriorly beaked, widely gaping in
young stage, closed with complete callum in
adult; posteriorly rounded and closed.
Anterior slope sculptured with moderately
to tightly spaced, upturned, undulate, con-
centric ridges. Aligned undulations create a
distinct radial pattern. Umbonal-ventral
sulcus distinct, variable in width. Disc and
posterior slope sculptured with growth
lines, or weak low ridges in thin shelled
specimens. The posterior-dorsal margin is
relatively straight with no bump.

Umbones prominent, situated anterior

to middle of shell. Umbonal reflection varia-
ble, appressed for entire length, usually
broader anteriorly. Callum protrudes slight-
ly beyond beaks, heavy, ornamented with
weak concentric growth lines. Dorsal
extension of callum extends anteriorly
around beaks, dorsally over umbonal reflec-
tions, doubles upon itself, forms enclosure
for anterior part of anterior adductor
muscle, anteriorly very low and lobate in
thick shelled specimens, moderately narrow
and longitudinally symmetrical in thin-
shelled specimens.

Mesoplax only accessory plate, situated
posterior to umbones, covered dorsally,
truncate anteriorly, keeled ventrally, sharp-
ly pointed posteriorly with anteriorly
swept-back lateral wings. Juvenile meso-
plax transverse, V-shaped.

Umbonal-ventral ridge low, distinct,
beaded in thin-shelled specimens. Ventral
condyle present in active boring specimens.
Muscle scars and pallial line visible. Pallial
sinus broad, extends anteriorly past
umbonal-ventral ridge. Apophyses short,
thick, solid, weakly blade-Uke, extending
anterior to direction of umbonal ridge.

Siphonoplax entirely periostracal, wide-
ly diverging. Periostracum usually heavy
on posterior slope. Siphons capable of
complete retraction within shell. Foot in
immature specimens large, oval in outline,
truncate, atrophied in adult (Turner, 1955:
82).

The original description of Penitella
speloeitm Conrad is: Ovate, ventricose,
anteriorly inflated with fine radiating lines
and transverse wrinkles, transverse furrow
medial, angular, slightly oblique; posterior
side cuneiform, truncated at the extremity,
which is direct, and with prominent, acute,
wrinkled concentric lines; from dorsal
margin widely recurved, trisulcate; cardinal
plate broad, sulcated process slender.
TYPES.— Of Pholas penita Conrad, are
missing (Turner, 1955: 83), though perhaps
in the Gould collection (see Carpenter, 1857:
194, and Keen, 1966: 171). Conrad (1837:
237 [236]) notes the specimens were from
"the vicinity of Sta. |San] Diego and Sta.
Barbara," California although often cited by

52

GEORGE L. KENNEDY

authors as San Diego. Carpenter (1857: 194)
however suggested the specimens were
from Sta. Barbara. Recent.
TYPES.— Oi Pholas concamerate Deshayes,
are missing (Turner, 1955: 83). They are not
in the British Museum (Natural History)
(J.D. Taylor, in litt.). "Californie, dans les
marnes calcaires des rivages," Monterey,
California. Recent.

LECTOTYPE [7H0L0TYPE]. - Of Peni-
telLa speloeum Conrad, USNM 1868, here
designated. San Pedro, California (Conrad,
1855: 16). In accordance with Blake (1856:
55) the type locality is here redefined as the
summit of 30 foot high bluffs near the mouth
of the Los Angeles River, and south of the
landing. Bay of San Pedro [now Los Angeles
Harbor, California], collected by W.P.
Blake, 1853. "Recent Formation" [= late
Pleistocene, Palos Verdes Sand].
LECTOTYPE.— OiPenitella curvata Tryon,
ANSP 51004, designated by Turner (1955:
83). PARALECTOTYPES: ANSP 316742
(eight valves). Strait of San Juan de Fuca,
collected by W.M. Gabb. Recent.
HOLOTYPE.— Of Pholadidea sagitta Dall,
USNM 63312. Monterey, California. Recent.
DISTRIBUTION.- Recent; at least from
the Gulf of Alaska (Montague Island, ca. 60°
N. lat.; USGS-M loc. 3601), south to Punta
Pequeiia, Baja California, Mexico (26° 14' N.
lat.; LACMNH 71-181, and 71-179).
GEOLOGIC RECORD.- Pliocene to Recent.
Pliocene: "Merced" Formation, Moss
Beach, CAS loc. 34437. Etchegoin Forma-
tion, Reef Ridge quad., UCMP loc. D-1124
(Adegoke, 1969: 155; "cf. P. penita" [not
seen]). ?Careaga Sandstone, 3 miles south-
east of Orcutt, USGS Ico. 4476 (Arnold and
Anderson, 1907: 59; as Pholadidea ovoidea,
in part). Fernando Formation, southeast
flank of Mt. San Cayetano (Eldridge, 1907:
27; specimen not seen), in Los Angeles on
Fourthh Street between Broadway and Hill,
UCMP loc. 3030 (cf.) (Moody, 1916: 45;
Soper and Grant, 1932: 1060), Interstate 405
and Cherry Avenue, Long Beach, LACMNH
loc. 423. San Diego Formation, "quarry" at
end of Arroyo Drive, San Diego, LACMNH
loc. 107 (cf.) (Hertlein and Grant, 1972:
facing pi. 57), in southwest corner of San

Diego County, SDSNH loc. 0417 and UCLA
loc. 312 (both Hertlein and Grant, 1972:
333), SDSNH loc. 0429, on hill southwest of
Goat Canyon, LACMNH loc. 305. South end
of San Quintin Valley, Baja California,
Mexico, LACMNH loc. 453.

Pliocene or Pleistocene: South of Cape
Blanco, Oregon, UCMP loc. A-8709 (cf.). In
bluff near beach, San Juan Capistrano,
LACMNH loc. 1144. In bluff near beach
between San Quintin and Rancho Socorro,
Baja California, Mexico, SDSNH loc. 2658.
[Neogene], southwest of Rosario, Baja
California, Mexico, USGS loc. 10058 (cf.).

Pleistocene: Fivemile Point, near Ban-
don, LACMNH Iocs. 3950 and 3951,
USGS-M loc. 4623. Coquille Point, Bandon,
Oregon, USGS-M loc. 2798 (Zullo, 1969:
350). Cape Blanco, Oregon, LACMNH loc.
2641. Three miles north of Cayucos, CAS
loc. 31832. One half, IV2, and 2V2 miles west
of Cayucos Creek, UCLA Iocs. 3393 (in
part), 3448, and 3445, and at Cayucos,
UCLA loc. 3447 (all Valentine, 1958: 691).
Southeast of Point Sal Landing, USGS loc.
14966 (Woodring and Bramlette, 1950
[1951]: 54; cf.). West of Tajiguas Creek,
near Gaviota, USNM (field no. NT-37)
(Upson, 1951: 430). West of Punta Gorda
(Putnam, 1942: 699). Near Sea Cliff RR
station, north of Ventura City, SDSNH loc.
0078 (cf.). North end of Santa Rosa Island
(Orr, 1960: 1117). Mouth of Potrero Canyon
(Hoots, 1931: 120). Redondo Beach,
LACMNH loc. 14. Los Angeles City,
community of Watts, LACMNH loc. 2690,
Vermont and Sepulveda, north of San Pedro
(Cook and Clark, 1943: 17). Timms Point
Silt, north border of the Palos Verdes Hills,
UCLA loc. 3460 (Valentine, 1961: 407).
Undifferentiated Pleistocene, in San Pedro
(Arnold, 1906: 34), LACMNH loc. 5,
SDSNH loc. 1883, northwest of Whites
Point, USGS loc. 13130, San Pedro RR cut,
SDSNH loc. 1899, Nob Hill, SDSNH loc.
1885, and below, LACMNH loc. 300,
lumberyard near Timm's Point, LACMNH
loc. 1203, Deadman Island, CAS loc. 495,
LACMNH Iocs. 17 and 1206. Lomita Marl,
northeast corner of Host Place, and Park
Western and Coralmount Drives, San

WEST AMERICAN CENOZOIC PHOLADIDAE

53

Pedro, SDSNH loc. 2669. San Pedro Sand,
in San Pedro, at the "Chiton Bed" [of Chace
and Chace, 1919] on Point Firmin, SDSNH
loc. 0625, Peck Park, USGS loc. 13125, at
High School at 15th and Leland Streets,
SDSNH loc. 2138 [ = L-2138] (Chace, 1966:
170; in part), Nob Hill cut (Oldroyd, 1925:
8), Second and Beacon Streets, UCLA loc.
1824 (Valentine and Meade, 1961: 19),
southeast corner of Third and Mesa Streets,
LACMNH loc. 98, SDSNH loc. 2660, Eighth
Street and Palos Verdes Avenue, LACMNH
loc. 226, Deadman Island (Arnold, 1903: 15,
37; and Arnold, 1906: 31), CAS loc. 94.
Palos Verdes Sand, old Bixby Slough,
Harbor City, LACMNH loc. 229, in San
Pedro, at Southern Pacific RR depot, CAS
loc. 91 (cf.), at southeast corner of Pacific
Avenue and Hards Street, LACMNH loc.
440, Pacific Avenue and Bonita Street,
USGS loc. 12132, southeast corner of Pacific
Avenue and Oliver Street, USGS-M loc.
2017, Palos Verdes Avenue between Eighth
and Ninth Streets, UCLA loc. 3440 (Valen-
tine, 1961: 370; in part), old Crawfish
George's (Arnold, 1903: 25), Deadman
Island (Arnold, 1903: 23; Crickmay, 1929:
631), CAS Iocs. 90 and 92, north end of San
Pedro Bluff (Arnold, 1903: 27; = lumberyard
locality, p. 37), "Arnold's lumberyard," on
Harbor Boulevard, USGS-M loc. 1728, south
of Union Oil refinery, in Harbor District
Sanitation Yard, LACMNH loc. 1210, bluff
east of Gaffey Street, USGS loc. 12139, Los
Cerritos Hill [= Signal Hill] (Arnold, 1903:
31), Cherry Avenue, Signal Hill, USGS-M
loc. 2011, Pacific Coast Highway and
Newport Bay, LACMNH loc. 241, on west
bluff of "middle" Newport Bay, UCMP loc.
A-3104 (Bruff, 1946: 232), on east bluff
above Upper Newport Bay, LACMNH loc.
66-2 (Kanakoff and Emerson, 1959: 24; as
Pholadidea ovoidea, in part), SDSC loc. 533.
San Joaquin Bay [= Newport Bay], CAS
(CSMB 11896) (?Bowers, 1890: 408). Corona
del Mar (Human, 1972: 9). Near Calle
Fortuna, Capistrano Beacch, LACMNH loc.
58 (Willett, 1937 [1938]: 106), LACMNH loc.
137. San Nicolas Island, USGS loc. 21655
(Vedder and Norris, 1963: 46; in part).
Torrey Pines Beach State Park, UCLA loc.

2410 (Valentine, 1960a: 163; as UCLA loc.
3457). Pacific Beach, San Diego, UCLA loc.
3606 (Valentine, 1961: 360; as Pholadidea'?
sp.). Foot of Tourmaline Street, Pacific
Beach, SDSNH loc. 0289 (Bishop and
Bishop, 1972: 6), UCMP loc. 5092. West side
of Point Loma, UCLA loc. 3605 (cf.)
(Valentine and Meade, 1961: 10; in part),
SDSNH Iocs. 2530 and 2668. In Baja
California, Mexico, 10 miles south of the
U.S. border, SDSNH loc. 2576; 8, and 5.2
miles north of Rosarito Beach, UCLA Iocs.
3161 and 3160 (both Valentine, 1957: 297);
Rosarito Beach, UCLA loc. 2720 (Valentine,
1957: 297), SDSNH loc. 2531; 2.2, 5.7, 6.4,
and 8.5 miles south of Rosarito Beach,
UCLA Iocs. 2719, 2718, and 2717 (all
Valentine, 1957: 297), and SDSNH loc. 2629;
El Descanso, SDSC loc. 109; immediately
south of Punta San Jose (Emerson, 1960: 5);
south of Punta Cabras, UCMP loc. A-9587
(Addicott and Emerson, 1959: 17; "cf. P.
penita" [not seen]); northwest, and south-
west sides of Turtle Bay, UCMP Iocs.
B-3027, and B-3007.

DISCUSSION.— Penitella penita is the
commonest and best known of all Pacific
coast pholadids. It is widely distributed geo-
graphically and, due mostly to the variety of
substrates it can and will inhabit, is
extremely variable in form. It will bore into
clay, shale, mudstone, sandstone (all in
various stages of induration), though only
rarely into other shell (in Haliotis rufescens,
SDSNH 50959). Usually found on the open
coast, it frequents intertidal and subtidal
habitats, with burrows as deep as 13 cm
(Fitch, 1953: 97). Penitella penita is often
associated with Chaceia ovoidea, Penitella
fitchi, P. gabbii, P. tumerae, Parapholas
califomica, Nettastomella rostrata, Litho-
phagaplumula (}ian\ey, 1843), Adula falcata
(Gould, 1851) and Platyodon cancellatus
(Conrad, 1837).

Complete specimens of Penitella penita
are easily distinguished from other species
of Penitella by the sharp posteriorly-pointed
mesoplax with "swept-back" wings. Loose
valves of P. penita are readily separated
from those of P. fitchi by the pointed beaks
and the long, narrow, anterior-dorsal

54

GEORGE L. KENNEDY

margin of the shell, and from P. gabhii (and
juvenile Chaceia ovoidea) by the wider and
fully appressed umbonal reflection. From P.
conradi and P. turnerae, it is less easily
separated. Specimens of P. conradi that
bore into soft rock are small (up to 3 cm in
length), very perfectly formed, globose,
have roughened posterior muscle scars, and
usually thin and fragile apophyses and
callum. The dorsal margin posterior to the
umbo is humped, not straight as in P.
penita. Penitella turnerae has the anterior
margin immediately ventral to the beaks
strongly angled, a longitudinally symmetri-
cal umbonal reflection and a high and
longitudinally symmetrical, not lobate, dor-
sal extension of the callum. The apophyses
are usually flattened and gently curving,
unlike the stout, weakly blade-like apophy-
ses of P. penita.

Because of the relative abundance of P.
penita in the living fauna of California, it
has often been assumed, though incorrectly,
that any fossil Penitella was P. penita, and
the name has served for many years in this
capacity as a junk-basket term. In reported
literature, none of the Miocene or older
records can be substantiated with actual
specimens of P. penita, and the verified
geologic range is accordingly restricted to
Pliocene through Recent. In fact, actual
Pliocene occurrences are few, and the
species is not known from the lower
Pliocene at all. Known occurrences, in the
"Merced," Fernando, and San Diego forma-
tions, all are upper Pliocene or later.

Penitella penita, however, is quite
abundant in Pleistocene deposits of Califor-
nia and northern Baja California. Most were
associated with a large number of molluscan
species collected from detrital death assem-
blages representing a wide range of
habitats. Only a few instances of P. penita
occurring abundantly in situ have been
reported, although it is not uncommon to
find single specimens in cobbles in detrital
deposits.

Penitella turnerae Evans and Fisher, 1966
Figures 61-64

Ph()ladidea penita: Cooper, 1888: 259, ? in part {Penitella
penita? or P. turnerae'?). Dall, 1909: 134. Arnold and
Hannibal, 1913: 594. Howe, 1922: facing 92. Hertlein
and Crickmay, 1925: 274. Weaver, 1942 |1943]: 265,
639. Woodring and Bramlette, 1950 [1951]: facing 34,
41, 48, facing 48, 66, 91, in part; pi. 8, fig. 6, and pi.
14, fig. 3 {Penitella penita [Pleistocene, p. 54], in part
P. gabbii and P. turnerae [figures]).

Pholadidea ovoidea Conrad [sic]: Arnold, 1907: 423, in
part; pi. 55, fig. la-b. Arnold and Anderson, 1907: 59,
in part; pi. 22, fig. lab. {Penitella gabbii, P. penita,
and P. turnerae [figures]). [Author on plates is Gould].

? Pholadidea penita: Arnold, 1908: 355 [cf. Addicott,
1966a: 4]. Weaver, 1945: 56.

? Parapholas califomica: Arnold and Hannibal, 1913: 590.

Pholas borings: Arnold and Hannibal, 1913: 603. Howe,
1922: 89. Schenck, 1927: 454. Schenck, 1928: 19, 20.

? Parapholas califomica Hinds [sic]: Howe, 1922: facing
92.

Pholadidea califomica: Oldroyd and Grant, 1931: 91.

Parapholas califomica: Oldroyd and Grant, 1931: 92.

Pholadidea {Pholadidea) penita: Grant and Gale, 1931:
434, in part; pi. 24, fig. lab {Penitella penita, in part
P. conradi and P. turnerae [pi. 24, fig. lab]). Wilson,
1966: 108.

Pholadidea cf. P. penita: Woodring, Stewart, and Rich-
ards, 1940 [1941]: 70. Valentine, 1961: 389, in part
{Penitella turnerae and Parapholas califomica).

? Pholadidea califomica: Weaver, 1942 [1943]: 265, 639.
Weaver, 1945: 56 (as "?").

Pholas sp.: Weaver, 1945: 50. 51.

Zirfaea pilsbryi: Addicott, 1963: 344.

Penitella turnerae Evans and Fisher, 1966: 222, pi. 31
[in part].

Penitella penita: Addicott, 1966a: 4, pi. 4, fig. 1. Bradley
and Addicott, 1968: 1204. Wright, 1972: 691, in part
{P. turnerae and P. conradi).

DIAGNOSIS.— Very prominently beaked
in young stage, anterior margin strongly
angulate. Umbonal reflection longitudinally
symmetrical, not wide, appressed to
anterior slope except right near beaks.
Dorsal extension of callum usually high,
longitudinally symmetrical, and not lobate.
Mesoplax subacuminate to broadly crescent-
shaped posteriorly, with lateral wings,
anterior portion usually narrower than
posterior portion. Apophyses flattened their
entire length, gently curving, not blade-like.
DESCRIPTION.- Shell large, reaching 12
cm in length and 5 cm in height, somewhat
pear-shaped in outline, solid in structure,
and producing a callum in adult stage.
Immature specimens very strongly beaked,

WEST AMERICAN CENOZOIC PHOLADIDAE

55

anterior margin near beaks sharply
angulate.

Anterior slope sculptured with widely
to narrowly spaced, upturned, undulate
concentric ridges, supplemented by radial
pattern formed by alignment of undulations
of the ridges. These "radial ribs" may be
arranged in pairs. Anterior slope separated
from disc by prominent umbonal-ventral
sulcus. Undulating ridges of anterior slope
give sulcus ladder-like appearance as they
cross it, continue on disc as narrow, low
rounded, smooth ridges (or heavy growth
lines).

Umbonal reflection somewhat longitudi-
nally symmetrical, appressed to anterior
slope for entire length except near beaks.
Pedal gape large, sub-oval in young stage,
closed by complete callum in adult. Galium
sculptured by concentric growth lines
parallel to anterior margin, and by slight
radial ridges which are extensions of radial
pattern of anterior slope. The central part
of the callum is elevated above general
surface, probably due to vestigial presence
of foot. Callum protruded anterior to beaks,
dorsal extension of which is high, somewhat
longitudinally symmetrical.

Mesoplax only accessory plate, situated
posterior to umbones, somewhat V-shaped
in young stage, covered, semipointed with
lateral wings (remnants of juvenile plate) in
adult. The posterior end is almost crescent-
shaped in some specimens, centrally con-
stricted, or narrowed anteriorly.

Umbonal-ventral ridge prominent,
either beaded in thin specimens or smooth
in heavy shelled ones. Pallial line and
muscle scars well calcified and readily
apparent. Pallial sinus extends anteriorly
past umbonal-ventral ridge, sometimes
almost to mid-point of anterior margin.
Ventral muscle scar sausage-shaped. Poste-
rior muscle scar oval to sub-oval. Anterior
muscle scar pad not prominently calcified.
Apophyses extend anteriorly away from
umbonal-ventral ridge, usually flattened
their entire length, just barely spooned,
gently curving, not blade-like.

Periostracum thin, found primarily on
posterior slope, extends internally into

siphonal end of shell. Foot well developed,
oval and truncate (Evans and Fisher, 1966:
222). Siphons capable of complete retraction
within shell.

HOLOTYPE.— OiPenitella turnerae Evans
and Fisher, CAS 12445. PARATYPES: CAS
12445a, MCZ 170898 (4 specimens), RM
16284 (2 specimens), and UO 1334 (3
specimens). North end of Fossil Point in
Coos Bay, Coos Co., Oregon, "in soft muddy
sandstone at zero foot tide level." 43° 22' N.
lat., 124° 15' W. long. Recent.
DISTRIBUTION.— Recent; at least from
Newport, Oregon (46° 38.5' N. lat.; ANSP
130970, SDSNH 7046) south to Waddell
Beach, Santa Cruz Co., California (37° 06'
N. lat.; LACMNH 67-95).
GEOLOGIC RECORD.- Pliocene to Recent.
Pliocene: Empire Formation, Coos Bay
and vicinity, Oregon, USGS loc. 2954
(USNM 153957; Dall, 1909: 134 [as Miocene];
Weaver, 1942 [1943]: 265, 639), UCMP Iocs.
3321 [not seen] and 3322 (both Howe, 1922:
facing 92; as Parapholas calif ornica and
Pholadidea penita), UCMP loc. A-87, USGS
loc. 18284, east side of South Slough, UW
loc. 719 ("?" as Pholadidea califomica),
Fossil Point, UW loc. 725 (both Weaver,
1945: 56 [specimens not seen]), east of
Tunnel Point, UW loc. 752 (Weaver, 1945:
50, 51; as Oligocene, Pholas sp.), CAS loc.
243. Arroyo Murado, northwest of El
Pulgar, North Dome of Kettleman Hills,
USGS loc. 14118 (Woodring, Stewart, and
Richards, 1940 [1941]: 70; as Pholadidea
penita). Sisquoc Formation, Pennsylvania
asphalt mine, southeast of Orcutt, USGS
loc. 4472 (Arnold and Anderson, 1907: 59; as
Pholadidea ovoidea, in part; also Woodring
and Bramlette, 1950 [1951]: 91; as Phola-
didea penita, in part), NTU asphalt mine,
NNW of Casmalia, UCMP loc. D-2845 (cf.).
Foxen Mudstone, Waldorf asphalt mine,
SSE of Guadalupe, USGS loc. 4473 (Arnold,
1907: 423; and Arnold and Anderson, 1907:
59; both as Pholadidea ovoidea, in part),
USGS loc. 14879 (both Iocs. Woodring and
Bramlette, 1950 [1951]: 41; as Pholadidea
penita [specimens not seen]), CAS loc. 76.
Careaga Sandstone (Cebada Member), at
Fugler Point, north of Garey, USGS loc.

56

GEORGE L. KENNEDY

14768 ("cf."), on Graciosa Ridge, southeast
of Orcutt, USGS loc. 14648 (both Woodring
and Bramlette, 1950 [1951]: facing 48; as
Pholadidea penita) . "Bracket Mesa," Arroyo
Santa Catarina, Baja California, Mexico,
SDSNH loc. 2646 (cf.).

Pleistocene: Crescent City, USGS-M
loc. 1449 (Addicott, 1963: 344; as Zirfaea
pilshryi), LACMNH Iocs. 3944 and (all cf.)
3943, 3945, and 3946. Point Ano Nuevo,
USGS-M Iocs. 1690 and 2147, and Point
Santa Cruz, USGS-M loc. 1691 (all Addicott,
1966a: 3, 4; as Penitella penita). RR cut
west of Tajiguas Creek, near Gaviota,
UCLA loc. 3597 (Valentine, 1961: 389; as
Pholadidea cf. P. penita, in part). Isla Vista,
near Goleta (Oldroyd and Grant, 1931: 91,
92; Wright, 1972: 691; as Penitella penita),
SDSNH loc. 0074, LACMNH Iocs. 416 and
2694, ANSP [no locality number].
DISCUSSION. — Penitella turnerae is a
recently described species which was not
recognized until a large series of living
specimens was collected by Evans and
Fisher from Fossil Point in Coos Bay,
Oregon. Though morphologically distinct, it
is similar in certain aspects to both P. gabbii
and P. penita, and has often been cited as
the latter species, or as Parapholas cali-
fornica.

There is some disagreement as to the
validity of this species. Turner (pers. comm.
and in Evans and Fisher, 1966: 224)
believed that, because of its similarity to
the above mentioned species, and its
described occurrence from a single locality,
it should be treated as an infertile hybrid,
and cited as Penitella gabbii x Penitella
penita. I have seen Recent specimens from a
number of different localities on the coasts
of northern California and Oregon which
extend the range considerably, and prove
the areal extent beyond the type locality.
Noteworthy is the fact that P. turnerae
frequently occurs with P. gabbii and P.
penita. At the type locality all three species
occur together, and at Duxbury Reef at
Bolinas, California, P. gabbii and P. penita
are abundant, and beach worn specimens of
P. turnerae are not uncommon. Whether P.
turnerae is really a distinct species or a

hybrid needs to be investigated, though
both schools of thought recognize it as
morphologically distinct. In the light of
fossil evidence, I recognize P. turnerae as a
valid species.

Penitella turnerae can usually be
separated from P. penita by its large size,
the high and longitudinally symmetrical
dorsal extension of the callum, the strongly
angulate anterior margin ventral to the
beaks, and the umbonal reflection which is
not appressed at its anterior extremity.
Further, the mesoplax is not sharply
pointed posteriorly and the apophyses are
flattened and gently curving and unlike the
sharp blade-like apophyses of P. penita.

In the fossil record, P. turnerae is
rather common in certain localities in
California and Oregon. It is the large
Penitella which is found in situ on the low
late Pleistocene terrace at Isla Vista, near
Santa Barbara, California. Grant and Gale
(1931: pi. 24, fig. lab) figured one of these
specimens as Pholadidea penita, which has
caused confusion in subsequent paleontolog-
ical literature. Outside of the questionable
occurrence in Baja California at Arroyo
Santa Catarina, Santa Barbara, California,
is the most southerly occurrence of this
species in the Pleistocene, and Recent
specimens are known only from Santa Cruz
Co., California, to Newport, Oregon.

Two localities on a late Pleistocene
marine terrace in the vicinity of Point Ano
Nuevo in San Mateo Co., California
(Addicott, 1966a: 3; cited as Penitella penita)
contain large numbers of P. turnerae in
situ. On the south side of the Point (at
USGS-M loc. 1690) P. turnerae is found
inhabiting steeply inclined burrows and
associated with Zirfaea sp. aff. Z. pilshryi,
Saxidomus giganteus (Deshayes, 1839) and
Protothaca staminea ruderata (Deshayes,
1853). The substrate at this locality is the
Miocene Monterey Formation. At another
locality (USGS-M loc. 2147) north of Pt. Ano
Nuevo, a terrace platform (cut into the
Pliocene Purisima Formation) is extensively
pitted with holes of P. turnerae, many of
which are still in situ.

In the Santa Maria district of Califor-

WEST AMERICAN CENOZOIC PHOLADIDAE

57

nia, P. turnerae is quite common in the
asphalt mines in the Guadalupe-Orcutt area,
where it is associated with approximately
equal numbers of P. gabbii, and only rarely
with P. penita. The species occurs in a
succession of formations (Foxen Mudstone,
Cebada Member of the Careaga Sandstone,
and the Sisquoc Formation) without any
apparent change.

Poorly preserved specimens are not
uncommon in the Pliocene Empire Forma-
tion of the Coos Bay region of Oregon, and
it is the only fossil pholadid known from
this area. The reports of Dall and Weaver of
Penitella penita in the Empire Formation
refer to P. turnerae. It is quite probable
also that the references to occurrences of
Parapholas califomica in the "Miocene" and
Pliocene of Coos Bay (Arnold and Hannibal,
1913: 590; Howe, 1922; facing 92; Weaver,
1942 [1943]: 265, 639; and Weaver, 1945: 56)
refer to these large bulbous specimens
common to that area. Parapholas califomica
is the only species which might be confused
with P. turnerae on size alone, though no
specimens of Parapholas from here have
ever been figured, or are present in
numerous fossil collections examined.

Genus Martesia Sowerby, 1824

Martesia Leach [MS] Sowerby, 1824: no pagination |2nd
p. of Pholas]. Bartsch and Rehder, 1945: 2. Turner,
1955: 101.

DEFINITION.— Shells pear shaped, light
in structure, small, usually not over 3.5 cm
in length, divided into two regions by
umbonal-ventral sulcus. Beaks sinuously to
sharply truncate, widely gaping anteriorly
in young stage, closed by complete callum in
adult. Valves narrowly to broadly rounded
posteriorly and closed. Umbones prominent,
nearly centrally located in young shells,
near anterior end in adult due to dispropor-
tionate growth of posterior portion of shell.
Umbonal reflection closely appressed over
umbo, raising abruptly anteriorly to form
distinct funnel-shaped pit.

Mesoplax covered dorsally, broadly
circular to ellipsoidal, situated anterior to
umbones. Metaplax and hypoplax long,

narrow and pointed anteriorly, pointed,
truncate, or divided posteriorly. Dorsal
margin of shell posterior to umbo may be
reflected upon itself to form a narrow
enclosure (in Paramartesia). Umbonalven-
tral ridge distinct, narrow, usually beaded.
Chondrophore and internal ligament pres-
ent, but small. Apophyses long, thin, and
fragile. Siphons capable of complete retrac-
tion within shell.

Martesia differs from closely related
genera in the Martesiinae by the presence
of the mesoplax, metaplax, hypoplax,
funnel-shaped pit below the umbonal reflec-
tion, and complete callum. There is no
dorsal extension of the callum. The poste-
rior slope is not covered with periostracal
flaps and the umbonal-ventral sulcus (and
corresponding ridge) is the only radial
division of the shell. Species of Martesia are
wood-borers.

TYPE SPECIES.— Pholas clavata Lamarck
( = Martesia [M.] striata [Linne, 1758]), by
original monotypy.

TAX A INCLUDED.— Recent species of
Martesia are divided into two subgenera,
Martesia s.s. and Particoma Bartsch and
Rehder, on the basis of umbonal and
accessory plate morphology. The subgenus
Paramartesia, on the basis of shell morphol-
ogy alone, is described herein.

The two living species of Martesia
found in the eastern Pacific are M. (M.)
striata (Linne, 1758), and M. {M.) fragilis
Verrill and Bush, 1898, both occurring in
the warm waters of the tropics and
subtropics. Martesia striata occurs as far
north as the mangrove swamps of Magda-
lena Bay on the outer coast of Baja
California. Neither species has been
identified from fossil deposits in western
North America, though both have occasion-
ally been reported in the Neogene of the
eastern and Gulf coastal states.
DISCUSSION.— Martesia s.s. is distin-
guished from Particoma by the presence of
a non-bifurcate metaplax and hypoplax,
and by the shape of the mesoplax. In the
former it is broadly circular, and in the
latter it is ellipsoidal. The anterior adductor
muscle scar pad in Martesia s.s. is

58

GEORGE L. KENNEDY

sickle-shaped and attached anteriorly, while
that of Particoma is thicker and oval-
shaped. The nature of the sculpture on the
mesoplax, as well as the shapes of the ends
of the long dorsal and ventral plates are
useful in specific determination. The number
of concentric ridges or shape of the valves in
general are not however.

Reportedly, Martesia is the oldest
known genus of Pholadidae, occurring in the
Carboniferous (questionably), and from
Jurassic to Recent (see Turner, 1969: 711).
Some of these early occurrences may
acutally belong to Opertochasma Stephen-
son, 1952, a wood boring genus not uncom-
mon in the Cretaceous of North America. I
have seen no specimens of true Martesia
older than early Tertiary. References to
nominal species of Martesia in the Paleocene
and Eocene of the eastern and southeastern
United States are listed in Palmer and
Brann (1965: 191).

Fossil specimens of Martesia are rare in
Cenozoic deposits of western North Amer-
ica. Burrows in fossil wood figured by
MacNeil (1957: pi. 12, fig. 1; USNM 561882)
as possibly belonging to a Martesia with
Atlantic affinities were made by teredinids.
Besides M. meganosensis Clark and Wood-
ford, and M. (Paramartesia) tolkieni Ken-
nedy, subgen. et sp. nov., the only
occurrences of Martesia which can be
documented by specimens are:

1) One small, poorly preserved speci-
men from the upper Eocene or lower
Oligocene Keasey Formation from Rock
Creek, south of the Keasey Post Office,
Keasey, Oregon (UCMP loc. 4194). No
accessory plates are preserved.

2) Forty-two specimens of ''Martesia
sp." cited by Hickman (1969: 69, pi. 8, fig. 4,
6) from the middle Oligocene Eugene
Formation, near Eugene, Oregon (UO Iocs.
80, 2544, 2553, and 2554). Several speci-
mens are still preserved in a fragment of
fossil wood (UO 27326) with the mesoplax
present. They belong to Martesia s.s.

3) Two single valves belonging to
Martesia have been collected from Pleisto-
cene deposits at Puerto Libertad, Sonora,
Mexico, by T.E. Stump and R.J. Dowlen in

1972 [field no. S2-SD-5]. The specimens
represent the only known fossil pholadids
from the Gulf of California region.

Subgenus indet.

Martesia meganosensis Clark and Woodford,

1927

Figures 65-66

Martesia meganosensis Clark and Woodford, 1927: 103,
pi. 18, fig. 7-8. Keen and Bentson, 1944: 65.

DIAGNOSIS.— No features considered dis-
tinctive below the generic level are present
on the poorly preserved types. Further re-
cognition of the species can only be
speculative.

ORIGINAL DESCRIPTION.- Shell some-
what variable in length, roughly elongate,
ovate in outline; umbones broad, fairly
prominent, strongly inturned, and slightly
prosogyrous. Anterior edge sloping rather
abruptly down to the anterior end; posterior
dorsal margin long, straight to slightly con-
vex; ventral margin straight. Anterior end
with a sharp V-shaped notch which shows
very decidedly in the concentric lines of
growth. Surface sculptured by heavy,
broadly rounded concentric ribs or undula-
tions on and between which are finer incre-
mental lines; the interspaces between these
undulations are about half their width. A
very distinct umbonal groove extends
obliquely and posteriorly from the umbones
to the ventral edge.

SUPPLEMENTARY DESCRIPTION. -
Anterior gape and (or) callum rhomboidal,
upper two sides shortened, slightly concave.
Both the type and paratype are small, poorly
preserved, and in matrix. The accessory
plates are absent and the umbonal regions
are obscured.

HOLOTYPE. — Of Martesia meganosensis
Clark and Woodford, UCMP 31297. PARA-
TYPE: UCMP 31298. Casts of each are in
the California Academy of Sciences, type
nos. 6206 and 6207. Northeast of Mt. Diablo,
on ridge immediately east of hill 392, near
margin of Byron quadrangle. Contra Costa
Co., California (UCMP loc. 3577). Elevation
375 feet. Early Eocene, Meganos Formation
(division D).

WEST AMERICAN CENOZOIC PHOLADIDAE

59

GEOLOGIC RECORD.— Eocene.

Eocene: Meganos Formation (division
D), northeast of Mt. Diablo, on ridge im-
mediately east of hill 392 near western
margin of Bryon quadrangle, UCMP loc.
3577 (holotype), on top of ridge in NW cor.
of SW 'A sec. 21, T. 1 N., R. 2 E., MDBM,
UCMP loc. 3159 (paratype; both Clark and
Woodford, 1927:103).

DISCUSSION.— This species is not placed
subgenerically because characters presently
used in the definition of subgeneric and
specific taxa rely essentially on the morphol-
ogy of the umbonal region and of the three
accessory plates, and these are not pre-
served. Both specimens of M. meganosensis
are in matrix and represent detrital valves.
Neither is associated with any woody mate-
rial. The dimensions of the holotype (juve-
nile, "a small specimen") and the paratype
(adult) are, respectively: length 4.5 mm,
height 3.2 mm, and length 14 mm, height 6
mm; length to height ratios are 1.4 and 2.34
respectively.

Clark and Woodford (1927:103) com-
pared M. meganosensis with "M. " clausa
Gabb, 1864 (see Fig. 94) from the Cretaceous
of California. Gabb's species however be-
longs to Opertochasma (q.v.) and differs
from Martesia in a number of subtle ways.

Paramartesian. subgen.

DEFINITION.— Shell martesia-form, pear-
shaped, small, ranging to 3 cm in length.
Dorsal margin posterior to umbo folded upon
itself to form elongate enclosure. Mesoplax
quadrate to broadly circular, metaplax and
hypoplax present. Anterior margin with V-
shaped notch. Umbonal reflection appressed
to anterior slope, raised at beaks to form
funnel-shaped pit. Posterior adductor muscle
scar long, relatively narrow.

Paramartesia differs from other sub-
genera of Martesia by the folded dorsal
margin and the long posterior muscle scar,
both similar to those of Parapholas. Para-
martesia however is smaller, has the distin-
guishing pit below the umbonal reflection,
the V-shaped notch in the anterior margin,
and a wood-boring habit. Parapholas and

Opertochasma have periostracal flaps on the

posterior slope, and a divided mesoplax.

TYPE SPECIES.— Martesia {Paramartesia)

tolkieni Kennedy, sp. nov.

TAXA INCLUDED.- The type species is

the only representative of the group known

to me.

ETYMOLOGY.— The name Paramartesia is

derived from the generic names Parapholas

and Martesia, to both of which it bears

similarities.

Martesia (Paramartesia) tolkieni n. sp.

Figures 67-70: frontispiece

DIAGNOSIS.— Dorsal margin folded upon
itself to form an elongate enclosure. Meso-
plax roughly quadrate to broadly circular,
sculptured with irregular wrinkles. Meta-
plax and hypoplax non-bifurcate, pointed
anteriorly and posteriorly. Umbonal reflec-
tion folded over beaks to form funnel-shaped
pit. Posterior adductor muscle scar long,
narrow.

DESCRIPTION.— Shell pear-shaped, lat-
erally compressed posteriorly, thin, light in
structure, ranging to approximately 3 cm in
length and 1.2 cm in height. Anterior gape
rhomboidal, two dorsal sides shorter, closed
in adult with complete hemispherical,
smooth callum. Posterior gape narrow,
slit-like, if present. Shell divided by um-
bonal-ventral sulcus, anterior portion one
third to one fourth size of posterior. Anterior
slope sculptured with thin, closely spaced
concentric ridges, minutely denticulated but
too fine to form a radial pattern. Concentric
ridges constricted by broad V-shaped notch
in anterior margin, widening, smoother
posterior to constriction, approaching size
and shape of posterior ridges where cross
sulcus. Umbonal-ventral sulcus manifested
as change in type of sculpture between
anterior slope and disc. Disc and posterior
slope sculptured with broad, low rounded,
smooth ridges.

Dorsal margin immediately posterior to
umbo reflected back, doubled upon itself,
forms an elongate enclosure, wide, broadly
rounded anteriorly, narrowing posteriorly,
disappearing approximately halfway be-

60

GEORGE L. KENNEDY

tween umbo and posterior extremity, similar
to that oi Parapholas califomica (Conrad).

Umbonal reflection covered by adult
mesoplax posteriorly, folded anteriorly to
form distinct funnel-shaped pit. Mesoplax
situated above and anterior to umbones,
roughly quadrate to broadly circular, sculp-
tured with irregular wrinkles. There are no
lateral wings. Metaplax rests on or between
dorsal reflection of valves, divided longitudi-
nally by growth line, pointed posteriorly,
centrally widened, curved, and ventrally
pointed anteriorly. Hypoplax narrow,
divided longitudinally by growth line,
pointed anteriorly and posteriorly.

Umbonal-ventral ridge narrow, pro-
nounced, either smooth, or in thin-shelled
specimens ornamented with little bumps
corresponding externally to intersection of
concentric ridges with sulcus. Posterior
adductor muscle scar long, narrow, resembl-
ing that of Parapholas. Internal morphology
surrounding umbo, including apophyses,
unknown.

HOLOTYPE.— Of Martesia (Paramartesia)
tolkieni, USNM 163803. PARATYPES:
USNM 163804. In foothills on west side of
San Joaquin Valley, between Ortigalito and
Little Panoche Creeks, near top of hill on
east side of small strike valley at center of
north line of sec. 19, T. 12 S., R. 11 E.,
MDBM, Merced Co.. California (USGS loc.
5712). Collected by R. W. Pack and E. L.
Ickes, July, 1910. "Eocene gray sandstone
overlying Cantua Shale member of the Lodo
Formation."
GEOLOGIC RECORD. - Eocene.

Eocene: Lodo Formation, at the type
locality, USGS loc. 5712.
DISCUSSION.- The type lot of P. tolkieni
is in a piece of fossilized wood (see frontis-
piece) approximately 12 by 10 by 5 cm in
size, and it contains at least 25 specimens
exposed solely on its surfaces. It was broken
off a much larger piece, probably in the
field, and has had one end trimmed with a
rock saw, exposing a single specimen. The
burrows average 2.5 cm in length, though
the animals themselves are a little shorter.
The burrows are filled with a fine dark
brown sediment which has completely sur-

rounded and filled the shells, which in turn
have been leached away leaving a large
number of internal and external molds. The
wood has also been infested with teredinids,
and many calcareous Hned burrows are pre-
sent below the level of the Martesia, and
are generally boring in a direction perpen-
dicular to the pholadids. The wood was
presumably penetrated first by the Mar-
tesia, since none of the pholadid burrows
intersect those of the teredinids. From sub-
merged test boards it has been found that
Recent Martesia will not avoid teredinid
burrows if encountered, though teredinids
will make every effort to avoid any obstruc-
tion or other tube, even to the point of com-
pletely reversing the direction of boring
(Turner, 1955:65).

Except for the folded dorsal margin,
the similarity of M. tolkieni to true Mar-
tesia is striking, and there can be no doubt
that it evolved from the typical genus.

The name tolkieni honors the late
J.R.R. Tolkien, creator of The Hobbit, The
Lord of the Rings, and many delightful
creatures of long ago in the time of Middle-
earth.

Genus Opertochasma Stephenson, 1952

Opertochasma Stephenson, 1952: 139. Turner, 1969: 715.

DEFINITION.— Shell divided by two radial
"sulci" in anterior slope-disc region. Meso-
plax quadrate to broadly circular, divided
into two pieces, situated above and anterior
to umbones, perhaps actually only a dorsal
extension of the callum. Metaplax and
hypoplax present. Concentric ridges conspic-
uously narrow. Posterior slope covered by
periostracal flaps, often not preserved in
fossil specimens. Umbonal reflection may
form funnel-shaped pit at anterior end.
Anterior margin notched with sharp V-
shaped indentation. Callum complete except
for small ellipsoidal gape. Radial internal
ridge (not the umbonal-ventral ridge) broad,
follows just dorsally of external disc-
posterior slope division.

Opertochasma differs from similar gen-
era by its periostracal flaps, divided "meso-

WEST AMERICAN CENOZOIC PHOLADIDAE

61

plax," double radial division of the shell, and
the broad internal ridge which parallels the
external division of disc and posterior slope.
TYPE SPECIES.— Opertochasmavenustum
Stephenson, by original designation, Steph-
enson (1952:139).

TAXA INCLUDED.— The following
nominal taxa belong to the genus: Martesia
clausa Gabb, 1864, Parapholas mersa
Stoliczka, 1870, Turnus sphenoideus White,
1876, 0. venustum Stephenson, 1952, 0.
subconicum Stephenson, 1952, and Martesia
tumerae Hickman, 1969.
DISCUSSION.— Except for Martesia tum-
erae from the Oligocene all of the nominal
species assigned to Opertochasma are known
only from the Cretaceous. There is, how-
ever, a single poorly preserved specimen,
possibly assignable to Opertochasma, known
from the Eocene of the southern Simi Valley
in Ventura Co. (UCMP loc. 3776) (Nelson,
1925: facing 402; as "Martesia (?) species").
The relationships of these species to one
another is unknown, though all are wood
borers.

The original description of Opertoc-
hasma (Stephenson, 1952:139) suggested
the absence of a hypoplax, the lack of which
has subsequently been used by Turner
(1969:715) to partially characterize the
genus. Examination of the types and para-
types of Stephenson's two nominal species,
0. venustum and 0. subconicum, reveal
that both species have both a metaplax, and
a hypoplax, as do Martesia tumerae, Turnus
sphenoideus, and Martesia clausa.

Opertochasma tumerae (Hickman, 1969)
Figures 71-72

Martesia tumerae Hickman, 1969: 68, 13, 16, 66, pi. 8,
fig. 10-11, 13-14, 16.

DIAGNOSIS.— Shell small, less than 1 cm
in length. Posterior slope covered with
periostracal plates, separated from disc by
slight angular change, present internally as
broad ridge. Shell divided by two radial sulci
in anterior slope-disc region, manifested
internally as double or bifurcate ridge.
Anterior slope very finely sculptured. Nar-

row ellipsoidal gape present between halves
of callum. Metaplax and hypoplax present.
"Mesoplax" divided longitudinally, quadrate
to circular, situated above and anterior to
umbones, perhaps actually only a dorsal
extension of the callum. Inhabits wood.
ORIGINAL DESCRIPTION.- Shell more
or less pear-shaped and small, the largest
specimen reaching 9 mm; twice as long as
high; callum present in adults, unsculptured;
umbones prominent and recurved, forming
funnel-shaped pits anteriorly; metaplax and
hypoplax thin and elongate, undivided,
pointed anteriorly and bluntly rounded
posteriorly; protoplax lacking; mesoplax
unusually small and subrectangular, divided
longitudinally into two parts by median
groove, notched posteriorly, somewhat
pointed anteriorly; valves divided into two
distinct areas by moderately incised um-
bonal-ventral sulcus; surface without raised
concentric ribs, covered with extremely fine
concentric lines of growth, over 100 counted
on holotype; sculpture slightly denticulate
on anterior portion of shell; shell interior
not exposed. Dimensions of holotype: length
8.5 mm, altitude 4.5 mm, convexity 4.5 mm.
HOLOTYPE.— Of Martesia tumerae Hick-
man, UO 27314. PARATYPES: UO 27315-
27319, 27732-27733; (=47 specimens). Road-
cuts along Interestate 5, in NW V4 sec. 3, T.
18 S., R. 3 W., WBM, Eugene quadrangle.
Lane Co., Oregon, UO loc. 2553. Oligocene,
Eugene Formation.
GEOLOGIC RECORD.- Oligocene.

Oligocene: Eugene Formation, at the
type locality, UO loc. 2553 (Hickman,
1969:69).

DISCUSSION.— This is the only positive
known occurrence of Opertochasma from
strata younger than Cretaceous. Operto-
chasma is a wood boring genus, and the
type lot of 48 specimens were all contained
in a single piece of fossilized wood (from
UO loc. 2553).

62

GEORGE L. KENNEDY

Genus Parapholas Conrad, 1848

Parapholas Conrad. 1848: 121. Turner. 1955: 123.

DEFINITION.- Shell moderate to large in
size, reaching 15 cm in length, beaked and
gaping anteriorly in young stage, closed by
a complete callum in the adult. Shells closed,
broadly rounded to acuminate posteriorly.
Valves divided into three distinct regions in
living specimens, though not readily ap-
parent on fossils. Posterior slope covered by
series of regularly spaced periostracal
plates, separated from disc by a slight
groove (in very young shells) or ridge
extending from umbones to posterior ventral
extremity. Posterior dorsal margin reflected
upon itself to form an elongate enclosure.
Mesoplax, metaplax, and hypoplax present.
Posterior end of burrow filled with chimney
of cemented sediment.

Parapholas differs from other Martesi-
inae in having the valves divided into three
distinct areas, and in having periostracal
flaps on the posterior slope. There are three
accessory plates, and the dorsal margin
posterior to the umbo is folded upon itself to
form an elongate enclosure. Aspidopholas
differs by having a bare posterior slope.
Martesia s.L, and Lignopholas have a funnel
shaped pit under the umbonal reflection,
and Opertochasma has a double radial divi-
sion of the shell and a small ellipsoidal
opening between the opposing halves of the
callum.

TYPE SPECIES.- Pholas californica Con-
rad, by original monotypy.
TAX A INCLUDED.- Parapholas is not
divided subgenerically. The genus occurs
worldwide, and is represented in the eastern
Pacific by P. californica (Conrad) in temper-
ate waters of California, and by P. calva
(Sowerby, 1834) and P. acuminata (Sow erhy ,
1834) in tropical and semitropical waters of
the Panamic Province.

DISCUSSION.- The geologic range of
Parapholas is often cited as Cretaceous to
Recent (Oldroyd, 1924:210; Turner, 1969:
715). Records of Parapholas in the Cretace-
ous (White, 1879; Stanton, 1893; and
Schuchert, 1905) are referable to Operto-

chasma Stephenson. Parapholas kneiskerni,
described by Whitfield (1885:241, pi. 30, fig.
22-24), from the Eocene Greensand marls of
Shark River, New Jersey, is an unidentifi-
able internal mold probably not that of a
Parapholas (R. D. Turner, pers, comm.).
The oldest fossil occurrence of Parapholas in
western North America is from the Pliocene,
and in Japan, from the Miocene, or possibly
Oligocene.

Besides P. californica, the only other
known fossil Parapholas from western
North America is one poorly preserved
specimen (see Fig. 93) collected from near
La Purisima, Baja California, Mexico (USGS
loc. 9330). It resembles both P. calva and P.
acumiyiata in size and shape, but cannot be
specifically identified.

Parapholas californica (Conrad, 1837)
Figures 73-75

P. [holds] Californica Conrad, 1837: 236, pi. 18, fig. 5-6.

Pholas Janellii Deshayes, 1839: 557.

Pholas californica: Conrad, 1848: 121.

Parapholas californica: Cooper, 1888: 257, in part, ? not
fossil. Bowers, 1890: 407, 408. Bruff, 1946: 232. Fitch,
1953: 96, fig. 62. Turner. 19.55: 124. pi. 73-77. Kanakoff
and Emerson, 19.59: 23. Valentine, 1960a: 163. Valen-
tine, 1961: 364. Vedder and Norris, 1963: 46. .50. in
part (P. californica, in pari Zirfaea pilsbryi and Chaceia
ovoidea). McLean. 1969: 92. fig. 53.6. Wright, 1972:
691.

not? Parapholas californica: Arnold and Hannibal, 1913:
.590. Oldroyd and Grant. 1931: 92. C>=Peniiella iur-
nerae).

not? Parapholas californica Hinds [sic]: Howe, 1922: fac-
ing 92 {'!=Penitella tumerae).

Pholadidea (Parapholas) californica: Grant and Gale,
1931: 435, in part (Parapholas californica [Recent], in
part PenitelUi tumerae [fossil occurrences]).

Pholadidea penita: Valentine. 1957: 297, in part (Peni-
tella penita, in part Parapholas californica) . Valentine
and Meade. 1961: 10, in part (Penitella sp. cf. P.
penita, Parapholas californica and NettastomeUa
rostrata).

not? Pholadidea californica: Oldroyd and Grant, 1931: 91.
Weaver, 1942 [1943]: 265. 639. Weaver, 1945: 56.
('!=Penitclla tumerae).

Pholas sp. indet.: Glen, 1959: 177.

Pholadidea cf. P. penita: Valentine, 1961: 389, in part
(Penitella tumerae and Parapholas californica) .

DIAGNOSIS.- Shell large, divided into
three regions. Concentric ridges on anterior
slope closely spaced. Umbonal reflection
reflected over, but not appressed to, anterior

WEST AMERICAN CENOZOIC PHOLADIDAE

63

slope. Dorsal margin posterior to umbo re-
flected upon itself to form an elongate en-
closure. Mesoplax divided longitudinally,
not readily distinguishable from umbonal
reflection and dorsal extension of callum, to
which it is often fused. Metaplax pointed
posteriorly, blunt, abutting mesoplax anteri-
orly. Hypoplax broadly rounded posteriorly,
pointed anteriorly.

DESCRIPTION.- Shell solid in structure,
pear-shaped, divided into three well defined
regions, reaching about 15 cm in length, and
just over 7 cm in height. Immature speci-
mens long for height (see Turner, 1955: pi.
76), prominently beaked, widely gaping
anteriorly. Anterior slope sculptured with
very close-set, upturned, undulate, concen-
tric ridges. Umbonal-ventral sulcus prom-
inent. Disc sculptured only by pronounced
growth lines. Disc separated from posterior
slope in very young specimens by a thin
furrow near the umbo, and in subsequent
life, by an angular change from disc to pos-
terior slope. Posterior slope sculptured with
prominent growth lines representing the
regular attachment of rounded and over-
lapping periostracal plates found on living
specimens. These are attached to an
aragonitic layer which deteriorates readily
on fossil specimens, thus disguising the
tripartite division of the valve.

Umbonal reflection simple, reflected
back over the anterior-dorsal margin, but
not appressed to it. Callum complete, heavy,
slightly ribbed by forward extensions of the
radial pattern of the anterior slope, extends
dorsally between the beaks, but only over
the anterior half of the umbonal reflection.

Mesoplax broadly oval, divided longit-
udinally into two pieces, covers posterior
half of umbonal reflection, not readily distin-
guishable from dorsal extension of callum,
from which it is separated by a suture. In
older specimens this suture line becomes
fused. Juvenile mesoplax small, thin, more
or less U-shaped, enlarged and produced
anteriorly in adult, when dorsal portion is
added (Turner, 1955:125).

Dorsal margin posterior to umbo re-
flected back and appressed to valve, extend-
ing one half the distance to the posterior

extremity. Presumably at, or near, cessation
of active boring, a dorsal portion is added,
forming an enclosure, usually widest at its
central part, upon which the metaplax wall
lie. The reflections do not extend to the line
of commissure, but leave a narrow dorsal
gape.

Metaplax long, narrow, covers gape left
between dorsal reflections, butts against
posterior end of mesoplax, truncate and
bent sharply down anteriorly, tapered to
narrow point posteriorly. Hypoplax pointed
anteriorly, widening posteriorly to broadly
rounded extremity, covers narrow ventral
gape.

Posterior adductor muscle scar narrow,
elongate, situated near the posterior-dorsal
margin. Ventral muscle scar sausage-shaped,
situated on ventral margin and superimposed
on umbonal-ventral ridge. Umbonal-ventral
ridge often prominent, condyle present at
ventral extremity in young specimens. Pal-
lial sinus nearly as broad as shell is high,
extends anteriorly about one third length of
shell, nearly intersects umbonal-ventral
ridge. Apophyses heavy, strong, broad,
spoon-shaped, truncated ventrally, extend
anteriorly away from the umbonal-ventral
ridge.

Posterior slope covered by large semi-
circular, and overlapping periostracal flaps.
On large specimens they may be spaced at
regular 2 to 3 mm intervals, though their
point of juncture with the valve are only
evident as pronounced, barely curved,
"growth" lines, and not indicative of the
shape of the flaps. Siphons capable of
complete retraction within shell. Foot in
young specimens more or less ellipitical in
outline, rounded anteriorly, pointed pos-
teriorly and truncate, atrophied in the adult
(Turner, 1955:127).

"SYNTYPE?".— Oi Pholas califomica Con-
rad, BM(NH) 61.5.21.157 (Keen, 1966:171).
"Sta. Diego and Sta. Barbara in soft rocks"
(Conrad, 1837:237). Carpenter (1857:194),
however, suggested Sta. Barbara for the
type locality after examining the Nuttall
collection. Recent.

TYPES.— Of Pholas janellii Deshayes, are
not known to still exist, though they may be

64

GEORGE L. KENNEDY

in the British Museum (Natural History)

(Turner, 1955:128). The type locality is the

shores of California.

DISTRIBUTION.- Recent; Bodega Bay,

Sonoma County, California (38° 18' N. lat.;

Turner, 1955:128) south to Punta Pequefia,

Baja California, Mexico (26° 14' N. lat.;

LACMNH 71-181).

GEOLOGIC RECORD.— Pliocene to Recent.

Pliocene: Merced Formation, Capitola
Beach, LACMNH loc. 314. "Merced" Forma-
tion, Moss Beach, UCMP loc. B-4793 (Glen.
1959:177, as Pholas sp. indet.).

Pleistocene: Near mouth of Tajiguas
Creek, near Gaviota, UCLA loc. 3597 (Val-
entine, 1961:389; as Pholadidea cf. P. peiiita,
in part). Isla Vista, near Santa Barbara
(Wright, 1972:691), LACMNH loc. 2694.
Terrace seven, Palos Verdes Hills, LACMNH
loc. 1307. Gaffey Street Bridge, San Pedro,
USGS [no locality number]. San Joaquin
Bay [?=Newport Bay] (Bowers, 1890:407,
408). Palos Verdes Sand, on east bluff above
Upper Newport Bay, LACMNH loc. 66-2
(Kanakoff and Emerson, 1959:23), on west
bluff of Upper Newport Bay, UCMP loc.
A-3101, and in north bluff of Newport Bay
proper, opposite Lido Isle, UCMP loc.
A-3132 (both Bruff, 1946:232). San Nicolas
Island, east of hill 818, USGS loc. 21655,
and at east end of island, USGS loc. 21664
(both Vedder and Norris, 1963:46, in part).
San Clemente, UCLA loc. 2774 (Valentine,
1961:364). Torrey Pines Beach State Park,
UCLA loc. 2410 (Valentine, 1960a:163; as
UCLA loc. 3457), CAS loc. 102. On west
side of Point Loma, UCLA loc. 3605 (Valen-
tine and Meade, 1961:10, as Pholadidea
penita, in part), SDSNH loc. 2419. In Baja
California, 4V2 miles south of Rio Morro,
UCLA loc. 3569 (Valentine, 1957:297; as
Pholadidea penita), and at Campo del
Arroyo, Cedros Island, SDSNH loc. 2630.
DISCUSSION.— Fossil specimens of Para-
pholas californica can be identified by their
distinctive anterior sculpture, reflected
posterior-dorsal margin, and by the dorsal
extension of the callum which extends only
half the distance to the umbo.

Although this species is quite common
in the living fauna of California and northern

Baja California, it is not common in the fossil
record, even though it inhabits the same
substrates as does Penitella penita. It lives
in clay, shale, or sandstone (all in various
stages of induration), usually on the open
coast, and may burrow 20 cm or more in the
substrate (Fitch, 1953:96).

Pliocene occurrences of P. californica
are rare. The specimens upon which the
record of Arnold and Hannibal (1913:590) is
based have not been found, although one
specimen used by Howe (1922: facing 92) is
Penitella tumerae. There are no other
species with which P. californica may be
confused. However, it is probable that
Arnold and Hannibal had large bulbous and
poorly preserved Penitella tumerae which
are quite common in the Empire Formation
of the Coos Bay region of Oregon. Both P.
tumerae and P. californica are similarly
shaped, and specimens of Parapholas from
this area have never been figured, nor are
they present in any of the numerous collec-
tions examined.

The specimen cited by Glen (1959:177)
as Pholas sp. indet. from the Pliocene
"Merced" Formation at Moss Beach, San
Mateo Co., is poorly preserved, but the
distinctive anterior-dorsal margin serves to
clarify its affinities, although it is not evident
that the shell is divided into three regions.

Pleistocene occurrences of P. californica
are surprisingly few in number. Only one
specimen has ever been collected in situ
(from the late Pleistocene Palos Verdes
Sand of Upper Newport Bay, UCMP loc.
A-3132 [see Fig. 74]). The other known fossil
specimens are from detrital deposits and are
either worn or fragmentary.

Parapholas californica is most closely
related to P. minoensis, described by
Itoigawa (1960:273, pi. 3, fig. 1) from the
middle Miocene Shukunohora Sandstone
member of the Oidawara Formation, from
central J apaO' Parapholas acuminata (Sow-
erby) and P. calva (Sowerby) from tropical
west American waters are smaller than P.
californica, and each have a large mesoplax
which envelops the entire anterior dorsal
region of the shell.

WEST AMERICAN CENOZOIC PHOLADIDAE

65

Subfamily JOUANNETIINAE Tryon, 1862

DEFINITION.— Shell pholadiform, beaked,
and widely gaping anteriorly in young stage.
Gape partially or completely closed by a
callum in adult. In Nettastomella the callum
is a peripheral band of calcareous material
with the large central region being perios-
tracal; in Pholadopsis and Jouannetia it is
entirely calcareous and very large. Anterior
adductor muscle housed by a dorsal exten-
sion of the callum. Accessory plates lacking
except in Pholadopsis which possesses a
mesoplax. The siphonoplax may be paired,
or present only on the right valve. Shells
divided into two distinct areas by an um-
bonal-ventral sulcus. Apophyses lacking.
Foot well developed in the young stage,
atrophied in the adult. Animal capable of
complete retraction within the shell.
TYPE GENUS.— Jouannetia Des Moulins,
1828.

TAXA INCLUDED.— The subfamily in-
cludes Nettastomella, Pholadopsis, and
Jouannetia. All three are found in, though
not restricted to, the eastern Pacific. They
occur in both modern and fossiliferous sedi-
ments. A fourth genus, Scyphomya Dall,
1898, may be of questionable validity (R.D.
Turner, pers. comm.).

Genus Nettastomella Carpenter, 1865

Netastoma Carpenter, 1864: 637. Yokes, 1956: 768.
Nettastomella Carpenter, 1865: 202. Turner, 1955: 141.
Turner, 1962: 291.

DEFINITION.- Shell small, fragile, light
in structure. Bilaterally symmetrical in
young stage, widely gaping anteriorly,
closed posteriorly, adult shell equivalve or
slightly inequivalve. Callum partial, sculp-
tured with growth lines or thin vertical
lamellae, produced equally on both valves as
peripheral band on anterior margin, or
much wider on left valve. Periostracum
encloses portion of adult pedal gape not
closed by callum. Valves constricted consid-
erably at umbonal-ventral sulcus. Anterior
slope triangular in outline, sculptured by
imbricate, concentric ridges. Disc and
posterior slope sculptured with concentric

ridges and (or) growth lines. Umbonal
reflection free anterior to umbo, which it
just touches. Siphonoplax calcareous, pres-
ent on both valves or only on right, short or
long, straight or divergent at base. Acces-
sory plates and apophyses lacking. Chron-
drophore small, present on left valve.

Nettastomella differs from the larger
Pholadopsis, to which it is most closely
related, by the absence of both a mesoplax,
and a very large, unequal callum. In
addition, the siphonoplax of the right valve
of Pholadopsis is serrated on its posterior
margin.

TYPE SPECIES.— "Nettastomella darwinii,
Sby." of Carpenter, 1865 {= Nettastomella
rostrata [Valenciennes, 1846], not Pholas
darwinii Sowerby, 1849), by original mono-
type (see discussion in Turner, 1955: 141).
TAXA INCLUDED.— The genus is not
divided subgenerically. There are three
known living species; N. darwinii (Sowerby,
1849) from southern South America, N.
rostrata (Valenciennes) from the northern
eastern Pacific, and N. japonica (Yokoyama)
from the northern Pacific. The last two are
also known as fossils.

DISCUSSION.— The genus Netastoma was
described by Carpenter in 1864. Because the
procedure at that time dictated his original
name a homonym of A^eiias^oma Rafinesque,
1810, a genus of fish, he proposed the new
name Nettastomella Carpenter, 1865, which
has been in constant use since. The latter
name is here used for the sake of uniformity
with existing literature.

Nettastomella is most closely related to
Pholadopsis and the juvenile stages are quite
similar, including the characteristic umbonal
reflection. Although the two genera are
morphologically similar, they differ in their
geographic distribution. Pholadopsis is
known only from tropical and semitropical
areas, while Nettastomella inhabits more
temperate and boreal waters. The ranges of
the two genera meet, with little overlap, in
the vicinity of Cedros Island, Baja Califor-
nia, Mexico. Nettastomella japonica
(Yokoyama) of the northern Pacific, morpho-
logically resembles both genera by possess-
ing features of each in the adult stage.

66

GEORGE L. KENNEDY

Nettastomella rostrata (Valenciennes, 1846)
Figures 76-78

Pholas rostrutu Valenciennes, in du Petit-Thouars, 1846:
pi. 24, fig. 4, 4a [no description]. Lamy, 1921: 182.

Nettastomella darwinii: Carpenter, 1865: 202.

Nettastomella rostrata: Dall, 1916a: 43. Turner, 1955:
143, pi. 87. Turner, 1962: 298, pi. 48 (fig. 1), 49.50.
Evans, 1967b: 175, in part, pi. 17, fig. 2 [N. rostrata
[Recent], not fossil reference to Adegoke, 1966). Addi-
cott and Galehouse, 1973: 510, fig. 3e, j.

Pholadidea rostrata: Hertlein and Grant, 1944: 68.
Chace, 1966: 170.

Pholadidea penita: Valentine and Meade, 1961: 10, in
part {Penitella sp. cf. P. penita, Parapholas califomica,
and Nettastomella rostrata).

Netastoma rostrata: McLean, 1969: 92, fig. 53.7.

DIAGNOSIS.— Shell small, equivalve.
Galium partial, exists as peripheral band
along anterior margin. Siphonoplax long,
narrow, paired, reflected outward at base.
Umbonal reflection free, not appressed to
anterior slope.

DESCRIPTION.- Shell reaching about 2
cm in length (excluding the siphonoplax)
and 1 cm in height, equivalve in both
juvenile and adult stages. Shell beaked,
widely gaping anteriorly in young stage,
closed posteriorly. Anterior slope sculptured
with moderately spaced, thin, high, undu-
late, concentric ridges. Shell strongly
constricted at umbonal-ventral sulcus. Pos-
terior slope and disc sculptured with thin,
high, concentric ridges which are continua-
tions of ridges of anterior slope. Umbones
located near anterior third of shell. Umbonal
reflections narrow, barely touching at
umbo, free anterior to point of contact.
Galium partial, equal on both valves, exists
as narrow peripheral band along anterior
margin, fragile, sculptured with thin, high,
undulate ruffles paralleling anterior margin.
Gentral portion of anterior gape not
enclosed by callum is periostracal. Calcare-
ous dorsal extension of callum only partially
covers anterior-dorsal gape. Siphonoplax
calcareous, length and width dependent on
size of burrow (from which it takes its
shape), reflected outward at its base.

Posterior adductor muscle scar elon-
gate-oval in outline, positioned near pos-
terior-dorsal margin. Pallial sinus extends
anteriorly to umbonal-ventral ridge. Siphons

capable of complete retraction within shell.
Foot large, rounded and truncate in young
specimens, atrophied in adult. Soft part
morphology given in Turner (1962: 303, pi.
51).

HOLOTYPE.— Of Pholas rostrata Valenci-
ennes, in the Museum National d'Histoire
Naturelle in Paris (Lamy, 1921: 182).
Monterey, Galifornia is given on the original
label, although not published by Valenci-
ennes (Lamy, 1921: 182). Recent.
DISTRIBUTION.- Recent; Puget Sound
(ca. 48° N. lat.; Dall, 1916a: 43) and
vicinity, to San Cristobal Bay, Baja
Galifornia, Mexico (27° 17' 35" N. lat.;
LAGMNH 71-173).
GEOLOGIC RECORD.- Pliocene to Recent.

IHioceiie: Sail Joaqu-in Formation, Kot-
-Oeiiuii Hills, UCMP loc. D-7727.

Pliocene: San Joaquin Formation, Ket-
tleman Hills, UCMP loc. B-7727. Paso Robles
Formation, east of Atascadero USGS-M loc.
4621 (Addicott and Galehouse, 1973: 510).

Pleistocene: Lomita Marl, in San Pedro
at northeast corner of Coralmount Drive
and Park Western Drive, LAGMNH loc.
435. San Pedro Sand, in San Pedro, at high
school at 15th and Leland Streets, SDSNH
loc. 2138 [=L-2138] (Chace, 1966: 170),
"Chiton Bed" [of Chace and Chace, 1919] on
Point Firmin, SDSNH loc. 0625, and corner
of 8th and Palos Verdes Streets, LAGMNH
loc. 226. Palos Verdes Sand, on east bluff
above Upper Newport Bay, LAGMNH loc.
487, SDSC Iocs. 533 and 537. West side of
Point Loma, UCLA loc. 3605 (Valentine and
Meade, 1961: 10, as Pholadidea penita, in
part). Spanish Bight, San Diego (Hertlein
and Grant. 1944: 68).

DISCUSSION.- Though known to occur as
deep as 100 m (Turner, 1955: 145), N.
rostrata is commonly found in the intertidal
zone, often associated with species of
Penitella and other rock boring bivalves.
The burrows are usually short and not often
straight.

The occurrence of A^. rostrata in the
fossil record is rare, having been reported
three times (from San Diego by Hertlein and
Grant, 1944: 68, from San Pedro by Chace,
1966: 170, and from near Atascadero by

WEST AMERICAN CENOZOIC PHOLADIDAE

67

Addicott and Galehouse, 1973: 510). The
species occurs, however, most abundantly in
the late Pleistocene Palos Verdes Sand on
the east bluff above Upper Newport Bay in
California. The molluscan fauna of this for-
mation includes seven species of pholadids,
and specimens of A^. rostrata have been
found in association with numerous Chaceia
ovoidea, and lesser numbers of Penitella
fitchi, Barnea subtruncata, and P. penita. In
addition to Pleistocene records, N. rostrata
occurs in the Pliocene Paso Robles Forma-
tion of San Luis Obispo Co., and the Kettle-
man Hills of central California. The single
specimen from the Kettleman Hills is an
internal-external mold-pair from which all
shell material has been leached away. It was
associated with several specimens of an
Adula.

Recently, Evans (1967b), in a re-
interpretation of silicified mud filled pholadid
burrows described by Adegoke (1966) from
the Miocene Pismo Formation of San Luis
Obispo Co., California, attributed one
specimen, an unusually bulbous burrow
(UCMP 31410), to A^. rostrata on the basis
of the similarity in shape of the burrow with
those of that species. The specimen is not
nearly so full-bottomed as it seems, and the
larger size is caused by a conchoidal
fracture in the cherty matrix surrounding
and paralleling the surface of the burrow.
This feature does not show in Adegoke's
figure (1966: pi. 21, fig. 8) and is difficult to
discern even on the specimen itself. The
burrows were made by an unidentified
species of Penitella and are discussed
further under Chaceia.

The fossil distribution of A^. rostrata is
considerably less extensive than that of
Recent specimens, and it should be expected
to occur both north and south of known
fossil occurrences.

Nettastomella japonica (Yokoyama, 1920)
Figures 79-81, 85

Joua7inetia japonica Yokoyama, 1920: 105, pi. 7, fig. lac.

Hanzawa, Asano, and Takai, 1961: 247.
N.[ettostomella] japonica: Habe, 1952: 244. Taki and

Oyama, 1954: 50, pi. 8, fig. lac.

Nettastomella japonica: Habe, 1955: 24, pi. 4 (fig. 9), 7
(fig. 3). Taki and Habe, 1955: 14, pi. 2, fig. 3-4. Tur-
ner, 1962: 292, pi. 47, 48 (fig. 2). 50.

Netastomella [sic\ japonica: Hanna, 1966: 71, 78, fig. 82.

DIAGNOSIS.- Slightly inequivalve, callum
on left valve larger than on right, only
partial. Siphonoplax on right valve longer
than on left, not serrated posteriorly or
reflected outward at base.
ORIGINAL DESCRIPTION.- Shell small,
thin, fragile, globose, widely gaping in
front, with the anterior end bluntly pointed
and smooth, and the posterior end rounded.
Surface divided into two parts by a deep
groove running from beak [=umbo] to
antero-ventral angle, whence the margin
which is crenate, ascends obliquely upward
anteriorly. The sculpture consists of distant
concentric laminae which in the anterior
portion are wavy, the crests of the waves
forming about eight radiating ribs whose
interspaces are unequal, being broader in
the anterior portion. Accessory plates not
preserved.

SUPPLEMENTARY DESCRIPTION. -
Shell reaching about 2.5 cm in length,
widely gaping anteriorly, closed posteriorly,
equivalve in juvenile, inequivalve in adult.
Callum greater near ventral margin, larger
on left valve than on right. Siphonoplax of
right valve longer than that of left, not
reflected outward at base. Callum of right
valve greatly reduced, as is siphonoplax of
left valve.

Anterior slope sculptured with widely
spaced, high, weakly undulate concentric
ridges, supplemented by radial pattern
formed by alignment of undulations or
projections on ridges. Umbonal-ventral
restriction prominent. Posterior slope orna-
mented with concentric growth lines and
occasionally by thin low, plain or ruffled,
ridges.

Umbonal reflection narrow, equally
produced on both valves, barely touching
above umbones, but free anterior to them.
Dorsal extension of callum extends anterior
to and around beaks, greater on left valve,
only partially covers anterior-dorsal gape.

Posterior muscle scar deeply impressed,
situated close to the posterior-dorsal margin.

68

GEORGE L. KENNEDY

Ventral muscle scar only lightly impressed,
situated at base of umbonal-ventral ridge
(Turner, 1962: 294). Pallial sinus not
marked. Apophyses and accessory plates
absent. Foot large, rounded, truncate in
young specimens, atrophhied in adult
(Turner, 1962: 294).

LECTOTYPE.— Of Jouannetia japonica
Yokoyama, in the Geological Institute,
University of Tokyo, no. CM20333, here
designated. This is the specimen figured by
Yokoyama (1920: pi. 7, fig. la-c). PARA-
LECTOTYPES: In the Geological Institute,
no. CM20334 (3 specimens [?valves]). Otsu
on the Miura Peninsula, Ishikawa Prefec-
ture, Honshu, Japan. Pliocene [= middle
Pleistocene], Lower Musashimo Formation,
Yokosuka Zone (zone 5).
DISTRIBUTION.- Recent; From Noto
Peninsula, on the north coast of Honshu (ca.
37.5° N. lat.; Taki and Habe, 1955: 14),
north, perhaps around the Aleutian Island
Arc, and on the west coast of Canada to the
Strait of Juan de Fuca and vicinity (48° 27'
N. lat.; Turner, 1962: 298).
GEOLOGIC RECORD.— Pleistocene to
Recent.

Pleistocene: Lower Musashimo Forma-
tion, Yokosuka zone, at Otsu on the Miura
Peninsula, Honshu, Japan (type locality;
Yokoyama, 1920: 106).

DISCUSSION.— This is a Japanese species
which has only recently been recognized
living on the west coast of British Columbia,
Canada (Turner, 1962: 289). Described from
the middle Pleistocene Otsu Shell Bed (J.
Itoigawa, in litt.), on the island of Honshu,
Japan, it has been reported living off the
coasts of Honshu and Hokkaido. Though
little is known of the ecology of this species,
specimens have been recorded from 305 m
off the Noto Peninsula (Honshu) and 117 m
off Sado Island (both Taki and Habe, 1955:
14). Specimens taken at Masset Inlet,
British Columbia were collected alive in soft
friable sandstone at the low tide line
(Turner, 1962: 295). Although the species is
known from only a few Recent localities in
Japan and British Columbia, it may range
northward and around the Aleutian Island
Arc.

Nettastomella japonica is interesting
because it possesses the inequivalve condi-
tion previously considered peculiar to
Pholadopsis and Jouannetia. The callum on
the left valve is enlarged, though not to the
extent that it is in the other two genera.
Furthermore, the siphonoplax on the right
valve is longer than that of the left, and is
not reflected outward at the base as in other
species of Nettastomella.

Aside from the type specimens from
the middle Pleistocene Otsu Shell Bed, no
other fossil specimens of A'^. japonica are
known from any Japanese Tertiary or
Quaternary deposits. It certainly has not
been recorded as fossil from the eastern
Pacific, though this may be due to the
scarcity of appropriate late Cenozoic depos-
its along the Canadian and Alaskan coasts.

In recent years there has been some
confusion about the types of Jouannetia
japonica Yokoyama, and the following
information was kindly offered by Dr. Junji
Itoigawa, Nagoya University, who inquired
about the type material. According to Dr.
Kiyotaka Chinzei (Itoigawa, in litt.) of the
Geological Institute, University of Tokyo,
Yokoyama described J. japonica from four
specimens [?valves], one of which he
figured. Yokoyama did not designate a type
or assign catalogue numbers to any of his
specimens, nor did he indicate how many
specimens were in the type lot. The
specimens, now in the Geological Institute,
are registered as no. CM20333 (figured
specimen) and no. CM20334 (3 remaining
specimens [?valves]). The "Holotype" desig-
nation of Taki annd Oyama (1954: 50), oppo-
site a reproduction of Yokoyama's original
plate, and the "Syntype" listing in Hanzawa,
Asano, and Takai (1961: 247) are considered
invalid. The figured specimen is here
designated the lectotype, and the three
remaining specimens considered paralec-
totypes.

Genus Pholadopsis Conrad, 1849

Pholadopsis Conrad, 1849: 156. Turner, 1955: 136.
THomphalia Sowerby [11], 1849: 500.

WEST AMERICAN CENOZOIC PHOLADIDAE

69

DEFINITION.— Shell small to moderate in
size, globose or pear-shaped, juvenile
beaked anteriorly, rounded and closed
posteriorly, adult closed anteriorly by
callum, gaping posteriorly. Umbonal-ventral
sulcus prominent. Callum large, globose,
that of left valve larger than that of right
valve. Siphonoplax of right valve serrated
posteriorly, lacking on left valve, replaced
by ventral and posterior growth of callum
material. Mesoplax only accessory plate,
small, fused to dorsal extension of callum in
adult. Umbonal reflection high and free, not
appressed to anterior slope. Chondrophore
present, apophyses lacking.

Pholadopsis differs from other Jouan-
netiinae by possessing a mesoplax. The
umbonal reflection of Jouannetia is ap-
pressed to the anterior slope. Pholadopsis
differs from Nettastomella by its mesoplax,
very large callum, gross inequivalve shape,
and the serrated right siphonoplax.
TYPE SPECIES.— Pholadopsis pectinata
Conrad, by original monotypy.
TAXA INCLUDED.- The known living
representatives of Pholadopsis are: P.
quillingi (Turner, 1955), from the western
Atlantic and the Gulf of Mexico, P.
pectinata Conrad from the tropical eastern
Pacific, P. globulosa (Quoy and Gaimard,
1834) from the Indo-Pacific, and P. vignoni
Fischer, 1862, from the eastern Atlantic of
Africa.

DISCUSSION.— Pholadopsis has long been
placed as a subgenus of Jouannetia des
Moulins. Though both genera have a large
bulbous callum, the juvenile shells are less
similar, and Pholadopsis appears more
closely related to Nettastomella. Pholadop-
sis also possesses a mesoplax which neither
of the other two have. The inequivalve adult
condition, distinctive of Jouannetia and
Pholadopsis, is also present in N. japonica
to a lesser degree, and should not be used
as a generic character.

Pholadopsis pectinata Conrad, 1849
Figures 82-84, 86-90

P.[holadopsis] pectinata Conrad, 1849: 156.
Triumphalia pulcherrima Sowerby, 1849: 501, pi. 106,
fig. 58 .59.

Pholadidea ovoidea (Gould), short var.: Woodring, Stew-
art, and Richards, 1940 [1941]: facing 78, pi. 14, fig. 6.

Jouannetia (Triomphalia) pectinata: Hertlein and Strong,
19.50: 248, pi. 2, fig. 6.

Jouannetia (Pholadopsis) pectinata: Turner, 1955: 137,
pi. 83. Olsson, 1961: 451, pi. 80, fig. 3, 3a. Turner,
1962: pi. 53. Keen, 1971: 276, fig. 704.

Jouannetia pectinata: Keen, 1958: 216, fig. 549.

DIAGNOSIS.- Shell globose or pear-
shaped. Callum very large, bulbous, irregu-
larly sculptured, that of left valve much
larger, overlapping that of right valve, fused
to mesoplax. Umbonal reflection free ante-
rior to umbo. Siphonoplax of right valve
finely serrated posteriorly, greatly reduced
on left valve.

DESCRIPTION.- Adult shell about 5 cm in
length, 3 cm in height, inequivalve, globose,
pear-shaped in outHne. Juvenile shell equi-
valve, beaked, widely gaping anteriorly,
closed posteriorly. Anterior slope sculptured
by numerous wavy concentric ridges, and
weak radial pattern formed by rows of
undulations of these ridges. Umbonal-
ventral sulcus prominent, posterior margin
indefinite, especially on right valve. Disc
and posterior slope sculptured with sharp,
precise, growth striae which are continua-
tions of concentric ridges of anterior slope.

Umbonal reflection narrow, high, and
free, touches just anterior to umbo. Callum
very large, globose, complete, that of right
valve nearly typical, greatly enlarged on
left valve and overlapping that of right.
Callum extends prominently anteriorly and
ventrally to beaks. Dorsal extension of
callum not distinguishable from callum
proper, that of left valve very much
enlarged, covers anterior adductor muscle.
Ventrally, callum of right valve stops at
umbonal-ventral sulcus, on left valve addi-
tional material is added along ventral
margin of the disc and posterior slope
(Turner, 1955: 137). Siphonplax present
only on right valve, finely serrated poste-
riorly, replaced on left valve by callum
material, margin smooth.

Mesoplax only accessory plate, small,
deltoidal, sculptured with concentric growth
lines, fused to dorsal extension of callum in
adult. Enlargement of callum displaces
mesoplax at an angle to longitudinal axis of

70

GEORGE L. KENNEDY

shell (Turner, 1955: 137).

Umbonal-ventral ridge low, distinct.
Chondrophore on left valve small, apophyses
lacking. Posterior adductor muscle scar
small, elongate-oval in outline, located
internally high on posterior slope. Pallial
sinus broad, extends only to umbonal-
ventral ridge.

HOLOTYPE.— Of Pholadopsis pectinata
Conrad, ANSP 51075. PARATYPE: ANSP
136743 (ex 51075). No specific locality is
cited by Conrad (1849: 155), though the
several species described by him were
"from the coasts of Lower California and
Peru." Hertlein and Strong (1950: 249) have
subsequently restricted the type locality to
the east coast of Lower [Baja] California.
Recent.

HOLOTYPE. — Of Triomphalia pulcherrima
Sowerby, in the British Museum (Natural
History) (Turner, 1955: 138). West Colum-
bia, in soft stone at low water, collected by
Hugh Cuming. Recent.

DISTRIBUTION.- Recent; Off Cedros
Island, Baja California, Mexico (28° 05' N.
lat.; Turner, 1955: 138), into the Gulf of
California, and south to Peru (Olsson, 1961:
451).

GEOLOGIC RECORD.- Pliocene, Pleisto-
cene?, Recent.

Pliocene: San Joaquin Formation, in
the Kettleman Hills, UCMP loc. B-7727
(cf.), on the North Dome, at La Lomica,
USGS loc. 12365, and Arroyo Conchoso,
USGS loc. 12374 (both Woodring, Stewart,
and Richards, 1940 [1941]: facing 78).

Pleistocene or Recent: Southwest of
San Carlos Bay, near Guaymas, Sonora,
Mexico, MCZ 228109.

DISCUSSION.— Pholadopsis pectinata is a
rare species and living examples are
uncommon even in large collections of
Recent moUusks. Although Hertlein and
Strong (1950) restricted the type locality of
P. pectinata to the east coast of Lower
California, they did not include Baja
California in their distribution for the
species. If the specimens from San Carlos
Bay are Recent, rather than Pleistocene,
this would establish a known northern limit
for the species in the Gulf of California.

The fossil record of P. pectinata almost
does not exist. One lot of specimens (MCZ
228109) from a small peninsula directly
southwest of San Carlos Bay, near Guay-
mas, Sonora, Mexico, can only tentatively
be assigned an age older than Recent, since
it is not known if the pholadids were really
collected from land. High oxidation of the
extrusive volcanic rock in which they were
boring, and lack of any organic matter or
marine life on the rocks suggest they are
not Recent, but to assign a Pleistocene age
to them would also be speculative.

The Pliocene record of P. pectinata is
based on specimens cited by Woodring,
Stewart, and Richards (1940 [1941]) as
Pholadidea ovoidea (Gould), short var. The
specimens have slightly thicker shells than
some Recent specimens, but fall in the
range of variation expected by different
substrates. They were collected from two
separate localities in the Pliocene San
Joaquin Formation in the Kettleman Hills of
California. Another specimen from the same
general area is an internal mold of the
anterior portion of a left valve, and is only
tentatively referred to P. pectinata.

Subfamily XYLOPHAGAINAE Purchon,
1941

DEFINTTION.— Shell beaked and gaping
anteriorly throughout life. Beaks nearly rec-
tangularly truncate, giving shells a teredo-
like appearance. Valves rounded and closed
posteriorly. Anterior slope sculptured with
numerous rows of finely denticulate ridges
as in the Teredinidae. Disc and posterior
slope separated from anterior slope by
umbonal-ventral sulcus, sculptured only by
growth lines. Umbonal reflection narrow,
simple, barely reflected. Only accessory
plate a small divided mesoplax. Galium and
apophyses absent. Umbonal-ventral ridge
pronounced, usually possessing a ventral
condyle. Posterior adductor muscle scar
large, generally oval in outline, placed near
the posterior-dorsal margin. The foot does
not atrophy in the adult. The animal is
usually capable of complete retraction
within the shell. Xyloredo deposits a calcar-

WEST AMERICAN CENOZOIC PHOLADIDAE

71

eous lining in its burrow similar to that
produced in the Teredinidae.

Xylophagainae differ from Teredinidae
in that they possess an accessory plate
while lacking apophyses and pallets.
TYPE GENUS.- Xylophaga Turton, 1822.
TAXA INCLUDED.- Only three genera
are known in the Xylophagainae: Xylophaga
Turton, 1822, Xylophagella Meek, 1864 [in
Meek and Gabb], and Xyloredo Turner,
1972. Three Recent species of Xylophaga
were recognized by Turner (1955; see also
Knudsen, 1961: 203) in the eastern Pacific.
They are: X globosa Sowerby, 1835
(Panama to Chiloe Island, Chile), X.
mexicana Bartsch, 1921 (California [33° 29'
N.] to off Acapulco, Mexico [16° 47' N.]),
and X. washingtona Bartsch, 1921 (Wash-
inton [48° 31' N.] to California [33° 31' N.]).
Subsequently, Knudsen (1961) described six
new species, all from deep water in the Gulf
of Panama. They are: X. aurita, X. concava,
X. duplicata, X. obtusata, X. panamensis,
and X. tumerae. In addition, one species of
Xyloredo, X. naceli, was described from
deep water off San Miguel Island, California
by Turner (1972: 6).

DISCUSSION.- A description of the
subfamily has been added for reference
although no Xylophagainae have ever been
found in Cenozoic rocks in western North
America. Xylophagella, described from the
Cretaceous of Idaho, is however known
from Campanian strata in La JoUa, San
Diego Co., California.

Good accounts of the taxonomy, varia-
tion, reproduction, and distribution of
Xylophaga are given in Knudsen (1961). The
Xylophagainae are essentially deeper water
inhabitants and usually bore into wood or
other plant debris, though they are known
to occur in other substrates. Species of
Xylophaga appear to have unusually re-
stricted geographic ranges (Turner, 1966a:
444; Knudsen, 1961: 201) and only rarely
occur in shallow water, and then only in
temperate regions. {Xylophaga washingtona
Bartsch is the only species from the eastern
Pacific recorded from shallow depths.) The
rarity of Xylophaga s.l. in shallow marine
sediments (which predominate in the west

American Cenozoic record) and similarity to
teredinids in habitat, small size, and
superficial morphology would probably dis-
guise their true relationship even if found.

INCERTAE SEDIS

"Zirphaea" plana White, 1889
Figure 101

Zirphaea plana White, 1889: 15, pi. 4, fig. 22. Schuchert,

1905: 704.
Z. \irfaea] plana: Dall, 1898: 818, 820.

HOLOTYPE.- Of Zirphaea plana White,
USNM 20129. Martinez, Contra Costa Co.,
California, collected by H. W. Turner.
Cretaceous or Eocene, "Chico-Tejon series."
DISCUSSION.- White's (1889: 15) com-
ments on the species are: "Among the
fossils collected by Mr. H.W. Turner from
the Chico-Tejon strata at Martinez, Contra
Costa Co., is a single valve of a shell which
seems to possess the essential characters of
Zirphaea. The shell is small, irregularly
suboval in marginal outline; the anterior
portion inflated, larger than the posterior
portion, from which it is separated by a
well-defined depression that extends from
near the beak to the base of each valve, and
also by the abrupt inflation of the anterior
portion; cardinal border of the anterior
portion somewhat reflexed. The shell
substance of the specimen is mostly
exfoliated, but remains of narrow, concen-
tric, raised striae are observable, which are
separated by rather wide interspaces and
which seem to have covered the whole
surface. Length, 14 mm; height, 11 mm."

The actual age of the species is in
doubt. Dall (1898: 818) referred it to the
Eocene Tejon Formation, though Schuchert
(1905: 704) considered it to belong to the
Cretaceous Chico Formation.

The specimen somewhat resembles the
genus Pholadopsis , but because of the poor
preservation and greater antiquity, it seems
best not to place it systematically at this
time. It is not a Zirfaea. The species may be
synonomous with "Jouannetia" sp. of Clark
and Woodford (1927: 102; see Figs. 91-92)
from the Eocene Meganos Formation.

72

GEORGE L. KENNEDY

"Jouannetia" sp. Clark and Woodford, 1927
Figures 91-92

Jouannetia sp. Clark and Woodford, 1927: 102, pi. 18,
fig. 6. Keen and Bentson, 1944: 55.

HYPOTYPE.— Of Jouannetia sp. Clark and
Woodford. UCMP 31340. Mt. Diablo quad-
rangle, on top of ridge at middle of north
edge of SE V4 sec. 20, T. 1 N., R. 2 E.,
MDBM, Contra Costa Co., California (UCMP
loc. 3158). Lower Eocene, Meganos Forma-
tion [division D].

DISCUSSION.— Among the molluscan
species reported from the Eocene Meganos
Formation by Clark and Woodford (1927)
was an indetermined pholadid tentatively
assigned to the genus Jouannetia on the
basis of its outline and sculpturing, though
too poorly preserved to be named. The
specimen (UCMP 31340) upon examination
shows very little sculpture, is composed of
indurated sand, and is either a cast or
internal mold with no shell remaining. It is
globose and pear-shaped, with a prominent
constriction running from the umbones to
the ventral margin. The species somewhat
resembles the genus Pholadopsis , but the
type of sculpture on the anterior slope (see
Fig. 91) differs remarkedly from that genus,
and so is not placed systematically. "Zir-
phaea" plana White (1889: 15; see Fig. 101)
may be synonomous with "Jouannetia" sp.
of Clark and Woodford.

''MartesiaC?)" sp. Dickerson, 1914
Figure 99

Martesia (?), sp. Dickerson, 1914: 96, 140.

rounded; posterior end slightly flaring;
ventral margin nearly straight. One beaded
umbonal groove diverges from the beak
[=umbo]. A posterior groove, which indi-
cates the position of an internal rib, makes a
very obtuse angle with the ventral margin.
Tube unknown. Height, 13 mm; length
unknown."

"Martesia(l) sp." was based on a
unique specimen (Fig. 99), which does not
closely resembly any known west American
pholadid, though the family in the Paleo-
gene is still inadequately known. The
specimen is an internal mold with only little
shell remaining, though not enough to make
out any sculpture. A callum appears to be
present. Posterior to the umbonal-ventral
sulcus another groove runs from the
posterior side of the umbo to the center
edge of the posterior margin, vaguely
suggesting the genus Tumus Gabb (see Fig.
98), though actually quite different. The
posterior margin, from the umbonal-ventral
sulcus to near the umbo, is flared outward
slightly and fused to what may have been a
calcareous tube, only remnants of which are
preserved. This condition parallels that
found in the Cretaceous to middle Miocene
genus Teredina Lamarck, 1818 (see Turner,
1969: 717) in which a calcareous tube is
fused simultaneously to both valves of the
shell. The "tube" on this specimen appears
to be fused separately to each valve (only
one is present), or is divided dorsally and (?)
ventrally. This division may only be an
artifact however. Further description of this
species must await better preserved
material.

HYPOTYPE.- Of Martesia (?) sp. Dicker-
son, UCMP 10607. About one-fourth to one-
half mile east and a little south of Lower
Lake on Knoxville Road, Lake Co., Califor-
nia (UCMP loc. 784). Paleocene, Martinez
Formation.

DISCUSSION.- Dickerson (1914: 140)
described the species as: "Shell elongate
with thin test; beaks [= umbones] anterior,
incurved, approximate; posterior dorsal
margin concave and undulating; anterior
dorsal margin short, rounded; anterior end

INCONCLUSIVE RECORDS

Below are records, listed chronologically
by date of publication, of Pholadidae whose
taxonomic position is not posible to deter-
mine at the present. Some are literature
citations for specimens which could neither
be found or recognized in the various
collections examined, and some are only
casual references to borings attributed to
pholadids. Still others are from early

WEST AMERICAN CENOZOIC PHOLADIDAE

73

paleontologic literature and, generic con-
cepts being broader than now, can not be
positively identified without the aid of
comparative material. Additional records of
unidentifiable pholadids, here noted for the
first time, are included in the Register of
Localities.

Antisell (1856: 44, 45, 199) noted the
presence of beds "pierced by pholadines" in
the Santa Margarita Valley of California.-

Blake (1857: 186, 187) reported finding
rock "perforated in every direction by
boring mollusks", Pholadidae "undisturbed
in their self-excavated domicils" from San
Pedro, and rock perforated by boring shells
and by ''Pholas" at Monterey.

Newberry (1857: 14, 15) reported
"Pholas" on a twenty foot terrace on the
south shore of San Pablo Bay, California.

Newberry (1861: 12) reported finding
"stones bored by Pholas" on the road from
San Pedro to Los Angeles and "in the
ancient sea bottoms at San Pedro, San Luis
Obispo, and the bay of San Pablo." Also
cited (Newberry, 1861: 133) were: "Infusor-
ial rock with Pholas, St. Luis Obispo,"
"Shale with Entomostraca and Pholas,
Monterey," and "infusorial clays bored by
Pholas" from a "raised sea bottom, Mon-
terey" and from a place "eighty feet above
sea, San Pedro."

Gabb (1869: 175, 233) recorded Mar^esia
clausa Gabb "from the Martinez Group at
Martinez, and from the Tejon Group at
Martinez, ten miles west of Griswold's and
Tejon." Martesia clausa Gabb, described
from the Cretaceous Chico Group of
California (Gabb, 1864: 145, pi. 22, fig. 115),
belongs to the genus Opertochasma. Dall
(1898: 820), however, followed Gabb in this
range extension, though Anderson and
Hanna (1925: 147) in their study of the type
Tejon, could find no material or justification
of this age assignment and thought it best
to consider it erroneous. The possible poor
preservation of Gabb's specimens, the
whereabouts of which are unknown, may be
responsible for Gabb's inability to separate
his Eocene and Cretaceous specimens, and
it is now impossible to determine what the
Eocene specimens were in reference to.

Cooper (1888: 250) reported "Martesia
intercalata Carpenter" from the Quaternary
at Santa Barbara, California. Though
Carpenter's species is considered to be
Penitella conradihy Turner (1955: 75), what
Cooper had must remain unknown until the
specimen is recognized.

Bowers (1890: 407) reported finding, on
the west side of San Joaquin Bay (=Newport
Bay), "The soft underlying rock [of the
terrace] contains vast quantities oi Pholas in
a vertical position. The stratum ... is about
a foot thick, and the cavities are filled with
inspissated bitumen, leaving casts of the
rock-boring shells." Some of these Bowers
reported were of the chimney building Para-
pholas califomica.

Arnold (1907: 423) reported 'Tholadidea
(?) species indeterminate" from the Pliocene
Fernando Formation from the Santa Maria
district of California. This is probably one of
several species oi Penitella found in this area.

Arnold and Anderson (1907: 59) also
report "Pholadidea (?) sp. indet." from the
same region. Two fragments in the U.S.
National Museum may also be the same
ones referred to by Arnold (1907: 423)
above. They are from USGS loc. 4506,
Pliocene Fernando Formation, Lompoc
quadrange, Santa Barbara Co., and repre-
sent a species of Penitella.

Dickerson (1911: 175, 177) suggested
"Zirphaea (?)" as being responsible for
pholadid burrows in boulders in a basal
conglomerate of the Eocene Tejon Forma-
tion north of Mount Diablo, and for borings
in the Cretaceous Chico "Formation" along
the Chico-Martinez contact south of Stew-
artville. The burrows are filled with
material entirely different from the rock
penetrated (Dickerson, 1911: 177), which
suggests a rock-boring genus rather than
the mud-boring Zirfaea (see section on
Burrows in this paper).

Clark (1915: facing 408) reported
'Pholas, sp. indt." from four localities
(UCMP Iocs. 481, 482, 490, and 1485) near
Tassajara, Contra Costa Co., from the
Miocene San Pablo "Group." Since Zirfaea
dentata was also identified from the same
area, the specimens may be a Penitella, but

74

GEORGE L. KENNEDY

they could not be found in the collections of
the University of California Museum of
Paleontology.

Dickerson (1916: facing 372) reported
"Pholadidea, sp." from four localities (UCMP
Iocs. 143, 476, 709, and 1430) in the basal
Tejon strata south of Mt. Diablo, Contra
Costa Co. "Pholadidea, sp." was also
reported (p. 446) from north of Mt. Diablo,
and in the TurhinoUa zone of the California
Eocene. None of the specimens have been
seen and no guess as to the proper
systematic placement can be made.

Nomland (1917b: 303) reported ''Pholas
(?), sp." and ''Pholas (?) borings" at the base
of the mapped "Monterey Shale." The
numerous borings are in a Mesozoic
serpentine in the San Luis quad., near the
north boundary of sec. 18, T. 29 S., R. 11
E., MDBM.

Gester (1917: 225) found shell "frag-
ments, with Pholas borings" in the Etche-
goin Formation at a depth of 928 feet, from
Well #9 of the United Oil Co., west of
Fellows, San Luis Obispo Co. (?).

Howe (1922: 89) quoted an earlier
reference to Arnold and Hannibal (1913:
602) which probably refer to Penitella
tumerae: "An angular unconformity marked
by Pholas borings may be observed in a
niche of the sea cliffs which form the type
section of the Tunnel Point beds." He
however believed the borings to be within
the Oligocene beds, and not between them
and the overlying Pliocene Empire
Formation.

Berry (1922: 413, footnote) recorded a
''Pholad sp." from the "coal mine" on the
Pleistocene terrace on the west side of Point
Loma, San Diego Co.

Clark and Arnold (1923: 156, pi. 16, fig.
2) cited a small pholad as Zirfaea sp. from
the Oligocene Sooke Formation from west of
Otter Point, Sooke, Vancouver Island,
British Columbia. The small specimen
appears similar to, and may represent, a
Zirfaea pilsbryi. The specimen (SU 295,
not UCMP 30065 as cited) is from SU loc.
N.P. 129.

Nelson (1925: facing 402) reported
"Martesia (?) species" from the Eocene

"Martinez Marine Member of the Martinez
Group" [see Keroher, et al., 1966: 2404] on
the south side of the Simi Valley (UCMP
loc. 3776), Ventura Co., California. The
single left valve is too poorly preserved to
be identified, although it may be an
Opertochasma rather than a Martesia.

Hanna (1926: 462) in his discussion of
"'Bamea" costata suggested either Litho-
phaga (MytiUdae) or Pholadidea for holes in
coral from Alverson Canyon, Coyote Moun-
tain, Imperial Formation (CAS loc. 701). All
holes examined to date from this formation
in both coral and oyster shell have had the
characteristic shape of rock-boring mytilids
(such as Lithophaga).

Santillan and Barrera (1930: 25) re-
ported ''Pholadidea sp." from the late
Pliocene Cantil Costero Formation from
between El Rosario and San Antonio del
Mar on the northwest coast of Baja
California, Mexico.

Weaver (1953: 58, 62) reported finding
"Pholad borings at [the] contact with [the]
Sobrante formation" on the east limb of the
Pacheco syncline, and, also in the Sobrante
Formation, a "shale containing Pholad
borings at top" on the west limb of the same
structure.

Hertlein and Allison (1959: 21) repeat
Santillan and Barrera's (1930) record of
''Pholadidea sp." from northwestern Baja
California.

Higgins (1960: 199, 204, 208, 214, 221,
fig. 5, pi. 20, fig. a) used holes bored in the
Franciscan Formation in Sonoma Co.,
California, and associated with the Ohlson
Ranch Formation of Pliocene age, to map
and delimit the extent of this latter
formation. These holes were only referred
to as "mollusk borings" by Higgins.
However, Peck (1960: 238), in reference to
the same, noted that "sea stacks containing
many "pholad" borings are locally abundant
on the Franciscan-Ohlson Ranch contact."

Stanton (1966: fig. 2, p. 31) reported
"boring pelecypods" from seven localities
(CIT Iocs. 234, 1849, 2069, 2083, 2099, 2105,
and 2106) in the upper Miocene Castaic
Formation near Castaic, Ventura Co.,
California. Most may possibly be mytilid

WEST AMERICAN CENOZOIC PHOLADIDAE

75

borings since they "are lined with a variable
number of carbonate layers." However, "At
loc. 2069, a rounded tuff pebble is pitted by
several shallow borings about three mm. in
diameter. The borings resemble those made
by Recent pholads." None of the specimens
have been seen.

Frazier (1968 [1967]: 13. and 1968: 25)
reported finding both Zirfaea and Para-
pholas on the "large terrace exposed at
Newport Beach. This is about a mile back
from the coast overlooking Upper Newport
Bay." This is from the late Pleistocene Palos
Verdes Sand. The specimens were not
available for examination and may be the
large Chaceia ovoidea common to this area.

Evans (1968a: 277) notes that "Fossil
pholad beds ... of rather recent origin can
be seen as a horizontal foot deep layer
running for many miles south along the
coastal cliffs ... in the Coos Bay area" of
Oregon. "This bed ranges from about 7 to 50
feet above high tide level." Apparently no
shell material has ever been found in the
cavities along the three mile extent of
discontinuous occurrences of the borings,
which are thought to be late Pleistocene in
age (J.M. Armentrout, in litt.).

Zullo (1969: 350) recorded a "Pholadid
species" as rare in a Pleistocene terrace
deposit at Grave Point, near Bandon, Coos
Co., Oregon (UCMP loc. B-7493). The
specimen could not be found at the
University of California Museum of
Paleontology.

Rowland (in Anon., 1970: 147) records
''Penitella" from the Pliocene San Diego
Formation in northwestern Baja California,
10.2 miles south of the U.S. -Mexican
border. This may be from UCD loc. A-249.

Kennedy (1973: 122) recorded "Penitella
sp." from the lower Pleistocene Lindavista
Formation in San Diego, California, from
SDSNH Iocs. 0325 ("?") and 0326. The

umbonal regions of the small specimens are
too damaged for specific identification.

Inconclusive Records, Addenda

Addicott and Galehouse (1973: 514)
report "exposures of the basal Paso Robles
in the vicinity of Santa Margarita are
characterized by angular boulders of Mon-
terey Shale and Vaqueros Sandstone bored
by moderately large marine pholadid bi-
valves (E.W. Hart, written commun., Oct. 2,
1972). A specimen collected from one of
these borings on Chalk Hill, about a mile
northeast of Santa Margarita, appears to be
a small Zirfaea." The specimens have not
been seen.

Edwards (1934: 796, 803, 804) has
reported several occurrences of ''Pholad
borings" from conglomerates and sedimen-
tary breccias in the Los Angeles basin,
"immediately east of the corner of Fourth
and Flower, Streets" [Los Angeles], "about
a mile north of Newport and Balboa", and
from the "Santa Monica Mountains". Also
reported (p. 806) were broken pieces of
Miocene Modelo Formation "attacKed by
Pholads and other burrowing invertebrates
. . . until . . . buried in the Pliocene
sediments."

Bowers (1901: 8) noted that in a wash
on the southeast side of Table Mountain in
Carrizo Valley [Imperial Co.], he found
"crystallized limestone containing the bur-
rows of pholads, or rock-borers." All
burrows seen by me from this area have
been made by rock-boring mytilids.

76

GEORGE L. KENNEDY

REGISTER OF LOCALITIES

The fossil localities cited in this report to which
institutional numbers have been assigned are given
below. All localities are from the State of California
unless otherwise noted. Geological age assignments are
generally those recognized by Keroher (1966, U.S. Geol.
Surv. Bull. 1200) in the Lexicon of Geologic Names of the
United States. Formational assignments usually follow
those of the original collector, although many of these
have since been restricted in time and space.

Specific names in quotation marks are identifica-
tions from the literature which are doubtful, and for
which specimens could not be found. A few specimens
cannot readily be assigned to any presently known phol-
adid genus, and these are also cited in quotation marks.

CALIFORNIA ACADEMY OF SCIENCES

CAS loc. 20.— Pleistocene. Near the top of the sea cliff

one half mile southeast of Cape Blanco, Curry Co.,

Oregon. Zirfaea sp. aff. Z. pilsbryi, Penitella tumerae.

CAS loc. 76.— Pliocene, Foxen Mudstone. At the

Waldorf asphalt mine three miles SSE of Guadalupe,

Santa Barbara Co. Penitella gabbii, P. tumerae, P. sp.

indet.

CAS loc. 90.— Pliocene, Saugus Formation. On the

point of a prominent ridge approximately one mile south

of the head of Torrey Canyon, south of Piru, Ventura

Co. Formation is composed of light gray sand and

gravel. Fossils quite abundant. Penitella penita, P. sp.

cf. P. conradi.

CAS loc. 91.— Pleistocene, Palos Verdes Sand. One

quarter mile north of the Southern Pacific Railroad

Depot, San Pedro, Los Angeles Co. Fossils occur

abundantly in nearly horizontal beds a foot or more in

thickness. Zirfaea pilsbryi, Penitella sp. cf. P. penita.

CAS loc. 92.— Pleistocene, Palos Verdes Sand. On

Deadman Island, San Pedro, Los Angeles Co. Four to

six foot horizon six or eight feet below the top of the

island, and four feet stratigraphically below a Pecten

bed. Penitella penita.

CAS loc. 94. — Pleistocene. Deadman Island, San

Pedro Island, Los Angeles Co. Boring into the horizon

immediately underlying the Lower San Pedro Series.

Brown and gray medium grained sandstone. Penitella

penita.

CAS loc. 102.— Pleistocene. On terrace in sea cliff in

Torrey Pines Beach State Park, three miles south of Del

Mar, San Diego Co. Fossils were obtained from a coarse

gravel bed. Parapholas calif omica.

CAS loc. 243.— Pliocene, Empire Formation. In the se£

cliff about 200 yards east of Tunnel Point and about one

half mile southwest of Coos Head, Coos Co., Oregon.

Penitella tumerae.

CAS loc. 495.— Pleistocene. Deadman Island, San

Pedro, Los Angeles Co. Collected by F.M. Anderson.

Penitella penita.

CAS loc. 509.— Pliocene. Northhwest [? ESE] of
Alcade, in NE 1/4 sec. 25, T. 21 S., R. 15 E., MDBM,
Fresno Co. "Kreyenhagen, Coalinga." [V.A. ZuUo, in
litt., notes this locality is in error and that "The
associated fauna is characteristic of the latest Pliocene
San Joaquin Formation, and is very probably from the
Pecten zone."] Zirfaea pilsbryi.

CAS loc. 701.— Pliocene, Imperial Formation. "Fossils
received from the California State Mining Bureau
without locality data, but probably from Alverson
Canyon, Imperial Co. Collected by Dr. Stephen Bower."
Cyrtopleura costata.

CAS loc. 1154.— Miocene, Temblor Formation. About
9.6 km south of ranch house on Santa Rosa Island, Santa
Barbara Co., California. From oyster bed and beds on
slope of ridge down to San Augustine Canyon between
spring on top of ridge, to TurriteUa inezana bed at CAS
loc. 1153. Collected by L.G. Hertlein and E.L. Rixford,
July 13 and 15, 1927. Zirfaea dentata.
CAS loc. 1479.— Pleistocene, Palos Verdes Sand. Dead-
man Island, San Pedro, Los Angeles Co. Zone 7 of
Arnold. Collected by C.H. Crickmay, 1928. Penitella
conradi.

CAS loc. 1841.— Miocene, Temblor Formation. At the
base of Temblor Reef, Jasper Canyon, Fresno Co.
Collected by G D. Hanna, September, 1929. Unidentified
pholadid.

CAS loc. 2087.— Miocene, Temblor Formation. Reef bed
north of Coalinga, Fresno Co. Collected by F.M. Ander-
son. Zirfaea dentata.

CAS loc. 2088.— Miocene, Temblor Formation. "Reef
beds" north of Coalinga, on south side of sec. 20, T. 19
S., R. 15 E., MDBM, Fresno Co. Zirfaea dentata.
CAS loc. 27871A.— "Eocene." Tranquillon Mtn. 7-1/2"
quad., 924 feet N. 81° W. of El Tranquillon Peak, Santa
Barbara Co. Collected June, 1934. [Miocene; ? boring
into Eocene strata "through" an uncomformity. Zirfaea
dentata].

CAS loc. 28485.— Miocene, Temblor Formation [only in
part]. One mile southeast of Oil City in Fresno Co.
Collected by Joe Knowles, 1915-1935. "(Possibly the
Temblor and Santa Margarita fossils were slightly
mixed in Iocs. 28485 . . .)". Zirfaea dentata. [This
"locality" represents at least two different time periods,
one of which is probably Pliocene. Chaceia , ovoidea. ] .-.^
CAS loc. 31832.— Pleistocene. About ten to twelve feet
above high tide, three miles north of Cayucos, San Luis
Obispo Co. Collected by A.G. Smith, 1932-1933.
Penitella penita.

CAS loc. 34437.— Pliocene, "Merced" Formation. Moss
Beach, San Mateo Co. Collected by Don and Kelly
Castleberry, Feb. 22, 1955. Penitella penita, P. sp. cf. P.
penita, cast of pholadid burrow.

CAS loc. 36499.— Oligocene, San Ramon Formation.
Large highway cut at Carquinez, Contra Costa Co. Col-
lected just below the pebbly conglomerate which

WEST AMERICAN CENOZOIC PHOLADIDAE

77

appears to be slightly disconformable with the silty
shale of probable Eocene age. Received from E.H.
Drew, April 10, 1959. Penitella lorenzana.
CAS loc. 38432.— Pleistocene, Palos Verdes Sand. East
side of Upper Newport Bay, city of Newport Beach,
Orange Co. "From a large canyon since filled." Collected
by E.V. Coan, "probably 1961." Zirfaea pilsbryi.

CALIFORNIA INSTITUTE OF TECHNOLOGY
[Material not seen]

GIT loc. 234.— Miocene, Castaic Formation. Near
Castaic, Los Angeles Co. E 1/2 sec. 32, T. 5 N., R. 16
W., SBBM. "Boring pelecypods."

GIT loc. 1348.— Pleistocene, Palos Verdes Sand. South-
west slope of Signal Hill, 500 feet north and a litle east
of intersection of Raymond Avenue and 21st Street, city
of Signal Hill, Los Angeles Co. Collected by J.H.
DeLong, Jr., summer, 1938. Zirfaea pilsbryi.
GIT loc. 1849.— Miocene, Castaic Formation. On ridge
west of junction of Reynier and Sand Canyons, near
Castaic, Los Angeles Co. SW 1/4 SE 1/4 sec. 35, T. 4
N., R. 15 W., SBBM. "Boring pelecypods."
GIT loc. 2069.— Miocene, Castaic Formation. South
edge of Humphreys quadrangle, near Castaic, Los
Angeles Co. W 1/4 NW 1/4 SW 1/4 sec. 27, T. 4 N., R.
15 W., SBBM. "Shallow borings" which "resemble those
made by Recent pholads."

GIT loc. 2083.— Miocene, Castaic Formation. On a
broad flat ridge northwest of Castaic Creek, near
Castaic, Los Angeles Co. "Boring pelecypods."
GIT loc. 2099.— Miocene, Castaic Formation. 3750 feet
N. 72° E. from Cordova Ranch, in sec. 36, T. 6 N., R. 17
W., SBBM, near Castaic, Los Angeles Co. "Boring
pelecypods."

GIT loc. 2105.— Miocene, Castaic Formation. East of
junction of Castaic and Fish Creeks, near Castaic, Los
Angeles Co. "Boring pelecypods.",
GIT loc. 2106.— Miocene, Castaic Formation. Ridge
crest north of Elderberry Canyon, near Castaic, Los
Angeles Co. "Boring pelecypods."

LOS ANGELES COUNTY
MUSEUM OF NATURAL HISTORY

LAGMNH loc. 1. — Pleistocene. San Pedro, Los Angeles
Co. Mrs. Burton Williamson collection. Zirfaea pilsbryi.
LAGMNH loc. 2.— Pleistocene. Deadman Island, Los
Angeles Harbor, Los Angeles Co. Mrs. Burton William-
son collection. Bamea subtruncata.
LAGMNH loc. 5.— No data; possibly from the Pleisto-
cene of San Pedro, Los Angeles Co. Penitella penita.
LAGMNH loc. 14. — Pleistocene. Redondo, Los Angeles
Co. Mrs. Burton Williamson collection. Collected Febru-
ary 1892. Penitella penita.

LAGMNH loc. 17.— Pleistocene. Deadman Island, San
Pedro, Los Angeles Co. Williamson collection. Zirfaea
pilsbryi, Penitella sp. cf. P. penita.
LAGMNH loc. 32.— Miocene, Topanga Formation.
Topanga Canyon, Los Angeles Co., on a hillside north of
bend in Old Topanga Canyon Road, 1/4 mile north of the

Hiram Montgomery Ranch and 1/2 mile south of the
summit and junction with Dry Canyon Road. South of
middle of sec. 35, T. 1. N., R. 17 W., SBBM. Collected
by H.R. Hill and U.S. Grant, IV, August 13, 1930.
Zirfaea dentata.

LAGMNH loc. 58.— Pleistocene. Just east of Calle For-
tuna, between Camino Estrella and Avenida de las
Palmas, Capistrano Beach, Orange Co. Collected by
George Willett, 20-21 September, ? 1936. Zirfaea
pilsbryi, Penitella penita, P. sp. indet.
LAGMNH loc. 59.— Pleistocene, Palos Verdes Sand.
Just south of outfall sewer as it crosses Lincoln Avenue,
about 2 miles northeast of community of Playa del Rey,
Los Angeles Co. Fossiliferous stratum 8 to 12 inches
thick and from 2 to 4 feet below surface, at an elevation
of 50 feet. Collected by George Willett, 1935-1936.
Zirfaea pilsbryi, Penitella conradi.
LAGMNH loc. 66-2.— Pleistocene, Palos Verdes Sand.
One half mile southeast of the salt reducing plant at the
head of Upper Newport Bay, Orange Co. North facing
exposure in second erosion channel cut into the surface
of the lower of two terraces, near the base of the
second. Richly fossiliferous sand 20 to 36 feet thick,
immediately overlying a 1 to 2 foot thick basal conglom-
erate. 33° 38' 37" N., 117° 52' 37" W. Collected by G.P.
Kanakoff. Bamea subtruncata, Zirfaea pilsbryi, Chaceia
ovoidea, Penitella penita, Parapholas califomica.
LAGMNH loc. 66-10.— Pleistocene, Palos Verdes Sand.
On east bluff above Upper Newport Bay, near
LACMNH loc. 66-2, city of Newport Beach, Orange Co.
Collected by Jack Schwartz, March, 1966. Bamea sub-
truncata, Chaceia ovoidea.

LAGMNH loc. 68-A.— Pleistocene, Palos Verdes Sand.
Exposure in cliff face of Newport Mesa, on west side of
"middle" Newport Bay, city of Newport Beach, Orange
Co. Sediments 12 to 18 feet thick. Collected by G.P.
Kanakoff. Zirfaea pilsbryi, Chaceia ovoidea;[not seen].
LAGMNH loc. 77.— Pleistocene, Palos Verdes Sand.
"Outfall Sewer" ditch at corner of Lomita Boulevard and
Main Street, Wilmington, Los Angeles Co. Collected by
Chester Stock and G.P. Kanakoff, February 19, 1947.
Zirfaea pilsbryi.

LAGMNH loc. 98.— Pleistocene, San Pedro Sand.
Southeast corner of 3rd and Mesa Streets, San Pedro,
Los Angeles Co. Fossiliferous strata 2 to 10 feet thick
and 20 to 30 feet above street level. Zirfaea pilsbryi,
Penitella sp. cf. P. conradi, P. penita.
LAGMNH loc. 107.— Pliocene, San Diego Formation.
Quarry at end of Arroyo Drive, city of San Diego, San
Diego Co. Exposure 40 to 50 feet high. Scattered
boulders (clay concretions) contain molluscan material.
Collected by G.P. Kanakoff. Penitella conradi, Penitella
sp. cf. P. penita.

LAGMNH loc. 131.— Pleistocene, San Pedro Sand.
Street cut on north side of 500 block of N. Pacific
Avenue, San Pedro, Los Angeles Co. Sand stratum 2 to
10 feet thick and 10 to 20 feet above street level. Col-
lected by Museum's junior paleontology class. Zirfaea
pilsbryi.

LAGMNH loc. 136.— Pleistocene, Palos Verdes Sand.
On east bluff above Upper Newport Bay, Orange Co.

78

GEORGE L. KENNEDY

"Anomia Bed" 15 feet below level of airfield at elevation
of 87 feet. Collected by G.P. Kanakoff, October 16, 1947.
Bamea subtruncata, Zirfaea pilsbryi, Choceia ovoidea.
LACMNH loc. 137.— Pleistocene. Just east of Calle For-
tuna, between Camino Estrella and Avenida de las
Palmas, Capistrano Beach, Orange Co. Collected by
G.P. Kanakoff, 24 October 1947, and thereafter.
PeniteUa penita.

LACMNH loc. 147.— Pleistocene, Palos Verdes Sand.
Near intersection of Vermont Avenue and Sepulveda
Boulevard, west of Carson and north of San Pedro in an
unincorporated part of Los Angeles Co. Bamea
subtruncata.

LACMNH loc. 226.— Pleistocene, Palos Verdes Sand.
Area of 8th and Palos Verdes Streets, San Pedro, Los
Angeles Co. Collected by G.P. Kanakoff, December 29,
1951. PeniteUa sp. cf. P. conradi, P. penita, Nettastom-
ella rostrata.

LACMNH loc. 229.— Pleistocene, Palos Verdes Sand.
Deposit on south side of Anaheim St., east of intersec-
tion with Normandie Ave., Harbor Lake [=old Bixby
Slough], community of Harbor City, city of Los Angeles,
Los Angeles Co. Collected by G.P. Kanakoff, 29 Decem-
ber 1951. Bamea subtruncata, PeniteUa sp. indet.
LACMNH loc. 241.- Pleistocene, Palos Verdes Sand. A
one mile exposure 40 to 60 feet thick, one mile west of
the bridge over Newport Bay, on present Highway 1
(Pacific Coast Highway), city of Newport Beach, Orange
Co. Collected by G.P. Kanakoff, October 1952, and
thereafter. PeniteUa penita.

LACMNH loc. 300.— Pleistocene, San Pedro Sand.
Below "Nob Hill," San Pedro, Los Angeles Co. Collected
by G.P. Kanakoff, November 4, 1955. Bamea subtrun-
cata, Zirfaea pilsbryi, PeniteUa sp. cf. P. conradi, P.
penita.

LACMNH loc. 305.— Pliocene, San Diego Formation.
On hill southwest of Goat Canyon, 290 feet north of the
U.S. -Mexican border, southwestern San Diego Co. Sixty
foot exposure from 1 to 2 feet thick. Collected by G.P.
Kanakoff, July 20, 1956. Zirfaea pilsbryi, PeniteUa
conradi, P. penita.

LACMNH loc. 305-C.— Pliocene, San Diego Formation.
In small amphitheater on south side of Goat Canyon,
southwestern San Diego Co. 100' west and 440' south of
NE cor. sec. 8, T. 19 S., R. 2 W., SBBM. Collected by
G.P. Kanakoff. PeniteUa conradi.

LACMNH loc. 314.— Pliocene, Merced Formation. Two
mile stretch of outcrop at Capitola Beach, Santa Cruz
Co. Collected by G.P. Kanakoff, July 2, 1958. Para-
pholas califomica [chimneys only].
LACMNH loc. 317-J.— Miocene, Topanga Formation.
"Same as [LACMNH loc] 32 but with stratig^-aphic posi-
tions." Collected by G.P. Kanakoff, "3-10-59." Zirfaea
dentata.

LACMNH loc. 416.— Late Pleistocene. Exposures
between the University of California at Santa Barbara
and Devereaux School, Isla Vista, near Goleta, Santa
Barbara Co. Collected by G.P. Kanakoff. Zirfaea
pilsbryi, PeniteUa tumerae.

LACMNH loc. 423.— Pliocene, Fernando Formation.
Excavation 35' below freeway level, near the intersec-

tion of Interstate 405 and Cherry Avenue, Long Beach,
Los Angeles Co. Collected by Roger Reimer, 26-29 July
1963. PeniteUa penita.

LACMNH loc. 424.— Pleistocene. About 1/4 mile west
of intersection of Interstate 405 and Cherry Avenue,
Long Beach, Los Angeles Co. Collected by Roger
Reimer, July 23, 1963. Zirfaea pilsbryi.
LACMNH loc. 426.— Pleistocene. North facing bank on
south side of Interstate 405 at north end of Cheviot
Vista Place, Palms, city of Los Angeles, Los Angeles
Co. Collected by G.P. Kanakoff. Bamea subtruncata,
Zirfaea pilsbryi.

LACMNH loc. 427.— Pleistocene, Palos Verdes Sand.
Hillside 1/4 mile from San Pedro end of Harbor
Freeway, immediately after the Union Oil Co. refinery,
San Pedro, Los Angeles Co. Collected by G.P. Kanakoff,
J.E. Fitch, Jr., and N. Furjaner, August 1, 1964.
Zirfaea pilsbryi.

LACMNH loc. 435.— Pleistocene, Lomita Marl. Forty
foot exposure on south side of gully at intersection of
1200 Park Western Drive, 1200 West Coralmount Drive,
and 1100 Host Place, San Pedro, Los Angeles Co. Col-
lected 35 feet below Host Place level by G.P. Kanakoff.
PeniteUa conradi, NettastomeUa rostrata.
LACMNH loc. 440.— Pleistocene, Palos Verdes Sand.
Excavation at southeast corner of Pacific and Hards
Streets, San Pedro, Los Angeles Co. Collected at the
approaches to Vincent Tomas Bridge between San Pedro
and Wilmington, by G.P. Kanakoff, April 6, 1965.
Zirfaea pilsbryi, PeniteUa penita.

LACMNH loc. 452. — Pleistocene. 100 yard exposure
along RR tracks from San Clemente RR station and
south, 30 feet up cliff, San Clemente, Orange Co. Col-
lected by James Ingle and William Meisalis, 30 July
1960. PeniteUa sp. indet.

LACMNH loc. 453.— Pliocene. About 100 miles south of
Ensenada, at south end of San Quintin Valley, Baja Cali-
fornia, Mexico. On east side of highway in sandstone
cliffs just below top of mesa. Collected by M.L. Webster
and David Hyatt, September, 1965. PeniteUa penita.
LACMNH loc. 466.— Pliocene, Fernando Formation.
Excavation for Crocker Citizens Plaza Building, corner
of Sixth and Hope Streets, downtown Los Angeles, Los
Angeles Co. PeniteUa conradi.

LACMNH loc. 471.— Pliocene, Fernando Formation.
On east bluff above Newport Bay, Orange Co. Approxi-
mately 800 feet south and 50 feet west of NE cor. sec.
24, T. 6 S., R. 10 W., SBBM. Highly fossiliferous gray
unconsolidated silt exposed over an area of several
hundred square yards by bulldozers excavating housing
sites. Collected in 1966 or 1967. PeniteUa conradi.
LACMNH loc. 482.— Pleistocene, Norfolk Formation.
Virginia Beach, Princess Anne Co., Virginia. Cyrto-
pleura costata.

LACMNH loc. 487.— Pleistocene, Palos Verdes Sand.
On east bluff above Upper Newport Bay, city of
Newport Beach, Orange Co. Collected by Boris Savic
and J. A. Sutherland. NettastomeUa rostrata.
LACMNH loc. 1144.— Pliocene or Pleistocene. Bluff
near beach, San Juan Capistrano, Orange Co. PeniteUa
penita.

WEST AMERICAN CENOZOIC PHOLADIDAE

79

LACMNH loc. 1203.— Pleistocene. Lumberyard near
Timm's Point, San Pedro, Los Angeles Co. Collected by
E.J. Post. Penitella penita.

LACMNH loc. 1204.— pliocene, Etchegoin Formation.
On northeast side of Bitterwater Valley, San Benito Co.
NE 1/4 sec. 13, T. 18 S., R. 9 E., MDBM. Collected by
Carl Bleifus, November, 1956. Zirfaea pilsbryi
LACMNH loc. 1205.— Miocene, Monterey Formation.
Pinole, Contra Costa Co. "From contact between
Monterey and Chico." Penitella sp. indet.
LACMNH loc. 1206.— Pleistocene. Deadman Island,
San Pedro, Los Angeles Co. Penitella penita.
LACMNH loc. 1210.— Pleistocene, Palos Verdes Sand.
North end of the Los Angeles Harbor District Sanitation
Yard, in middle of low bluff parallel to and immediately
south of the Union Oil Company refinery, between the
communities of San Pedro and Wilmington, Los Angeles
Co. Locality is west of the Harbor Freeway and from
2/5 to 1 mile due east of the intersection of Gaffey
Street and Westmount Drive. Collected by E.C. Wilson,
and 603 helpers, October 4, 5, 11, 12, and 18, 1969.
Zirfaea pilsbryi, Chaceia ovoidea, Penitella penita.
LACMNH loc. 1219.— Pliocene, Fernando Formation.
Excavation 60 feet below surface for Atlantic-Richfield
Plaza basement, north corner of intersection of Sixth
and Flower Streets, downtown Los Angeles, Los
Angeles Co. Collected by P.I. LaFollette, J. Marr, B.
Savic, and S. Geldman, 30 December 1969 to 4 January,
1970. Penitella conradi.

LACMNH loc. 1307.— Pleistocene, Terrace 7. Palos
Verdes Peninsula, Los Angeles Co. "Building excavation
582 m . . . N4W from bench mark 832. Elevation 192 m.
W.H. Easton and L.N. Marincovich [loc. 7-1], collec-
tors." Chaceia ovoidea, Parapholas calif omica.
LACMNH loc. 2636.— Pleistocene. South face of gentle
slope on Coquille Point, southwest of benchmark on
point, Bandon, Oregon. SE 1/4 SE 1/4 sec. 26, T. 28 S.,
R. 15 W., WBM. Collected by G.L. Kennedy and G.G.
Sphon, 9 August 1972. Penitella sp. indet.
LACMNH loc. 2641.— Pleistocene. In cliff face of
natural amphitheater on southeast side of Cape Blanco,
Oregon. Center of S 1/2 NE 1/4 sec. 2, T. 32 S., R. 16
W., WBM. Collected by G.L. Kennedy and G.G. Sphon,
10 August 1972. Penitella penita.

LACMNH loc. 2658.— Pleistocene, Bay Point Formation.
Rear of building cut on Pomona Street, Coronado, 20 to
40 m west of entrance to the Coronado Yacht Club on
Glorietta Bay in San Diego Harbor, San Diego Co.
Lithologfy: detrital shell layers and unconsolidated beach
sand. Collected by G.L. Kennedy. Zirfaea pilsbryi.
LACMNH loc. 2687.— Pleistocene, Second Terrace.
Excavation for High School at 15th and Leland Streets,
San Pedro, city of Los Angeles, Los Angeles Co. Col-
lected by E.P. Chace, 1937. Zirfaea pilsbryi.
LACMNH loc. 2690.— Pleistocene. Storm drain ditch
south of railroad tracks, crossing 103rd Street, Watts,
city of Los Angeles, Los Angeles Co Penitella penita.
LACMNH loc. 2694.— Pleistocene. Deposit above the
beach at Isla Vista, near Goleta, Santa Barbara Co. Col-
lected by E.V. Coan. Zirfaea pilsbryi, Penitella tumerae,
Parapholas califomica.

LACMNH loc. 2719.— Pleistocene. Conflicting data, but
somewhere in the vicinity of San Juanica and Punta
Pequeiia, Baja California, Mexico. 26° 15' 35" N., 112°
26' 20" W. Collected by P.I. LaFollette, 25-27 October
1971. Zirfaea pilsbryi.

LACMNH loc. 2905.— Miocene, Topanga Formation.
Head of Topanga Canyon, two miles south of Calabasas
P.O., Los Angeles Co. Zirfaea dentata.
LACMNH loc. 3936.— Pleistocene. Flat on southeast
corner of Crannell Road and Highway 101 frontage road,
.2 miles south of Crannell offramp, Humboldt Co. 2200
feet west and 1350 feet south of NE cor. sec. 7, T. 7 N.,
R. 1 E., HBM. Collected by G.L. Kennedy, 31 July and
28 August, 1973. Zirfaea pilsbryi.

LACMNH loc. 3944.— Pleistocene, Battery Formation.
Beach cliff just below southeast corner of intersection of
Pebble Beach Drive and Murphy Drive, Crescent City,
Humboldt Co. Pholads boring into underlying Pliocene
mudstone. Collected by G.L. Kennedy, 4 August 1973.
Penitella tumerae.

LACMNH loc. 3950.— Pleistocene. Terrace deposit on
south side of Fivemile Point, between Bandon and Coos
Bay, Coos Co., Oregon. 450 feet W. and 1500 feet S. of
NE cor. sec. 19, T. 27 S., R. 14 W., WBM. Collected by
G.L. Kennedy, 9 August 1973. Penitella gabbii, P.
penita.

LACMNH loc. 3951.— Pleistocene. Terrace deposit on
north side of Fivemile Point, between Bandon and Coos
Bay, Coos Co., Oregon. 400 feet W. and 1150 feet S. of
NE cor. sec. 19, T. 27 S., R. 14 W., WBM. Collected by
G.L. Kennedy, 9 August 1973. Penitella penita.
LACMNH loc. 3952.— Pleistocene. Base of bluff on west
side of road on very eastern tip of Hinton Point,
opposite corrugated metal buildings, Yaquina Bay, near
Newport, Lincoln Co., Oregon. Collected by G.L.
Kennedy, 12 August 1973. Zirfaea pilsbryi.
LACMNH loc. 4556.— Pleistocene. "Border locality"
(supposedly =SDSNH loc. 118) in southwesternmost
San Diego Co. Collected by Mark Boeder. Zirfaea
pilsbry, Penitella sp. indet.

SAN DIEGO
NATURAL HISTORY MUSEUM

SDSNH loc. 0040.— Pleistocene. About 1-1/2 miles west
of Goleta Point and 4 miles WSW of Goleta, Santa Bar-
bara Co. At Campbell's Ranch, in bank of soft clay shale
overlain by a very rich fossiliferous sandy layer.
Collected by U.S. Grant, IV, 1927. Zirfaea pilsbryi,
Penitella tumerae.

SDSNH loc. 0051.— Pliocene. Imperial Formation.
Carrizo Creek, loc. B, about 3 mUes east of Old Carrizo
Creek Stage Station and one mile south of the road,
western Imperial Co. Collected ? by Frank Stephens.
Cyrtopleura costata.

SDSNH loc. 0074.— Pleistocene. Fossiliferous deposit
near top of embankment about 1 to 1-1/4 miles west of
Goleta Point, Santa Barbara Co. Same as SDSNH loc.
0040 but about 1/4 mile east along beach. Collected by
U.S. Grant, IV, September 19, 1928. Penitella tumerae.

80

GEORGE L. KENNEDY

SDSNH loc. 0078.— Pleistocene. Terrace 1/2 mile south
of Sea Cliff Station on Southern Pacific Railroad and 8
miles north of Ventura City, Ventura Co. At north end
of sea wall south of an evergreen grove. Collected by
Lynn Farish, July 3, 1926. (Deposit obscured by
widening of state highway; (s) U.S. Grant, 1928.)
Penitella sp. cf. P. penita.

SDSNH loc. 0120.— Pleistocene. About 125 yards north
of U.S. -Mexican border and 1/2 to 1/3 mile from the
ocean, southwestern San Diego Co. Mixed clay, sand
and boulders at 30 feet elevation on the west side of a
ravine heading across the border. Collected by Frank
Stephens, September 17, 1929. [Locality description on
label differs somewhat from that in locality book.]
Zirfaea pilsbryi

SDSNH loc. 0289.— Pleistocene. Terrace material
collected around mouth of Tourmaline Street canyon
(Tourmaline Street Surfing Park), Pacific Beach, city of
San Diego, San Diego Co. Collected by M.J. Bishop and
S.J. Bishop. Penitella penita.

SDSNH loc. 0325. — Pleistocene, Lindavista Formation.
North-facing bank on south side of residence at 10735
Montego Drive (in southeast corner of first cul-de-sac on
Montego Drive west of El Noche Way), San Diego, San
Diego Co. Fossiliferous unconsolidated conglomeratic
sandstone. Altitude 131 m. Approximate coordinates,
32° 49.7' N., 117° 5.8' W. Collected by G.L. Kennedy,
September 1971. Zirfaea pilsbryi, Penitella sp. indet.
SDSNH loc. 0326. — Pleistocene, Lindavista Formation.
West-facing bank on east side of residence at 10735
Montego Drive (in southeast corner of first cul-de-sac on
Montego Drive west of El Noche Way), San Diego, San
Diego Co. Approximate coordinates, 32° 49.7' N.,
117° 5.8' W. Collected by G.L. Kennedy, September
1971. Penitella sp. indet.

SDSNH loc. 0417.— Pliocene, San Diego Formation.
About 1/4 mile and fifth ravine north of U.S. -Mexican
border, and 3/4 mile east of ocean on west face of
terrace, southwestern San Diego Co. Collected by E.H.
Quayle, August 28, 1932. Penitella penita.
SDSNH loc. 0429.— Pliocene, San Diego Formation.
About 250 yards north of the U.S. -Mexican border and
1/2 mile from the ocean in a small gulch in the cliff
bordering the Tia Juana River, southwestern San Diego
Co. Collected by Frank Stephens, July 20 and August
12, 1932. Penitella penita.

SDSNH loc. 0624.— Pleistocene. Southwest corner of
Turtle Bay, Baja California, Mexico, at south end of hills
on the peninsula between the bay and the Pacific Ocean.
Collected by E.P. Chace, 16 July 1954. Penitella fitchi.
SDSNH loc. 0625.— Pleistocene. "Chiton Bed," on Point
Firmin, a few yards west of the western boundary of the
picnic grounds around Peck's Pavillion, San Pedro, Los
Angeles Co. Gray sand, sometimes considerably indur-
ated, about 10 feet below the upper edge of the bluff.
Collected by E.P. Chace and E.M. Chace, 1918. Penitella
penita, Nettastomella rostrata.

SDSNH loc. 0702.- Pleistocene. San Nicolas Island,
Channel Islands, Ventura Co. Collected ? by Malcolm
Rogers. Chaceia ovoidea.
SDSNH loc. 1883.— Pleistocene. San Pedro, Los

Angeles Co. Collected ? by Ralph Arnold. Penitella
penita.

SDSNH loc. 1885.— Pleistocene. Nob Hill, San Pedro,
Los Angeles Co. Penitella penita.

SDSNH loc. 1899.— Pleistocene. San Pedro Railroad
Cut, San Pedro, Los Angeles Co. Collected by Kate
Stephens. Zirfaea pilsbryi, Penitella penita.
SDSNH loc. I960.— Pleistocene. New San Pedro
Lumber Yard, San Pedro, Los Angeles Co. Collected by
E.P. Chace. Zirfaea pilsbryi.

SDSNH loc. 2138 [=L-2138].- Pleistocene, San Pedro
Sand. In foundation hole, two feet below surface, for the
San Pedro High School, 15th and Leland Streets, San
Pedro, Los Angeles Co. 33° 43' 52.5" N. lat., 118° 17' 42"
W. long. Collected by E.P. Chace, 1936. Bamea
subtruncata, Zirfaea pilsbryi, Chaceia ovoidea, Penitella
fitchi, P. penita, Nettastomella rostrata.
SDSNH loc. 2419.— Pleistocene. Below California
Western University campus of the U.S. International
University, west side of Point Loma, San Diego, San
Diego Co. Collected by R.C. Schwenkmeyer and
Museum paleontology class. Parapholas califomica.
SDSNH loc. 2454.— Pliocene, San Diego Formation.
Arroyo Drive, city of San Diego, San Diego Co.
Penitella conradi.

SDSNH loc. 2455.— Pliocene, San Diego Formation.
Laural Canyon, city of San Diego, San Diego Co.
Collected ? by O.H. Reinhold. Penitella conradi.
SDSNH loc. 2528.— Pleistocene. Coronado Beach, San
Diego Co. Collected by C.L. Hubbs. Zirfaea pilsbryi.
SDSNH loc. 2529.— Pliocene, San Diego Formation.
Northeast corner of Upas and India Streets, city of San
Diego, San Diego Co. Penitella sp. cf. P. conradi
SDSNH loc. 2530.— Pleistocene. Point Loma, San Diego
Co. Collected by C.H. Hubbs. Penitella penita.
SDSNH loc. 2531.— Pleistocene. Rosarito Beach, Baja
California, Mexico. Collected ? by Kate Stephens. Peni-
tella gabbii, P. penita, unidentified pholadid burrow.
SDSNH loc. 2532.— Pliocene, Imperial Formation.
Coyote Mountain, Imperial Co. Collected by Frank
Stephens. Cyrtopleura costata.

SDSNH loc. 2561.— Pleistocene, Palos Verdes Sand. On
the east bluff above Upper Newport Bay, approximately
140 meters north of north corner of bridge on Vista del
Oro Street, city of Newport Beach, Orange Co. Richly
fossiliferous. unconsolidated detrital sand. 33° 38' 26" N.
lat., 117° 53' 02" W. long. Collected by L.M. Kennedy,
June 5. 1966. Penitella fitchi

SDSNH loc. 2575.— Pliocene or Pleistocene. Dredged in
Oakland Creek [?San Francisco Bay], California. Col-
lected by Henry Hemphill. Bamea subtruncata.
SDSNH loc. 2576.— Pleistocene. "At the ocean beach"
about 10 miles south of the U.S. -Mexican border, Baja
California, Mexico. Penitella penita.
SDSNH loc. 2629.— Pleistocene. Approximately 8.4
miles south of Rosarito Beach, Baja California, Mexico.
About 4-5 feet below the surface of old Highway 1, "200
yards south of Happy's Club." Collected by Arnold Ross
and J.R. Jehl, Jr., November 7, 1968. Penitella penita.
SDSNH loc. 2630.— Pleistocene. Pavement on bluffs at
Campo del Arroyo, Cedros Island, Baja California,

WEST AMERICAN CENOZOIC PHOLADIDAE

81

Mexico. Collected by F.H. Wolfson, January, 1968.
Parapholas califomica.

SDSNH loc. 2631. — Late Pleistocene. Terrace deposit
on west side of Point Loma, San Diego Co. Collected by
G.D. Webster, April, 1968. Chaceia ovoidea.
SDSNH loc. 2646.— Pliocene or Pleistocene. "Bracket
Mesa," Arroyo Santo Catarina, Baja California, Mexico.
Pholadids boring into Paleocene strata with a "Martinez"
fauna. Collected by M.L. Webster. PeniteUa sp. cf. P.
tumerae.

SDSNH loc. 2658.— Pliocene or Pleistocene. From a
shallow cave near the top of the bluff that parallels the
coast between San Quintin and Rancho Socorro, Baja
California, Mexico. Collected by M.L. Webster. PeniteUa
penita.

SDSNH loc. 2660.— Pleistocene. Corner of Third and
Mesa Streets, San Pedro, Los Angeles Co. Collected by
E.P. Chace. Zirfaea pilsbryi, PeniteUa penita.
SDSNH loc. 2669.— Pleistocene, Lomita Marl. Near
bottom of northeast facing slope below Coralmount and
Park Western Drives, San Pedro, Los Angeles Co. Col-
lected in situ in cobbles, by G.L. Kennedy and R.P.
Battelle, 13 September, 1970. PeniteUa conradi, P.
penita.

SDSNH loc. 2670.— Pleistocene. From south-facing
cove on south side of Point Ano Nuevo, San Mateo Co.
Collected by G.L. Kennedy, 21 June 1970. Zirfaea sp.
aff. Z. pilsbryi.

SAN DIEGO STATE COLLEGE

Collected by G.L. Kennedy, fall, 1966. Bamea subtrun-
cata, Chaceia ovoidea, PeniteUa penita, NettastomeUa
rostrata.

SDSC loc. 534.- Pleistocene, Palos Verdes Sand. On
the east bluff above Upper Newport Bay, 166 meters
northwest of north corner of bridge on Vista del Oro
Street, city of Newport Beach, Orange Co. Same
lithology as SDSC loc. 531 but somewhat indurated with
lime. Collected by G.L Kennedy, fall, 1966. Zirfaea
pilsbryi.

SDSC loc. 535.— Pleistocene, Palos Verdes Sand. On
the east bluff above Upper Newport Bay, 163 meters
northwest of north corner of bridge on Vista del Oro
Street, city of Newport Beach, Orange Co. Very coarse
sand and cobbles, highly stained with iron oxide. Two
feet stratigraphically above SDSC loc. 534. Collected by
G.L. Kennedy, fall, 1966. Zirfaea pilsbryi.
SDSC loc. 537.— Pleistocene, Palos Verdes Sand. On
the east bluff above Upper Newport Bay, 170 meters
NNW of north corner of bridge on Vista del Oro Street,
city of Newport Beach, Orange Co. Same lithology as
SDSC loc. 533. Collected by G.L. Kennedy, fall, 1966.
Chaceia ovoidea, PeniteUa fitchi; NettastomeUa rostrata
[not collected].

SDSC loc. 648.— Pleistocene. New San Pedro Lumber-
yard, on San Pedro and Wilmington Road, San Pedro,
Los Angeles Co. Collected by E.P. Chace. Zirfaea
pilsbryi.

SDSC loc. 736.— Pleistocene. San Pedro, Los Angeles
Co. Zirfaea pilsbryi.

SDSC loc. 71 ( = SDSC loc. 118).— Pleistocene, Bay Point
Formation. Glorietta Bay, 100 yards north of corner of
U.S. Highway 75 and Pomona Street, Coronado, San
Diego Co. Fine gray sandstone with cross bedded
coquina. Elevation nine feet. 32° 41' 15" N., 117° 10' 15"
W. Zirfaea pilsbryi.

SDSC loc. 109.— Pleistocene. El Descanso, northwest-
ern Baja California, Mexico. PeniteUa penita.
SDSC loc. 350.— Pliocene, Imperial Formation. South of
Yuha Buttes [Imperial County, California] in Baja Cali-
fornia, Mexico. Collected by R.G. Gastil and J. A. Minch,
December, 1963. Cyrtopleura cost/ata.
SDSC loc. 531.— Pleistocene, Palos Verdes Sand. On
the east bluff above Upper Newport Bay, 170 meters
NNW of north corner of bridge on Vista del Oro Street,
city of Newport Beach, Orange Co. Richly fossiliferous
detrital layer 1-1/2 to 2 feet thick, intermixed with
coarse friable sand. Collected by G.L. Kennedy, fall,
1966. Zirfaea pilsbryi.

SDSC loc. 532. — Pleistocene, Palos Verdes Sand. On
the east bluff above Upper Newport Bay, 230 meters
northwest of north corner of bridge on Vista del Oro
Street, city of Newport Beach, Orange Co. Same
lithology as SDSC loc. 531. Collected by G.L. Kennedy,
fall, 1966. Zirfaea pilsbryi.

SDSC loc. 533.— Pleistocene, Palos Verdes Sand. On
the east bluff above Upper Newport Bay, 183 meters
NNW of north corner of bridge on Vista del Oro Street,
city of Newport Beach, Orange Co. Exposure of paleo-
bottom in outcrop of massive fine grained sandstone.

STANFORD UNIVERSITY

SU loc. N.P. 129.— Oligocene, Sooke Formation. Sea
cliffs of Kirby (formerly Coal Creek) and Muir Creeks,
west of Otter Point, Sooke, Vancouver Island, British
Columbia, Canada. "Zirfaea sp." [The specimen appears
similar to, and may represent, a Pliocene to Recent
Zirfaea pilsbryi. ]

UNIVERSITY OF CALIFORNIA AT DAVIS

UCD loc. A-249.— Pliocene, San Diego Formation.
North end of a steep east-west trending canyon which
begins just north of the village of La Gloria, on Route 1,
past Escuela Amando Nervo, to the coast, northwestern
Baja CaHfornia, Mexico. The canyon head is approxi-
mately 4.2 road miles from Highway 1. Gray sandstone
with large cobbles. Collected by R.W. Rowland, spring
1968. Burrow with PeniteUa sp. indet.

UNIVERSITY OF CALIFORNIA
AT LOS ANGELES

UCLA loc. 167.— Miocene, Topanga Formation. "On"
road. Old Topanga Canyon, Los Angeles Co. About 2200
feet east and 250 feet north of the southwest corner of
sec. 35, T. 1 N., R. 17 W., SBBM, Dry Canyon quad-
rangle. Greenish-brown, medium to fine-grained sand-
stone with interbedded gray shale cut by basalt

82

GEORGE L. KENNEDY

intrusions. Zirfaea dentata, "Pholadidea penita"; (not
seen).

UCLA ioc. 312.— Pliocene, San Diego Formation. Fifth
ravine north (about 1/4 mile) of the U.S. -Mexican bor-
der, at west face of terrace 3/4 mile east of the coast,
southwestern San Diego Co. PeniteUa penita.
UCLA Ioc. 1824.— Pleistocene, San Pedro Sand. South-
east corner of Second and Beacon Streets, San Pedro,
Los Angeles Co. PeniteUa penita.

UCLA loc.2410.— Pleistocene. Marine terrace deposit
about 100 feet (?) above strand, at mouth of staircase
canyon, Torrey Pines State Park, south of Del Mar, San
Diego Co. Collected by G. Weir. Zirfaea piLsbryi,
PeniteUa penita, P. sp. indet., Parapholas califomica.
UCLA Ioc. 2717.— Pleistocene. Sandy rubble in sea cliff
approximately 6.4 miles south of the radio tower at
Rosarito Beach, and about 0.3 miles south of kilometer
36 on [old] Highway 1, Baja California, Mexico. Collected
by J.S. Cunningham and J. W. Valentine, February,
1952. PeniteUa penita.

UCLA Ioc. 2718.— Pleistocene. Sandy rubble exposed in
sea cliff approximately 5.7 miles south of the radio tower
at Rosarito Beach, at kilometer 36 on [old] Highway 1,
Baja California, Mexico. Collected by J.S. Cunningham
and J.W. Valentine, February, 1952. PeniteUa penita.
UCLA Ioc. 2719.— Pleistocene. Unconsolidated pebble
conglomerate exposed in sea cliff approximately 2.2
miles south of the radio tower at Rosarito Beach, at kilo-
meter 30 on [old] Highway 1, Baja California, Mexico.
Collected by J.W. Valentine, December, 1952. PeniteUa
penita.

UCLA Ioc. 2720. — Pleistocene. Sandy rubble exposed in
sea cliff at the second small re-entrant in first sea cliffs
south of the radio tower at Rosarito Beach, Baja Cali-
fornia, Mexico. Collected by J.W. Valentine, December,
1952. Zirfaea pilsbryi, PeniteUa penita.
UCLA Ioc. 2774.— Pleistocene. Terrace near San
Clemente, Orange Co. Coarsegrained sands with
cobbles in lenses, about 5 feet thick, exposed in gully
west of U.S. Highway 101 about 150 feet on a line
projecting from the end of Magdalena Avenue. Collected
by R.J. Smith, 1953. Parapholas califomica.
UCLA Ioc. 3160.— Pleistocene. Unconsolidated cobble
conglomerate exposed in low sea cliff approximately 5.2
miles north of the radio tower at Rosarito Beach, Baja
California, Mexico. Collected by J.S. Cunningham and
J.W. Valentine, January, 1952. PeniteUa penita.
UCLA Ioc. 3161.— Pleistocene. Unconsolidated cobble
conglomerate exposed in sea cliff approximately 8 miles
north of the radio tower at Rosarito Beach, Baja Cali-
fornia, Mexico. Collected by J.S. Cunningham and J.W.
Valentine, January, 1952. PeniteUa penita.
UCLA Ioc. 3175. — Pleistocene. Terrace near the U.S.-
Mexican border, southwestern San Diego Co. Fine
grained sandstone about 1 foot thick, locally cemented,
exposed in the first north-south trending gully cutting
the terrace and draining into the Tia Juana River valley
east of the ocean, along road running to the Interna-
tional Boundary Monument. Collected by J.S. Cunning-
ham and J.W. Valentine, winter, 1951. Zirfaea pilsbryi.
UCLA Ioc. 3225.— Pleistocene. At the head of Potrero

Canyon, Pacific Palisades, Los Angeles Co. Collected by
F.C. Clark. Zirfaea pilsbryi, Chaceia ovoidea.
UCLA Ioc. 3393.— Pleistocene. Sea cliffs approximately
1/2 mile west of the mouth of Cayucos Creek, and 75
feet west of intersection of frontage road with Califor-
nia State Highway 1, near Cayucos, San Luis Obispo Co.
Collected by J.W. Valentine. Chaceia ovoidea, PeniteUa
pejiita.

UCLA Ioc. 3440.- Pleistocene, Palos Verdes Sand.
Near Palos Verdes Street, between 8th and 9th Streets,
San Pedro, Los Angeles Co. Medium grained sand.
Zirfaea pilsbryi, Chaceia ovoidea, PeniteUa penita.
UCLA Ioc. 3445.— Pleistocene. Sea cliffs approximately
2-1/2 miles west of mouth of Cayucos Creek, just west
of the headland which is west of Cayucos Point, San Luis
Obispo Co. Collected by J.W. Valentine. PeniteUa penita.
UCLA Ioc. 3447.— Pleistocene. Sea cliffs at small point
nearly opposite intersection of frontage road and
Highway 1, Cayucos, San Luis Obispo Co. Collected by
J.W. Valentine. PeniteUa penita.

UCLA Ioc. 3448.— Pleistocene. Sea cliffs approximately
1-1/2 miles west of mouth of Cayucos Creek, just west
of first stream gully east of Cayucos Point, San Luis
Obispo Co. Collected by J.W. Valentine. PeniteUa
penita.

UCLA Ioc. 3457.— Pleistocene. Terrace in hanging
valley approximately 1/2 mile south of the parking lot
on the beach at Torrey Pines Beach State Park, San
Diego Co. Collected by J.W. Valentine, April 19, 1958.
Chaceia ovoidea.

UCLA Ioc. 3458. — Pleistocene. Terrace in hanging
valley approximately 7/8 mile south of the parking lot
on the beach at Torrey Pines Beach State Park, San
Diego Co. Collected by J.W. Valentine, April 19, 1958.
Chaceia ovoidea, PeniteUa sp. indet.
UCLA Ioc. 3460.— Pleistocene, Timms Point Silt. On
the northern border of the Palos Verdes Hills, Los
Angeles Co. Exposure is 1,000 feet east of Crenshaw
Boulevard and 2,250 feet slightly west of south of the
intersection of Crenshaw and U.S. Highway 101, at
about 345 feet elevation, in the second ravine east of
Crenshaw cutting the north slope of 400 foot hill.
Collected by Carl Helms and J.W. Valentine. PeniteUa
penita.

UCLA Ioc. 3569. — Pleistocene. Unconsolidated cobble
conglomerate exposed in gully 20 feet inland from sea
cliff, approximately 4-1/2 miles south of the mouth of
Rio Morro, and about 150 yards north of kilometer 45 on
[old] Highway 1, Baja California, Mexico. Collected by
J.W. Valentine, November, 1952. Parapholas califomica.
UCLA Ioc. 3597.— Pleistocene. On platform surface on
north side of the first railroad cut west of Tajiguas
Creek, near Gaviota, Santa Barbara Co. In sands above
sea cliffs. Collected by J.W. Valentine, spring, 1956.
PeniteUa tumerae, Parapholas califomica.
UCLA Ioc. 3600.— Pleistocene, Palos Verdes Sand.
South side of ravine opposite loading platform on siding
of Western Oil and Refining Co., 2,200 feet southwest of
intersection of Harbor Boulevard and Frigate Avenue,
Torrance quadrangle, Los Angeles Co. Medium grained
sand. Collected by J.W. Valentine, spring, 1956. Barnea

WEST AMERICAN CENOZOIC PHOLADIDAE

83

subtruncata.

UCLA loc. 3602.— Pleistocene. Palos Verdes Sand.
Near top of cut on east side of Western Avenue, 900 feet
south of valley of lower George F Canyon, Torrance
quadrangle, Los Angeles Co. Ostrea lurida-Anomia
peruviana association in sand, overlying San Pedro
Sand. Collected by J.W. Valentine, spring, 1956.
Chaceia ovoidea.

UCLA loc. 3605. — Pleistocene. Terrace sands exposed
in a building site cut at the end of Sunset Cliffs Street,
1/4 mile south of Ladera Street, Point Loma, San Diego
Co. Penitella sp. cf. P. penita, Parapholas califomica,
Nettastomella rostrata.

UCLA loc. 3606.— Pleistocene. Sand at northeastern-
most end of fossiliferous Pleistocene beds at Pacific
Beach, San Diego Co. Collected by R.F. Meade and J.W.
Valentine, winter, 1957. Penitella penita.
UCLA loc. 3657.— Pleistocene. Sand and gravel pit on
west face of ridge north of oil sumps in N 1/2 NE 1/4
sec. 34, T. 5 S., R. 11 W., SBBM, Huntington Beach
Mesa, Orange Co. Two foot pebble conglomerate in
northeast corner of pit. Collected by P.U. Rodda and
J.W. Valentine, spring, 1957. Zirfaea pilsbryi.
UCLA loc. 4243. — Pleistocene, fourth terrace. Cut
along Fort McArthur Upper Reservation on the west
side of Gaffey Street, 50 feet north of 38th Street, San
Pedro, Los Angeles Co. Collected by R.F. Meade and
J.W. Valentine. Chaceia ovoidea [fragment).

UNIVERSITY OF CALIFORNIA

MUSEUM OF PALEONTOLOGY

(BERKELEY)

UCMP loc. 51.- Error by Hanna. 1926; =W.S.W. Kew
locality number.

UCMP loc. 305. — Miocene, Briones Sandstone. On
northeast side of Shell Ridge about 1 mile west of east
edge of Concord quadrangle. Elevation 700 feet. Col-
lected by J.C Merriam [loc. 305]. Zirfaea dentata.
UCMP loc. 143.— Eocene, Tejon Group. South of Mt.
Diablo, Mt. Diablo quad., NE 1/4 sec. 4, T. 1 S., R. 1
W., MDBM, Contra Costa Co. Near contact of Chico and
Tejon "Formations." "Pholadidea, sp." [not seen).
UCMP loc. 360.— Miocene. Two-thirds of a mile south-
west of Vallejo Junction, in bluff close to the railroad
tracks at the lowest Miocene contact with the Martinez
Formation. Collected by J.C. Merriam [loc. 408].
Penitella sp. indet.

UCMP loc. 476.— Eocene, Tejon Group. South of Mt.
Diablo, Mt. Diablo quad., SW 1/4 NW 1/4 sec. 22, T. 1
S., R. 1 W., MDBM, Contra Costa Co. Elevation 1200
feet, in little wash near creek, below 1250 foot hill. Col-
lected by W.S.W. Kew, 1912. "Pholadidea, sp." [not
seen].

UCMP loc. 48L — Miocene, San Pablo group. In small
gully leading southeast into Riggs Canyon, Black Hills,
north of Tassajara, Contra Costa Co. Astrodapsis
whitneyi zone, near center of NE 1/4 sec. 28, T. 1 S.,
R. 1 E., MDBM. "Pholas, sp. indt." [not seen].
UCMP loc. 482.— Miocene, San Pablo group. Near
Alamo Creek, northwest of Tassajara, Contra Costa Co.

Near center of south side of NW 1/4 sec. 28, T. 1 S., R.
1 E., MDBM. Elevation 1200 feet. "Pholas, sp. indt."
[not seen].

UCMP loc. 490.— Miocene, San Pablo group. East of
Riggs Canyon and north of Tassajara, Contra Costa Co.,
a little to east of center of south side of sec. 21, T. 1 S.,
R. 1 E., MDBM. "Pholas, sp. indt." [not seen].
UCMP loc. 492.— Miocene, San Pablo group. East of
Riggs Canyon and north of Tassajara, Contra Costa Co.,
in SW 1/4 SE 1/4 sec. 21, T. 1 S., R. 1 E., MDBM. Ele-
vation 1750 feet. Zirfaea dentata.

UCMP loc. 709.— Eocene, Tejon Group. On east side of
Cave Point, Mt. Diablo quad.. Contra Costa Co.
Collected by R. E. Dickerson, 1912. "Pholadidea, sp."
[not seen].

UCMP loc. 784.— Eocene, Martinez Group. Well at old
brickyard, about 1/4 to 1/2 mile east and a little south of
Lower Lake on Knoxville road, 1000 feet (horizontal)
above the Chico-Martinez contact. Lake Co. NW 1/4 NE
1/4 sec. 11, T. 12 N., R. 7 W., MDBM. "Martesiai?), sp."
[see INCERTAE SEDIS\.

UCMP loc. 1131. — Oligocene, San Ramon Formation.
One half mile southwest of the town of Walnut Creek,
Contra Costa Co. In creek bed about 100 yards east of
Oakley-Antioch Bridge. Elevation 150 feet. 37° 53' 07"
N., 122° 04' 08" W. Collected by B.L. Clark [loc. 72].
Penitella lorenzana.

UCMP loc. 1430.— Eocene, Tejon Group. South of Mt.
Diablo, Mt. Diablo quad., SE 1/4 sec. 11, T. 1 S., R. 1
W., MDBM, Contra Costa Co. On north side near top of
2018 foot hill. Collected in 1911. "Pholadidea, sp." [not
seen].

UCMP loc. 1485.— Miocene, San Pablo group. On south
side of Black Hawk Ridge, near Mt. Diablo, Contra Costa
Co., near west edge of SE 1/4 NW 1/4 sec. 19, T. 1 S.,
R. 1 E., MDBM. Elevation about 1250 feet. "Pholas, sp.
indet." [not seen].

UCMP loc. 1600.— Miocene, San Pablo group. About
2-1/2 miles east and a little south of Rodeo, Contra
Costa Co., on south side of 700 foot hill near the head of
a deep north-south gulch. Zirfaea dentata.
UCMP loc. 1607.— Miocene, San Pablo group. Near
Tormey, Contra Costa Co., on hill over tunnel just south
of Tormey railroad station, in coarse sandstone on north
side of a quarry, and just west of a big oil tank. Zirfaea
dentata.

UCMP loc. 1722.— Pliocene, Merced Formation. In a
gulch a few yards east of the main coast road about 3/4
of a mile due southeast of Mussel Rock, San Mateo Co.
Near the south side of NE 1/4 sec. 23, T. 3 S., R. 6 W.,
MDBM. Zirfaea sp. cf. Z. pilsbryi.

UCMP loc. 1891.— Miocene, San Pablo group. South of
Pittsburg, on south side of 594 foot hill, very near the
top, near center of SW 1/4 sec. 29, T. 2 N., R. 1 E.,
MDBM. Zirfaea dentata.

UCMP loc. 1905.— Pliocene, Purisima Formation.
Sargent Oil Field, on slope of hill north of Pescadero
Creek, west of Sargent, Santa Clara Co. Zirfaea pilsbryi.
UCMP loc. 2112.— Pleistocene, Palos Verdes Sand.
"Cornwall. Arnold. San Pedro," Los Angeles Co. Zirfaea
pilsbryi.

84

GEORGE L. KENNEDY

UCMP loc. 2300.— Miocene, Vaqueros Formation.
North of Coalinga, near Oilfields, in canyon west of red
cliffs in the NW cor. of SW 1/4 NE 1/4 sec. 10, T. 19 S.,
R. 15 E., MDBM, Fresno Co. Elevation 1250 feet. Col-
lected by B.L. Clark [loc. 19]. Zirfaea dentata.
UCMP loc. 2309.— Miocene, Vaqueros Formation. Near
Oil City, Fresno Co. Near section line on side of creek
above SE corner of NE 1/4 NE 1/4 sec. 4, T. 19 S., R.
15 E., MDBM. Collected by B.L. Clark [loc. 51]. Zirfaea
dentata.

UCMP loc. 2313.— Miocene, Vaqueros Formation. West
of Oil City and north of Oilfields, in reef beds somewhat
below the middle of the Vaqueros in NW 1/4 SE 1/4 sec.
16, T. 19 S., R. 15 E., MDBM, Fresno Co. Collected by
B.L. Clark [loc. 205]. Zirfaea dentata.
UCMP loc. 2388.— Pleistocene. San Pedro, including
Terminal Island, and Deadman Island, Los Angeles Co.
UCMP loc. 2668.— Pliocene, Etchegoin Formation.
Southwest of Coalinga, in hills to north of Jacalitos
Creek, near middle of north line of NE 1/4 SW 1/4 sec.
34, T. 21 S., R. 14 E., MDBM, Fresno Co. Zirfaea sp. cf.
Z. pilsbryi.

UCMP loc. 3016.— Pliocene, Etchegoin Formation.
Bank of creek in hills on northeast side of Priest Valley,
Fresno Co. Southeast cor. NE 1/4 NE 1/4 sec. 14, T. 20
S., R. 12 E., MDBM. Zirfaea pilsbryi.
UCMP loc. 3030.— Pliocene, Fernando Formation.
Thirty-four feet below surface in excavation for depart-
ment store on 4th Street between Broadway and Hill
Streets, Los Angeles, Los Angeles Co. Collected by J.G.
Gilbert. Penitella sp. cf. P. penita.
UCMP loc. 3158.— Eocene, Meganos Formation. On top
of ridge in the middle of north edge of SE 1/4 sec. 20, T.
1 N., R. 2 E., MDBM, Contra Costa Co. "Jouannetiasp."
[see Incertae sedis. ]

UCMP loc. 3159.— Eocene, Meganos Formation. On top
of ridge in the NW cor. of SW 1/4 sec. 21, T. 16 N., R. 2
E., MDBM, Contra Costa. Martesia meganosensis.
UCMP loc. 3321.— Pliocene, Empire Formation. Basal
beds of formation 150 yards east of Tunnel Point, Coos
Bay, Coos Co., Oregon. Collected by H.V. Howe. "Para-
pholas califomica" [not seen; probably Penitella
tumerae].

UCMP loc. 3322.— Pliocene, Coos Conglomerate,
Empire Formation. Three miles southwest of Empire,
on South Slough, Coos Bay, Coos Co., Oregon. Penitella
tumerae.

UCMP loc. 3577.— Eocene, Meganos Formation. On
ridge immediately east of Hill 392, northeast of Mount
Diablo. At west edge of Byron quadrangle, 1/4 mile
southwest of L in Los Meganos. Collected by A.O.
Woodford [loc. 458A]. Martesia meganosensis.
UCMP loc. 3776.— Eocene, "Martinez Formation." In
SW 1/4 SE 1/4 sec. 23, T. 2 N., R. 18 W., SBBM, about
5300 feet N. 3° W. of 2150 foot hill in the Simi Hills,
Ventura Co. About 900 feet north of main fork in creek,
on west side of bottom of canyon, a little northeast of
mouth of small canyon coming southeast. Elevation 1145
feet. fOpertochasma sp.

UCMP loc. 4194.— Oligocene, Keasey Formation. In
shaley sandstone bluffs along Rock Creek, 1-1/2 miles

below the Keasey Post Office, Keasey, Columbia Co.,
Oregon. Sec. 33, T. 5 N., R. 5 W., WBM. Collected by
H.G. Schenck. Martesia sp.

UCMP loc. 5092.— Pleistocene. Bluffs at mouth of Tour-
maline Street Canyon, Pacific Beach, city of San Diego,
San Diego Co. Elevation 20 feet. Collected by Vorge and
Hanna, summer, 1922 [loc. 255]. Penitella penita.
UCMP loc. 7098.— Pliocene, "Pico" Formation. South
Mountain, about 500 feet north of an artificial cut in low
ridge in SW cor. sec. 34, T. 3 N., R. 21 W., SBBM,
Ventura Co. Collected by L.N. Waterfall. Zirfaea
pilsbryi.

UCMP loc. 7180.— Miocene, ?Vaqueros Formation. On
east side of small ridge in N center of SE 1/4 sec. 35, T.
10 N., R. 21 W., SBBM, just northwest of farthest
southern spring in Neason's Flat, Kern Co. Collected by
T.B. Stewart. Zirfaea dentata.

UCMP loc. A-87.— Pliocene, Empire Formation. In the
vicinity of Coos Bay, Coos Co., Oregon. Sec. 3, T. 26 S.,
R. 14 W., WBM. Collected by H.G. Schenck [loc. S 110].
Penitella tumerae.

UCMP loc. A-218.— Pleistocene. Excavation in lot
behind Seamen's Church Institute, E. First Street and
Harbor Boulevard, San Pedro, Los Angeles Co.
Collected by Simpson and Winterer. Zirfaea pilsbryi.
UCMP loc. A-221.— Pleistocene, Palos Verdes Sand.
Large excavation on southern flank of Signal Hill, 1200
feet S. of summit and 500 feet NE of Junipero Avenue,
city of Signal Hill, Los Angeles Co. Collected by Simpson
and Winterer, January, 1927. Zirfaea pilsbryi.
UCMP loc. A-252. — Miocene, Vaqueros Formation.
Along NE-SW ridge west of mouth of Wiley Canyon,
Santa Clara Valley, Ventura Co. In alternating hard and
soft sandstones and shaley sandstones of lower
Turritella inezana zone, near south center of SE 1/4 sec.
34, T. 4 N., R. 19 W., SBBM. Zirfaea dentata.
UCMP loc. A-551.— Miocene, Vaqueros Formation.
Between Ensenal Canyon and unnamed canyon to west,
on abut 600-700 foot contour, Santa Monica Mountains,
Los Angeles Co. Near south boundary line of SW 1/4
sec. 28, T. 1 S., R. 19 W.. SBBM. Collected by W.H.
Corey. Zirfaea dentata.

UCMP loc. A-557.— Miocene, Temblor Formation.
Quarry at end of trail, east side of upper Malibu Canyon,
1/2 mile north of entrance to creek [?], Los Angeles Co.
Collected ? by W.H. Corey. Zirfaea sp. cf. Z. dentata.
UCMP loc. A-649.— Pliocene, Etchegoin Formation. In
NW 1/4 SW 1/4 sec. 24, T. 22 S., R. 15 E., MDBM,
Fresno Co. Zirfaea sp. indet.

UCMP loc. A-650.— Pliocene, Etchegoin Formation. In
west central part of NE 1/4 sec. 22, T. 21 S., R. 15 E.,
MDBM, Fresno Co. Zirfaea pilsbryi.
UCMP loc. A-1036.— Miocene, Temblor Formation.
"Button Bed" on hill to east of Oil Canyon, just above
southern boundary line of sec. 20, T. 19 S., R. 15 E.,
MDBM, Fresno Co. Zirfaea dentata.
UCMP loc. A-1483.— Pleistocene, [? Palos Verdes
Sand). Signal Hill, city of Signal Hill, Los Angeles Co.
Zirfaea pilsbryi.

UCMP loc. A-2549. — Miocene. In small narrow gully
just east of Union Oil Service Station [in 1936], on east

WEST AMERICAN CENOZOIC PHOLADIDAE

85

side of El Toro Valley, southwest of Salinas, Monterey
Co. Just above northern boundary of T. 16 S., in SW 1/4
sec. 35, T. 15 S., R. 2,E.. MDBM. Collected by A.G.
Bennison [loc. 99], fall, 1936. Penitella conradi.
UCMP loc. A-2550.— Miocene, ?Monterey Formation.
Near end of road leading north from Klondike Canyon
(north off of Carmel Valley), Monterey Co. In sec. 1,
T. 17 S.. R. 2 E., MDBM. Collected by A.G. Bennison
lloc. 101], fall, 1936. Penitella sp. cf. P. conradi.
UCMP loc. A-3101.— Pleistocene. Palos Verdes Sand.
On west bluff of Upper Newport Bay, Orange Co. About
10-20 feet below brow of palisade in gray, loosely
consolidated and cross bedded coarse sand, and below a
buff-brown sandy clay. Collected by S.C. Bruff [loc.
75a). Zirfaea pilsbryi, Parapholas califomica.
UCMP loc. A-3104.— Pleistocene, Palos Verdes Sand.
On west bluff of "middle" Newport Bay, Orange Co.
Exposure of sands containing shells down to 50 feet
below brow of cliff and unconformably overlying
exposed anticline in the Monterey Shale. Collected by
S.C. Bruff [loc. 80). Penitella penita.
UCMP loc. A-3129.— Pleistocene, Palos Verdes Sand.
Gully in westward facing escarpment on the Santa Ana
River channel, 2 miles from the ocean, Costa Mesa,
Orange Co. Fossils from a horizon 45 feet above the
flood-plain and 30 feet below the terrace. Collected by
S.C. Bruff [loc. 108], December, 1938. Zirfaea pilsbryi.
UCMP loc. A-3132.- Pleistocene, Palos Verdes Sand.
In cliff opposite and north of Lido Isle, Newport Bay
proper. Orange Co. Fossils in basal conglomerate below
cross-bedded sand; saturated with oil and tar. Collected
by S.C. Bruff [loc. 78], December, 1938. Penitella
gabbii, Parapholas califomica.

UCMP loc. A-3241.— Miocene, Santa Margarita
Formation. East of Peachtree Valley, Monterey Co.
Center of sec. 1, T. 21 S., R. 11 E., MDBM. Collected by
N.L. Taliaferro and geology field class, June 10, 1937.
Zirfaea dentata.

UCMP loc. A-3345.— Miocene, Temblor Formation.
Near Oil City, in reef beds at top of hill running N-S in
center of W 1/2 sec. 21, T. 19 S., R. 15 E., MDBM,
Fresno Co. Collected by Paleontology 103 class, April 15,
1940. Zirfaea dentata.

UCMP loc. A-3415.— Miocene, Pismo Formation.
Frazer property, about one mile southeast of the Huasna
school house, San Luis Obispo Co. Near west central
part of sec. 29, T. 23 S., R. 15 E., MDBM. Collected by
J.O. Nomland and G.C. Gester, 1916. Penitella sp.
indet.

UCMP loc. A-4261.— Miocene, Monterey Formation. In
cliffs south of railroad tracks and 100 yards west of the
Selby Railroad Station, Selby, Contra Costa Co. Col-
lected by S.P. Welles, August, 1947. Unidentified small
pholadid.

UCMP loc. A-4296.— Oligocene, San Ramon Formation.
In facing roadcuts, 1-1/4 miles east of Muir Station on
California State Highway 4 (Arnold Industrial Highway),
Contra Costa Co. Collected by Paleontology 103 class,
fall, 1947. Penitella durhami.

UCMP loc. A-7583.— Miocene, Temblor Formation. In
reef beds paralleling Garza Creek in SE 1/4 SE 1/4 sec.

3, T. 23 S., R. 16 E., MDBM, Kings Co. From hard
calcareous sandstones containing TurriteUa ocoyana.
Collected by Paleontology 137 class, October 3. 1951.
Zirfaea dentata.

UCMP loc. A-7762.— Oligocene, San Ramon Formation.
On north side of California State Highway 4 (Arnold
Industrial Highway) about 1/2 mile northeast of Atchi-
son, Topeka, and Santa Fe Railroad tunnel (west of the
turnoff to Avon), Contra Costa Co. Pholadids boring 1-3"
below contact between Eocene Alhambra Formation and
San Ramon Formation. Collected by J.W. Durham and
J.H. Peck, Jr., December 8, 1951, and O.S. Adegoke,
1966. Penitella durhami.

UCMP loc. A-8709.— Pliocene or Pleistocene. Two miles
southeast of Cape Blanco, SW 1/4 NE 1/4 sec. 12, T. 32
S., R. 16 W., WBM, Curry Co., Oregon. Poorly consoli-
dated 12 foot conglomerate between massive sands in
cliffs about 30 feet above sea level. Collected by Paleon-
tology 137 class, September, 1952. Penitella sp. cf. P.
penita.

UCMP loc. A-8712.— Pleistocene. About 200 feet south
of access road to Cape Blanco Light House, Curry Co.,
Oregon. Fossils in basal 2 to 3 feet, conglomerate trun-
cating steeply dipping older sediments. In center of NE
1/4 sec. 2, T. 32 S., R. 16 E., WBM. Collected by Pale-
ontology 137 class, September, 1952. Zirfaea pilsbryi.
UCMP loc. A-9003.— Pleistocene. Small gully in terrace
250 feet along shore line north of the U.S. -Mexican
border, southwestern San Diego Co. Soft poorly sorted
sands with occasional cobbles and boulders overlying
channeled Pliocene (?) sediments. Elevation 35 feet.
32° 32' 05.7" N.. 117° 07' 19.5" W. Collected by R.O.
Fox, J.W. Emerson, W.K. Emerson, and W.O. Addi-
cott. Zirfaea pilsbryi [in situ].

UCMP loc. A-9004. — Pleistocene. North face of terrace,
700 feet north of U.S. -Mexican Boundary Monument
258, southwestern San Diego Co. Gray, fine grained,
unconsolidated sand from 1 to 3 inches thick overlying
sandy siltstone of the Pliocene San Diego Formation.
Elevation 20-25 feet. Collected by R.O. Fox, J.W.
Emerson, and W.K. Emerson [loc. E305]. Zirfaea
pilsbryi.

UCMP loc. A-9005.— Pleistocene. Northwest face of
terrace, 700 feet north and 600 feet east of U.S. -Mexican
Boundary Monument 258, southwestern San Diego Co.
Highly fossiliferous, gray, well sorted, fine grained
sand, 6-12 inches thick, exposed in cut along road to
Boundary Monument. 32° 32' 10.6" N. lat., 117° 07' 11.5"
W. long. Elevation 30 feet. Collected by R.O. Fox, J.W.
Emerson, W.K. Emerson [loc. E-307], and W.O. Addi-
cott. Zirfaea pilsbryi.

UCMP loc. A-9006.— Pleistocene. North face of terrace
immediately east of 250 foot wide, north trending ravine
and 1,750 feet inland from the ocean, southwestern San
Diego Co. Poorly sorted sand with occasional cobbles,
from 4-8 inches thick, and overlying a boulder
conglomerate. 32° 32' 09.4" N. lat., 117° 07' 06.3" W.
long. Collected by R.O. Fox, J.W. Emerson and W.K.
Emerson [loc. E-306]. Zirfaea pilsbryi.
UCMP loc. A-9587.— Pleistocene. Terrace remnant 1200
feet south from shore line angle from Punta Cabras,

86

GEORGE L. KENNEDY

Baja California, Mexico. White coquina strata, four feet
thicit, forming a broad bench about 12 feet above sea
level and overlying an alternating brown sandstone and
pebble conglomerate of late Cretaceous age. 31° 19' 03"
N. lat., 116° 26' 25" W. long. Collected by W.O. Addi-
cott, February 7, 1953, and W.K. Emerson, June, 1953.
Zirfaea pilshryi, "Penitella cf. P. penita" [not seen].
UCMP loc. A-9589.— Pleistocene. Sea cliff approxi-
mately 3/4 of a mile north of Punta Cabras, Baja Califor-
nia, Mexico. Fossils from pockets of fine grained sand in
well indurated, four foot thick, basal conglomerate
overlying Cretaceous sandstone and underlying 30 feet
of unfossiliferous sands. 31° 19' 45" N. lat., 116° 27' 05"
W. long. Collected by W.O. Addicott [loc. 227],
February 7, 1953. "?Zirfaea pilshryi" [not seen].
UCMP loc. A-9590.— Pleistocene. First rocky point
NNE of Punta Baja, Baja California, Mexico. Poorly
sorted, unconsolidated, sandy gravel with small
boulders, 4 feet thick, and overlying a well indurated
upper Cretaceous conglomerate. 29° 57' 32" N. lat., 115°
44' 35" W. long. Collected by W.O. Addicott [loc. 229],
February 9, 1953. Zirfaea pilshryi.

UCMP loc. A-9591. — Pleistocene. Sea cliff at intersec-
tion of sea cliff and mouth of small south trending ravine
about 1-1/2 miles east of Punta Baja, and on north shore
of Bahia del Rosario, Baja California, Mexico. Outcrop
from 1 to 4 feet thick, exposed 12 feet above sea level in
face of cliff. Lithology same as at UCMP loc. A-9590.
29° 57' 35" N. lat., 115° 47' 15" W. long. Collected by
W.O. Addicott [loc. 228] and W.K. Emerson, February
9, 1953. Zirfaea pilshryi.

UCMP loc. A-9713.— Pleistocene. Terrace deposit 4700
feet south from shore line angle from Punta Cabras,
Baja California, Mexico. Abundantly fossiliferous calcar-
eous sandstone containing well-rounded cobbles and
boulders of upper Cretaceous sandstone at the base.
Collected by W.K. Emerson, November, 1953. Zirfaea
pilshryi.

UCMP loc. A-9731.— Miocene, Santa Margarita Forma-
tion. Bed of Domengine Creek, Fresno Co. NW 1/4 SW
1/4 sec. 34. T. 18 S., R. 15 E., MDBM. Orange to buff
sand and clay with abundant filled borings. Collected by
Paleontology 137 class, September, 1953. Zirfaea
dentata.

UCMP loc. A-9738.— Pliocene, ? Etchegoin Formation.
Down embankment in north fork in road in SE 1/4 NE
1/4 SW 1/4 sec. 7, T. 22 S., R. 18 E., MDBM, La
Cuesta, Kettleman Hills, Kings Co. Lower Mtdinia zone?
Collected by Paleontology 137 class, September, 1953.
Zirfaea pilshryi.

UCMP loc. A-9739.— Miocene, Temblor Formation.
From the gullies east of Big Tar Canyon Road, Kings
Co. Turritella zone 500 feet north of north edge of
prominent rock spine of Reef Ridge. NE 1/4 NE 1/4 NE
1/4 see. 18, T. 23 S., R. 17 E., MDBM. Collected by
Paleontology 137 class, September, 19.53. Zirfaea
dentata.

UCMP loc. A-9742.— Miocene, Temblor Formation.
From gullies east of Big Tar Canyon Road, Kings Co.
Mixed zone 800 feet north of north edge of prominent
rock spine of Reef Ridge. Collected by Paleontology 137

class, September, 1953. Zirfaea dentata.
UCMP loc. A-9917.— Pleistocene. Marine terrace 3700
feet south along coast from Punta Cabras, Baja Califor-
nia, Mexico. Subheadlands on 30 foot terrace, in 1/2-1
foot poorly consolidated sandstone bed. Collected by
W.K. Emerson [loc. E-1002], November 12, 1953.
Zirfaea pilshryi.

UCMP loc. B-469.— Pleistocene, Palos Verdes Sand.
Gaffey Street anticline, opposite the San Pedro Lumber
Co., 4300 feet northeast of intersection of Harbor Boule-
vard and Pacific Avenue, San Pedro, Los Angeles Co.
Eight foot thick fossiliferous layer of gray silty sand.
Collected by E.P. Chace, and by Chace and W.K. Emer-
son, December, 19.53. Bamea subtruncata, Zirfaea
pilshryi.

UCMP loc. B-2178.— Pliocene, Etchegoin Formation.
Gabilan Range about 7 miles NNW of Pinnacles, San
Benito Co. Center of east boundary line of SW 1/4 SW
1/4 sec. 21, T. 15 S., R. 7 E., MDBM. Collected by LE.
Wilson, July 22, 1940. Zirfaea pilshryi.
UCMP loc. B-3007.— Pleistocene. Terrace deposit at
about 40 foot elevation N. 30° E. of peak on south side of
entrance to Turtle Bay, Baja California, Mexico. Col-
lected by E.C. Allison, June 18, 1956. Chaceia ovoidea,
Penitella penita.

UCMP loc. B-3027.— Pleistocene. Terrace immediately
behind long sandy beach along southwest portion of
peninsula northwest of Turtle Bay, Baja California,
Mexico. Elevation 15 to 20 feet. Collected by E.C.
Allison, June 27, 1956. Zirfaea pilshryi, Penitella penita.
UCMP loc. B-3033.— Miocene. Along east side of air
field at summer camp site east and northeast of the
village at Turtle Bay, Baja California, Mexico. Mega-
fossils from sandy horizons at base of white shale, and
immediately overlying Cretaceous-Miocene unconform-
ity. Collected by E.C. Allison, June 28. 1956. Small sand
filled pholadid burrows.

UCMP loc. B-3050. — Pleistocene. Terrace along shore
on northeast side of Turtle Bay, Baja California, Mexico.
Elevation 15 to 20 feet. Collected by E.C. Allison, July
3, 1956. Zirfaea pilshryi.

UCMP loc. B-4339.— Miocene, Temblor Formation.
"Button Bed" near ridge on steep hill south of Big Tar
Canyon, Kings Co. 700 feet south of BM 1307, in NE 1/4
NE 1/4 NE 1/4 sec. 18, T. 23 S., R. 17 E., MDBM. Col-
lected by Paleontology 137 class, September, 1956.
Zirfaea dentata.

UCMP loc. B-4793.— Pliocene, "Merced" Formation.
Intertidal zone on Moss Beach, 200 feet S. 28° |W.] from
mouth of first unnamed intermittant stream north of
San Vicente Creek, Moss Beach, San Mateo Co. Collected
by William and Marilyn Glen, fall, 1956. Zirfaea pilshryi,
Parapholas calif omica.

UCMP loc. B-4928.— Pliocene, '.■" Paso Robles Formation.
Northwest of Jolon, Monterey Co. SW 1/4 SW 1/4 sec.
9. T. 22 S., R. 7 E., MDBM. Collected by Robert
Weidman, ? 1955. Zirfaea pilshryi.

UCMP loc. B-6511. — Miocene, Temblor Formation.
Highest two (of four) Turritella ledges cropping out
along north bank of Garza Creek, Kings Co. Sec. 3, T. 23
S., R. 16 E., MDBM. Collected by O.S. Adegoke.

WEST AMERICAN CENOZOIC PHOLADIDAE

87

Zirfaea dentata.

UCMP loc. B-6518.— Miocene, Temblor Formation.
Ledges conspicuously exposed from slope of hill west of
Baby King Canyon westward to hill that flanks the east
bank of Garza Creek, Kings Co. Hard, coarse, gray
sandstone ledges overlying main "Reef Beds" and
containing Turritella. Sec. 11. T. 23 S., R. 16 E.,
MDBM. Collected by O.S. Adegoke, ? 1963. Zirfaea
dentata.

UCMP loc. B-6534.— Pliocene, Etchegoin Formation
|,Jacalitos "stage"]. In cut in road to Shell Oil well
155-15, in sec. 15, T. 19 S., R. 15 E., MDBM, Fresno Co.
Collected ? by O.S. Adegoke, 1963. Zirfaea dentata.
UCMP loc. B-6537.— Pliocene, San Joaquin Formation.
Reef Ridge quadrangle, sec. 22, T. 22 S., R. 16 E.,
MDBM, 2310 feet north, 870 feet east. From coarse,
brown, gravelly sandstone bed cropping out along crest
of hill. Zirfaea pilsbryi.

UCMP loc. B-6538.— Pliocene, San Joaquin Formation.
South slope of hill, 10 feet below crest, in sec. 22, T. 22
S., R. 16 E., MDBM, Kings Co. Collected by O.S. Ade-
goke, ? 1963. Zirfaea pilsbryi.

UCMP loc. B-7085.— Miocene, Temblor Formation.
Near Oil Canyon, Oil City — Oilfields region, Fresno Co.
"Button Bed" near top of hill in center of NW 1/4 SW
1/4 sec. 21, T. 19 S., R. 15 E., MDBM. Collected by
Paleontology 137 class, October, 1959. Zirfaea dentata.
UCMP loc. B-7086.— Miocene, Temblor Formation.
Float on hillside below UCMP loc. B-7085, and about 75
yards west of the NE corner of NW 1/4 SW 1/4 sec. 21,
T. 19 S., R. 15 E., MDBM, Fresno Co. Collected by
Paleontology 137 class, October, 1959. Zirfaea dentata.
UCMP loc. B-7493.— Pleistocene. Sea cliff on south side
of Grave Point, three-fourths of a mile southwest of
Bandon, Coos Co., Oregon. 10-20 foot thick bed of poorly
sorted unconsolidated sandstone with subrounded
pebbles. Collected in 1960. "Pholadid species" [not seen].
UCMP loc. B-7727.— Pliocene, San Joaquin Formation.
Kettleman Hills, Fresno [? Kings] Co. Collected by A.C.
Hall. Zirfaea pilsbryi, Nettastomella rostrata, Pholadop-
sis sp. cf. P. pectinata, unidentified pholadid burrows.
UCMP loc. B-8348.— Pliocene, Merced Formation. Road
cut about 1/4 mile west of Page Mill Road on Arastra-
dero Road, Santa Clara Co. Conglomeratic sands with
abundant fossil material at the base of the Merced.
37° 23' 08" N., 122° 10' 09" W. Collected by R.J. Fleck,
October 7, 1963. Zirfaea pilsbryi.

UCMP loc. B-8579.— Miocene, Temblor Formation.
Near Gres Canyon, N 1/2 NE 1/4 NW 1/4 sec. 12, T. 14
S., R. 11 E., MDBM, Fresno Co. Fine grained
sandstone, near contact of basal Temblor. Collected by
Paleontology 237 class, September, 1964. Zirfaea sp.
indet., Penitella sp. indet.

UCMP loc. B-8589. — Pliocene, San Joaquin Formation.
Crest of ridge paralleling the eastern tributary to
Arroyo Murado, North Dome, Kettleman Hills, Kings
Co. In SE 1/4 sec. 6, T. 22 S., R. 18 E., MDBM. Pecten
coalingaensis zone. Collected by Paleontology 237 class,
September, 1964. Zirfaea pilsbryi.

UCMP loc. B-8605.— Miocene, Santa Margarita Forma-
tion. South bank of Salt Creek, 1000 feet west of east

boundary of sec. 11, T. 18 S., R. 14 E., MDBM, Fresno
Co. Massive fine grained sandstone. Collected by William
Read, October 27, 1960. Zirfaea sp. indet.
UCMP loc. B-8609.— Miocene, Temblor Formation.
West bank of stream 2000 feet NNW of SE corner of
sec. 32, T. 17 S., R. 14 E., MDBM, Fresno Co. Light
grained, resistant sandstone. Collected by William
Read, October 4, 1960. Zirfaea dentata.
UCMP loc. D-115.— Miocene, Temblor Formation. Oil
City — Oilfield region north of Coalinga, Fresno Co. In
SW 1/4 NW 1/4 sec. 21, T. 19 S., R. 15 E., MDBM, 500
feet southwest of hill 2021. Collected by Paleontologfy
237 class, September, 1962. Zirfaea dentata.
UCMP loc. D-116.— Miocene, Temblor Formation. Float
below UCMP loc. D115. Zirfaea dentata.
UCMP loc. D-330. — Pliocene, San Joaquin or Etchegoin
formations. Near El Rascador, 1250 feet ESE of hill
1054, North Dome, Kettleman Hills, Kings Co. SE 1/4
SE 1/4 SE 1/4 NE 1/4 NE 1/4 sec. 17, T. 22 S., R. 18
E., MDBM. Coarse blue sandstone below Cascajo Con-
glomerate {s.s.). Collected by C.T. Williams, October,
1967. Zirfaea pilsbryi.

UCMP loc. D-390.— Pleistocene, Palos Verdes Sand.
Second and Mesa Streets, San Pedro, Los Angeles Co.
Collected ? by J.W. Durham, 1961. Zirfaea pilsbryi.
UCMP loc. D-599.— Miocene, "Monterey Group." From
a bank on the southeast side of Interstate Highway 80,
near the turn off to Crockett, Contra Costa Co. Pholadid
borings from irregular contact 150 feet above present
road bed. T. 2 N., R. 3 W., MDBM. Collected by J.W.
Durham and D. Alsip, 1958. Penitella sp. cf. P.
lorenzana.

UCMP loc. D-1048.— Miocene, Temblor Formation.
East of Big Tar Canyon Road, in sec. 18, T. 23 S., R. 17
E., MDBM, Kings Co. Brown indurated sandstone ledge
overlying UCMP loc. A-9739. Collected by O.S. Ade-
goke, ? 1963. Zirfaea dentata.

UCMP loc. D-1059.— Miocene, Temblor Formation.
From the lowest two of four Turritella beds that crop
out on north bank of Garza Creek, Reef Ridge quad-
rangle, sec. 3, T. 23 S., R. 16 E., MDBM, 1085 feet
north, 1390 feet west. Collection was made intermit-
tently for about 200 feet downstream below the east-
ward bend in the creek. Zirfaea dentata.
UCMP loc. D-1066.— Miocene, Temblor Formation.
Northwest of Dirty Spring, on east slope of hill 2168,
Reef Ridge, Fresno Co. Sec. 33, T. 22 S, R. 16 E.,
MDBM, 650 feet north, 3,400 feet west. Conglomeratic
sandstone ledge. Collected by O.S. Adegoke, ? 1963.
Zirfaea dentata.

UCMP loc. D-1072.— Miocene, Temblor Formation.
Domengine Ranch quadrangle, in sec. 20, T. 19 S., R. 15
E., MDBM, 850 feet north, 2130 feet east. Collected
from top of loc. D-1071 to base of white diatomaceous
shale ("Indicator" bed). Lateral extent of collection
about 400 feet. Zirfaea dentata.

UCMP loc. D-1073.— Miocene, Temblor Formation. 800
feet laterally along slope of hill east of Oil Canyon,
Fresno Co. Sec. 20, T. 19 S., R. 15 E., MDBM, 600 feet
north, 2,400 feet east. Stratigraphically above white dia-
tomaceous shale. Collected by O.S. Adegoke, ? 1963.

88

GEORGE L. KENNEDY

Zirfaea dentata.

UCMP loc. D-1076.— Miocene, Temblor Formation.
From the lowest three gray-white calcareous sandstone
ledges cropping out on the west slope of hill 2021,
Domengine Ranch quadrangle, in sec. 21, T. 19 S., R. 15
E., MDBM, 1800 feet south, 1100 feet east. Lateral
extent of collection about 300 feet. Zirfaea dentata.
UCMP loc. D-1078.— Miocene, Temblor Formation. Oil
City — Oilfield region north of Coalinga, Fresno Co.
Sec. 21, T. 19 S., R. 15 E., MDBM, 2200 feet south, 1080
feet east. From very prominent reddish-brown sand-
stone ledges. Collected by O.S. Adegoke, ? 1963. Zirfaea
dentata.

UCMP loc. D-1124.— Pliocene, Etchegoin Formation.
Reef Ridge quadrangle, in sec. 6, T. 23 S., R. 17 E.,
MDBM, 1510 feet north, 1400 feet west. Buf colored
concretionary mudstone overlying coarse blue sandstone
bed, poorly exposed on northeast slope of hill. Fossil bed
about 125 feet below base of basal San Joaquin Forma-
tion. "Pholadidea sp. cf. P. penita" [not seen].
UCMP loc. D-1203.— Pliocene, San Joaquin Formation.
Domengine Ranch quadrangle, in sec. 24, T. 19 S., R. 15
E., MDBM, 1975 feet north, 2130 feet west. From north-
west slope of hill, about 50 feet above creek bed. Fossils
in hard concretions, "exposures" of which are rather
poor. Zirfaea pilsbryi.

UCMP loc. D-1627.- Pleistocene. San Pedro Bluffs,
Second and Beacon Streets, San Pedro, Los Angeles Co.
Collected by Ralph Arnold. Zirfaea pilsbryi.
UCMP loc. D-2845.— Pliocene, Sisquoc Formation. NTU
asphalt mine, 3-1/3 miles NNW of Casmalia, Santa Bar-
bara Co. Throughout quarry, but mostly from talus
slope at base of southern cliff. Outcrop of tar sands.
34° 53' 28" N., 120° 38' 20" W. Collected by J.C. Holden,
September 26, 1965. Penitella sp. cf. P. gabbii, P. sp. cf.
P. tumerae.

UNIVERSITY OF OREGON
(EUGENE)

UO loc. 80.— Oligocene, Eugene Formation. Beneath
the cemetery in a prominent cut on the main line of the
Southern Pacific Railroad in SW 1/4 sec. 34, T. 17 S.,
R. 3 W., WBM, Eugene quadrangle, Lane Co., Oregon.
Martesia sp.

UO loc. 2544. — Oligocene, Eugene Formation. Excava-
tion for Science II Annex, University of Oregon campus,
Eugene, Lane Co., Oregon. S 1/2 sec. 32, T. 17 S., R. 3
W., WBM. Martesia sp.

UO loc. 2553.— Oligocene, Eugene Formation. Roadcuts
along Interstate Freeway 5 in NW 1/4 sec. 3, T. 18 S.,
R. 3 W., WBM, Eugene quadrangle. Lane Co., Oregon.
Martesia sp., Opertochasma tumerae.
UO loc. 2554.— Oligocene, Eugene Formation. At base
of hill on east side of Interstate Freeway 5 in NW 1/4
sec. 3, T. 18 S., R. 3 W., WBM, Eugene quadrangle,
Lane Co., Oregon. Gray tuffaceous siltstone with layers
of concentrated fossil shells. Martesia sp.

UNITED STATES GEOLOGICAL SURVEY
(WASHINGTON, D.C.)

|A number of the following collections are now housed at
the Menlo Park Branch.]

uses loc. 93.- Miocene. Lake Co. Collected ? by H.W.
Turner, December 14, 1882. Zirfaea dentata.
USGS loc. 104.— Miocene. "Locality 13. Martineze. Cali-
fornia (See old register). H.W. Turner coll.". Zirfaea
dentata.

USGS loc. 2463.— Pleistocene. San Pedro, Los Angeles
Co. Collected by R.E.C. Stearns, 1892. Zirfaea pilsbryi,
Penitella penita.

USGS loc. 2954.— Pliocene, Empire Formation. Near
Empire City, Coos Bay, Coos Co., Oregon. Penitella
tumerae.

USGS loc. 3751.— Pleistocene. Peluche [Peluk] Creek,
Seward Peninsula, Alaska. Collected ? by A.H. Brooks.
Penitella kamakurensis.

USGS loc. 3752.— Pleistocene, "Second Beach." Mine
dump on claim 2, Peluk Creek, near Nome, Seward
Peninsula, Alaska. Collected by F.L. Hess, 1903.
Penitella kamakurensis.

USGS loc. 3857.— Pliocene, Imperial Formation.
Carrizo Creek, San Diego Co. Collected by Stephen
Bowers, 1903. Cyrtopleura costata.
USGS loc. 3921.— Pliocene, Imperial Formation.
Barrett's Oil Well, about 20 miles north of the U.S.-
Mexican border, Imperial Co. Sec. 11, T. 15 S., R. 9 E.,
SBBM. Collected by Stephen Bowers, 1904. Cyrtopleura
costata.

USGS loc. 4472.— Pliocene, Sisquoc Formation. Penn-
sylvania asphalt mine, 3-1/2 miles southeast of Orcutt,
Santa Barbara Co. Collected by Ralph Arnold, 1906.
''Zirfaea pilsbryi, Penitella tumerae, P. gabbii.
USGS loc. 4473.— Pliocene, Foxen Mudstone. Waldorf
asphalt mine, 3 miles SSE of Guadalupe, Santa Barbara
Co. Collected by Ralph Arnold, 1906. Penitella gabbii, P.
tumerae.

USGS loc. 4475.— Pliocene, Careaga Sandstone, Cebada
Member. Fugler Point asphalt mine, 1 mile NNW of
Garey, Santa Barbara Co. Collected by Ralph Arnold,
1906. Penitella gabbii, P. sp. indet.
USGS loc. 4476.— Pliocene. Asphaltum layer above
Monterey Shale near Folsom well no. 3, Santa Maria oil
fields, 3 miles southeast of Orcutt, Santa Barbara Co.
Collected by Ralph Arnold, 1906. Penitella penita.
USGS loc. 4500.— Pleistocene [?]. In Miocene shale in
asphalt mine at Carpinteria, Santa Barbara Co.
Collected by Ralph Arnold. Penitella sp. indet.
USGS loc. 4506.— Pliocene, Fernando Formation. One
mile southeast of summit of Redrock Mountain, along
ridge near 1700 foot knob, Santa Barbara Co. Collected
by Robert Anderson, October, 1906. Zirfaea sp. indet.
USGS loc. 4625.— Miocene, Vaqueros Formation. "Reef
beds" in Sulphur Spring Canyon, Kings Co. Sec. 23,
T. 22 S., R. 16 E., MDBM. Zirfaea dentata.
USGS loc. 4627. — Miocene, Vaqueros Formation. "Reef
beds" just west of Big Tar Canyon, Kings Co. North
part of sec. 18, T. 23 S., R. 16 E., MDBM. Zirfaea
dentata.

WEST AMERICAN CENOZOIC PHOLADIDAE

89

USGS loc. 4632.— Miocene, Santa Margarita Formation.
At, and northwest of the San Joaquin Valley Coal Mine,
near the Miocene-Eocene contact, Fresno Co. Sec. 26,
T. 20 S., R. 14 E., MDBM. Collected by Ralph Arnold,
1907. Zirfaea dentata.

USGS loc. 4633.— Miocene, Vaqueros Formation.
Turritella bed about 11 miles north-northeast of
Coalinga, Fresno Co. On ridge, just below "Big Blue" in
sec. 10, T. 19 S., R. 15 E., MDBM. Collected by Ralph
Arnold, 1907. Zirfaea dentata [not seen].
USGS loc. 4710.— Pliocene, Etchegoin Formation.
North side of ravine, 3/4 miles northwest of BM 806 on
Zapato Creek, Fresno Co. Pecten coalingaensis zone, in
west central part of NE 1/4 sec. 5, T. 22 S., R. 16 E.,
MDBM. Zirfaea pilsbryi

USGS loc. 4745.— Pliocene, Jacalitos Formation. "Big
Trophoii bed" on ridge south of Garcas Creek, Kings Co.
Sec. 2, T. 23 S., R. 16 E., MDBM. Collected by Ralph
Arnold, 1905. Zirfaea sp. indet.

USGS loc. 4750.— Pliocene, Etchegoin Formation. On
ridge south of Garcas Creek, Kings Co., 2700 feet stra-
tigraphically above USGS loc. 4745. Collected by Ralph
Arnold. Penitella sp. indet.

USGS loc. 4758.— Pliocene, Etchegoin Formation. East
side of 1900 foot hill near Henry Spring, 4 miles SSW of
Coalinga, Fresno Co. SW 1/4 sec. 18, T. 21 S., R. 15 E.,
MDBM. Zirfaea pilsbryi.

USGS loc. 4803.— Miocene, Vaqueros Formation. On
Laval grade, 8-1/2 miles north of Coalinga, Fresno Co.
"Button bed" 200 ± feet above Eocene unconformity in
SW 1/4 sec. 21, T. 19 S., R. 15 E., MDBM. Zirfaea
dentata.

USGS loc. 5718.— Eocene, Lodo Formation. Foothills
between Ortigalito and Little Panoche Creeks, west side
of the San Joaquin Valley, Merced Co. Near top of hill
on east side of strike valley, at center of north line of
sec. 19, T. 12 S., R. 11 E., MDBM. Basal part of Eocene
gray sandstone overlying the Cantua Shale. Collected by
R.W. Pack and E.L. Ickes, July, 1910. Martesia
tolkieni.

USGS loc. 5802.— Miocene, Temblor Formation. Cantua
district, 4.5 miles southeast of Ciervo Mountain, Ciervo
Hills, in SE 1/4 sec. 12, T. 17 S, R. 13 E., MDBM. Col-
lected by R.W. Pack, September, 1909. Zirfaea dentata.
USGS loc. 5828.— Miocene, Santa Margarita Formation.
Cantua district. Big Blue Hills, 2-1/2 miles northwest of
Domengine place, on east face of blue serpentine con-
glomerate hills west of longitudinal valley of Martinez
Creek, Fresno Co. Collected by R. Anderson and Olaf
Jenkins, August, 1909. Zirfaea dentata.
USGS loc. 5829.— Miocene, Santa Margarita Formation.
Cantua district, about 1-1/2 miles up Cantua Creek from
the San Joaquin Valley, 1/3 mile up stream from where
creek turns from southeast to northeast, Fresno Co.
Near center of west line of SE 1/4 sec. 34, T. 17 S.,
R. 14 E., MDBM. Collected by R.W. Pack, September,
1909. Zirfaea dentata.

USGS loc. 6847. — Pliocene, Imperial Formation. Ravine
about 1 mile south of Alverson Canyon, Carrizo Moun-
tain, Imperial Co. Collected by Stephen Bowers and
W.C. Mendenhall, ? January 20, 1904. Cyrtopleura

costata.

USGS loc. 7498.— Pleistocene. San Quintin, Baja Cali-
fornia, Mexico. Collected by C.R. Orcutt, November,
1887. Zirfaea pilsbryi.

USGS loc. 7499. — Pleistocene. "Turritella bed, south
side of wharf," San Quintin, Baja California, Mexico.
Collected by C.R. Orcutt, November, 1887. Zirfaea
pilsbryi.

USGS loc. 9156.— ? Pliocene. Bluffs opposite San
Antonio Ranch, "Cudije" [?] Arroyo, Baja California,
Mexico. Collected by W.S.W. Kew, 1920. [Two modes of
preservation are represented.] Zirfaea pilsbryi, Penitella
sp. indet.

USGS loc. 9330.— Neogene. Arroyo 11 miles north and
5 miles west of La Purisima, Baja California, Mexico.
Parapholas sp. indet.

USGS loc. 9393.- Pliocene. About 2 miles north of
pump station #3, on spur ridge on south side of ridge
east of canyon road. Priest Valley quadrangle, Fresno
Co. In center of SW 1/4 sec. 24, T. 20 S., R. 12 E.,
MDBM. Basal bed of formation above the Etchegoin.
Collected by R.W. Pack, "9/11/13." Penitella gabbii.
USGS loc. 10057.— Pliocene or Pleistocene. Rosario,
Baja California, Mexico. Collected by J.B. Orynski,
1920. Penitella penita.

USGS loc. 10058.— Pliocene or Pleistocene. Fine con-
glomerate and float on beach southwest of Rosario, Baja
California, Mexico. Collected by J.B. Orynski, 1920.
Pejiitella sp. cf. P. penita.

USGS loc. 10460.— Pleistocene. Near top of sea cliff
about 150 feet above sea level, near Resort Point, city of
Palos Verdes Estates, Los Angeles Co. Thin layer of
rocks, gravel, and sand, lightly indurated in spots.
Collected by E.P. Chace, May 6, 1923. Penitella sp.
indet.

USGS loc. 11729.— Pleistocene. San Quintin Bay, Baja
California, Mexico. Collected by C.R. Orcutt. Zirfaea
pilsbryi.

USGS loc. 12132.— Pleistocene, Palos Verdes Sand. Cut
on west side of Pacific Avenue, midway between Oliver
and Bonita Streets, San Pedro, Los Angeles Co. Col-
lected by W.P. Woodring, July 14, 1930. Zirfaea
pilsbryi, Penitella penita.

USGS loc. 12134.— Pleistocene, Palos Verdes Sand.
East side of Palos Verdes Street, 75 feet north of Third
Street, San Pedro, Los Angeles Co. Collected by W.P.
Woodring, July 21, 1930. Zirfaea pilsbryi.
USGS loc. 12138.— Pleistocene, Palos Verdes Sand. In
Fort McArthur Lower Reservation, on north side of
ravine 350 feet SE of [old] foot of 22nd Street [now
intersection of 22nd and Mesa Streets], San Pedro, Los
Angeles Co. Collected by W.P. Woodring, July 26, 1930.
Zirfaea pilsbryi.

USGS loc. 12139.— Pleistocene, Palos Verdes Sand. On
south side of deep ravine in bluff east of Gaffey Street,
2350 feet N. 4° E. of [old] intersection of Harbor
Boulevard and Gaffey Street, San Pedro, Los Angeles
Co. Collected by W.P. Woodring, August 2, 1930.
Penitella penita.

USGS loc. 12141.— Late Pleistocene. Bluff along Harbor
Boulevard [now Wilmington and San Pedro Road], 4400

90

GEORGE L. KENNEDY

feet N. 55° E. of the [old] intersection of Harbor
Boulevard and Gaffey Street, midway between entrance
to San Pedro Lumber Co., San Pedro, Los Angeles Co.
Collected by W.P. Woodring, August 2, 1930. [?] Zirfaea
pilshryi.

USGS loc. 12192.— Pleistocene. Top of sea cliff 300 feet
north of Flatrock Point, city of Palos Verdes Estates,
Los Angeles Co. Collected by W.P. Woodring,
September 18, 1930. Penitella conradi
USGS loc. 12257.— Pleistocene, Lomita Marl. Foot of
waterfall in ravine north of Hawthorne Street,
community of Walteria, city of Torrance, Los Angeles
Co. 2600 feet W. 7° S. of intersection of Hawthorne
Street and Pacific Coast Highway. Collected by W.P.
Woodring, August 25, 1930. Penitella sp. indet.
USGS loc. 12327.— Pliocene, San Joaquin Formation.
North fork of Arroyo Bifido, North Dome, Kettleman
Hills, Kings Co. Sec. 35, T. 21 S., R. 17 E., MDBM.
Pecten zone. Collected by Ralph Stewart. Unidentified
pholadid burrow.

USGS loc. 12328.— Pliocene, San Joaquin Formation.
Across small gully (200 feet east of USGS loc. 12327),
north fork of Arroyo Bifido, North Dome, Kettleman
Hills, Kings Co. Sec. 35, T. 21 S.. R. 17 E., MDBM.
Pecten zone. Collected by Ralph Stewart. Unidentified
small pholadid in burrow.

USGS loc. 12336.— Pliocene, San Joaquin Formation.
Near west fork of Arroyo Hondo, North Dome,
Kettleman Hills, Kings Co. Sec. 5, T. 22 S., R. 18 E.,
MDBM. Collected by Ralph Stewart. Zirfaea pilshryi.
USGS loc. 12365.— Pliocene, San Joaquin Formation.
La Lomica, south end of North Dome, Kettleman Hills,
Kings Co. Center of southern boundary line of sec. 6, T.
23 S., R. 19 E., MDBM. Collected by Ralph Stewart.
Pholadopsis pectinata.

USGS loc. 12370a.— Pliocene, San Joaquin Formation.
Arroyo del Camino, west flank of Nortn Dome, Kettle-
man Hills, Kings Co. Sec. 10, T. 22 S., R. 17 E., MDBM.
Collected by Ralph Stewart. Zirfaea pilshryi.
USGS loc. 12372.— Pliocene, San Joaquin Formation.
Arroyo del Camino, west flank of North Dome, Kettle-
man Hills, Kings Co. Sec. 15, T. 22 S., R. 17 E., MDBM.
Acila zone. Collected by Ralph Stewart. Zirfaea pilshryi.
USGS loc. 12373.— Pliocene, San Joaquin Formation.
Arroyo Somero, North Dome, Kettleman Hills, Kings
Co. Sec. 14, T. 22 S., R. 17 E., MDBM. Pecten zone.
Collected by Ralph Stewart. Zirfaea pilshryi.
USGS loc. 12374.— Pliocene, San Joaquin Formation.
Arroyo Conchoso, North Dome, Kettleman Hills, Kings
Co. Sec. 19, T. 22 S., R. 18 E., MDBM. Pecten zone?
Collected by Ralph Stewart. Pholadopsis pectinata.
USGS loc. 12421.— Pliocene, Etchegoin Formation.
West side of ridge extending north from El Chichon,
North Dome, Kettleman Hills, Kings Co. Sec. 12, T. 22
S., R. 17 E., MDBM. Macoma zone. Collected by Ralph
Stewart. Zirfaea pilshryi.

USGS loc. 12424.— Pliocene, Etchegoin Formation.
South slope of east end of El Serrijon, North Dome of
Kettleman Hills, Kings Co. Macoma zone. Collected by
Ralph Stewart [loc. 280S1. Zirfaea pilshryi.
USGS loc. 12426.— Pliocene, Etchegoin Formation.

Fork of Arroyo Doblegado, southeast of Las Paredes,
North Dome, Kettleman Hills, Kings Co. Sec. 17, T. 22
S., R. 18 E., MDBM. Twenty feet below barnacle layer.
Collected by Ralph Stewart. Zirfaea pilshryi.
USGS loc. 12511. — Pliocene, San Joaquin Formation.
Arroyo Torcido, North Dome, Kettleman Hills, Kings
Co. NE 1/4 sec. 1, T. 22 S., R 17 E., MDBM. Top of
greenish-gray mud below Neverita sandstone. Collected
by W.P. Woodring. Penitella sp. indet.
USGS loc. 12628.— Pleistocene, San Pedro Sand. Gaffey
anticline on [old] Harbor Boulevard [now Wilmington
and San Pedro Road], opposite the San Pedro Lumber
Co., San Pedro, Los Angeles Co. Collected by W.P.
Woodring, September 11, 1981. Bamea suhtruncata.
USGS loc. 12630.— Pleistocene. Crest of hill on east side
of Cherry Avenue, city of Signal Hill, Los Angeles Co.
Collected by W.P. Woodring, September 13, 1931.
Bamea suhtruncata, Zirfaea pilshryi.
USGS loc. 12645.— Pliocene, San Joaquin Formation.
Cascajo Hill, west flank of South Dome, Kettleman
Hills, Kern Co. NW 1/4 sec. 3, T. 25 S., R. 19 E.,
MDBM. Collected by W.P. Woodring, October 17, 1931.
Zirfaea pilshryi.

USGS loc. 12653. — Pliocene, San Joaquin Formation.
Near El Arco, on west flank of South Dome, Kettleman
Hills, Kings Co. SE 1/4 sec. 33, T. 24 S., R. 19 E.,
MDBM. Collected by W.P. Woodring, October 31, 1931.
Zirfaea pilshryi.

USGS loc. 12656.— Pliocene, San Joaquin Formation.
West of Oyster Hill, South Dome of Kettleman Hills,
Kings Co. Sec. 21, T. 24 S., R. 19 E., MDBM. Collected
by W.P. Woodring [loc. IIIW], Zirfaea pilshryi.
USGS loc. 12657.— Pliocene, San Joaquin Formation.
North of Oyster Hill, South Dome of Kettleman Hills,
Kings Co. Sec. 21, T. 24 S., R. 19 E., MDBM. Collected
by W.P. Woodring [loc. 112W]. Zirfaea pilshryi.
USGS loc. 12660.— Pliocene, San Joaquin Formation.
West of 25th Avenue, and ESE of Oyster Hill, east flank
of South Dome, Kettleman Hills, Kings Co. NE 1/4 sec.
27, T. 24 S., R. 19 E., MDBM. Collected by W.P. Wood-
ring, November 3, 1931. Zirfaea pilshryi.
USGS loc. 12793.— Pliocene, San Joaquin Formation.
North of Oyster Hill, South Dome, Kettleman Hills,
Kings Co. NW 1/4 NW 1/4 sec. 27, T. 24 S., R. 19 E.,
MDBM. Collected by Ralph Stewart. Zirfaea pilshryi
USGS loc. 12794.— Pliocene, San Joaquin Formation.
North of Oyster Hill, South Dome, Kettleman Hills,
Kings Co. NW 1/4 NW 1/4 sec. 27, T. 24 S., R. 19 E.,
MDBM. Collected by Ralph Stewart. Zirfaea pilshryi.
USGS loc. 12818.— Pliocene, Etchegoin Formation.
Southwest of Discovery Ridge, North Dome, Kettleman
Hills, Kings Co. NE 1/4 sec. 11, T. 22 S., R. 17 E.,
MDBM. Siphonalia zone. Collected by Ralph Stewart.
Zirfaea pilshryi.

USGS loc. 12956.- Pliocene. "On 3000 foot point of ridge
in southeast corner of sec. of 2610 foot hill," northeast
flank of Caliente Mountains, San Luis Obispo Co. Col-
lected by Robert Anderson, July 20, 1909. Zirfaea
pilshryi.

USGS loc. 13125.- Pleistocence, Second terrace. Along
path in Peck Park, 650 feet SSE of 252 foot hill, San

WEST AMERICAN CENOZOIC PHOLADIDAE

91

Pedro, Los Angeles Co. Collected by W.P. Woodring,
June 24, 1933. Zirfaea pihhryi, Penitella penita.
USGS loc. 13130.- Pleistocene, Second terrace. Top of
sea cliff near east end of Warmouth Street, V2 mile
northwest of Whites Point, San Pedro, Los Angeles Co.
Collected by W.P. Woodring, July 22, 1933. Penitella
penita.

USGS loc. 13775.- Pleistocence, Pales Verdes Sand.
East face of Graham Bros, [in 1935] sand pit, ca. 1400
feet southeast of south end of Madison St., community
of Walteria, city of Torrance, Los Angeles Co. Collected
by W.P. Woodring, July 15, 1935. Penitella sp. indet.
USGS loc. 13779.- Pleistocene, Palos Verdes Sand.
West side of Mesa Street, 100 feet south of 3rd Street,
San Pedro, Los Angeles Co. Collected by W.P. Wood-
ring, July 23, 1935. Zirfaea pilsbryi.
USGS loc. 14087.— Pliocene, San Joaquin Formation,
Cascajo Conglomerate. South slope of Cerro Ultimo,
North Dome, Kettleman Hills, Kings Co. NW 1/4 NW
1/4 sec. 34, T. 22 S., R. 18 E., MDBM. Collected by
Ralph Stewart. Zirfaea pilsbryi.

USGS loc. 14113.- Pliocene, Etchegoin Formation. Just
above road on west side of Las Paredes, North Dome,
Kettleman Hills, Kings Co. NW 1/4 NW 1/4 sec. 17, T.
22 S., R. 18 E., MDBM. Collected by Ralph Stewart.
Zirfaea pilsbryi.

USGS loc. 14118.- Pliocene, Etchegoin Formation.
Upper part of Arroyo Murado, northwest of El Pulgar,
North Dome, Kettleman Hills, Kings Co. NW 1/4 NW
1/4 sec. 18, T. 22 S., R. 18 E., MDBM. Collected by
Ralph Stewart. Penitella tumerae.

USGS loc. 14119.— Pliocene, Etchegoin Formation.
East slope of La Tusa, North Dome, Kettleman Hills,
Kings Co. SE 1/4 SE 1/4 sec. 12, T. 22 S., R. 17 E.,
MDBM. Base of Patinopecten zone. Collected by Ralph
Stewart. Zirfaea pilsbryi.

USGS loc. 14122.- Pliocene. Etchegoin Formation.
Arroyo Murado, southeast of La Clavija, North Dome,
Kettleman Hills, Kings Co. SW 1/4 NW 1/4 sec. 7, T. 22
S., R. 18 E., MDBM. Barnacle layer. Collected by Ralph
Stewart. Zirfaea pilsbryi.

USGS loc. 14397.— Miocene, Temblor Formation, upper
member. Reef Ridge northwest of Garza Peak, Kings
Co. Center of sec. 12, T. 23 S., R. 16 E., MDBM. Zirfaea
dentata.

USGS loc. 14408,— Miocene, Temblor Formation, upper
member. Near Beltram Creek on Reef Ridge, Fresno
Co. SW 1/4 sec. 30, T. 22 S., R. 16 E., MDBM. Zirfaea
dentata.

USGS loc. 14409.— Miocene, Temblor Formation, upper
member. Arroyo Pinoso on Reef Ridge, Fresno Co. SE
1/4 sec. 23, T. 22 S., R. 15 E., MDBM. Zirfaea dentata.
USGS loc. 14410.— Miocene, Temblor Formation, upper
member. West side of Zapato Creek, Fresno Co. NW
1/4 NE 1/4 sec. 21, T. 22 S., R. 16 E., MDBM. Zirfaea
dentata.

USGS loc. 14609.— Pliocene, Careaga Sandstone,
Graciosa Member. West side of cut on Southern Pacific
Railroad, 0.8 miles northeast of Schuman's siding, north
slope of the Casmalia Hills, Santa Barbara Co. Collected
by W.P. Woodring, August 24, 1938. Zirfaea pilsbryi.

USGS loc. 14622.- Pliocene, Careaga Sandstone,
Graciosa Member. Graciosa Ridge, on edge of slump on
west side of canyon, 200 feet WSW of Union Oil Co.
Newlove No. 30 well, 3.4 miles southeast of Orcutt,
Santa Barbara Co. Collected by W.P. Woodring [loc.
W611]. "Pholadidea penita" [not seen].
USGS loc. 14648.— Pliocene, Careaga Sandstone,
Cebada Member. 1000 feet northwest of Union Oil well
Newlove No. 42, south slope of Orcutt Hill, 3.7 miles
southeast of Orcutt, Santa Barbara Co. Collected by
W.P. Woodring, August 24, 1939. Penitella gabbii, P.
tumerae.

USGS loc. 14722.- Pliocene, Careaga Sandstone,
Graciosa Member. Loose blocks on west side of Howard
Canyon, Solomon Hills, 2.6 miles NNE of Los Alamos,
Santa Barbara Co. Collected by R.P. Bryson, July 25,
1939. Penitella gabbii, P. sp. indet.
USGS loc. 14768.- Pliocene, Careaga Sandstone,
Cebada Member. Fugler Point, 1.1 miles north of Garey,
Santa Barbara Co. Four foot fossil bed at southeast end
of bluff. Collected by W.P. Woodring and R.P. Bryson,
August 16, 1939. "Pholadidea cf. P. penita" [not seen;
probably Penitella gabbii and/or P. tumerae].
USGS loc. 14769.- Pliocene. Careaga Sandstone,
Cebada Member. Fugler Point, 1.1 miles north of Garey,
Santa Barbara Co. From below 4 foot fossil bed [see
USGS loc. 14768] and southeast of brachiopod bed. Col-
lected by W.P. Woodring and R.P. Bryson, August 16,
1939. Penitella sp. indet.

USGS loc. 14867.— Pliocene, Sisquoc Formation. Crest
of Purisima Hills, one mile southeast of Redrock Moun-
tain, Santa Barbara Co. Center of sec. 16, T. 7 N., R. 32
W., SBBM. Penitella sp. indet.

USGS loc. 14879.- Pliocene, Foxen Mudstone. Dump at
Waldorf asphalt mine, 3 miles SSE of Guadalupe, Santa
Barbara Co. Collected by W.P. Woodring and M.N.
Bramlette, August 17, 1938. "Pholadidea penita" [not
seen; probably Penitella gabbii and/or P. tumerae].
USGS loc. 14966.— Pleistocene [?]. Canyon in marine
terrace 1/2 mile southeast of Point Sal Landing and 100
feet inland, Santa Barbara Co. Elevation 40 feet. [This
station number represents both a Pleistocene terrace
deposit and the Pliocene Foxen Mudstone. neither of
which is listed on the label with the specimen.] Collected
by W.P. Woodring. October 19, 1940. Penitella sp. cf. P.
penita.

USGS loc. 15052. — Pleistocene. Rear of lowest terrace
(900 feet inland) on east side of first canyon southeast of
Lions Head, Santa Barbara Co. Elevation 115 feet.
Collected by W.P. Woodring, October 9, 1940. Zirfaea
pilsbryi.

USGS loc. 15864.- Pleistocene. Yakatat Bay region.
Gulf of Alaska, Alaska. Penitella kamakurensis.
USGS loc. 18284.- Pliocene, Empire Formation.
Dredged from the channel adjacent to North Spit, Coos
Bay. Coos Co., Oregon. Collected from spoil bank by
Ellen James [Moore], 1949-1950. Penitella tumerae.
USGS loc. 18459.- Miocene. North of Santiago Canyon
Road and ca. 0.7 miles southwest of the spillway of
Irvine Lake, Orange Co. Elevation 1,150 feet. Collected
by J.G. Vedder. Zirfaea dentata.

92

GEORGE L. KENNEDY

uses loc. 18558.- Pliocene, ? Etchegoin Formation.
Low hills on east side of San Benito River, southeast of
San Benito, San Benito Co. Collected by C.J. Bleifus,
1936. Zirfaea sp. cf. Z. pilsbryi.

USGS loc. 18732.— Miocene. West side of road south of
the divide. Old Topanga Canyon, Los Angeles Co. N.
55° E. from Calabasas Peak. Collected by W. A. English
and W.S.W. Kew, October 25, 1918. Zirfaea dentata.
USGS loc. 18740.— Miocene. In largest NE-SW canyon
in the Bacon Hills, western Kern Co. Mulinia (?) bed
about 100 feet below conglomerate. Center of N 1/2 sec.
27, T. 28 S., R. 20 E., MDBM. Collected by Mr. Lohman,
August 6, 1934. Zirfaea dentata.

USGS loc. 18743.— Pliocene. Mount Pinos quadrangle,
California. Penitella conradi.

USGS loc. 21653.— Pleistocene. Near Army Camp
Beach, San Nicolas Island. 8400 feet north and 3650 feet
east of lat. 33° 14' 30" N., long. 119° 30' 30" E. Altitude
45-60 feet. Collected by J.G. Vedder, S.R. Dabney, and
D.J. Milton, 1955 [loc. SN-1]. Penitella conradi.
USGS loc. 21654.— Pleistocene. On main ridge east of
hill 818, San Nicolas Island, 4575 feet south and 600 feet
west of lat. 33° 14' 30" N., 119° 28' 00" E. Altitude 730±
feet. Collected by J.G. Vedder, 1955 [loc. SN-2].
"?Penitella sp." [not seen].

USGS loc. 21655.— Pleistocene. On main ridge west of
hill 818, San Nicolas Island. 3300 feet south and 1875
feet west of lat. 33° 14' 30" N., 119° 28' 00" E. Altitude
735±feet. Collected by J.G. Vedder, 1955 and 1956 [loc.
SN-31. Penitella penita, P. conradi, P. gabbii, Parapholas
califomica.

USGS loc. 21664.— Pleistocene. At east end of San
Nicolas Island, 5000 feet south and 9375 feet east of lat.
33° 14' 30" N., 119° 28' 00" E. Altitude 65-70 feet. Col-
lected by J.G. Vedder and N.C. Privrasky, 1956 [loc.
SN-12]. Zirfaea pilsbryi, Chaceia ovoidea, Parapholas
califomica.

USGS loc. 23621.— Pliocene, Foxen Mudstone. Waldorf
asphalt mine, 3 miles SSE of Guadalupe, Santa Barbara
Co. Collected September 23, 1931. Penitella gabbii.

UNITED STATES GEOLOGICAL SURVEY
(DENVER)

[Collection now housed at Menlo Park Branch.]
USGS-D loc. 49.— Pliocene, Nuwok Formation. At a
sharp bend in Carter Creek, flowing into Camden Bay,
Arctic coast, Alaska. Arctica carteriana zone, from 110
to 210 feet below top of measured section. 69° 57' 45" N.
lat., 144° 46' W. long. Collected by R.H. Morris.
"?Martesia sp." [=teredinid burrows].

UNITED STATES GEOLOGICAL SURVEY
(MENLO PARK)

USGS-M loc. 979.— Pliocene, Pancho Rico Formation.
South side of Pancho Rico Creek, Salinas Valley,
Monterey Co. 700 feet S., 1200 feet W. of NE corner
sec. 15, T. 22 S., R. 10 E., MDBM. Collected by D.L.
Durham, 1960. "Zirfaea sp." [not seen).

USGS-M loc. 980.— Pliocene, Pancho Rico Formation.
Base of bluff on south side of Pancho Rico Creek, Salinas
Valley, Monterey Co. 1600 feet north and 1400 feet west
of SE cor. sec. 11, T. 22 S., R. 10 E., MDBM. Collected
by D.L. Durham, 1960. Zirfaea dentata.
USGS-M loc. 1071.— Miocene, ? Topanga Formation.
Hill 2049, on ridge north of Mesa Peak, Santa Monica
Mountains, northwest of community of Malibu Beach,
Los Angeles Co. Collected by J.G. Vedder, R.F. Yerkes,
and J.E. Schoellhamer. Zirfaea dentata.
USGS-M loc. 1449.— Pleistocene, Battery Formation.
Exposure in sea cliff 600 feet west of intersection of
Modoc Street and Pebble Beach Drive, Crescent City,
Del Norte Co. Lens of fossiliferous sand overlying
truncated surface of hard Mesozoic sandstone. Elevation
22 feet. NW 1/4 NW 1/4 sec. 30, T. 16 N., R. 1 W.,
HBM. Collected by W.O. Addicott, November, 1958.
Penitella tumerae.

USGS-M loc. 1542.— Miocene, Montesano Formation. In
bed of Canyon River, 700 feet west of SE cor. sec. 35, T.
21 N., R. 7 W., WBM, Grisdale quadrangle, Grays
Harbor Co., Washington. Boring into underlying Astoria
Formation with Platyodon colobus foioleri. "Zirfaea sp."
(not seen], Penitella lorenzana.

USGS-M loc. 1676. — Upper Miocene or lower Pliocene,
Pancho Rico Formation. On first ridge west of Salinas
River, 1050 feet north and 2500 feet west of SE cor. sec.
29, T. 22 S., R. 10 E., MDBM, Monterey Co. Collected
by D.L. Durham and D.C. Wiese, 1962. Filled pholadid
burrow.

USGS-M loc. 1690.— Pleistocene. Terrace cut into
Miocene Monterey Formation on the south side of Point
Alio Nuevo, about 1 mile ENE of Aiio Nuevo Island, San
Mateo Co. Collected from 200-300 foot exposure along
beach, by W.O. Addicott, 1962. Zirfaea sp. aff. Z.
pilsbryi, Penitella tumerae; in situ.
USGS-M loc. 1691.— Pleistocene. Terrace cut into
Pliocene Purisima Formation, near top of sea cliff at the
outer edge of an incipient sea stack west of Point Santa
Cruz, Santa Cruz, Santa Cruz Co. Collected by W.O.
Addicott, July, 1962. Penitella tumerae.
USGS-M loc. 1710.— Pleistocene. Terrace deposits
exposed in cuts along California Highway 1 near the
eastern end of Escondido Beach, 2-1/2 miles northeast of
Point Dume, Los Angeles Co. Collected by W.O.
Addicott and R.F. Yerkes, April, 1963. Penitella sp. cf.
P. conradi.

USGS-M loc. 1715.— Pliocene, Merced (?) Formation.
Road cut and pipeline trench on north side of Arastradero
Road, 1200 feet west of intersection with Page Mill Road,
city of Los Altos Hills, Santa Clara Co. Collected by
E.H. Pampeyan, J.G. Vedder, and W.O. Addicott, 1962-
1963. Zirfaea pilsbryi.

USGS-M loc. 1722.— Pleistocene, Palos Verdes Sand.
Basal marine terrace deposit in major gully draining
NNE into salt pond area of Upper Newport Bay, north-
east of old landing strip, city of Newport Beach, Orange
Co. (=LACMNH loc. 66-2). Collected by M.E. Rogers.
Zirfaea pilsbryi.

USGS-M loc. 1728.— Pleistocene, Palos Verdes Sand.
Harbor Boulevard, San Pedro, Los Angeles Co. ("same

WEST AMERICAN CENOZOIC PHOLADIDAE

93

as Arnold's (1903) lumber yard locality"). Collected by
M.E. Rogers. Penitella penita.

LISGS-M loc. 1966.— Pliocene, Pancho Rico Formation.
North side of Powell Canyon, Salinas Valley, Monterey
Co. 50 feet N. 1,550 feet E of SW corner sec. 36, T. 22
S., R. 11 E., MDBM. Collected by W.O. Addicott and
D.L. Durham, 1964. "Zirfaeapilsbryi" [?=Z. dentata, not
seen].

USGS-M loc. 2011.— Pleistocene, Palos Verdes Sand.
Cherry Avenue, top of Signal Hill, city of Signal Hill,
Los Angeles Co. Collected by M.E. Rogers. Penitella
pejiita.

USGS-M loc. 2017.— Pleistocene, Palos Verdes Sand.
Southeast corner of Oliver and Pacific Streets, San
Pedro, Los Angeles Co. Collected by M.E. Rogers.
Zirfaea pilsbryi, Penitella penita.

USGS-M loc. 2147.— Pleistocene. Terrace deposit in
sea cliffs on north side of Point Aiio Nuevo, 900 feet
north of Green Oaks Creek, San Mateo Co. Elevation
1015 feet. Collected by W.O. Addicott, W.C. Bradley,
and R. Curry, September, 1964. Zirfaea pilsbryi,
Penitella tumerae; in situ.

USGS-M loc. 2798.— Pleistocene. Terrace deposit on
south side of Coquille Point, west of Bandon, Coos Co.,
Oregon. SE 1/4 sec. 26, T. 28 S., R. 15 W., WBM. Col-
lected by R. Janda, W.O. Addicott, and Mr. Hunter,
1966-1967. Penitella penita.

USGS-M loc. 3026.— Pleistocene? In very small cove
beneath circle drive in Yaquina Bay State Park, north of
north Yaquina Bay jetty, Lincoln Co., Oregon. 400 feet
west and 100 feet north of SE cor. sec. 7, T. 11 S., R. 11
W., WBM. Collected by E.W. Baldwin. Zirfaea pilsbryi.
USGS-M loc. 3073.— Miocene, Montesano Formation.
Basal formational contact in road cut just south of bridge
over Satsop River, Mason Co., Washington. 200 feet
west and 900 feet north of SE cor. sec. 36, T. 19 N., R. 7
W., WBM. Collected by G.A. Fowler. ?Zirfaea sp.
(?ancestoral to Chaceia).

USGS-M loc. 3117.— Miocene, Montesano Formation.
Basal formational contact, in stream bank on east side of
Canyon River, Grays Harbor Co., Washington. On
section line 450 feet west of SE cor. sec. 85, T. 21 N., R
7 W., WBM. Collected by G.A. Fowler. Penitella
lorenzana.

USGS-M loc. 3779.— Miocene, Escudo Formation.
"Buttonbed," on south side of Escudo Mountain, Kern
Co., in coarse to very coarse grained sandstone. 1575 feet
north and 2450 feet west of SE cor. sec. 36, T. 25 S., R.
18 E., MDBM. Collected by W.O. Addicott, April, 1968.
Zirfaea sp. cf. Z. dentata.

USGS-M loc. 4621.— Pliocene, Paso Robles Formation.
In quarry on south side of Atascadero-Creston road
about two miles east of Atascadero, San Luis Obispo Co.
Collected by W.O. Addicott, J.S. Galehouse, and D.L.
Durham. Nettastomella rostrata.

USGS-M loc. 4622.— Pleistocene? Near base of channel
cut into Nye Formation and lying unconformably beneath
late Pleistocene marine terrace at Hinton Point, Yaquina
Bay, Lincoln Co., Oregon. Near SE 1/4 sec. 16, T. 11 S.,

R. 11 W., WBM. Collected by R. Janda, 1970. Zirfaea

pilsbryi.

USGS-M loc. 4623.— Pleistocene. Bluffs on north side of

Fivemile Point, Coos Co., Oregon. 1.100 feet S and 600

feet W of NE cor. sec. 19, T. 27 S., R. 14 W., WBM.

Collected by R. Janda. 1970. Penitella penita.

UNIVERSITY OF WASHINGTON
(SEATTLE)

[Probably all collected by C.E. Weaver. Most of the
specimens below are no longer in the University's
collections.]

UW loc. 719. — Pliocene, Empire Formation. In the sea
cliffs on the east side of South Slough in Coos Bay, Coos
Co., Oregon. Fossils from the base of a massive, medium-
grained, brown sandstone. Fossils well preserved
"?Pholadidea califomica" [not seen; probably Penitella
tumerae].

UW loc. 725.— Pliocene, Empire Formation (Coos Con-
glomerate). Fossil Point on the east side of South Slough
in Coos Bay, Coos Co., Oregon. Very firmly cemented
conglomerate containing thin lenses of sandstone. Fossils
are abundant. "Pholadidae penita" [not seen; probably
Penitella tumerae].

UW loc. 752.— Pliocene, Empire Formation. From a
sandstone layer in the sea cliffs 630 feet east of Tunnel
Point, Coos Bay, Coos Co., Oregon. 660 feet above the
base of the Tunnel Point Formation. Penitella tumerae.
UW loc. 1238.— Oligocene, San Ramon Formation.
Pholadid borings at base of the San Ramon in the east
limb of the Pacheco syncline; in a cut along Industrial
Highway, Contra Costa Co. "Pholadidea {Penitella)
lorenzana" [not seen; =Penitella durhami].
UW loc. 3374.— Miocene, Sobrante Sandstone. Exposure
of sandstone in pasture-land in the east limb of Pacheco
syncline (south of Vine Hill Fault), Contra Costa Co.
5,200 feet S. 50° W. from overpass at intersection of
Pacheco Road and Santa Fe Railway. "Pholadidea cf.
penita" [not seen].

UW loc. 3378.— Miocene, Briones Sandstone. West limb
of Pacheco syncline 6,700 feet S. 40° W. from the over-
pass at intersection of Pacheco Road and Santa Fe
Railway, Contra Costa Co. From lower part of the
formation. "Pholadidea cf. penita" [not seen].
UW loc. 3379.— Oligocene, San Ramon Formation.
Exposure in cut along Santa Fe Railway in east limb of
Pacheco Syncline, 6,100 feet due west of overpass at
intersection of Pacheco Road and Santa Fe Railway,
Contra Costa Co. "Pholadidea cf. penita" [not seen].
UW loc. 3414.— Miocene, Briones Sandstone. Exposure
in west limb of Pacheco Syncline, 3.200 feet S. 41° W.
from intersection of Morello Road and Santa Fe Railway,
Contra Costa Co. Zirfaea dentata Jnot seen].
UW loc. 3415.— Miocene. Briones Sandstone. Exposure
in east limb of Pacheco Syncline. 3,500 feet S. 8° W.
from intersection of Morello Road and Santa Fe Railway,
Contra Costa Co. Zirfaea dentata [not seen).

94

GEORGE L. KENNEDY

LITERATURE CITED

Addicott, W. 0.

1963a. Interpretation of the invertebrate
fauna from the upper Pleistocene
Battery Formation near Crescent
City, Cahfornia. Proc. California
Acad. Sci., ser. 4, 31(13): 341-347.

1963b. An unusual occurrence of Tresus
nuttalli (Conrad, 1837) (Mollusca:
Pelecypoda). Veliger5(4): 143-145,
fig. 1-3.

1964a. A late Pleistocene invertebrate
fauna from southwestern Oregon.
Jour. Paleont. 38(4): 650-661, fig.
1-3, pi. 107-108, 2 tables.

1964b. Pleistocene invertebrates from the
Dume Terrace, western Santa
Monica Mountains, California. Bull.
So. California Acad. Sci 63(3):
141-150. fig. 1-2.

1966a. Late Pleistocene marine paleo-
ecology and zoogeography in cen-
tral California. U.S. Geol. Surv.,
Prof. Paper 523-C: 1-21, fig. 1-6,
pi. 1-4.

1966b. New Tertiary marine moUusks
from Oregon and Washington.
Jour. Paleont. 40(3): 635-646, 1
fig., pi. 76-78.

1969. Late Pliocene mollusks from San
Francisco Peninsula, California,
and their paleogeographic signifi-
cance. Proc. California Acad. Sci.,
ser. 4, 37(3): 57-93, fig. 1-3, pi. 1-4,
4 tables.
Addicott, W. 0. and W. K. Emerson

1959. Late Pleistocene invertebrates
from Punta Cabras, Baja Califor-
nia, Mexico. Amer. Mus. Novi-
tates 1925: 1-33, fig. 1-8, 3 tables.
Addicott, W.O. and J.S. Galehouse

1973. Pliocene fossils in the Paso Robles
Formation, California. Jour. Res.
U.S. Geol. Surv. 1(5): 509-514,
fig. 1-4.
Adegoke, 0. S.

1966. Silicified sand-pipes belonging to
Chaceia (?) (Pholadidae: Marte-
siinae) from the late Miocene of

California. Veliger 9(2): 233-235,
pi. 21.
1967. Earliest Tertiary west American
Seaside Lab., no. 31].
The Tertiary and Quaternary pec-
tens of California. U.S. Geol.
species ot Flatyodon and Feniteiia.
Proc. California Acad. Sci., ser. 4,
35(1): 1-22, fig. 1-28, 2 tables.

1969. Stratigraphy and paleontology of
the marine Neogene formations of
the Coalinga region, California.
Univ. California Publ. Geol. Sci.
80: iv + 1-269, fig. 1-6, 6a, maps.

Anderson, F. M.

1905. A stratigraphic study in the Mount
Diablo Range of California. Proc.
California Acad. Sci., ser. 3(Geol.),
2(2): 155-250, pi. 13-35.
1908. A further stratigraphic study in
the Mount Diablo Range of Cali-
fornia. Proc. California Acad. Sci.,
ser. 4, 3(1): 1-40.

Anderson, F. M. and G D. Hanna

1925. Fauna and stratigraphic relations
of the Tejon Eocene at the type
locality in Kern County, California.
Occ. Paper California Acad. Sci.
11: 1-249, fig. 1-10, pi. 1-16.

Anonymous

1970. Road log: San Diego to Ensenada
by Mexico Highway ID (toll road),
in E. C. Allison, et al., eds.. Pacific
slope geology of northern Baja
California and adjacent Alta Cali-
fornia [Geol. guidebook, fall field-
trip, Pac. sects., AAPG, SEPM,
and SEG]: 145-154.

Antisell, Thomas

1856. Geological report. U.S. 33rd Cong.,
2nd sess.. Senate Exec. Doc. no.
78 and House Repr. Exec. Doc. no.
91, V. 7, [Report of explorations
for railroad routes from San Fran-
cisco Bay to Los Angeles, Cali-
fornia, . . ., by J. G. Parke], pt. 2:
1-188, 197-204, pi. 1-14, maps 1-2.

Arnold, Ralph

WEST AMERICAN CENOZOIC PHOLADIDAE

95

1903. The paleontology and stratigraphy
of the marine Pliocene and Pleisto-
cene of San Pedro, California.
Mem. California Acad. Sci. 3:
1-420, pi. 1-37 [reprinted as (Stan-
ford Univ.) Contrib. Biol., Hopkins

■ Surv., Prof. Paper 47: 1-264, pi.

1-53.

1907. New and characteristic species of
fossil mollusks from the oil-bearing
Tertiary formations of Santa Bar-
bara County, California. Smith-
sonian Misc. Coll. [publ. 1781],
50(4): 419-447, pi. 50-58.

1908. Descriptions of new Cretaceous
and Tertiary fossils from the Santa
Cruz Mountains, California. Proc.
U.S. Natl. Mus. 34(1617): 345-389,
pi. 31-37.

1909. [Jan. 15, 1910]. Paleontology of the
Coalinga district, Fresno and Kings
counties, California. U.S. Geol.
Surv., Bull. 396: 1-173, pi. 1-30.

Arnold, Ralph and Robert Anderson

1907. Geology and oil resources of the
Santa Maria oil district, Santa
Barbara County, Cal. U.S. Geol.
Surv., Bull. 322: 1-161, pi. 1-26.

1910. Geology and oil resources of the
Coalinga district, California. U.S.
Geol. Surv., Bull. 398: 1-354, fig.
1-8, pi. 1-52.

Arnold, Ralph and Harold Hannibal

1913. The marine Tertiary stratigraphy
of the north Pacific coast of Amer-
ica. Proc. Amer. Philos. Soc.
52(212): 559-605, pi. 37-48, 2 tables.

Ashley, G. H.

1895. The Neocene of the Santa Cruz
Mountains. I— Stratigraphy. Proc.
California Acad. Sci., ser. 2, 5(1):
273-367, pi. 22-25 [reprinted as
Leland Stanford Junior Univ.
Publ., Geol. and Palaeont., no. 1].

Barrows, A. L.

1917. Geologic significance of fossil rock-
boring animals. Bull. Geol. Soc.
Amer. 28: 965-972.

Bartsch, Paul, and H. A. Rehder

1945. The west Atlantic boring mol-
lusks of the genus Martesia.
Smithsonian Misc. Coll. [publ.

3804], 104(11): 1-16, pi. 1-3.
Bayle, E.

1880. Liste rectificative de quelques

noms de genres de d'especes.

Jour. Conchyl. 28(3): 240-251.
Berry, S. S.

1922. Fossil chitons of western North

America. Proc. California Acad.

Sci., ser. 4, 11(18): 399-526. fig.

1-11, pi. 1-16.
Bishop, M. J. and S. J. Bishop

1972. New records of Pleistocene marine

Mollusca from Pacific Beach, San

Diego, California. Veliger 15(1):6.
Blake, W. P.

1856. General report upon the geological
collections. U.S. 33rd Cong., 2nd
sess.. Senate Exec. Doc. no. 78
and House Repr. Exec. Doc. no.
91, v. 3 [Report of explorations for
a railway route, . . . from the
Mississippi River to the Pacific
Ocean, by A. W. Whipple], pt. 4
[Report on the geology of the
route], no. 1: i + 1-98, 106-119,
illus.

1857. Geological report. U.S. 33rd Cong.,
2nd sess.. Senate Exec. Doc. no.
78 and House Repr. Exec. Doc.
no. 91, v. 5 [Report of explorations
in California for railroad routes,
. . ., by R. S. Williamson], pt. 2:
i-xvii + 1-310, 87 figs., pi. 1-14,
4 maps, 14 cross sections.

Bowers, Stephen
1890. Orange County, California. State
Mining Bur., Ann. Rept. State
Mineral, for 1890, 10: 399-409.
1901. Reconnaissance of the Colorado
Desert mining district. California
State Mining Bur., Sacramento,
19 pp.
Bradley, W. C. and W. 0. Addicott

1968. Age of first marine terrace near
Santa Cruz, California. Geol. Soc.
Amer. Bull. 79: 1203-1210, pi. 1,
1 table.
Bruff, S. C.

1946. The paleontology of the Pleisto-
cene moUuscan fauna of the New-
port Bay area, California. Univ.
California Publ., Bull. Dept. Geol.

96

GEORGE L. KENNEDY

Burch, J^

1947. Comparison

Sci. 27(6): 213-240, fig. 1-2. 1963.

Q. and T. A. Durch B. L .

of the molluscs of

three Pleistocene beds with the

Recent fauna of Los Angeles Clark, B.

County, California. Min. Conch. 1912.

Club So. California 73: 1-18.
Burch, J. Q. and T. A. Burch

1943. The Timm's Point Pleistocene

horizon at San Pedro, California. 1915.

Min. Conch. Club So. California

22: 7-9.
Carpenter, P.P.

1857. Report on the present state of our 1918.

knowledge with regard to the Mol-

lusca of the west coast of North

America. Rept. Brit. Assoc. Adv.

Sci. for 1856: 159-368, pi. 6-9.

1864. Supplementary report on the pres-
ent state of our knowledge with
regard to the Mollusca of the west

coast of North America. Rept. 1925.

Brit. Assoc. Adv. Sci. for 1863:
517-686 [reprinted in Smithso-
nian Misc. Coll.. 10(252): 1-172
(1872)]. [1929].

1865. Diagnoses of new forms of Mol-
lusca from the Vancouver district.
Proc. Sci. Meet. Zool. Soc. London

for 1865, ser. 3, signature 13: Clark, B.

201-204. 1923.

Catlow, Agnes, and Lovell Reeve

1845. The conchologist's nomenclator.

Reeve Brothers, London, viii +

326 pp.
P.

Field notes on some west coast Clark, B.

mollusks. Nautilus 56(2): 41-43. 1927.

Additional notes on the Pliocene

and Pleistocene fauna of the Turtle

Bay area, Baja California, Mexico.

Trans. San Diego Soc. Nat. Hist.

12(9): 177-179.

Pleistocene Mollusca from the sec- Clark, E.

ond terrace at San Pedro, Califor- 1943.

nia. Trans. San Diego Soc. Nat.

Hist. 14(13): 169-172. Clark, W

P. and E. M. Chace 1906.

An unreported exposure of the

San Pedro Pleistocene. Lorquinia

2(6): 1-3.
Clapp, W. F. and Roman Kenk

Chace, E
1942.

1956.

1966.

Chace, E
1919.

Marine borers — An annotated
bibliography. Office Naval Res.,
Dept. Navy, Washington, D.C.,
xii + 1136 pp.
L.

The Neocene section at Kirker
Pass on the north side of Mount
Diablo. Univ. California Publ.,
Bull. Dept. Geol. 7(4): 47-60, pi. 7.
Fauna of the San Pablo Group of
middle California. Univ. California
Publ., Bull. Dept. Geol. 8(22):
385-572, pi. 42-71.
The San Lorenzo Series of middle
California — A stratigraphic and
paleontologic study of the San
Lorenzo Oligocene series of the
general region of Mt. Diablo, Cali-
fornia. Univ. California Publ., Bull.
Dept. Geol. 11(2): 45-234, 4 figs.,
pi. 3-24.

Pelecypoda from the marine Oligo-
cene of western North America.
Univ. California Publ., Bull. Dept.
Geol. Sci. 15(4): 69-136, pi. 8-22.
Stratigraphy and faunal horizons
of the Coast Ranges of California.
Privately published, Berkeley, 30
pp., 50 pis., 1 chart.
L. and Ralph Arnold
Fauna of the Sooke Formation,
Vancouver Island, with description
of a new coral by T. Wayland
Vaughan. Univ. California Publ.,
Bull. Dept. Geol. Sci. 14(5):
123-234, pi. 15-42.
L. and A. 0. Woodford
The geology and paleontology of
the type section of the Meganos
Formation (lower middle Eocene)
of California. Univ. California
Publ., Bull. Dept. Geol. Sci. 17(2):
62-142, pi. 14-22, 1 map.
M.

Turritella terrace. Min. Conch.
Club So. California 29: 3-4.
. B.

Mollusca, in Maryland Geological
Survey. Pliocene and Pleistocene.
Johns Hopkins Press, Baltimore,
pp. 176-210, pi. 42 (fig. 5-10),
43-65, 66 (fig. 1-6).

WEST AMERICAN CENOZOIC PHOLADIDAE

97

Conrad,
1837.

1848.

1849.

1855.

1856.

1857.

1868.

1869.

Cook, E
1943.

T. A.
Descriptions of new marine shells,
from Upper California. Collected
by Thomas Nuttall, Esq. Jour.
Acad. Nat. Sci. Philadelphia 7(2):
227-268, pi. 17-20.
Descriptions of two new genera
and new species of Recent shells,
&c. Proc. Acad. Nat. Sci. Phila-
delphia 4(6): 121.

Descriptions of new fresh water
and marine shells. Proc. Acad.
Nat. Sci. Philadelphia 4: 152-156.
Report of Mr. T. A. Conrad on the
fossil shells collected in California
by Wm. P. Blake, geologist of the
expedition under the command of
Lieutenant R. S. Williamson,
United States Topographical Engi-
neers. U.S. 33rd Cong., 1st sess.,
House Repr. Exec. Doc. no. 129,
append. [/or Preliminary geological
report, by W.P. Blake], art. 1: 5-20
[octavo edition; partially reprinted
by Dall. 1909: 163-171].
[Editor's condensation and partial
reprint of Conrad, 1855]. Amer.
Jour. Sci. Arts, ser. 2, 21(62):
268-270.

Descriptions of the fossil shells.
U.S. 33rd Cong., 2nd sess., Senate
Exec. Doc. no. 78 and House Repr.
Exec. Doc. no. 91, v. 5 [Report of
explorations in California for rail-
road routes, . . . , by R.S.William-
son], pt. 2 [Geological report, by
W.P. Blake], append., art. 2: 317-
329, pi. 2-9 [quarto edition of
Conrad, 1855].

Synopsis of the invertebrate fossils
of the Cretaceous formation of
New Jersey [Appendix A], in G.H.
Cook, Geology of New Jersey.
[New Jersey Geol. Surv.] Board of
Managers, Newark: 721-732.
Notes on Recent Mollusca. Amer.
Jour. Conch. 5(2): 104-108, pi. 10
(fig. 1, la), 12-13.
T. and E.M. Clark
List of Mollusca found in ''Anomia
Bed". Min. Conch. Club So. Cali-
fornia 21: 17.

Cooper, J.G.

1888. Catalogue of Californian fossils.
California State Mining Bur., Ann.
Rept. State Mineral, for 1887,
7: 221-308.

Crickmay, C.H.

1929. The anomalous stratigraphy of

Deadman's Island, California. Jour.

Geol. 37(7): 617-638, 1 table.
Dall, W.H.

1878a. Fossil mollusks from the later ter-

tiaries of California. Proc. U.S.

Natl. Mus. 1: 10-16.
1878b. Distribution of California Tertiary

fossils. Proc. U.S. Natl. Mus.

1: 26-30.

1889. Notes on the anatomy of Pholas
(Barnea) costata Linne, and Zir-
phaea crispata Linne: Proc. Acad.
Nat. Sci. Philadelphia 41(3) :274-
276.

1898. Contributions to the Tertiary
fauna of Florida, with special ref-
erence to the Silex beds of Tampa
and the Pliocene beds of the
Caloosahatchie River. Part IV.
Trans. Wagner Free Inst. Sci.
Philadelphia 3(4): viii + 571-947,
pi. 23-35.

1909. Contributions to the Tertiary pal-
eontology of the Pacific coast. I.
The Miocene of Astoria and Coos
Bay, Oregon. U.S. Geol. Surv.,
Prof. Paper 59: 1-278, pi. 1-23
[with reprints of papers by Con-
rad, Dana, Evans and Shumard,
Carpenter, and Dall].

1916a. Checklist of the Recent bivalve
mollusks (Pelecypoda) of the north-
west coast of America from the
Polar Sea to San Diego, California.
Southwest Museum, Los Angeles,
44 pp., 1 pi.

1916b. Diagnoses of new species of
marine bivalve mollusks from the
northwest coast of America in the
collection of the United States
National Museum. Proc. U.S. Natl.
Mus. 52(2183): 393-417.
Delong, J.H., Jr.

1941. The paleontology and stratigraphy
of the Pleistocene at Signal Hill,

98

GEORGE L. KENNEDY

Emerson,
1951.

1960.

Emerson,
1953.

Long Beach, California. Trans.
San Diego Soc. Nat. Hist. 9(25):
229-252, fig. 1-4.
Deshayes, G.P. Eldridge,

1839. Nouvelles especes de Mollusques, 1907.

provenant des cotes de la Cali-
fornie, du Mexique, du Kamt-
schatka, et de la Nouvelle Zelande,
descrites par M. Deshayes. Revue
Zoologique par la Societe Cuvieri-
enne (Paris), pp. 356-361 [not
seen].

1843. Mollusques, pi. 79 [description of
Pholas spathulata], Magasin de
Zoologie, ser. 2, 5(11-12): 1, pi. 79.
Dickerson, R.E.

1911. The stratigraphic and faunal rela-
tions of the Martinez Formation to
the Chico and Tejon north of
Mount Diablo. Univ. California
Publ., Bull. Dept. Geol. 6(8):
171-177.

1914. Fauna of the Martinez Eocene of
California. Univ. California Publ.,
Bull. Dept. Geol. 8(6): 61-180, fig.
1-5, pi. 6-18.

1916. Stratigraphy and fauna of the 1958.

Tejon Eocene of California. Univ.
California Publ., Bull. Dept. Geol.
9(17): 363-524, fig. 1-14, pi. 36-46,
1 map. Emerson,

Diller, J.S.

1896. A geological reconnaissance in
northwestern Oregon. U.S. Geol.
Surv., Ann. Kept. 17, part 1: 441-
520, fig. 4-17, pi. 4-16.
DuBar, J.R.

1958. Stratigraphy and paleontology of
the late Neogene strata of the
Caloosahatchee River area of
southern Florida. Florida Geol.
Surv., Geol. Bull. 40: 1-267, fig.
1-49, pi. 1-12.
Durham, D.L. and W.O. Addicott

1965. Pancho Rico Formation, Salinas
Valley, California. U.S. Geol.
Surv., Prof. Paper 524- A: iii +
1-22, fig. 1-7, pi. 1-5, 1 table.
Edwards, E.G.

1934. Pliocene conglomerates of Los 1968b.

Angeles basin and their paleogeo-

Evans, J
1967a.

1967b.

1968a.

graphic significance. Bull. Amer.

Assoc. Petrol. Geol. 18(6): 786-812,

fig. 1-7.

G.H.

The Santa Clara Valley oil district,
southern California, in G.H. Eld-
ridge and Ralph Arnold, The Santa
Clara Valley, Puente Hills and Los
Angeles oil districts, southern
California. U.S. Geol. Surv., Bull.
309: 1-101, fig. 1-11, pi. 1-9.

W.K.

An unusual habitat for Zirfaea
pilsbryi (MoUusca: Pelecypoda).
Bull. So. California Acad. Sci.
50(2): 89-91, pi. 31.
Pleistocene invertebrates from
near Punta San Jose, Baja Califor-
nia, Mexico. Amer. Mus. Novi-
tates 2002: 1-7, fig. 1.

W.K. and W.O. Addicott
A Pleistocene invertebrate fauna
from the southwest corner of San
Diego County, CaHfornia. Trans.
San Diego Soc. Nat. Hist. 11(17):
429-444, 1 map.

Pleistocene invertebrates from
Punta Baja, Baja California, Mex-
ico. Amer. Mus. Novitates 1909:
1-11, fig. 1-2, 2 tables.

W.K. and E.P. Chace
Pleistocene mollusks from Tecolote
Creek, San Diego, California.
Trans. San Diego Soc. Nat. Hist.
12(21): 335-346, fig. 1-2, 3 tables.
W.

Relationship between Penitella
penita (Conrad, 1837) and other
organisms of the rocky shore.
Veliger 10(2): 148-151, pi. 16.
A re-interpretation of sand-pipes
described by Adegoke. Veliger
10(2): 174-175, pi. 17.
The effect of rock hardness and
other factors on the shape of the
borrow of the rock-boring clam,
Penitella penita. Palaeogeog., Pal-
aeoclimitoL, Palaeoecol. 4(4): 271-
278, fig. 1, 2 tables.
Factors modifying the morphology
of the rock-boring clam, Penitella

WEST AMERICAN CENOZOIC PHOLADIDAE

99

pemfa( Conrad, 1837). Proc. Malac.
Soc. London 38 (2): 111-119, fig.
1-6, pi. 1-4, 1 table.

1968c. The role of Penitella penita (Con-
rad 1837) (family Pholadidae) as
eroders along the Pacific coast of
North America. Ecology 49(1):
156-159, fig. 1-3.

1968d. Growth rate of the rock-boring
clam Penitella penita (Conrad
1837) in relation to hardness of
rock and other factors. Ecology
49(4): 619-628, fig. 1-5, 3 tables.

1970. Palaeontological implications of a
biological study of rock-boring
clams (family Pholadidae), in T.P.
Crimes and J.C. Harper, ed..
Trace Fossils. (Geol. Jour., Spec,
issue no. 3) Seal House, Liverpool:
127-140, pi. 1-7, table 1.
Evans, J.W. and David Fisher

1966. A new species of Penitella (family
Pholadidae) from Coos Bay, Ore-
gon. Veliger 8(4): 222-224, fig. 1,
pi. 31, 2 tables.
Evans, J.W. and M.H. LeMessurier

1972. Functional micromorphology and
circadian gprowth of the rock-
boring clam Penitella penita. Ca-
nadian Jour. Zool. 50(10): 1251-
1258, pi. 1-5, table 1.
Faustman, W.F.

1964. Paleontology of the Wildcat Group
at Scotia and Centerville Beach,
California. Univ. California Publ.
Geol. Sci. 41(2): 97-159, fig. 1-7,
pi. 1-3.
Finlay, H.J.

1930. Notes on recent papers deaUng
with the Mollusca of New Zealand.
Trans. Proc. New Zealand Insti-
tute 61(2): 248-258, pi. 46.
Fischer, P.H.

1880-1887. Manuel de conchyliologie et de
paleontolgie conchyliologique ou
histoire naturelle des mollusques
vivants et fossiles [suivi d'un
appendice sur les brachiopodes par
D.P. Oehlert]: F. Savy, Paris,
XXV + 1369 pp., 1138 figs., 23 pis.,
frontis.

Fitch, J.E.

1953. Common marine bivalves of Cali-
fornia. Calif. State Fish Game
Comm., Fish Bull. 90: 1-102, fig.
1-63, 1 pi.
Frazier, Kenneth

1968. [Late Dec, 1967.] Marine fossils in
southern California. Earth Sci. 21
(1): 13-16, 1 fig., 3 pis. [reprinted
in Fossils from our Earth: Earth
Science Publ. Co., Downers Grove
(Illinois), pp. 25-28, n.d. (August,
1968)].
Gabb, W.M.

1866-1869. Palaeontology of California.
Volume II: [Geol. Surv. Calif.],
Sherman and Co., Philadelphia,
XV +299 pp., 36 pis.
Gardner, Julia

1943. Mollusca from the Miocene and
lower Pliocene of Virginia and
North CaroUna. Part 1. Pelecy-
poda. U.S. Geol. Surv., Prof.
Paper 199-A: 1-178, pi. 1-23.
Gester, G.C.

1917. Geology of a portion of the
McKittrick district, a typical ex-
ample of the west side San Joaquin
Valley oil fields, and a correlation
of the oil sands of the west side
fields. Proc. California Acad. Sci.,
ser. 4, 7(9): 207-227, pi. 32-33.
Gigoux, E.E.

1934. Los moluscos marinos de Atacama:
Revista Chilena de Historia Nat-
ural 38: 274-286 [not seen].
Glen, William

1959. Pliocene and lower Pleistocene of
the western part of the San Fran-
cisco Peninsula. Univ. California
Publ. Geol. Sci. 36(2): 147-198, fig.
1-5, pi. 15-17.
Gould, A.A.

1851. Descriptions of new shells from
California collected by Maj. Wil-
liam Rich and Lieut. T.P. Green,
U.S.N. Proc. Boston Soc. Nat.
Hist. 4: 87-93.
1853. Descriptions of shells from the
Gulf of California and the Pacific
coasts of Mexico and California.

100

GEORGE L. KENNEDY

Boston Jour. Nat. Hist. 6(3), art.
24: 374-408. pi. 14-16.
Gmelin, J.F.

1791. Caroli a Linne Systema naturae
per regna tria naturae. Editio dec-
ima tertia. Leipzig, Germany,
vol. 1, pt. 6, cl. 6, Vermes, pp.
3021-3910.
Grant, U.S., IV, and H.R. Gale

1931. Catalogue of the marine Pliocene
and Pleistocene Mollusca of Cali-
fornia and adjacent regions. Mem.
San Diego Soc. Nat. Hist. 1:
1-1036, fig. 1-15, pi. 1-32.
Gray, J.E.

1840. Synopsis of the contents of the
British Museum. Ed. 42. London.
iv + 370 pp. [not seen].

1842. Synopsis of the contents of the
British Museum. Ed. 44. London,
iv -I- 308 pp. [not seen].

1847. A list of the genera of Recent
Mollusca, their synonyma and
types. Proc. Zool. Soc. London
15: 129-219.

1851. An attempt to arrange the species
of the family Pholadidae into nat-
ural groups. Ann. Mag. Nat. Hist.,
ser. 2, 8(47), art. 32: 380-386.
Gualtieri, Nicolai

1742. Index testarum conchyliorum quae
adservantur in Museo Nicolai
Gualtieri. Florence, xxiii pp.,
illus. + pi. 1-110.
Habe, Tadsashige

1952. Genera of Japanese shells. Pele-
cypoda no. 3. T. Habe, Kyoto,
Japan, pp. ii + 187-278, fig. 429-
730.

1955. The fauna of Akkeshi Bay. XXI.
Pelecypoda and Scaphopoda. Publ.
Akkeshi Mar. Biol. Stat. 4: 1-31,
pi. 1-7.
Hall, C.A., Jr.

1958. Geology and paleontology of the
Pleasanton area, Alameda and
Contra Costa counties, California:
Univ. California Publ. Geol. Sci.
34(1): 1-90, fig. 1-2, pi. 1-12, 5
maps.

1960. Displaced Miocene molluscan prov-

inces along the San Andreas Fault,
California. Univ. California Publ.
Geol. Sci. 34(6): 281-308, 1 chart,
3 maps.
Hanna, G D.

1926. Paleontology of Coyote Mountain,

Imperial County, California. Proc. J
California Acad. Sci., ser. 4, 14 "
(18): 427-503, fig. 1, pi. 20-29.

1966. Introduced mollusks of western

North America. Occas. Paper

California Acad. Sci. 48: 1-108,

fig. 1-85, pi. 1-4.

Hanzawa, Shoshiro, Kiyoshi Asano, and

Fuyuji Takai

1961. Catalogue of type-specimens of
fossils in Japan. Palaeont. Soc.
Japan, Tokyo, vii + 422 pp.
Hertlein, L.G. and E.C. Allison

1959. Pliocene marine deposits in north-
western Baja California, Mexico
with the description of a new spe-
cies of Acanthina (Gastropoda).
Bull. So. California Acad. Sci.
58(1): 17-26, pi. 7-8, 1 table.
Hertlein, L.G. and C.H. Crickmay

1925. A summary of the nomenclature
and stratigraphy of the marine
Tertiary of Oregon and Washing-
ton. Proc. Amer. Philos. Soc.
64(2): 224-282.
Hertlein, L.G. and U.S. Grant, IV

1944. The geology and paleontology of
the marine Pliocene of San Diego,
California. Part 1, geology. Mem.
San Diego Soc. Nat. Hist. 2(1):
1-72, fig. 1-6, pi. 1-18, 1 map.

1972. The geology and paleontology of
the marine Pliocene of San Diego,
California (Paleontology: Pelecy-
poda). Mem. San Diego Soc. Nat.
Hist. 2(2B): 135-411, fig. 7-13,
frontis., pi. 27-57.
Hertlein, L.G. and A.M. Strong

1950. Eastern Pacific expeditions of the
New York Zoological Society.
XLII. Mollusks from the west
coast of Mexico and Central Amer-
ica. Part IX. Zoologica 35(4): 217-
252, pi. 1-2.
Hickman, C.J.S.

WEST AMERICAN CENOZOIC PHOLADIDAE

101

1969. The Oligocene marine molluscan
fauna of the Eugene Formation in
Oregon. Bull. Mus. Nat. Hist.,
Univ. Oregon 16: iv + 1-112, fig.
1-4, pi. 1-14, 4 tables.
Higgins, C.G.

1960. Ohlson Ranch Formation, Plio-
cene, northwestern Sonoma
County, California. Univ. Califor-
nia Publ. Geol. Sci. 36(3): 199-231,
fig. 1-6, pi. 18-20, 2 tables, 1 map.
Holmes, F.S.

1860. Post-Pleiocene fossils of South-
Carolina. Russel & Jones, Charles-
ton (S.C). vi + ix + 122 pp., 27 pis.
Hoots, H.W.

1931. Geology of the eastern part of the
Santa Monica Mountains, Los
Angeles County, California. U.S.
Geol. Surv., Prof. Paper 165-C:
83-134, fig. 7, pi. 16-34.
Hopkins, D.M.

1967. Quaternary marine transgressions
in Alaska, in Hopkins, D.M. ed.,
The Bering land bridge. Stanford
Univ. Press, Stanford, Chapt. 4,
pp. 47-90, fig. 1-5, 2 tables.
Hoskins, C.W.

1957. Paleoecology and correlation of the
lowest emergent California marine
terrace, from San Clemente to
Halfmoon Bay. Unpubl. doctoral
dissertation, Dept. Geol., Stanford
Univ., vii + 188 pp., 14 figs., 4 pis.,
1 table. [Specimens not examined
and data not incorporated into
text.]
Howe, H.V.

1922. Faunal and stratigraphic relation-
ships of the Empire Formation,
Coos Bay, Oregon. Univ. Cali-
fornia Publ., Bull. Dept. Geol.
Sci. 14(3): 85-114, pi. 7-12.
Human, V.L.

1972. Geology and paleontology of a
Pleistocene marine terrace at
Corona del Mar, Orange County,
California. Tabulata 5(3): 8-10.
Itoigawa, Junji

1960. Paleoecological studies of the Mio-
cene Mizunami Group, central

Japan. Jour. Earth Sci., Nagoya
Univ. 8(2): 246-300, fig. 1-5, pi.
1-6, charts.

1963. Miocene rock- and wood-boring bi-
valves and their burrows from the
Mizunami Group, central Japan.
Jour. Earth Sci., Nagoya Univ.
11(1): 101-123, fig. 1-4, pi. 1-7,
2 tables, 1 chart.

Johnson, R.I.

1964. The Recent Mollusca of Augustus
Addison Gould. U.S. Natl. Mus.,
Bull. 239: v + 1-182, pi. 1-45.

Jordan, E.K.

1924. Quaternary and Recent molluscan
faunas of the west coast of Lower
California. Bull. So. California
Acad. Sci. 23(5): 145-156.
1926. Expedition to Guadalupe Island,
Mexico, in 1922 — No. 4. Mollus-
can fauna of the Pleistocene of San
Quintin Bay, Lower California.
Proc. California Acad. Sci., ser. 4,
15(7): 241-255, 1 fig., pi. 25.

Kanakoff, G.P. and W.K. Emerson

1959. Late Pleistocene invertebrates of
the Newport Bay area, California.
Los Angeles Co. Mus. Contrib.
Sci. 31: 1-48, fig. 1-5.

Kanno, Saburo, and Kyuya Matsuno

1960. Molluscan fauna from "the Chiku-
betsu Formation", Hokkaido, Ja-
pan. Jour. Geol. Soc. Japan
66(772): 35-45, fig. 1-2, pi. 4-5,
table 1.

Keen, A.M.

1958. Sea shells of tropical west Amer-
ica. Stanford Univ. Press, Stan-
ford, 624 pp., illus.

1966. West American mollusk types at
the British Museum (Natural His-
tory), I. T.A. Conrad and the
Nuttal collection. Veliger 8(3):
167-172, fig. 1.

1971. Sea shells of tropical west Amer-
ica [Second edition]. Stanford
Univ. Press, Stanford, 1064 pp.,
illus.
Keen, A.M. and Herdis Bentson

1944. Check list of California Tertiary
marine Mollusca. Geol. Soc.

102

GEORGE L. KENNEDY

Amer., Spec. Papers 56: viii +
1-280, fig. 1-4, tables 1-2.
Kennedy, G.L.

1973. A marine invertebrate faunule
from the Lindavista Formation,
San Diego, California. Trans. San
Soc. Nat. Hist. 17(10): 119-127,
fig. 1-3.
Keroher, G.C., et al.

1966. Lexicon of geologic names of the
United States for 1936-1960. U.S.
Geol. Surv., Bull. 1200(1): iv -i-
1-1448; (2): 1449-2886; (3): 2887-
4341.
Kew, W.S.W.

1914. Tertiary echinoids of the Carrizo
Creek region in the Colorado Des-
ert. Univ. California Publ., Bull.
Dept. Geol. 8(5): 39-60, fig. 1,
pi. 1-5.
Kira, Tetsuaki

1965. Shells of the western Pacific in
color. Vol. I. [Revised edition].
Hoikusha Publ. Co., Osaka (Ja-
pan), [ix] -f 224 pp.
Knudsen, J0rgen

1961. The bathyal and abyssal Xylo-
phaga (Pholadidae, Bivalvia). Gal-
athea Kept. 5: 163-209, fig. 1-41,
3 tables.
Kuhnelt, Wilhelm

1951. Contributions a la connaissance de
I'endofaune des sols marins durs:
Annee Biologique, ser. 3, 27(7):
513-523.
Lamarck, J.B.P.A. de M. de

1818. Histoire naturelle des animaux
sans vertebres, .... Tome cinqui-
eme. d'Abel Lanoe, Paris, [4] +
612 pp.
Lamy, Edouard

1921. Sur quelques pholades figurees
par Valenciennes. Bull. Mus. Natl.
d'Hist. Nat., ser. 1, 27(2): 178-183.

1925-1926. Revision des Pholadidae vi-
vants du Museum National d'His-
toire Naturelle de Paris. Jour.
Conchyl. 69(1): 19-51, fig. 1-2 [5
July 1925];. (2): 79-103 [10 Oct.
1925]; (3): 136-168, 3 figs. [31 Jan.
1926]; (4): 194-222 [15 May 1926].

Leach, W.E.

1852. MoUuscorum Britanniae synopsis:
A synopsis of the MoUusca of
Great Britain, arranged according
to their natural affinities and ana-
tomical structures, ed. by J.E.
Gray. John van Voorst, London,
376 pp., 13 pis. [not seen].

Linnaeus, Carl

1758. Systema naturae per regna tria
naturae. Editio decima, reformata:
Stockholm, Tomus I, Regnum
animale, 824 pp. [Facsimile re-
printed by the British Museum
(Natural History), London, 1956].

Lloyd, F.E.

1897. On the mechanisms in certain
lamellibranch boring molluscs.
Trans. New York Acad. Sci. 16:
307-316, pi. 25-26.

Loel, Wayne, and W.H. Corey

1932. The Vaqueros Formation, lower
Miocene of California. L Paleon-
tology. Univ. California Publ.,
Bull. Dept. Geol. Sci. 22(3): 31-410,
pi. 4-65. 2 maps.

Lowe, H.N.

1931. Note on the west coast Zirfaea.
Nautilus 45(2): 52-53, pi. 3, fig. 1-2.

MacNeil, F.S.

1957. Cenozoic megafossils of northern
Alaska. U.S. Geol. Surv.,. Prof.
Paper 294-C: iii + 99-126, fig. 48,
pi. 11-17.

MacNeil, F.S., J.B. Mertie, Jr., and H.A.
Pilsbry

1943. Marine invertebrate faunas of the
buried beaches near Nome, Alaska.
Jour. Paleont. 17(1): 69-96, pi.
10-16.

Manger, G.E.

1934. The geology of San Quintin Bay.
Johns Hopkins Univ. Studies Geol.
11: 273-304, pi. 21.

Mansfield, W.C.

1928. Notes on Pleistocene faunas from
Maryland and Virginia and Plio-
cene and Pleistocene faunas from
North Carolina. U.S. Geol. Surv.,
Prof. Paper 150-F: 128-140.

Martin, Bruce

WEST AMERICAN CENOZOIC PHOLADIDAE

103

1916. The Pliocene of middle and nor-
thern California. Univ. California
Publ., Bull, Dept. Geol. Sci. 9(15):
215-259.

Masuda, Koichiro, and Yoshiaki Matsushima
1969. On the bi^;alves boring into vol-
canic rock at Cape Manazuru,
Kanagawa Prefecture, Japan. Ve-
nus 28(2): 101-108, fig. 1, pi. 6.

Masuda, Koichira and Hiroshi Noda

1969. Pliocene boring shells and their
burrows from the environs of
Sendai, Japan. Trans. Proc. Palae-
ont. Soc. Japan, n.s., no. 75: 130-
135, fig. 1, pi. 14.

McCulloch, D.S.

1967. Quaternary geology of the Alas-
kan shore of Chukchi Sea, in Hop-
kins, D.M., ed.. The Bering land
bridge. Stanford Univ. Press,
Stanford, chapt. 5, pp. 91-120,
fig. 1-3, 1 table.

McLean, J.H.
1969. Marine shells of southern Califor-
nia. [Los Angeles Co. Mus. Nat.
Hist.], Sci. Ser. 24, Zool. 11:
1-104, fig. 1-54.

Meek, F.B.

1876. A report on the invertebrate Cre-
taceous and Tertiary fossils of the
upper Missouri country. U.S. Geol.
Surv. Terr. 9: Ixiv + 1-629, fig.
1-85, pi. 1-45.

Meek F.B. and W.M. Gabb

1864. Palaeontology of California. Vol-
ume 1: [Geol. Surv. Calif.], Sher-
man and Co., Philadelphia, xx +
243 pp., 32 pis.

Meredith, S.E.

1968. Notes on the range extension of
the boring clam Penitella conradi
Valenciennes and its occurrence in
the shell of the California mussel.
Veliger 10(3): 281-282, pi. 42.

Merriam, J.C.
1895. A list of type specimens in the
Geological Museum of the Univer-
sity of California, which have
served as originals for figures and
descriptions in the Palaeontology
of the State Geological Survey of

California under J.D. Whitney.
Geol. Dept., Univ. California,
Berkeley, 3 pp.
Moody, C.L.

1916. Fauna of the Fernando of Los
Angeles. Univ. California Publ.,
Bull. Dept. Geol. 10(4): 39-62,
pi. 1-2.
Natland, M.L.

1957. Paleoecology of west coast Terti-
ary sediments, in H.S. Ladd, ed..
Treatise on marine ecology and
paleoecology. Volume 2, paleoecol-
ogy. Geol. Soc. Amer., Mem. 67,
v. 2, chap. 19: 543-571, fig. 1-2,
pi. 1-6.
Nelson, R.N.

1925. A contribution to the paleontology
of the Martinez Eocene of Califor-
nia. Univ. California Publ., Bull.
Dept. Geol. Sci. 15(11): 397-466,
pi. 49-61.
Newberry, J.S.

1857. Report upon the geology of the
route. U.S. 33rd Cong., 2nd sess..
Senate Exec. Doc. no. 78 and
House Repr. Exec. Doc. no. 91,
V. 6 [Report . . . upon explorations
for a railroad route, from the Sac-
ramento Valley to the Columbia

River by H.L. Abbot], pt. 2

[Geological report], no. 1: 5-68,
fig. 1-11, pi. 1.

1861. Geological report. U.S. 36th Cong.,
1st sess.. Senate Exec. Doc. no —
[Report upon the Colorado River
of the west, explored in 1857 and
1858 .... by J.C. Ives], pt. 3:
1-154, fig. 1-27, pi. 1-3, 1-3,
maps 1-2.
Newcombe, C.F.

1914. Pleistocene raised beaches at Vic-
toria, B.[ritish] C.[olumbia]. Otta-
wa Nat. 28(8): 106-110, 1 fig.,
1 map.
Nomland, J.O.

1916. Fauna from the lower Pliocene at
Jacalitos Creek and Waltham Can-
yon, Fresno County, California.
Univ. California Publ., Bull. Dept.
Geol. 9(14): 199-214, pi. 9-11.

104

GEORGE L. KENNEDY

1917a. The Etchegoin Pliocene of middle
California. Univ. California Publ.,
Bull. Dept. Geol. 10(14): 191-254,
fig. 1-2, pi. 6-12.

1917b. Fauna of the Santa Margarita beds
in the north Coalinga region of
California. Univ. California Publ.,
Bull. Dept. Geol. 10(18): 293-326,
fig. 1-2, pi. 14-20.
Oldroyd, I.S.

1924. The marine shells of the west coast
of North America. Vol. I [Pelecy-
poda, Brachiopoda]. Stanford
Univ. Publ. Geol. Sci. 1(1): 1-247,
pi. 1-57.

Oldroyd, I.S. and U.S. Grant, IV

1931. A Pleistocene molluscan fauna
from near Goleta, Santa Barbara
County, California. Nautilus 44(3):
91-94.

Oldroyd, T.S.

1925. The fossils of the Lower San
Pedro fauna of the Nob Hill cut,
San Pedro, California. Proc. U.S.
Natl. Mus. 65(22): 1-39, pi. 1-2.

Olsson, A. A.

1961. Mollusks of the tropical eastern
Pacific particularly from the south-
ern half of the Panamic-Pacific
faunal province (Panama to Peru).
Panamic-Pacific Pelecypoda. Pale-
ont. Res. Inst., Ithaca (N.Y.),
574 pp., 86 pis.
Olsson, A. A. and Anne Harbison

1953. Pliocene Mollusca of southern
Florida with special reference to
those from north Saint Peters-
burg. Acad. Nat. Sci. Philadel-
phia, Monog. 8: vii + 1-457, pi.
1-65, maps 1-2.
Orcutt, C.R.

1889. Some notes on Tertiary fossils of
California. West Amer. Sci. 6(45):
70-71.

1921. Pleistocene beds of San Quintin
Bay, Lower California. West
Amer. Sci. 19(3): 23-24.
Orr, P.C.

1960. Late Pleistocene marine terraces
on Santa Rosa Island, California.
Bull. Geol. Soc. Amer. 71: 1113-

1119, fig. 1-8, pi. 1, 1 table.
1968. Prehistory of Santa Rosa Island.
Santa Barbara Mus. Nat. Hist.,
Santa Barbara, xxi + 253 pp., 79
figs., frontis., 34 tables.

Osmont, V.C.

1905. Areas of the California Neocene.
Univ. California Publ., Bull. Dept.
Geol. 4(4): 89-100, pi. 8-11.

Owen, Buzz, J.H. McLean, and R.J. Meyer
1971. Hybridization in the eastern Pacific
abalones (Haliotis). Bull. Los An-
geles Co. Mus. Nat. Hist., Sci. 9:
V + 1-37, fig. 1-21, frontis., map,
14 tables.

Palmer, K.V.W. and D.C. Brann

1965. Catalogue of the Paleocene and
Eocene Mollusca of the southern
and eastern United States. Part I.
Pelecypoda, Amphineura, Pterop-
oda, Scaphopoda, and Cephalop-
oda. Bull. Amer. Paleont. 48(218):
1-466, pi. 1-3.

Peck, J.H., Jr.

1960. Paleontology and correlation of the
Ohlson Ranch Formation. Univ.
California Publ. Geol. Sci. 36(4):
233-241, pi. 21, 2 tables.

DuPetit-Thouars, Abel

1846. Voyage autour du Monde sur la
Fregate la Venus, pendant les
Annees 1836-1839; Atlas de Zool-
ogie. Mollusques. Gide et C^^,
Paris, [no text] 27 pis.

Pugh, G.T.

1905. Pleistocene deposits of South Car-
olina. [? privately published],
Nashville (Tenn.), 74 pp.

Putnam, W.C.

1942. Geomorphology of the Ventura
region, California. Bull. Geol. Soc.
Amer. 53: 691-754, fig. 1-11, pi.
1-5, 1 table.

Richards, H.G.

1962. Studies on the marine Pleistocene:
Part I. The marine Pleistocene of
the Americas and Europe; Part II.
The marine Pleistocene mollusks
of eastern North America. Trans.
Amer. Philos. Soc, n.s., 52(3):
1-141, fig. 1-35, pi. 1-21, tables

WEST AMERICAN CENOZOIC PHOLADIDAE

105

1-22.
Risso, Antoine

1826. Aper9u sur I'histoire des mol-
lusques qui vivent sur les bords de
la Mediterranee boreale et des
coquilles, terrestres fluviatiles, et
marines, subfossiles, fossiles et
petrifiees, qui gisent dans les di-
verses formations des Alpes Mari-
times. Histoire naturelle des prin-
cipales productions de I'Europe
meridionale, 4: vii +1-439, pi. 1-12.
Santillan, Manuel, and Tomas Barrera

1930. Las posibilidades petroliferas en la
costa occidental de la Baja Califor-
nia, entre paralelos 30° y 32° de
latitud norte. An. Inst. Geol.
[Mexico] 5(1): 1-37, fig. 1-12, 1
map.
Say, Thomas

1819-1820. Observations on some species
of zoophytes, shells, &c. princi-
pally fossil. Amer. Jour. Sci. Arts
1(4), art. 12: 381-387 (1819); [con-
tinued in] 2(1), art. 4: 34-45 (1820).

1822. An account of some of the marine
shells of the United States. Jour.
Acad. Nat. Sci. Philadelphia 2(2):
221-248, 257-276, 302-325.
Schenck, H.G.

1927. Marine Oligocene of Oregon. Univ.
California Publ., Bull. Dept. Geol.
Sci. 16(12): 449-460, fig. 1.

1928. Stratigraphic relations of western
Oregon Oligocene formations.
Univ. California Publ., Bull. Dept.
Geol. Sci. 18(1): 1-50, fig. 1-18,
2 tables.

Schuchert, Charles
1905. Catalogue of the type specimens of
fossil invertebrates in the Depart-
ment of Geology, United States
National Museum. Bull. U.S. Natl.
Mus. 53, pt. 1: V + 1-704.
Sellards, E.H., W.S. Adkins, and F.B.
Plummer

1932. The geology of Texas. Volume I,
stratigraphy. Univ. Texas. Bull.
3232: 1-1007, fig. 1-54, pi. 1-11
[reprinted several times].
Sieverts, Hertha

1933. Beitrage zur Palaontologie des
Ostindischen Archipels. IX. Jou-
annetia cumingi (Sowerby) aus
dem Pliocan von Timor. Nebst
Bermerkungen iiber andere Arten
dieser Gattung. Neues Jahrb. f.
Mineral., Geol. u. Palao., Beil.-Bd.
71, Abt. B, Heft 2: 267-302,
fig. 1-2.
Smith, E.H.

1969. Functional morphology of PemYeZfa
conradi relative to shell-penetra-
tion. Amer. Zool. 9(3), ed. 2: 869-
880, fig. 1-7.
Smith, J.P.

1912. Geological range of Miocene inver-
tebrate fossils of California. Proc.
California Acad. Sci., ser. 4, 3(8):
161-182.

1919. Climatic relations of the Tertiary
and Quaternary faunas of the Cali-
fornia region. Proc. California
Acad. Sci., ser. 4, 9(4): 123-173,
pi. 9.
Soper, E.K.

1938. Geology of the central Santa Mon-
ica Mountains, Los Angeles Coun-
ty. California Jour. Mines Geol.
34(2): 131-180, fig. 1-15, pi. 1,
2 tables.
Soper, E.K. and U.S. Grant, IV

1932. Geology and paleontology of a
portion of Los Angeles, California.
Bull. Geol. Soc. Amer. 43: 1041-
1067, fig. 1-7.
Sowerby, G.B. [I]

1821-1834. The genera of Recent and
fossil shells. G.B. Sowerby [I],
London, v. 1, unpaginated text,
pi. 1-126 (1821-1825); v. 2, unpag-
inated text, pi. 127-262 (1825-
1834).

1834. Characters of new genera and spe-
cies of Mollusca and conchifera,
collected by Mr. Cuming. Proc.
Zool. Soc. London, 2(13): 6-8;
(15): 17-19, 21-22; (18): 46-47; (19):
68-72 [Pholadidae]; (20): 87-89;
(23): 123-128.
Sowerby, G.B., Jr.

1849. Monograph of the genus Pholas.

106

GEORGE L. KENNEDY

Monograph of the genus Triom-
phalia. Monograph of the genus
Xylophaga. Thesaurus Conchyli-
orum, or figures and descriptions
of Recent shells 2(10): 485-505, pi.
102-108.
Stanton, R.J., Jr.

1966. Megafauna of the upper Miocene
Castaic Formation, Los Angeles
County, California. Jour. Paleont.
40(1): 21-40, fig. 1-2, pi. 5-7.
Stanton, T.W.

1893. The Colorado Formation and its
invertebrate fauna. Bull. U.S.
Geol. Surv. 106: 1-288, pi. 1-45.
Stearns, R.E.C.

1871. PreUminary descriptions of new
species of marine Mollusca from
the west coast of North America.
Conch. Memoranda 7: 1-2.
Stephenson, L.W.

1941. The larger invertebrate fossils of
the Navarro Group. Univ. Texas
Publ. 4101: 1-641, pi. 1-95.

1952. Larger invertebrate fossils of the
Woodbine Formation (Cenoman-
ian) of Texas. U.S. Geol. Surv.,
Prof. Paper 242: iv + 1-226, fig.
1-8, pi. 1-59, 1 table.
Stewart, R.B.

1930. Gabb's California Cretaceous and
Tertiary type lamellibranchs.
Acad. Nat. Sci. Philadelphia, Spec.
Publ. 3: 1-314, fig. 1-5, pi. 1-17.

1946. [1947]. Geology of Reef Ridge,
Coalinga district, California. U.S.
Geol. Surv., Prof. Paper 205-C:
iii + 81-115, fig. 10-13, pi. 9-17,
tables 1-2.
Stoliczka, Ferdinand

1870-1871. Cretaceous fauna of south-
ern India. Vol. IIL The Pelecy-
poda, with a review of all known
genera of this class, fossil and
Recent. Mem. Geol. Surv. India,
Palaeont. Indica, ser. 6, 3: 1-222,
pi. 1-12 (1870); i-xxii + 223-538.
pi. 13-50 (1871).
Taki, Isao, and Katsura Oyama

1954. Matajiro Yokoyama's The Pliocene
and later faunas from the Kwanto

region in Japan. Palaeont. Soc.
Japan, Spec. Paper 2: ii + 1-68,
pi. 1-49.
Taki, Iwao, and Tadashige Habe

1955. Pholadidae in Japan: Illus. Cata-
log. Japan. Shells 2(2): 7-15, pi. 2.
Thompson, D.E.

1967. Paleoecology of the San Diego
marine Pleistocene. Unpubl. mas-
ters thesis, Dept. Biol., San Diego
State College, 100 pp., 3 figs.,
10 tables.
Trask, P.D.

1922. The Briones Formation of middle
California. Univ. California Publ.,
Bull. Dept. Geol. Sci. 13(5): 133-
174, pi. 1-8.
Tryon, G.W., Jr.

1862a. On the classification and synonymy
of the Recent species of Pholadi-
dae. Proc. Acad. Nat. Sci. Phila-
delphia 14: 191-221.

1862b. Description of a new genus and
species of Pholadidae. Proc. Acad.
Nat. Sci. Philadelphia 14: 449-451,
Ifig.

1863. Contributions towards a mono-
graphy of the order of Pholadacea,
with descriptions of new species.
—No. 2. Proc. Acad. Nat. Sci.
Philadelphia 15(3): 143-146, pi. 1,
fig. 1-3.

1865. Descriptions of new species of
Pholadidae. Amer. Jour. Conch.
1(1): 39-40, pi. 2.
Tuomey, Michael, and F.S. Holmes

1857. Pleiocene fossils of South-CaroHna.
Russell & Jones, Charleston (S.C),
xvi + 152 pp., 30 pis.
Turner, H.W.

1898. Notes on some igneous, meta-
morphic, and sedimentary rocks of
the coast ranges of California.
Jour. Geol. 6(5): 483-499, fig. 1,
pi. 13.
Turner, R.D.

1954. The family Pholadidae in the wes-
tern Atlantic and the eastern
Pacific. Part I— Pholadinae. John-
sonia 3(33): 1-63, pi. 1-34.

1955. The family Pholadidae in the wes-

I

WEST AMERICAN CENOZOIC PHOLADIDAE

107

tern Atlantic and the eastern
Pacific. Part II — Martesiinae, Jou-
annetiinae and Xylophaginae.
Johnsonia 3(34): 65-160, pi. 35-93.

1956. Additions to the Pholadidae— Part
II. Johnsonia 3(35): 188.

1962. Nettastomella japonica Yokoyama
in North America and notes on
the Pholadidae. Occas. Papers on
Mollusks 2(28): 289-308, pi. 47-53.

1966a. Implications of recent research in
the Teredinidae. Holz u. Organis-
men. Heft 1: 437-446, fig. 1-4.

1966b. A survey and illustrated catalogue
of the Teredinidae (Mollusca: Bi-
valvia). Mus. Comp. Zool., Cam-
bridge (Mass.), vii + 265 pp., 25
figs., 64 pis.

1969. Superfamily Pholadacea Lamarck,
1809, in R.C. Moore, ed., Treatise
on invertebrate paleontology. Mol-
lusca 6. Part N, Bivalvia, volume
2. Geol. Soc. Amer. and Univ.
Kansas, Law^rence (Kansas), pp.
702-741, fig. E162-E213.

1972. Xyloredo, a new teredinid-like
abyssal wood-borer (Mollusca,
Pholadidae, Xylophagainae). Bre-
viora 397: 1-19, pi. 1-6.
Turton, William

1819. A conchological dictionary of the
British Islands. John Booth, Lon-
don, iii-xxvi + 272 pp., 28 pis.
[100 figs.].

1822. Conchylia insularum Britannicar-
um. The shells of the British
Islands, systematically arranged.
Combe and Son, Leicester, and
M.A. Nattali, London, xlvii + 279
pp., 20 pi.
Upson, J.E.

1951. Former marine shore lines of the
Gaviota quadrangle, Santa Bar-
bara County, California. Jour.
Geol. 59(5): 415-446, fig. 1-3, 1
table.
Valenciennes, Achille

1846. See Du Petit-Thouars, Abel, 1846.
Valentine, J.W.

1956. Upper Pleistocene Mollusca from
Potrero Canyon, Pacific Palisades,

California. Trans. San Diego Soc.
Nat. Hist. 12(10): 181-205, fig. 1,
pi. 13.

1957. Late Pleistocene faunas from the
northwestern coast of Baja Cali-
fornia. Trans. San Diego Soc. Nat.
Hist. 12(16): 289-308, fig. 1-6,
tables 1-3.

1958. Late Pleistocene megafauna of
Cayucos, California, and its geo-
graphic significance. Jour. Pale-
ont. 32(4): 687-696, fig. 1-2, 2
tables.

1959. Pleistocene molluscan notes, II.
Faunule from Huntington Beach
area mesa, California. Nautilus
73(2): 51-57, 1 table.

1960a. Habitats and sources of Pleisto-
cene mollusks at Torrey Pines
Park, California. Ecology 41(1):
161-165, fig. 1-2, 1 table.

1960b. Pleistocene molluscan notes, 3.
Rocky coast faunule, Bahia San
Quintin, Mexico. Nautilus 74(1):
18-23, 1 table.

1961. Paleoecologic molluscan geography
of the Californian Pleistocene.
Univ. CaHfornia Publ. Geol. Sci. 34
(7): 309-442, fig. 1-16, tables 1-33.

1962. Pleistocene molluscan notes, 4.
Older terrace faunas from Palos
Verdes Hills, California. Jour.
Geol. 70(1): 92-101, fig. 1-2, 2
tables.

Valentine, J.W. and R.F. Meade

1961. Californian Pleistocene paleo-
temperatures. Univ. California
Publ. Geol. Sci. 40(1): 1-46, fig.
1-4, tables 1-4.

Vaughan, T.W.

1917. The reef-coral fauna of Carrizo
Creek, Imperial County, Califor-
nia, and its significance. U.S. Geol.
Surv., Prof. Paper 98-T: 355-386,
fig. 43-46, pi. 92-102.

Vedder, J.G. and R.M. Norris

1963. Geology of San Nicolas Island,
California. U.S. Geol. Surv., Prof.
Paper 369: vi + 1-65, fig. 1-19,
frontis., pi. 1-5, 9 tables.

Verrill, A.E. and K.J. Bush

108

GEORGE L. KENNEDY

1898. Revision of the deep-water Mol-
lusca of the Atlantic coast of North
America, with descriptions of new
genera and species. Part I.— Bival-
via. Proc. U.S. Natl. Mus. 20
(1139): 775-901, pi. 71-97.
Vincent, E.G.

1891. [1892]. Contribution a la paleon-
tologie de I'Eocene Beige. Pholadi-
dae. Mem. [Annales de la] Soc.
Royale Malacol. Belgique 26: 164-
168, pi. 4.
Yokes, H.E.

1956. Some pelecypod illustrations of the
effect of the Copenhagen decision
defining the limits of generic hom-
onymy. Jour. Paleont. 30(2): 765-
768.

1967. Genera of the Bivalvia: A syste-
matic and bibliographic catalogue.
Bull. Amer. Paleont. 51(232): 103-
394.
Wagner, F.J.E.

1959. Palaeoecology of the marine Pleis-
tocene faunas of southwestern
British Columbia. Geol. Surv.
Canada, Bull. 52: ix +1-67, fig. 1-3,
pi. 1, tables 1-20.
Waterfall, L.N.

1929. A contribution to the paleontology
of the Fernando Group, Ventura
County, California. Univ. Califor-
nia Publ., Bull. Dept. Geol. Sci.
18(3): 71-92, 1 fig., pi. 5-6.
Watts. W.L.

1900. [1901]. Oil and gas yielding forma-
tions of California. California State
Mining Bur., Bull. 19: 1-236, fig.
1-26, photogr. 1-35, fig. [map] A-M.
Weaver, C.E.

1909. Stratigraphy and paleontology of
the San Pablo Formation in middle
California. Univ. California Publ.,
Bull. Dept. Geol. 5(6): 243-269.

1942. [Dec. 31, 1943]. Paleontology of
the marine Tertiary formations of
Oregon and Washington. Univ.
Washington [Seattle] Publ. Geol.
5(1): xiii + 1-268; (2): 275-562; (3):
563-789, pi. 1-104.

1945. Stratigraphy and paleontology of

the Tertiary formations at Coos
Bay, Oregon. Univ. Washington
[Seattle] Publ. Geol. 6(2): 31-62,
pi. 1-10.

1953. Eocene and Paleocene deposits at
Martinez, California. Univ. Wash-
ington [Seattle] Publ. Geol. 7:
1-102, pi. 1, 2A-H, 3, 4A-C.
White, C.A.

1889. Invertebrate fossils from Califor-
nia, Oregon, Washington, and
Alaska. U.S. Geol. Surv., Bull. 51:
1-102, pi. 1-14. I

Whitfield, R.P. '

1885. Brachiopoda and Lamellibranchi-
ata of the Raritan Clays and
Greensand Marls of New Jersey.
U.S. Geol. Surv., Monogr. 9: xx +
1-388, fig. 1-2, pi. 1-35, map.

1902. Description of a new Teredo-like

shell from the Laramie Group.

Bull. Amer. Mus. Nat. Hist.

16(art. 6): 73-76, 1 fig., pi. 28-29.

Willett, George

1937. An upper Pleistocene fauna from
the Baldwin Hills, Los Angeles
County, California. Trans. San
Diego Soc. Nat. Hist. 8(30): 379-
404, pi. 25-26.

1937. [Jan. 25, 1938]. Report on Pleis-
tocene molluscan fauna at Capis-
trano Beach, Orange County, Cali-
fornia. Bull. So. California Acad.
Sci. 36(3): 105-107.
Wilson, E.C.

1966. Type specimens of fossil inverte-
brates in the San Diego Natural
History Museum. Trans. San Diego
Soc. Nat. Hist. 14(9): 97-132.

Wilson, E.C. and G.L. Kennedy

1967. Type specimens of Recent inverte-
brates (except Arachnida and
Insecta) in the San Diego Natural
History Museum. Trans. San Diego
Soc. Nat. Hist. 14(19): 237-279.

Wilson, LF.

1943. Geology of the San Benito Quad-
rangle, California. California Jour.
Mines Geol. 39(2): 183-270, fig.
1-30, 1 map.

Woodring, W.P. and M.N. Bramlette

WEST AMERICAN CENOZOIC PHOLADIDAE

109

1950. [Jan. 24, 1951]. Geology and pale-
ontology of the Santa Maria dis-
trict, California. U.S. Geol. Surv.,
Prof. Paper 222: iv + 1-185, fig.
1-9, pi. 1-23.
Woodring, W.P., Ralph Stewart, and R.W.

Richards

1940. [June 7, 1941]. Geology of the
Kettleman Hills oil field, Califor-
nia. U.S. Geol. Surv., Prof. Paper
195: v + 1-170, fig. 1-15, pi. 1-57.
Wright, R.H.

1972. Late Pleistocene marine fauna,
Goleta, California. Jour. Paleont.
46(5): 688-695, fig. 1-2, tables 1-3.

Yokoyama, Matajiro

1920. Fossils from the Miura Peninsula
and its immediate north. Jour.
Coll. Sci., Imp. Univ. Tokyo 39(6):
1-193, pi. 1-20.

1922. Fossils from the upper Musashino
of'Kazusa and Shimosa. Jour. Coll.
Sci., Imp. Univ. Tokyo 44(1): 1-200
+ i-viii, pi. 1-17.
Zullo, V.A.

1969. A late Pleistocene marine inverte-
brate fauna from Bandon, Oregon.
Proc. California Acad. Sci., ser. 4,
36(12): 347-361, fig. 1-39, 3 tables.

110 GEORGE L. KENNEDY

FIGURES 3-12

Bamea (Anchomasa) subtruncata (Sowerby)

Fig. 3-4. SDSNH 04276. Pleistocene, Palos Verdes Sand, Upper
Newport Bay, Orange Co., California (SDSC loc. 533).
Exterior and interior of right valve. Apophysis broken.
X3.

Fig. 5 LACMNH 2450. Pleistocene, Palos Verdes Sand, San

Pedro, Los Angeles Co. (LACMNH loc. 300). Muscle scar
pad is abnormally produced. X 1-1/2.

Fig. 6. SDSNH 62941. Recent, Alamitos Bay, Los Angeles Co.

(?). Protoplax, posterior is up. X 1-1/2.

Fig. 7 SDSNH 53165. Same. Interior of left valve. X 1.

Cyrtopleura (Scobinopholas) costata (Linne)

Fig. 8. SDSNH 04277. Pliocene, Imperial Formation, Carrizo

Creek, Imperial Co. (SDSNH loc. 51). Internal mold of
right valve with some shell remaining. X 1-1/4.

Fig. 9-10. LACMNH 2451. Pleistocene, Norfolk Formation, Virginia
Beach, Princess Anne Co., Virginia (LACMNH loc. 482).
Exterior and interior of right valve. X 1.

Cyrtopleura (Scobinopholas) sp.

Fig. 11-12. USNM 5913. "Miocene? Neeah Bay, Pugets Sound,
Oregon" [Washington]. Left valve, and dorsal view of
same specimen. Complicated "hinge" structure is charac-
teristic of Cyrtopleura s.l. X 1-1/2.

WEST AMERICAN CENOZOIC PHOLADIDAE

111

\

10

/■

( » . ... T " 4

•^s*

"-N

12

V

112 GEORGE L. KENNEDY

FIGURES 13-19

Zirfaea dentata Gabb

Fig. 13 USNM 165573. Miocene, Vaqueros Formation, north of
Coalinga, Fresno Co. (USGS loc. 4803). Exterior of left
valve. X 1.

Fig. 14-15. UCMP 31180. Miocene, San Pablo group, no locality data.
Left valve, and dorsal view of same specimen. X 1.

Zirfaea pilsbryi Lowe

Fig. 16-17. SDSNH 53166 [ex 7041]. Recent, Bolinas Bay, Marin Co.
Interior and exterior of left valve. X 1.

Fig. 18. LACMNH 2452. Pleistocene, San Pedro Sand, San Pedro,
Los Angeles Co. (LACMNH loc. 300). Exterior of left
valve. X 1.

Zirfaea sp. att. Z. pilsbryi Lowe

Fig. 19. CAS 54822. Pleistocene, Cape Blanco, Coos Co., Oregon
(CAS loc. 20). Exterior of right valve. This variety is close
to Chaceia ovoidea and to Zirfaea pilsbryi. X 1.

WEST AMERICAN CENOZOIC PHOLADIDAE

113

■ .*■ -J*^ -l /« !

13

4

^;^ -\

18

114 GEORGE L. KENNEDY

FIGURES 20-27

Chaceia ovoidea (Gould)

Fig. 20. SDSNH 04278. Pleistocene, Palos Verdes Sand, Upper
Newport Bay, Orange Co. (SDSNH loc. 0330). Interior of
right valve. X 2.

Fig. 21. SDSNH 04279. Same (SDSC loc. 537). Right valve of
stunted and deformed specimen. Dorsal extension of
callum is partially broken, ca. X 1-1/3.

Fig. 22. SDSNH 04280. Same (SDSC loc. 537). Exterior of left
valve. X 1-1/4.

Fig. 23. SDSNH 04281. Same (SDSC loc. 537). Interior of broken
right valve. Struts inside of callum are unusual. Shape of
ventral muscle scar is characteristic. X 1.

Fig. 24. SDSNH 53167 [ex 22685]. Recent, no data. Exterior of left
valve of typical specimen. X 1.

Fig. 25-26. SDSNH 53168. Recent, Carpenteria, Santa Barbara Co.
Dorsal, and ventral views of unusually complete adult
mesoplax; from specimen ca. 84 mm in length. X 2.

Fig. 27. SDSNH 40221. Recent, Seal Beach, Orange Co. Interior
of right valve. Beak protrudes past callum. X 1.

WEST AMERICAN CENOZOIC PHOLADIDAE

115

116 GEORGE L. KENNEDY

FIGURES 28-40

Penitella lorenzana (Clark)

Fig. 28-30. UCMP 33491. Oligocene, San Ramon Formation, Walnut
Creek, Contra Costa Co. (UCMP loc. 1131). Left valve,
mesoplax, and dorsal view of paratype. X 1-1/2.

Fig. 31. UCMP 30323. Same (UCMP loc. 1131). Left valve of holo-
type. X 1-1/2.

Fig. 32. CAS 54823. Oligocene, San Ramon Formation, Carquinez,
Contra Costa Co. (CAS loc. 36499). Right valve. Callum
extends beyond beak. X 1-1/4.

Penitella durhami Adegoke

Fig. 33-34. UCMP 30108. Oligocene, San Ramon Formation, Contra
Costa Co. (UCMP loc. A-4296, not A-7762). Right valve,
and dorsal view of holotype. X 1.

Fig. 35. UCMP 30102. Same (UCMP loc. A-7762). Left valve of a
paratype. Beak does not imbed in callum. Umbonal reflec-
tion appears loosely appressed. X 1-1/2.

Penitella gabbii (Try on)

Fig. 36-38. SDSNH 53169 (ex 50958). Recent, Bolinas, Marin Co.
Right valve, and dorsal and ventral views of mesoplax of
same specimen. Apophysis flattened, ca. X 1-3/4.

Fig. 39-40. SDSNH 53170 (ex 17908). Recent, Monterey Bay, Mon-
terey Co. Right valve, and dorsal view of same specimen.
Folded periostracum between valves is common. Loosely
appressed umbonal reflection is diagnostic. X 1-1/2.

WEST AMERICAN CENOZOIC PHOLADIDAE

117

■^

28

^,.

»;3fc:.™

31

' .'■• J

m

1^, vg|a

ig^l

|k,H

I'Im

i^^^

H

29

118 GEORGE L. KENNEDY

FIGURES 41-54

Penitella conradi Valenciennes

Fig. 41-43. LACMNH 2453. Pleistocene, Lomita Marl, San Pedro,
Los Angeles Co. (LACMNH loc. 435). Fig. 41-42, LACMNH
2453b: Dorsal and ventral views of adult mesoplax. Fig.
43, LACMNH 2453a: Interior of right valve. All X 2.

Fig. 44-45. LACMNH 2454. Same (LACMNH loc. 435). Dorsal view,
and exterior of left valve of same specimen. Apophysis
broken. X 2.

Penitella penita (Conrad)

Fig. 46. SDSNH 53171 (ex 22695). Recent, Anaheim Bay, Orange
Co. Exterior of left valve. Excessive callum is due to
individual boring into soft substrate. X 1-1/2.

Fig. 47-48. SDSNH 04283. Pleistocene, Palos Verdes Sand, Upper
Newport Bay, Orange Co. (SDSC loc. 533). Exterior and
interior of left valve of typical specimen. X 2.

Fig. 49. CAS 54824. Pleistocene, Palos Verdes Sand, Deadman
Island, Los Angeles Co. (CAS loc. 92). Exterior of right
valve showing extreme crowding of concentric ridges.
X 1-1/2.

Fig. 50-51. USNM 1868. Pleistocene, Palos Verdes Sand, San Pedro,
Los Angeles Co. Interior of right valve (apophysis broken),
and exterior of left valve. Lectotype of Penitella speloeum
Conrad. X 1-1/2.

Fig. 52. CAS 54831. Same as Fig. 49 (CAS loc. 92). Right valve
showing repaired injury caused by boring of neighboring
pholadid. X 1-1/2.

Fig. 53-54. SDSNH 04284. Pleistocene, Rosarito Beach, Baja Cali-
fornia, Mexico (SDSNH loc. 2531). Dorsal view showing
mesoplax, and exterior of right valve. X 1.

WEST AMERICAN CENOZOIC PHOLADIDAE

119

50

52

120 GEORGE L. KENNEDY

FIGURES 55-64

Penitellafitchi Turner

Fig. 55-56. SDSNH 04186. Pleistocene, Palos Verdes Sand, Upper
Newport Bay, Orange Co. (SDSNH loc. 2561). Exterior of
left valve and interior of right valve of juvenile specimen.
Bladed apophysis and rounded beak are characteristic. X 2.

Fig. 57. USNM 111401. Recent, San Diego, San Diego Co. Exterior
of right valve. Periostracal leaves missing. X 1-1/2.

Fig. 58. LACMNH A.2777. Recent, Redondo Beach, Los Angeles
Co. Exterior of right valve. Periostracal leaves are
diagnostic. X 1-1/2.

Fig. 59. SDSNH 04282. Same as Fig. 55-56 (SDSC loc. 537). Ex-
terior of broken right valve. Dorsal "bump" is distinctive.
Ca. X 1 + .

Penitella kamakurensis (Yokoyama)

Fig. 60. USNM 189802. Pleistocene, near Yakatat Bay, Alaska
(USGS loc. 15864). Left valve of paired specimen. X 1.

Penitella tumerae Evans and Fisher

Fig. 61-62. SDSNH 00200. Pleistocene, near Goleta, Santa Barbara
Co. Interior, and exterior of left valve. Apophysis, and
umbonal reflection are characteristic. X 1.

Fig. 63. LACMNH 2455. Same (LACMNH loc. 416). Exterior of
juvenile specimen left valve. Note angled anterior margin.
X 1-1/2.

Fig. 64. USNM 189803. Pliocene, Foxen Mudstone, near Guada-
lupe, Santa Barbara Co. (USGS loc. 4473). Dorsal view of
adult specimen. Mesoplax and dorsal extension of callum
are characteristic. X 1.

WEST AMERICAN CENOZOIC PHOLADIDAE

121

122 GEORGE L. KENNEDY

FIGURES 65-75

Martesia meganosensis Clark and Woodford

Fig. 65. UCMP 31297. Eocene, Meganos Formation, northeast of Mt.
Diablo, Contra Costa Co. (UCMP loc. 3577). Right valve of
juvenile holotype. X 8.

Fig. 66. UCMP 31298. Same (UCMP loc. 3159). Right valve of adult
paratype. X 3.

Martesia (Paramartesia) tolkieni Kennedy, sp. nov.

USNM 163804a. Eocene, Lodo Formation, west side of San
Joaquin Valley, Merced Co. (USGS loc. 5712). Internal mold
of right valve of adult paratype. X 2-1/2.

SDSNH 04292 [latex mold of USNM 163804bl. Same (USGS
loc. 5712). Oblique dorsal view showing mesoplax, metaplax,
and dorsal reflection of valve, of a paratype. X 3.

USNM 163804c. Same (USGS loc. 5712). Specimen showing
several paratypes. X 2.

USNM 163804d. Same (USGS loc. 5712). Ventral view of
paratype showing hypoplax (posterior is up). X 2.

Opertochasma tumerae (Hickman)

UO 27314. Oligocene, Eugene Formation, Eugene, Land Co.,
Oregon (UO loc. 2553). Dorsal view of holotype. X 5.

UO 27733. Same (UO loc. 2553). Exterior of left valve of a
paratype. X 5-6.

Parapholas calif ornica (Conrad)

Fig. 73. SDSNH 04285. Pleistocene, Point Loma, San Diego Co.
(SDSNH loc. 2419). Exterior of right valve. Disc-posterior
slope ridge and attachment lines of periostracal plates have
have eroded away. Fne anterior slope sculpture is typical.
X 1-1/2.

Fig. 74. UCMP 10608. Pleistocene, Palos Verdes Sand, Newport
Beach, Orange Co. (UCMP loc. A-3132). Dorsal view of
paired specimen. Divided mesoplax is complete. X 1.

Fig. 75. SDSNH 04291. Pleistocene, Cedros Island, Baja Cahfornia,
Mexico (SDSNH loc. 2630). Interior of left valve. Buildup of
calcium carbonate on apophysis is not uncommon. X 1.

Fig.

67

Fig.

68

Fig.

69

Fig.

70

Fig.

71

Fig.

72,

WEST AMERICAN CENOZOIC PHOLADIDAE

123

124 GEORGE L. KENNEDY

FIGURES 76-90

Nettastomella rostrata (Valenciennes)

Fig. 76. SDSNH 04286. Pleistocene, Palos Verdes Sand, Upper
Newport Bay, Orange Co. (SDSC loc. 533). Exterior of
juvenile left valve. X 4.

Fig. 77-78. SDSNH 04287. Same (SDSC loc. 533). Exterior, and
interior of right valve of adult. X 3.

Nettastomella japonica (Yokoyama)

Fig. 79-81, MCZ 229137. Recent, Masset Island, Queen Charlotte

85. Islands, British Columbia, Canada. Exterior of adult left

valve; exterior and interior of adult left valve; dorsal view

of adult specimen. Galium is larger on left valve, ca. X 2-3.

Pholadopsis pectinata Conrad

Fig. 82. USNM 495749. Pliocene, San Joaquin Formation, Kettle-
man Hills, Kings Co. (USGS loc. 12374). Exterior of adult
left valve. X 1-1/2.

Fig. 83-84. USNM 189804. Same (USGS loc. 12374). Interior and ex-
terior of juvenile right valve. X 1-1/2.

Fig. 86-87. MCZ 228109. Recent?, San Carlos Bay, near Guaymas,
Sonora, Mexico. Exterior and interior of adult left valve.
X 1-1/2.

Fig. 88. USNM 189805. Same as Fig. 83-84 (USGS loc. 12374).
Internal mold of adult left valve. X 1-1/2.

Fig. 89-90. MCZ 228109. Same as Fig. 86-87. Interior and exterior
of adult right valve. X 1-1/2.

WEST AMERICAN CENOZOIC PHOLADIDAE

125

126 GEORGE L. KENNEDY

FIGURES 91-103

"Jouannetia" sp. Clark and Woodford

Fig. 91-92. UCMP 31340. Eocene, Meganos Formation, Contra Costa Co. (UCMP loc. 3158).
Dorsal view, and right valve of unique specimen. X 2.

Parapholas sp. indet.

Fig. 93. USNM 189806. Pliocene?, near La Purisima, Baja California, Mexico (USGS loc.
9330). Posterior half of left valve, showing preserved periostracal plates. X 1-1/2.

Opertochasma clausa (Gabb)

Fig. 94. UCMP 11947. Cretaceous, Chico group, Pentz's Ranch, Butte Co. Left valve of
holotype of Martesia clausa Gabb. X 2.

Anomia peruviana d'Orbigny

Fig. 95. SDSNH 04288. Pleistocene, Palos Verdes Sand, Upper Newport Bay, Orange
Co. (SDSC loc. 533). Specimen began growth in truncated pholad burrow and
spread out on the surface. X 1.

Chama pellucida Broderip

Fig. 96. SDSNH 04289. Same (SDSC loc. 533). Growth began at right, moved down,
around, and straight up. X 1-1/4.

Ostrea lurida Carpenter

Fig. 97. SDSNH 04290. Same (SDSC loc. 533). Deformed oyster has taken shape of
pholadid burrow it inhabited. X 1-1/4.

Turnus plenus Gabb

Fig. 98. UCMP 31459. Cretaceous, "Division A" (probably Horsetown Formation),
Cottonwood Creek, Shasta Co. Left valve of lectotype. X 2.

"Martesiai?)" sp. Dickerson

Fig. 99. UCMP 10607. Paleocene, Martinez Formation, Lower Lake, Lake Co. (UCMP
loc. 784). Note similarity to Turnus [Fig. 98). X 1-3/4.

Cast of pholadid burrow

Fig. 100. CAS 54827. Pliocene, Merced Formation, Moss Beach, San Mateo Co. (CAS loc.
34437). Probably formed by Penitella penita, which was associated with this
specimen. X 1.

"Zirphaea" plana White

Fig. 101. USNM 20129. Cretaceous or Eocene, "Chico-Tejon series," Martinez, Contra
Costa Co. Right valve of holotype. X 4.

Unidentified pholadid

Fig. 102. CAS 54826. Miocene, Temblor Formation, Jasper Canyon, Fresno Co. (CAS loc.
1841). Right valve of poorly preserved paired specimen. X 1.

Burrow of Chaceia/pvoidea (Gould)

Fig. 103. CAS 54825. Pliocene?, near Oil City, Fresno Co. (CAS loc. 28485). Scratch marks
on bottom were caused by rasping action of shell. X 1.

WEST AMERICAN CENOZOIC PHOLAniDAE

127

Date Due

ACME
BOOKPINO!NG CO., INC.

NOV 28 1984

100 CAMBRIDGE STREET
C^#.RLESTOWN, MASS.

3 2044 093 SsT i"?