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SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 148, NUMBER 3
Charles B. and Mary Wanx a
Research Hund | a
| Lopy 2 OY a Io
UPPER CAMBRIAN TRILOBITE FAUNAS ~
OF NORTHEASTERN TENNESSEE
(Wit 21 PLATEs)
By
FRANCO RASETTI
The Johns Hopkins University
Baltimore, Md.
(PuBLicaTIon 4598)
CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
June 10, 1965
ty
he
SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 148, NUMBER 3
Charles B. and Mary Wanx Walrott
Research Fund
UPPER CAMBRIAN TRILOBITE FAUNAS
OF NORTHEASTERN TENNESSEE
(Wit 21 PLaTEs)
By
FRANCO RASETTI
The Johns Hopkins University
Baltimore, Md.
(PusticaTION 4598)
CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
June 10, 1965
CONNECTICUT PRINTERS, INC.
HARTFORD, CONN., U.S.A.
CONTENTS
Part I. Stratigraphy and Faunas
RRATICE Als CAPE TTIERIES arene oh Vas hav eaie etnies, Se Ree on Sie RI Aorta
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Part II. Systematic Paleontology
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Descriptions of Trilobite Genera and Species
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Charles B. and Mary Wanx Waleott Research Fund
UPPER CAMBRIAN TRILOBITE FAUNAS
OF NORTHEASTERN TENNESSEE
By
FRANCO RASETTI
The Johns Hopkins University
PART I. STRATIGRAPHY AND FAUNAS
THE PURPOSE of this paper is both to describe the fossils and to
present them in their proper stratigraphic setting. In the study of the
Cambrian of the southern Appalachians, there has been in the past
little collaboration between geologists and paleontologists. Strati-
graphic work was done by geologists who had only a secondary inter-
est in fossil collecting; on the other hand, almost all the species
described by Walcott and by Resser were derived from old collections
that bear more or less precise locality labels but no accurate indication
of the stratigraphic position. In his paper on the Cambrian of the
southern Appalachians, Resser (1938a) tried to refer the Upper
Cambrian fossils to several zones. This assignment was essentially
based on the occurrence of the genera in question in better-understood
areas of the United States, chiefly the Upper Mississippi valley, and in
a broad sense succeeded in providing an approximately correct time
order for the fossils of the southern Appalachians. However, none of
the finer details of the time succession could be determined.
The obvious procedure was therefore to locate well-exposed, rela-
tively undisturbed, fossiliferous sections, to collect fossils from care-
fully measured horizons, and to rely on these alone, and not on the old
collections, in establishing the faunal succession. Many of the previ-
ously known Upper Cambrian trilobites from Tennessee were thus
collected again from known strata; those that could not be found
seldom represent more than slightly variant forms related to the ones
of ascertained age. A number of new forms were discovered. In gen-
eral, the collections are much larger than the ones previously in ex-
istence, and provide indications on intraspecific variability in popula-
tions from a single bed and similar questions that cannot be discussed
on the basis of a few scattered specimens from different localities.
SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 148, NO. 3
2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
On the basis of published records, first a brief reconnaissance was
made of various areas of Cambrian outcrop in northeastern Tennessee
and some adjacent areas of Virginia in search for sections that might
yield the desired biostratigraphic information. Several belts of Cam-
brian outcrop did not appear promising for either one of two reasons.
For example, those north of Clinch Mountain yield a few well-exposed
sections, such as the ones at Thorn Hill, described by Hall and Amick
(1934), and at Lee Valley, described by Rodgers and Kent (1948).
However, most of these sections, with the notable exception of the one
near Washburn, hold few fossiliferous beds of the Crepicephalus and
Aphelaspis zones, and the preservation leaves much to be desired. On
the other hand, other Cambrian belts, such as those in the vicinity of
Greeneville and Morristown, yielded good fossils to the early collec-
tors, but the sections are fragmentary and poorly exposed. Several
localities were found that offered undisturbed, well-exposed, and highly
fossiliferous sections.
Upper Cambrian fossils occur in northeastern Tennessee chiefly in
the upper portion of the Maryville limestone and in the Nolichucky
formation (including the Maynardville limestone). The overlying
Copper Ridge dolomite, which seems to represent most of the Fran-
conian and Trempealeauian stages, is almost totally barren. The few
trilobites collected from this formation are mentioned by Rodgers
(1953) and Bridge (1956). No search was made in the Copper Ridge
dolomite.
Since the purpose of this paper is essentially paleontologic, no at-
tempt was made to discuss the stratigraphy and nomenclature of the
formations in question. This problem has been dealt with by Hall and
Amick (1934), Rodgers and Kent (1948), Rodgers (1953), and
Bridge (1956). The main points under discussion are whether the
Maynardville limestone should be recognized as a separate formation
or considered as the uppermost portion of the Nolichucky shale, and
where the Maynardville-Copper Ridge contact should be placed. Sev-
eral sections were measured and are described herein only in order to
precisely locate the fossiliferous beds and establish the succession of
the faunules. Questions of stratigraphic nomenclature are of secondary
importance for these purposes.
Rodgers’ geologic map of northeast Tennessee at the scale of
1:125,000 and the geologic map of the Mascot—Jefferson City zinc
district by Bridge were found exceedingly useful in searching for
possible sections and fossil localities. Dr. Charles R. L. Oder, Chief
Geologist of the American Zinc Company of Tennessee, who has been
studying the Maynardville limestone for years, showed the writer
several interesting sections.
The area under consideration is covered by recent U.S. Geological
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 3
Survey 714-minute quadrangles at the scale of 1:24,000. Localities
are always indicated herein by coordinates (x = abscissa, y = ordi-
nate) in millimeters, measured from the southeast corner of the map.
The present study has been limited to trilobites. In the Dresbachian
formations of Tennessee the brachiopods are, as usual, the next in-
vertebrate group in order of abundance. The phylum is represented
mostly by inarticulates. Recent studies, such as those by Palmer
(1954) and Bell and Ellinwood (1962) in Texas, have shown that
adequate investigation of these fossils requires extensive etching of
limestone with acetic or formic acid, since mechanical preparation
generally yields only the exterior of the shell, of scarce taxonomic
significance. It is possible that etching of large amounts of limestone
of the Aphelaspis zone—the only portion of the Upper Cambrian in
the area where brachiopods are relatively abundant—might yield
interesting results. For a number of reasons such a program was not
undertaken.
The other invertebrates observed are indeterminable echinoderm
plates, fairly common in certain beds but poorly preserved; a small
gastropod of the “Helcionella” type, and a few dendroid graptolites in
shale beds. The description of these groups of fossils would not bring
any significant contribution to paleontology.
ACKNOWLEDGMENTS
The present work was started as part of a research project under a
grant from the Penrose Bequest of The Geological Society of America.
This grant had already produced two papers (Rasetti, 1959, 1961)
on the Cambrian of the central Appalachians. When funds from this
source were no longer available, the work was continued and com-
pleted with grant No. 2829-P from the Penrose Fund of the American
Philosophical Society. The author is greatly indebted to both institu-
tions for their support.
Thanks are also due to Dr. Allison R. Palmer for valuable discus-
sions on problems of taxonomy and biostratigraphy and for communi-
cating unpublished results of his investigations in the Upper Cambrian
of the western United States; to Dr. Robert B. Neuman for strati-
graphic information ; and to Dr. Charles R. L. Oder for communicating
his unpublished measurements of sections and for accompanying the
author in some field excursions.
DESCRIPTIONS OF LOCALITIES AND SECTIONS
GENERAL STATEMENT
This part of the paper presents the stratigraphic evidence that was
used in arranging the Upper Cambrian faunules in their proper time
4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
order. Sections were measured, and are described in some detail,
whenever they yielded several faunules in unquestionable stratigraphic
succession. Descriptions of lithology are generally limited to those
indications that may be useful to a geologist in order to identify in the
field the units from which the fossils were collected. In several cases,
when the topography was not favorable to an accurate measurement
of the thickness, the section was described qualitatively, by giving the
succession of the various lithic units and an estimate of their thick-
nesses. Even in these cases the time order of the fossils collected is
certain. Sections where any kind of structural complication might
bring doubt about the sequence of the strata were never used.
The localities are indicated in the text only approximately with
respect to towns, roads, etc., since a complete list of the fossil localities
defined by coordinates on the U.S. Geological Survey topographic
maps follows.
Faunal lists given in the descriptions of the sections usually assign
to each species an indication of relative abundance (cc = very com-
mon, c = common, r = rare, rr = very rare). These indications are
missing when the collection was too small to supply significant data.
For brevity, author’s names are omitted, since all the species listed are
discussed elsewhere in this paper. An asterisk preceding the name in-
dicates the type locality for the species.
Fossil collections are all labeled with the letters cn (for Cambrian,
Nolichucky) followed by a third letter designating the horizon and a
number indicating the locality. At least for the later collections, the
same number is applied to all the collections from a given section.
As far as possible it was attempted to designate by the same letters
correlative beds in the different sections; a few discrepancies are in-
evitable since precise correlation was not always apparent at the time
when the fossils were labeled. Collections designated by cna to cne
belong to the Cedaria zone, cnk to cnn to the Crepicephalus zone, and
cno to cnx to the Aphelaspis zone.
HAWKINS COUNTY
Big Creek section, near Rogersville —The most complete and satis-
factory section of the entire fossiliferous portion of the Upper Cam-
brian was found along Big Creek, just south of U.S. Route 11-W, a
few miles east of Rogersville, Hawkins County (Burem quadrangle).
The U.S. National Museum collections contain numerous fossils from
unspecified horizons in this section; several species were described
by Walcott (1916a, 1916b) and Resser (1938a).
A section of the upper portion of the Maryville formation and the
entire Nolichucky formation were measured chiefly on the hill slopes
on the east bank of Big Creek; the rest of the Maryville formation was
added from complete sections exposed a short distance east along the
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 5
strike. This section with its numerous fossil-bearing beds represents
a standard with which partial sections studied in other areas will be
correlated. The upper boundary of the Nolichucky formation is here
set at the first appearance of dolomite beds, which at Big Creek coin-
cides with the disappearance of limestone. However, Rodgers (1953)
assigned some of the lower, noncherty dolomite beds to the upper
portion of the Nolichucky (Maynardville limestone member) rather
than to the overlying Copper Ridge dolomite. The author, without
questioning the reasons that prompted this assignment, has provision-
ally placed all the dolomite in the Copper Ridge formation because this
boundary was more readily recognized in the field. In other sections
there is an interval where limestone and dolomite beds alternate, mak-
ing the definition of the formational boundary more uncertain than
at Big Creek.
Big Creek section, measured 3 miles northeast of Rogersville,
Hawkins County, Tenn. :
Nolichucky formation Ee
ec
8. Limestone and shale; aphanitic, dark-gray, gray-weathering limestone
in thin, often nodular beds, ribboned with tan-weathering shale
or dolomite. Some crystalline lenses are fossiliferous ............... 67
Collection 66 feet above base (cnx/1) :
Cheilocephalus brachyops r
Dytremacephalus angulatus c
Dytremacephalus sulcifrons tr
Collection 42 feet above base (cnw/1) :
Aphelaspis tarda r
Dytremacephalus angulatus Cc
Collection 3-4 feet above base (cnv/1) :
Abhelaspis tarda Cc
7. Limestone and shale: similar to preceding unit, with lesser percentage
of limestone in more distinctly nodular layers ..............0ecce0e. 6
Collection 0-1 feet above base (cnu/1) :
Aphelaspis tarda Cc
Gx Shiale. tacking limestone: beds’ & 5 2is.s sisi dash sete claves a. whet els x/orsidtoncselacom cihrciens 16
5. Shale, with several limestone lenses and nodules .................00000- 10
Collection 1 foot below top (cnt/1) :
Aphelaspis arsoides r
Abhelaspis tumifrons c
Pseudagnostus communis r
Collection 4 feet below top of interval (cns/1) :
Apbhelaspis arsoides Cc
Aphelaspis tumifrons €
4. Limestone: one bed, massive, crystalline and conglomeratic, well ex-
posediacross Stream bedi leia sk iseraetavar te ercrs te eres ies repel cintetei clone Netsoralciote 1
The above portion of the section was measured on the slopes SE of a
dry creek bed at x = 182, y = 297 mm, Burem quadrangle.
3. Shale: finely fissile, with a few siltstone beds near the top .............. 40
2. Limestone: mostly very thick-bedded, light-gray, aphanitic, in part
crystalline or oolitic, with some intervals of intraformational
6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VoL. 148
Thickness
Feet
pebble conglomerate. At the base some thin beds alternating with
shale. Very sharp contact with overlying shale .............+++++0+- 156
Collection in top few inches (cnn/1) :
Blountia arcuosa r
Blountia montanensis i
Coosia alethes Cc
Coosia robusta if
Coosia, sp. undet. ig
Crepicephalus cf. convergens r
Kingstonia inflata Cc
Maryvillia arion c
Meteoraspis mutica r
Terranovella dorsalis r
Tricrepicephalus thoosa Cc
Collection from loose blocks in lower third of
interval (cnk/3) :
Blountia alexas r
Dresbachia amata r
Kingstonia inflata Cc
1. Shale: finely fissile, green or tan, with a few siltstone beds in upper-
most portion. In the lower 15 feet a few lenses of silty or crys-
talline rlimestore ree meses wets roereramccte rs cic oomeleraneenete sobs eeereieree imc emer 337
Collections in lower 15 feet both in shale and
limestone lenses (cne/1, cne/2) :
Genevievella, sp. undet. r
Kormagnostus simplex Cc
Norwoodella saffordi Cc
diotalsthickness of Nolichuckytormationlen eee eeesee ce eee 633
Maryville formation
3. Dolomite and limestone: massive, gray, gray-weathering dolomite in
lower part, grading upward to massive, gray, more coarsely crys-
talline or oolitic limestone. Fossile not rare in top 30 feet, more
common in‘top 10 feet onic: oc Je -or un neta eee fee ae eee 185
Collections made at various places (cnc/2 to cnc/5) :
Hyolithes, sp. undet. c
Bomneterrina appalachia c
Coenaspis spectabilis rr
Coosella andreas r
Genevievella, sp. undet. r
Holcacephalus praecursor r
Kormagnostus simplex Cc
Menomonia tuberculata r
Menomonia, sp. undet. r
Modocia crassimarginata c
Modocia dubia Cc
Modocia ? agatho r
Norwoodia, sp. undet. r
Tricrepicephalus, sp. undet. c
2. Dolomite: very light gray, weathering almost white ..................- 67
1. Dolomite: gray, weathering tan or dark gray .s.cso.c) + isos. eee eee 740
Dotalithicknessjon Maryville tormation. aerate eee eeeeenee 992
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 7
The following comments may be made about this section and the
contained fossils :
The Maryville formation here consists mostly of dolomite, except
in the uppermost portion which is rather pure, crystalline or oolitic
limestone. The contact of the formation with the underlying Rogers-
ville shale is very sharp. Presumably the Middle-Upper Cambrian
boundary lies somewhere within the Maryville, since the uppermost
portion holds a faunule of the Cedaria zone, of very early Dresbachian
age. The author was unable to find fossils in the lower parts of the
formation in the Rogersville area. However, a collection in the U.S.
National Museum (loc. 107x, 11 miles NW. of Knoxville) mentioned
by Walcott (1916b, p. 394) yielded the types of Asaphiscus glaber
Walcott and a species of Olenoides. These are undoubted Middle
Cambrian fossils and were certainly collected from limestone of the
Maryville formation, or at least its equivalent in the Conasauga group.
The Nolichucky formation at Big Creek and in other sections studied
in the Rogersville outcrop belt, as well as at many other localities,
consists in ascending order of four members: a shale, a limestone,
another shale, and the uppermost limestone. The lower limestone mem-
ber, although very thick and conspicuous in the present section, is
quite variable in thickness. It is essentially absent from some of the
sections north of Clinch Mountain, such as the Thorn Hill and Pur-
chase Ridge sections, and even from the section on Price School road
which is not far from Rogersville and in the same outcrop belt. At
several localities this limestone is in part of algal origin (Oder and
Bumgarner, 1961). Geologists who discussed the stratigraphy of
northeastern Tennessee generally recognized a Maynardville lime-
stone, either as a member of the Nolichucky or as a separate formation.
In the typical area, in the Maynardville quadrangle, there is essentially
one limestone succession above the shale of the lower Nolichucky, and
this was named the Maynardville limestone. It includes at least por-
tions of Crepicephalus and Aphelaspis faunizones (see discussion of
the Hurricane Hollow section). The question arises whether in areas
where the upper Nolichucky consists of two limestone units separated
by a shale, the name Maynardville should apply to this entire complex,
or to the upper limestone alone, the characteristic thin-bedded lime-
stone ribboned with shale and dolomite. Since the author’s purpose
is not to discuss stratigraphic nomenclature, the more noncommittal
attitude of assigning all the strata in question to the Nolichucky is
adopted, without implying any judgment on the validity and bound-
aries of the Maynardville limestone.
The faunules listed in the section show that the basal Nolichucky
shale holds essentially the same fossils as the uppermost Maryville
8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
limestone, indicating no considerable time interval between the deposi-
tion of the two units. In this section, younger faunules of the Cedaria
zone such as those found at several localities north of Clinch Mountain
seem to be absent, probably owing to the lack of limestone beds or
nodules in the shale. The next higher faunules occur in the lower
limestone unit, and these belong to the Crepicephalus zone. The upper,
unfossiliferous 40-foot shale unit separates the uppermost Crepiceph-
alus zone faunule from the lowest Aphelaspis zone faunule. As shown
in the later discussion of other sections, the faunules of the lower
portion of the Aphelaspis zone are here missing, while the faunules
of the upper Aphelaspis zone are well represented.
Forgey Creek.—A partial section of the Maryville and Nolichucky
formations is exposed along Forgey Creek, between Zion Hill and
Carter Valley road, in the NE. corner of the Burem quadrangle. The
uppermost beds of the Maryville hold the usual Cedaria zone fauna.
This was the easternmost locality examined.
U.S. Route 11-W, 6% miles NE. of Rogersville—Although the
section is poorly exposed here, the locality is important for the pres-
ence of unusual, highly fossiliferous red beds at the base of the Noli-
chucky shale. The best collecting locality (now deteriorated) was the
road cut on the S. side of U.S. Route 11-W at the foot of the hill
located at x = 326, y = 434, Burem quadrangle (U.S.N.M. locality
27d, author’s locality cnd/1). Good collections were also made here
in the underlying Maryville limestone, about 30 feet below the top of
the formation (cnc/1).
Yellow and pink layers, absent in other areas, begin to appear here
in the upper portion of the Maryville. The overlying Nolichucky
formation consists, for the lower 50 feet, of alternating red shale and
thick, irregular, partly lenticular beds of limestone. Each limestone
bed often presents an irregular alternation of aphanitic, brick-red or
pink limestone and coarse, yellow to light-brown calcarenite. Both
types of limestone are highly fossiliferous in places. The calcarenite is
sometimes a coquina of extremely fragmentary trilobite tests, among
which only the strong, compact pygidia of Ankoura triangularis have
escaped destruction. The red, aphanitic limestone supplies better-
preserved fossils, including numerous larval stages of trilobites. A list
of the species is given in the discussion of the faunas.
A search was made to ascertain how far along the strike these
peculiar beds extend. The red beds can be traced eastward, north of
the highway, to the south flank of the westernmost hill of Miller Ridge,
about half a mile E. of locality cnd/1. On the next hill, where the
Maryville—Nolichucky contact is well exposed, the red shale and lime-
stone have disappeared. West of locality cnd/1, the first exposure
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 9
of the formational contact occurs at a distance of about half a mile,
and no trace of red beds is present. In conclusion, the red beds prob-
ably extend for less than 1 mile along the strike. They were observed
at no other locality.
The lower limestone member of the Nolichucky is sharply defined
near this locality and has an approximate thickness of 180 feet.
One mile E. of Rogersville—A good section of the lower limestone
member of the Nolichucky was measured in a cut on the E. side of the
road leading to Bell Cemetery. The limestone is 175 feet thick; how-
ever, the lower 50 feet here alternate with shale. Good fossils were
collected about 40 feet above the lowest limestone bed (cnk/1).
Highly fossiliferous beds about 45 feet below the top of the lower
limestone member of the Nolichucky occur about 0.2 miles SW. of the
preceding locality, on the hill S. of a dirt road (loc. cnm/2). Loose
blocks on the hill slope (cnm/3) were partly derived from these beds,
partly seemingly from a higher horizon, as some hold a faunule more
similar to that found in the uppermost beds of the lower limestone.
Guntown Road.—The lower limestone member of the Nolichucky
is fairly well exposed on the E. side of the Guntown Road, about %
mile S. of Rogersville. Good collections were made from the top beds
of the lower limestone member of the Nolichucky (loc. cnn/2).
Crockett Creek.—Partial sections of the Nolichucky are exposed
on the hills S. of Crockett Creek (Pressmen’s Home quadrangle). A
good section of the lower limestone member was found near the end
of a dirt road branching off from U.S. Route 11-W near Bench Mark
SN-113. The limestone is approximately 145 feet thick. Numerous
fossils were collected from the top beds (loc. cnn/3).
Price School Road.—A partial section of the Nolichucky formation
is exposed on the east side of Price School Road (x = 99-102 mm.,
y = 475-485 mm., Bulls Gap quadrangle). Shale beds a few feet
above the top of the Maryville limestone yield Kormagnostus simplex
and Norwoodella saffordi as do the strata at the same level in the Big
Creek section. The lower limestone member of the Nolichucky, how-
ever, is here reduced to a small fraction of the thickness of 150 feet
observed in all the sections near Rogersville. It consists of about 30
feet of limestone alternating with shale. This limestone is overlain
by a thick succession of shale beds with a few, thin limestone lenses.
A lens 90 feet above the top of the limestone yielded Amiaspis? sp.;
one 140 feet above contained Coosina sp. and Crepicephalus sp.; and
one 170 feet above, Aphelaspis sp. and Glaphyraspis sp. Even though
the fossils are scarce and fragmentary, it is clear that the Crepi-
cephalus—Aphelaspis zone boundary is somewhere between 140 and
170 feet above the top of the limestone. This is in contrast with the
10 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
relationships at Big Creek and Lost Creek, where the faunizone
boundary approximately coincides with the limestone-shale contact,
and on Shields Ridge (Piedmont Road, Russell Gap), where the
boundary lies within the limestone unit. These observations indicate
that, in accordance with its erratically varying thickness, the lower
limestone member of the Nolichucky does not occupy the same time
span in different sections. Limestone units in the Nolichucky shale
are developed erratically at different levels, the only persistent one
being the characteristic “ribbon rock” at the top.
HAMBLEN COUNTY
Three Springs.—A section of the upper Nolichucky formation is
well exposed in a recent road cut on the E. shore of the Three Springs
embayment of Cherokee Reservoir (Russellville quadrangle). This
locality is in the same outcrop belt as the Big Creek section and is 14
miles distant along the strike. Unfortunately, some of the upper (May-
nardville) limestone and its contact with the Copper Ridge dolomite
are obscured by incomplete exposures and structural complications.
The section was measured in descending order (northward), starting
near an old stone bridge, where good exposures in the road cut on the
E. side of the road begin. An undetermined portion of the upper lime-
stone unit is therefore missing.
Thickness
Feet Inches
32. Limestone, in thin beds ribboned with shale or dolomite,
somewhat more shaly in lower portion ................... Not measured
Collection cnv/15, 0-5 feet above base :
Aphelaspis tarda c
Dytremacephalus angulatus r
SRSA ya Sheehy strc ida fone deecaar> eric dau ceRa en ico) Raa cer a eens eet cen 3 6
30. Shale and limestone, the latter in nodular beds ............ 4
Collection cnu/15:
Aphelaspis tarda c
29. Shale, partly slumped and poorly exposed. A prominent
lens of knobbly limestone 4 feet below top is exposed
alone irodd 524. Sea ..cdhas attamienie gee anes Eee a ee 10-30
28. Shale, with nodular limestone beds ..............--0eeeeees 14
Collection cnt/15 at top:
A phelaspis arsoides c
Aphelaspis tumifrons
Pseudagnostus communis i
Collection cnt’/15 at base:
Aphelaspis arsoides ie
Aphelaspis tumifrons cc
B/N SALE, ce bee's soe ce et peau eh eae oe ee eee 1
26. Limestone: massive, granular, with tan-weathering
Siri Gers: Mirae Sinks 2 amon ionie ec eRe Le ee ee 2
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI
25. Siltstone, with thin limestone beds and lenses .............
Collection ent’’/15:
Abhelaspis arsoides c
A phelaspis tumifrons cc
Pseudagnostus communis r
CTA ume rt Rete nk au ss eie alate Maske hia oi dete sree
Aatkamestone > massive, One, edo. hicies.<is ks ssw ies cos bees, co,b.ee
ZTE gis LET Tp Pe og ate wie a tad APN na a Re a ON
Ale Shale withothiny limestone beds 32.5 cieeeiis cs.ccleisea cc © cca
Collection cns’”/15, 2 feet above base:
Aphelaspidella macropyge
A phelaspis rotundata
Paraphelaspis vigilans
My LAmestOne > MASSIVE OME DEC) «(hc asis esi :g.ths 6a :0.diels «)sisreisiaens
19. Shale, with thin-bedded limestone ....................000-
Collection cns’/15, from limestone lenses at middle
and top of interval :
A phelaspis arses r
Aphelaspis rotundata
Paraphelaspis vigilans Cc
USleimestone + erantian tone Deduc. sasrinccs cet arincick cee ss <
fee LESEOTIE P= creh eS aioe A ha leek a caus wats Sais aoetiosels oie hed w0 aie we
ie: Mimestotie Massive: etamtlare. of i550 oerdie scfe aida aw odie cscte «
15. Shale, with some thin siltstone and limestone beds ..........
Collection cns/15, 5 feet below top:
Aphelaspis camiro c
Aphelaspis laxa r
A phelaspis quadrata c
Aphelaspis washburnensis r
Aphelaspis, sp. undet. r
14° Limestone conglomerate: one bed .......+...ss<4-a+ss000e
13. Shale, with a few thin limestone beds and lenses ...........
Collection cnr’/15, 2 feet below top:
Aphelaspis laxa Cc
12. Limestone: one bed, partly conglomerate ..................
11. Shale, with a few, thin limestone beds ....................
Collection cnr/15, 8 inches below top:
A phelaspis walcotti cc
Glaphyraspis declivis Cc
Glaphyraspis oderi c
10. Limestone: one bed of irregular thickness .................
ale hee Pee oe eae oS ee He ER RU a ae CO en We, Os
8. Limestone: one bed of irregular thickness, partly conglomerate
7. Shale, finely fissile
6. Limestone: silty, granular, one bed
5. Shale with thin siltstone and limestone beds, partly lenticular
Collection cnq/15, 6 inches below top:
Aphelaspis minor cc
Glaphyraspis ornata r
eee eee ere eee eee eee see eee ereeeesesreseses
Ce ry
11
Thickness
Feet Inches
Zz
3
1
6
4
2
5
1 2
2 5
1
9
5
10
5
1 6
2-4
2
1
2 8
6-7
4 8
12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Thickness
Feet Inches
Collection cnp’/15, 1 foot below top:
Aphelaspis lata c
Aphelaspis walcotti c
Collection cnp/15, 2 feet below top:
A phelaspis lata cc
Collection cno/15, 3-4 feet below top:
A bhelaspis buttst cc
Coosella perplexa :
Glaphyraspis parva cc
4. Limestone: 4 beds several inches thick, separated by shale
ATIGUSILESTOTIO) 2s o's cie cis aie wiciersinss (ove wcrorsions is meee mire ieistieie sie 3 4
3. Shale, siltstone, and limestone: one 3-inch limestone bed in
mirddles Gh Mhit™ ccc s cea dens bsu sean ashnee en enemies red 5 =
Collection cnn/15 from loose pieces at foot of cliff,
presumably derived from this or preceding unit:
Amuaspis, sp. undet.
Coosia alethes
Crepicephalus, sp. undet.
Terranovella dorsalis
2. Limestone conglomerate: one bed, well exposed near road .... 5-7
1. Shale, siltstone, and limestone in part conglomerate, alter-
nating as in preceding units, underlain by massive lime-
stone. This part of the section was not measured as it
yielded no fossils, and change in dip affects its lower
portion.
As it can be seen from the faunal lists, this section offers one of
the most complete successions of Aphelaspis zone faunules observed
anywhere. Noteworthy is the collection cno/14 at the base of the
Aphelaspis zone, yielding Coosella, a genus more characteristic of the
Crepicephalus zone, associated with Aphelaspis buttsi, so far known
only from this locality in Tennessee, where it is believed to be the
oldest species of the genus. Equivalent beds will be described from
the Russell Gap section.
GRAINGER COUNTY
Smith Hollow.—A continuous section of the upper portion of the
Nolichucky formation is exposed in a road cut at Smith Hollow,
Luttrell quadrangle. The writer is indebted to Dr. Oder for leading
him to this locality and supplying measurements of the section. Collec-
tions at various levels were made by Dr. Oder and the author. A brief
description of the section in descending order follows.
The uppermost part of the Nolichucky is the usual limestone in thin
beds, ribboned with shale or dolomite, alternating with minor shale
intervals. This suit is approximately 150 feet thick.
Oder’s collection No. 14A, about 80 feet below top of unit:
Abhelaspis tarda
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 13
Oder’s collection No. 14, a short distance below the preceding:
A phelaspis arsoides
Aphelaspis tumifrons
The above unit is underlain by a thick shale interval with minor
siltstone, limestone, and limestone conglomerate layers. Some of the
limestone beds are lenticular. The base of this shale rests on massive
limestone as in the sections of the Rogersville area. The thickness of
the limestone cannot be accurately measured but seems to be much
less than in the vicinity of Rogersville.
The following collections were all made from thin limestone beds
in the shale unit.
Collection cns/16 (= Oder’s collection No. 13),
about 100 feet below top of shale:
A phelaspis camiro c
Aphelaspis laxa 3
Aphelaspis quadrata c
Collection cnq/16, about 2 feet below the preceding :
A phelaspis walcotti
Glaphyraspis ornata
Glaphyraspis declivis
Collection cnr/16, about 2 feet below the preceding:
Aphelaspis walcotti cc
Glaphyraspis ornata r
Collection cnn/16, about 145 feet below top of shale:
Amuaspis erratica
Amuaspis obsolescens
Coosia alethes
Crepicephalus buttsi
This section affords a good sequence of Aphelaspis faunules and
confirms the order of the species of this genus observed in other sec-
tions. The lowest faunule belongs to the Crepicephalus zone. It is
notable for the presence of the genus Amiaspis.
Thorn Hill—tThe Nolichucky formation exposed in the Thorn Hill
section, measured by Hall and Amick, is not particularly fossiliferous.
The author collected from limestone beds interstratified with shale in
the lower portion of the formation (Cedaria zone, loc. cnd/13) the
following species:
Cedaria tennesseensis
Kormagnostus simplex
Menomonia, sp. undet.
Norwoodella walcotti
Washburn.—A richly fossiliferous and excellently exposed section
of the beds of the Aphelaspis zone was measured in a cut of the
Southern Railway about a mile north of Washburn. The locality is in
14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
the Dutch Valley quadrangle, in the same outcrop belt as the Thorn
Hill section studied by Hall and Amick, at a distance of 10 miles along
the strike. The beds dip 42°-45° S. The Nolichucky—Copper Ridge
contact is exposed in a ravine on the E. side of the railroad and seems
to be rather gradational, the dolomite content increasing upward
Only the basal part of the upper (Maynardville) limestone member
of the Nolichucky is exposed in the railroad cut, the best exposures
being on the E. side. Below the limestone, every bed to the base of the
A phelaspis zone is visible.
ee
eet
16. Limestone, ribboned with shale and dolomite, rather poorly exposed
in ravine; only lowest 6 feet exposed in railroad cut ................ 70
Collection cnx/20, 2-6 feet above base:
Abhelaspis tarda cc
MER Salley (oe eae ic Bian ais <ia'n , acavea 2 ial cone Bib. ae SPOTS EA OTC en eee 5
14, Limestone, ribboned with shale and dolomite ...................00000: 21
Collection cnw/20, 4-7 feet below top:
Aphelaspis punctata Cc
*A phelaspis tarda cc
Cheilocephalus brachyops r
Dunderbergia tennesseensis ie
TSi Shale, dinely Missiles. cass, Sac chs the sd Sides se Ae RO ee ee ee 12
12. Shale, with thin limestone beds and lenses .............-..ccceccececes 16
Collection cnt’/20, 8 feet above base:
Aphelaspis arsoides Cc
Aphelaspis tumifrons cc
Pseudagnostus communis Cc
Collection cnt/20, 2 feet above base:
Aphelaspis tumifrons Cc
Pseudagnostus communis r
Il. Shale: finely fissile; lacking limestone beds’... /:.....2.0eesce ee eee 14
10. Shale, with thin limestone beds and lenses; one thick limestone bed
At: Bases 5s iiz aiere His dois, e oeeliclow fete as Sa ee a en 10
Collection cns/20, 0-4 feet below top:
A phelaspidella macropyge c
Aphelaspis arses c
*A phelaspis rotundata Cc
*Paraphelaspis vigilans c
9. Shale: finely fissile, lacking limestone beds ..............eceececceeeces 9
8.) Shale; with’ thin: limestone letises 42.7.0. 42,0 .00 eet ee 2
Collection cnr’/20:
Aphelaspis camiro Cc
Aphelaspis laxa c
Aphelaspis quadrata Cc
Glaphyraspis oderi r
7. Shale: finely fissile, lacking limestone beds ............ecececcucececcee 5
6. Shale, with thin limestone beds and lenses ; a few limestone beds up to
4-5 inelies/thick,-one-at top: .’ 2.) . sa.(oce leas ee eee 22
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 5
Thickness
Feet
Collection cnr/20 in thin lenses in top 1 foot:
Aphelaspis camiro c
Aphelaspis laxa r
A phelaspis quadrata c
Collection cnq’/20 in thin bed 2% feet below top:
*A phelaspis washburnensis
A phelaspis, sp. undet.
Aphelaspidella macropyge
Glaphyraspis declivis
Collection cnq/20 in thin beds and lenses, 10-14 feet above base:
Aphelaspis walcotti cc
Glaphyraspis oderi c
Collection cnp’/20, in thin beds and lenses 6-8 feet above base :
A bhelaspis minor c
Glaphyraspis oderi r
Collection cnp/20 in lenses and nodules 1-4 feet above base:
Aphelaspis lata cc
Cheilocephalus brevilobus if
5. Limestone: in rather thick beds, with some shale intervals .............. 7
42 Shale-and: thin=bedded TimeStOne® 2 Sasi aisles clés des i stale one sta 2 0% wwe ce melee 5
Collection cnn/20, 1 foot above base:
Crepicephalus, sp. undet.
Terranovella dorsalis
3. Limestone: in rather thick beds, with some shale intervals .............. 6
2. Shale, siltstone, and thin-bedded limestone. Unit extends almost to
northern endior railroad: Cutts tse. coe durtya tt oo eke otis to dare Meta a hows 27
Collection cnm’/20, 314 feet below top:
*Amiaspis obsolescens
Coosia alethes
Collection cnm/20, 11 feet below top:
Kingstonia inflata
The Washburn section supplies one of the most complete successions
of Aphelaspis faunules observed in Tennessee, and is probably un-
equaled in the number of fossils of the Aphelaspis zone. The trilobites
are mostly well preserved, including the extremely numerous larval
stages of Aphelaspis present in collection cnw/20 (pl. 20, fig. 1).
JEFFERSON COUNTY
The Nolichucky formation is partly exposed near the crest of
Shields Ridge, in the New Market and Jefferson City quadrangles.
Three localities yielded important fossils and information about the
faunal succession.
New Market-Piedmont Road.—The Nolichucky formation is in-
completely exposed along the road on the N. and S. slopes of Shields
Ridge. The top of the lower limestone unit crops out where the road
crosses the summit. This locality yielded numerous trilobites to early
16 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
collectors, and several of the fossils in the U.S. National Museum
collections were used as types by Walcott and Resser (U.S.N.M.
locality 120). In these early collections fossils from the Crepicephalus
and Aphelaspis zones were indiscriminately mixed. Bridge (1956)
gave a description of the section in which, however, many intervals
were stated to be covered. His collection No. 2804, from which the
new species Aphelaspis bridgei is described herein, was made at this
locality.
The general lithology of the Nolichucky is very similar to that
described for the Rogersville Big Creek section. Thicknesses were not
measured because of the unfavorable topography and incomplete expo-
sures. The lower Nolichucky shale is followed by a massive limestone
unit that bears fossils at least in its upper portion. Fossils of the
Crepicephalus zone occur (loc. cnn/5) 30-40 feet below the top of the
limestone (Tricrepicephalus thoosa, Meteoraspis sp.). However, the
top of the massive limestone belongs in the Aphelaspis zone. Crystal-
line lenses in aphanitic limestone in the uppermost 1 foot of the unit,
as well as limestone lenses in the lower few feet of the overlying shale,
yielded collection cns/2. The species observed are:
*A phelaspis arsoides c
*A phelaspis inermis
Aphelaspis tumifrons cc
Cheilocephalus, sp. undet. r
Pseudagnostus communis r
Comparison with the faunules of the Big Creek, Three Springs, and
Washburn sections indicates that the above faunule is fairly high in
the middle portion of the Aphelaspis zone. The U.S. National Museum
collection 120 includes the types of Aphelaspis camiro, A. laxa, and
A. quadrata which, as it appears from other evidence, are somewhat
older than the species listed above. Collection 2804 of the U.S. Geo-
logical Survey yielded the types of Aphelaspis bridget, unknown from
other localities. Its association with Blountia bristolensis and Glaphyr-
aspis ornata, species that were found only in the basal beds of the
Aphelaspis zone at other localities, shows that this collection was
made from beds still lower than those yielding Aphelaspis camiro, A.
laxa, and A. quadrata. Unfortunately, the portion of the massive lime-
stone with interbedded shale intervals, from which all these fossils
are presumed to come, is now poorly exposed and shows only apha-
nitic, unfossiliferous beds.
The massive limestone is overlain by 40 to 50 feet of shale, the lower
portion of which contains the rare limestone lenses mentioned above.
The shale is in turn overlain by the usual limestone ribboned with
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 17
shale and dolomite. Its exposures are not extensive, and no fossils
were observed. The contact with the Copper Ridge dolomite is exposed
in a road cut on the S. slope of the ridge.
Russell Gap. —The lower limestone unit of the Nolichucky is more
favorably exposed where a dirt road crosses Shields Ridge at Russell
Gap, in the SW. corner of the New Market quadrangle. The overlying
shale is poorly exposed in a dip slope in the woods E. of the road.
The uppermost limestone is partly exposed only in a ravine E. of the
road. The best exposures of the fossiliferous upper portion of the lower
limestone unit are located near the crest of the ridge in the woods NE.
of the gap. Fossils were collected from the following beds in descend-
ing order.
Collection cnw/14.—Crystalline beds in lower portion (probably
lower 10 feet) of upper limestone unit of the Nolichucky.
These lower beds are predominantly calcareous, with little
shale or dolomite:
Aphelaspis tarda r
*Dunderbergia tennesseensis r
*D ytremacephalus angulatus Cc
*D ytremacephalus sulcifrons IT
Cheilocephalus brachyops r
Collection cnq/14.—Top 1-2 feet of lower limestone unit, under-
lying the upper shale unit, about 40-50 feet below the pre-
ceding collection. This and the underlying beds are massive,
aphanitic limestone with crystalline lenses :
Aphelaspis minor c
Blountia bristolensis e
Cheilocephalus brevilobus cc
Glaphyraspis ornata r
Collection cnp/14.—Massive limestone, about 3 feet below the
preceding, hence 4-5 feet below top of lower limestone unit:
*A phelaspis lata c
Blountia bristolensis ce
Cheilocephalus brevilobus c
Glaphyraspis ornata r
Collection cno/14.—Massive limestone, 11 feet below top:
Aphelaspis cf. lata (or butist) r
Blountia bristolensis Cc
Cheilocephalus brevilobus c
Coosella perplexa c
Glaphyraspis parva r
Tricrepicephalus, sp. undet. 5
Collection cnn/14.—Massive limestone, 14 feet below top:
Blountia, sp. undet. P
Blountiella, sp. undet. r
Coosia alethes r
Coosina, sp. undet. r
18 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Kingstonia inflata
Metearaspis, sp. undet.
Terranovella dorsalis
Tricrepicephalus thoosa
(7) en etn Yh}
Collection cnw/14 belongs to the uppermost Aphelaspis zone of
Tennessee, yielding an assemblage known from a number of sections.
The middle portion of the faunizone may be represented in the poorly
exposed shale unit. The underlying, massive limestone offers a re-
markable transition from the Crepicephalus to the Aphelaspis zone
within a few feet of beds. Collection cnn/14 contains a typical upper
Crepicephalus zone assemblage. Collection cno/14, only 3 feet higher,
still includes the typical Crepicephalus zone genera Coosella and Tri-
crepicephalus, associated with Aphelaspis and Cheilocephalus. The
specimens of Tricrepicephalus are too fragmentary to be specifically
identifiable, but the generic characters of the pygidium are unmistak-
able. An equivalent faunule was collected from the Three Springs
section, where, however, Tricrepicephalus was not found.
Lost Creek.—A partial section of the upper Nolichucky was studied
in a recent road cut near the headwaters of Lost Creek, 0.2 mile W. of
Tennessee Route 92, about 2 miles S. of Jefferson City. The lower,
massive limestone unit is partly exposed and is overlain by alternating
beds of shale, limestone, and limestone conglomerate. The exposed
section barely reaches the base of the uppermost limestone unit of the
Nolichucky. Notwithstanding the limited exposure, this locality yielded
a number of faunules in clear relative stratigraphic order. The section
is described below.
Thickness
Feet Inches
13. Limestone: massive, crystalline, banded with dolomite ...... 2
12. Shale, with small scattered limestone lenses ............... 12 0
Collection cnt/4, 0-2 feet above base:
Aphelaspis arsoides Cc
Aphelaspis tumifrons cc
Dytremacephalus angulatus Ir
Pseudagnostus communis r
11. Limestone? crystalline; one Bed. <<. cs. cence eon eee 1 0
10. Shale, with scattered limestone lenses ................-c000- 8 0
Collection cns/4, 3-4 feet above base:
Abhelaspis inermis Cc
Aphelaspis arses c
Aphelaspis camiro r
Aphelaspis laxa r
Chetlocephalus, sp. undet. iP
Pseudagnostus communis r
9. Limestone: coarsely granular, with insoluble stringers;
OME DEG Bis iad Wass ein dhobecelare veers Groin Sie eee ee 1 0
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 19
Thickness
Feet Inches
i BS] Fo Coal A RUA ts Ga PM Ee RR AL BA bs lee oe CO arr ee 5 0
7. Limestone: massive, coarsely granular, with siliceous stringers 3 6
Ga Shales withithinglimestone bedSias: ciictiecins cisios cca scene « 2 6
Collection cnr’/4 in limestone bed at top:
Aphelaspidella macropyge
Collection cnr/4 in limestone bed at base:
Aphelaspis arses r
A phelaspis cf. lata r
*A phelaspidella macropyge c
Chetlocephalus, sp. undet. r
Paraphelaspis vigilans r
=) Leimestone: coarsely, eranular, one/bed).....0....s00s+-4s60 f2
Sill eess corr naie ote oe re ere eo ore te od ha Ie waters Sasa ale b antere 2
Limestone pebble conglomerate: one bed .................-.- 1
. Shale, with limestone lenses and thin beds, especially in
Lp sCE OREO ee cS ie cts ins Seas beet aaiee es aisaraateee 18 0
Collection cnq’’/4 at top:
Aphelaspis cf. rotundata
Collection cnq’/4, 13 feet above base:
Aphelaspis cf. laxa
Collection cnq/4 in a limestone bed 8 feet above base:
Aphelaspis walcotti
Collection cnn/4 in 1l-inch limestone bed, 6 inches
above base:
Coosia alethes c
Crepicephalus, sp. undet. No. 1 r
Maryvillia arion c
Tricrepicephalus thoosa c
1. Limestone: massive, granular, aphanitic, or oolitic, poorly
bedded, with tan-weathering siliceous stringers ; incom-
Pletely GxpoOseul 352. ances se scenes seeiaein see aee es 60+
Ne Pm
ooo
Although this section is in the same outcrop belt as the Piedmont
Road and Russell Gap sections, it shows several differences. Here the
Crepicephalus zone includes all the lower, massive limestone unit and
extends a few feet above it. The overlying shale has much more inter-
bedded limestone. The earliest Aphelaspis zone faunule with Aphelas-
pis walcotti is younger than the earliest faunules observed in the
Russell Gap, Three Springs, Washburn, and Hurricane Hollow sec-
tions.
UNION COUNTY
Hurricane Hollow.—A section of the upper portion of the Noli-
chucky is exposed along the Hurricane Hollow embayment of Norris
Reservoir (Maynardville quadrangle) and was measured by Dr. C. R.
L. Oder, who showed it to the writer. The strata are exposed both
in the road cut and along the shores on both sides of the embayment.
20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Dr. Oder measured his section in the road cut, whereas the more
interesting fossils were found on the E. shore of the embayment,
where the writer measured a partial section. Difficulty was experienced
in correlating the road-cut section with the shore section, since the
strata could not be accurately traced through the intervening area.
However, all the fossils discussed herein were collected by Dr. Oder
and the author from the shore beds in unquestionable stratigraphic
order. The beds dip 25°-30° S. The section in descending order fol-
lows, beginning with the highest limestone beds below the dolomite.
Thickness
Feet Inches
12. Limestone: weathering blue-gray, mostly very massive, at
top and bottom thin-bedded, in part dolomitic ........... 20
11. Limestone: very massive, mottled with dolomite, weather-
ANeatO TOU SUTLACES) amar clenieieaje cerielsisletserteieeiietsireers 14
10. Limestone: thin-bedded, aphanitic, with tan-weathering
partings, weathering to smooth, blue-gray surfaces ...... 6
9. Limestone: crystalline, massive, with insoluble stringers
Weathering Atl TElEL imiacteiisvlesielets celeron eee 18
8. Shale and thin-bedded limestone: .« Sscuiw dae neues oe e ee oar z
Collection cnr’/17 (= Oder’s coll. No. 2) :
Aphelaspis walcotti
Blountia mimula
*Glaphyraspis declivis c
*Glaphyraspis oderi c
7. Limestone: crystalline, massive, weathering blue-gray;
basal part weathering to spongy residue ................ Z 6
6. Limestone: massive, mottled with dolomite, weathering to
rough surfaces; in lower part with regular, insoluble
SEIN GES kaaelensines outers wyere Sener RaG are Re ee eee 10
Sw Shale swithwlimestonemodulesmac a eeeeeeeeeee aceneenerie 1 4
4. Limestone: massive, mottled with dolomite, weathering to
POUCH sSUPLACESh yascatevss sens sic teketetet ate sles Meise nee etter 6
3. Shale, with limestone lenses and nodules ................... 8
Collection cnr/17, 2 feet below top:
Aphelaspis, sp. undet.
2. Limestone and shale: limestone in thin, partly lenticular
beds ; interval grades eastward to almost pure limestone .. 7
Collections cnq/17, 2% feet above base:
*A phelaspis minor Cc
Glaphyraspis ornata r
1. Limestone: mostly crystalline, massive, with a few thin-
bedded intervals. Base of unit forms bottom of ravine
On dace: SHOrG fj 35 esis ie Sevais iatassias aia eyo eras oe ate ee ea eee 18
Collection cnp/17 in thin limestone bed at top:
*A phelaspis transversa Cc
Blountia bristolensis c
Cheilocephalus brevilobus r
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 21
Collection cnn/17, in massive limestone beds 5-8 feet
below top:
Coosia, sp. undet.
Crepicephalus, sp. undet.
Tricrepicephalus, sp. undet.
The section extends into lower beds of similar lithology, with alter-
nating massive and thin-bedded limestones and shale, the latter becom-
ing more prevalent downward. Occasional very fragmentary fossils
of the Crepicephalus zone were seen in this lower, unmeasured portion
of the section.
This section, like the ones at Three Springs and Russell Gap, is
interesting for offering an Aphelaspis faunule a few feet above a
typical Crepicephalus zone faunule. The earliest Aphelaspis here is a
new species, A. transversa, closely related to A. butisi and A. lata
which are the first to appear in the two above-mentioned sections.
CLAIBORNE COUNTY
Comby Ridge.—An interesting fossil locality occurs where U.S.
Route 25-E crosses Comby Ridge (Howard Quarter quadrangle). On
the E. side of the road and creek, the lower part of the Nolichucky
formation consists of shale with numerous limestone beds and lenses.
One such lens collected by Dr. Gunnar Henningsmoen and Dr. Robert
B. Neuman yielded fossils of the Cedaria zone, some of which are
illustrated herein. The author found further fossiliferous beds, in
addition to collecting from the above-mentioned lens. Unfortunately,
the exposures are poor and some of the fossiliferous lenses are weath-
ered out of the shale, hence their stratigraphic order is not always
certain. Lenses or beds believed to occur in ascending order were
labeled cnb/10, cnd/10, and cne/10. There is a considerable thickness
of shale underlying these fossiliferous beds but overlying the Mary-
ville limestone.
The fossils are for the most part extremely fragmentary in a coarse-
grained calcarenite. The following faunules were observed.
Collection cne/10:
Cedaria tennesseensis
Kormagnostus simplex
Menomonia, sp. undet.
Norwoodella walcotti cc
Collection cnd/10:
Ankoura triangularis
Kormagnostus simplex
Norwoodella halli
Norwoodella walcotti
Lo Ya Fer)
mt! QQ) (C2) =
22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Collection cnb/10:
Ankoura triangularis
Kormagnostus simplex
Olenoides, sp. undet.
River Ridge.—A section of the uppermost part of the Nolichucky
formation (Maynardville limestone member) was measured in a deep
cut on the W. side of U.S. Route 25-E where it crosses River Ridge,
a short distance N. of the bridge on the Clinch River (Howard Quar-
ter quadrangle). At the top of the measured section are readily recog-
nizable, massive beds of dolomite that may be considered the base of
the Copper Ridge dolomite.
ae
eet
14. Dolomite: mottled, weathering to rough surface. This bed is almost
at top of exposures on west side of road; higher beds exposed on
GaSErSid Cyaan toric trwrelereleels aledale Chib See Dine ae: Se eerie 3
13. Dolomite: thick-bedded, weathering to smooth surface. This and the
overlying unit may be referred to the Copper Ridge dolomite ........ 6
D2. SALE? ccsvers 1 Hive eoajara ioe bose, eosyece aibloweuace eco Cree Ree Oe aan aoe tote rae Z
12 Dolomiteonevbed! &:<cesecieratal onde Sie scloe eheie CIO ereioe emai ee eee 2,
10. Shale: dark gray, hard, not fissile, with some interbedded dolomite
buts very: little limestone: +... so cle een in aceite aes 73
OF Shalecidarkvoray. fissilevs. coon cc One eee ee ae Se Tee 5
8. Shale: as unit 10, but containing thin limestone beds and lenses ......... 18
Collection cnv/21, 10 feet above base:
Aphelaspis tarda c
Collection cnu/21, 4 feet above base:
Abhelaspis tarda Cc
7. Shale: dark gray, fissile, with one limestone bed in middle of interval..... 3
6. Shale, alternating with thin-bedded limestone; more shaly in upper
Db ola SE Oe IRCRIG GATES OBOE ae MIG Aes ante ton eA ts Mabe cone od Be 22
Collection cnu’/21, in limestone bed at top:
Aphelaspis tarda
Sp ohale’s: finely: Ssile s,s ecnecve avasioision. casero Oe eee ee ee eae 3
4> Limestone, mibboned «with shale/or dolomite smassecoesoene tice cee 5
3; Shale, finely ‘fissile, Thickness approximate... 2... es cee eine eee 20
2. Limestone, ribboned with shale or dolomite ..............ccccccceceees 3%
1. Shale: finely fissile, only the uppermost portion exposed. Thin lime-
stone lenses present 20-25 feet below top ...........:..c00. not measured
Collection cnt/21 in limestone lenses :
Aphelaspis arsoides c
Aphelaspis tumifrons Cc
Pseudagnostus communis c
KNOX COUNTY
Copper Ridge-—Numerous Upper Cambrian fossils in the U.S.
National Museum collections were recovered from beds of the Ce-
daria, Crepicephalus, and Aphelaspis zones on the NW. slope of Cop-
per Ridge near Bull Run, south of Heiskell (Powell quadrangle).
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 23
This area appears to offer now neither the opportunity for measuring
good sections, nor plentiful fossils. A partial section of the Noli-
chucky is exposed in the cut of the Southern Railway, and some of
the material of Norwoodella walcotti illustrated herein was collected
at this locality (cnd/12). The fossils occurred in thin limestone beds
in shale, and their stratigraphic position could not be referred to
readily recognizable lithic units.
Mascot.—A partial section of the Nolichucky formation is exposed
in a road cut on the E. side of the road leading N. from Mascot to U.S.
Route 11-W. The lower limestone unit of the Nolichucky and some
of the overlying shale with thin-bedded, partly conglomeratic limestone
beds are exposed. Fossils of the Crepicephalus zone were collected
from limestone beds in shale about 5 feet above the top of the massive
limestone (loc. cnn/19).
MONROE COUNTY
Owing to flat topography, exposures are generally scarce in the
southwestern portion of the area investigated. A partial section of the
Nolichucky formation was studied by A. R. Palmer and R. H. Ray-
mond in the bluffs on the E. bank of the Little Tennessee River, near
the E. end of the bridge on U.S. Route 411. Two trilobite collections
were made. Collection U.S.G.S. 2970 is from a single bed at the top
of a 38-foot unit of thin-bedded, knobbly limestone; collection 2969
is from weathered siltstone about 45 feet higher. The author was able
to find only fossils of the upper Aphelaspis zone in the higher beds.
The U.S. Geological Survey collections are interesting because they
include 3 species not observed elsewhere. The list of species follows.
Collection 2969 :
Dytremacephalus angulatus (complete specimens )
Collection 2970:
Aphelaspidella macropyge
Aphelaspis arses
*A phelaspis palmert
Cheilocephalus, sp. undet.
*Dunderbergia longifrons
*D ytremacephalus strictus
Paraphelaspis vigilans
Collection 2970 may be correlated with collection cnr/4 from the
Lost Creek section and collection cns/20 from the Washburn section,
having in common with both Aphelaspidella macropyge, Aphelaspis
arses, Cheilocephalus sp. undet., and Paraphelaspis vigilans. Thus the
stratigraphic position of the three new species, Aphelaspis palmeri,
Dunderbergia longtfrons, and Dytremacephalus strictus, is at least
approximately determined in the middle Aphelaspis zone.
24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
PURCHASE RIDGE, SCOTT COUNTY, VIRGINIA
Although the section here discussed is outside of Tennessee, it was
deemed worth mentioning because it is close to the State line, and
occurs in the northernmost Cambrian outcrop belt in this portion of
the Appalachians.
Most of the Maryville and Nolichucky formations are exposed in
cuts on the road from Pattonsville to Clinchport, Scott County (Duf-
field quadrangle). The Nolichucky formation is mostly shale excepting
the upper (Maynardville) limestone unit. The contact with the Copper
Ridge dolomite is not well exposed. A partial section of the strata
of the Aphelaspis zone in descending order follows.
Thickness
Feet Inches
11. Limestone: in thin, often nodular beds, mostly aphanitic,
ribboned. with shalevor dolomite: <<< oss <icte aeiee sree tee «isis +
10. Limestone: similar to unit 11, but more readily weather-
ing to; separate layers’ .:cirscletcre cistern aeterele aera oieereeieis ole 13
Collection cnv’/7, one foot below top:
Aphelaspis tarda c
9. Shale, with some limestone lenses ............eeeeeecceeees 3
Collection cnv/7, 1 foot above base:
Aphelaspis tarda c
8. Limestone: thin-bedded, alternating with shale ............. 10
Fe Sale Teste chat ee aleve o eT Oe ea ee eee ele eealetencionra antes 1 4
6. Limestone: crystalline, one bed filled with trilobite frag-
MHERES eee isslaie nie SA Chico eS Me eae Te eoton tee rows 5
Collection cnu/7 :
Aphelaspis tarda cc
Dunderbergia tennesseensis Fr
5. Shale, with a) few;, thin limestone beds) ..<.4.0..00.5 occ cesie'se attere 6
4. Limestones thick=bedded sa. artcecanenicionienies cae 2
3: Shale, with; thin limestone beds: as ssa. sebeiecieee tee eee eee 5
2. Limestone sone bed. .52 Sse eae eoSeleee Geka eae 1 6
1. Shale, with some siltstone and limestone beds. Seemingly
several hundred feet thick and extending to limestones
of basal: Nolichucky'si.ho/s2 a eben eee ete not measured
Collection cnt/7 from thin limestone lens 10 feet
below top:
Aphelaspis tumifrons cc
Pseudagnostus communis c
The upper (Maynardville) limestone unit of the Nolichucky shows
the same lithology and faunal succession of the upper Aphelaspis zone
as in the Big Creek section. Fossils of the lower Aphelaspis zone could
not be found because of the unfavorable shaly lithology of the interval.
The massive lower limestone of the Nolichucky present in many other
sections is here lacking or greatly reduced. In most respects the lithol-
ogy of the Nolichucky is very similar to that described by Hall and
Amick (1934) for the Thorn Hill section.
No. 3
INDEX OF LOCALITIES
CEDARIA zone
UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI
25
Collection Quadrangle x y County Name of locality
Cne/L? ai caret Burem 325 435 Hawkins U.S. Route 11-W
eNne72 Zw bate sj VAGr SAS : Big Creek
cre (oye a a iy 172 312 Big Creek
GNC/4) Senn hin He 168 306 Big Creek
CNS, Seis 8 8 . 161 299 - Big Creek
enc/G <5..22 bbe. 3 61 181 = Rogersville
GHOIT wien ee s 437 497 « Forgey Creek
CHO AL ec See ue Hs 327 436 = U.S. Route 11-W
CHOP card. cies ‘ 343 442 LD Miller Ridge
(ott) fi en ES ae cs 179 318 <s Big Creek
ECNC/Zisrissches ine se 168 306 < Big Creek
cnb/10
end lO eases Howard Quarter 16 151 Claiborne Comby Ridge
cne/10
ene/lZ) So joes Powell 249 248 Knox Copper Ridge
ene/TS hase: Aeron oe Avondale 227 560 Grainger Thorn Hill
U.S.G.S. 2407 ... Howard Quarter = cnd/10 Claiborne Comby Ridge
WSNG:S.i2406:* es ay = cnb/10 5 Comby Ridge
CREPICEPHALUS zone
Collection Quadrangle x y County Name of locality
(cin f/f ee eee Burem 68 171 Hawkins Rogersville
enk/ Sivoo. Shes - 172 295 a Big Creek
ae “ ei (a Rogersville
GnVvA Seanugor s 68-73 171-174 § Big Creek
ENn/ Zi sc eens ss 13 127 tt Rogersville
Cnny/Sie ccs: Pressmens
Home 367 52 bed Crockett Creek
enn/AP ee ece Jefferson City 91 408 Jefferson Lost Creek
Cts er New Market 295 237, S Piedmont Road
enn/ 148 5. 3\. HE ‘ 140 191 Russell Gap
enm/15 ...-Russellville 305 260 Hamblen Three Springs
enn/15
CraraVAKG Gabonese Luttrell 353 270 Grainger Smith Hollow
enny/l Zee ee Maynardville 50 129 Union Hurricane Hollow
enn LO en Mascot 14 403 Knox Mascot
cnm/20
cnm’/20 Dutch Valley 98 266 Grainger § Washburn
cenn/20
APHELASPIS zone
Collection Quadrangle x: y County Name of locality
ens/1l—enx/T 2... Burem 180-183 290-296 Hawkins Big Creek
CHS Z ino neste New Market 292 235 Jefferson Piedmont Road
enq/4-cnt/4 ...... Jefferson City 91-94 411 Lost Creek
Cut/7=env/7 o.oo: Duffield, Va. 194 277 Scott Purchase Ridge
26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
cno/14—-cnq/14 ....New Market 138-141 190-193 Jefferson Russell Gap
CILWHL AoA a eiecc thay i . 142 188 ie Russell Gap
eno/15-cnv/15 ....Russellville 305-312 260-257 Hamblen Three Springs
enq/16-cns/16 .... Luttrell 354 271 Grainger Smith Hollow
enp/17-cnr/17 ....Maynardville 50 129 Union Hurricane Hollow
enp/20-cnx/20 ... Dutch Valley 98 266-263 Grainger Washburn
ent/21-cnv/21 .... Howard
Quarter 137 141-139 Claiborne River Ridge
U.S.G.S. 2969-70 . Vonore 144 481 Monroe Little Tennessee
River
FAUNA OF THE CEDARIA ZONE
Fossils of the Cedaria zone occur in the uppermost portion of the
Maryville limestone (only in the Rogersville area) and in the basal
part of the Nolichucky formation. At all the localities studied, an un-
fossiliferous interval in the Nolichucky shale separates the uppermost
beds carrying a Cedaria fauna from the lowermost beds holding a
Crepicephalus zone fauna. Hence assemblages transitional between
the two faunizones, as reported by Lochman and Duncan (1944)
from Montana and Palmer (1954) from Texas, have not been ob-
served.
The oldest Upper Cambrian faunule seems to be the one occurring
in the uppermost 10-30 feet of the Maryville limestone in the Rogers-
ville outcrop belt. The corresponding interval was examined at several
other localities but yielded no fossils. Collections were made at several
localities in the vicinity of Rogersville (author’s collections cnc/1 to
cnc/7 ; U.S.N.M. localities 102a, 123a). The species known from these
beds are listed below. An asterisk preceding the name indicates that
the types were collected from this area and horizon.
*Bonneterrina appalachia
*Coenaspis spectabilis
*Coosella andreas
Genevievella, sp. undet.
*Hawkinsia minuta
*Holcacephalus praecursor
Ithycephalus typicalis
Kormagnostus simplex
*Menomonia tuberculata
Menomonia, sp. undet.
*Modocia crassimarginata
Modocia dubia
*Modocia ? agatho
Norwoodella, sp. undet.
Norwoodia, sp. undet.
Tricrepicephalus, sp. undet.
The next higher faunule is especially well represented in the red
limestone beds at the base of the Nolichucky, of very limited extent
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 27
in the Rogersville area as previously discussed (author’s localities
end/1, cnd/2; U.S.N.M. locality 27d). The faunule from these beds,
excluding a few unrecognizable forms named by Resser, includes:
*Ankoura triangularis
Bonneterrina appalachia
Cedarina, sp. undet.
*Coosella resseri
Genevievella, sp. undet.
*Holcacephalus granulatus
*I thycephalus typicalis
*Kormagnostus simplex
*Loxoparia obliqua
*Menomonia prominens
*M odocia bidentata
Modocta crassimarginata
*Modocia dubia
Norwoodella saffordi
*Norwoodella rotundicollis
*N orwoodia rogersvillensis
Tricrepicephalus, sp. undet.
In the equivalent stratigraphic position in other parts of the Rogers-
ville outcrop belt, the basal beds of the Nolichucky consist of the usual
gray-green shale with rare lenses of crystalline limestone (author’s
localities cne/1, cne/2; U.S.N.M. localities 103, 124). The species
collected from these beds include:
Genevievella, sp. undet.
Kormagnostus simplex
Menomonia prominens
*Norwoodella saffordi
Outside of the immediate vicinity of Rogersville, fossils of the
Cedaria zone occur in Tennessee chiefly in the northwestern portion
of the Cambrian outcrop area, in the belts N. of Clinch Mountain
from Forked Deer Creek (Thorn Hill section) to Heiskell W. of
Knoxville. Trilobites occur at scattered localities, usually either in
shale or in a coarse, glauconitic calcarenite where most of the tests
have been ground to unrecognizable fragments. Very little information
about the faunal succession can be determined from these occurrences.
Species collected from several localities are listed below.
Seemingly the oldest Upper Cambrian fossils occur in U.S.G.S.
collection 2406 (= author’s collection cnb/10), where the following
species were identified :
Ankoura triangularis
Kormagnostus simplex
Olenotdes, sp. undet.
28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
The most striking fossil is the Olenoides, unfortunately known only
from fragmentary pygidia. Notwithstanding the presence of this pre-
dominantly Middle Cambrian genus, the abundance of Ankoura and
Kormagnostus suggests about the same age as the red beds at the base
of the Nolichucky in the Rogersville area.
Faunules collected from the Comby Ridge localities (cnd/10 =
U.S.G.S. collection 2407, cne/10), Thorn Hill (cne/13), and Copper
Ridge (cne/12) yielded:
Ankoura triangularis
Cedaria tennesseensis
Kormagnostus simplex
Menomonia, sp. undet.
Norwoodella halli
Norwoodella walcott
This faunule is presumably somewhat younger than any of those
of the Cedaria zone collected from the vicinity of Rogersville.
FAUNA OF THE CREPICEPHALUS ZONE
In all the sections studied, an unfossiliferous interval separates the
youngest observed faunule of the Cedaria zone from the oldest fossils
of the Crepicephalus zone. The lower and middle portions of the Noli-
chucky formation are in general sparingly fossiliferous, being repre-
sented either by shales with siltstone beds, or in part by the massive
lower limestone member. Only when either the shales contain fairly
pure, crystalline limestone layers, or the massive limestone is partly
replaced by a thin-bedded limestone, may well-preserved fossils be
expected. These conditions occur erratically at different localities,
hence a single section seldom supplies a succession of several faunules,
and it is difficult to place those collected in different areas in proper
stratigraphic order. In general, the beds of the Crepicephalus zone
become more fossiliferous upward, the richest in most sections being
those that just underlie the Aphelaspis zone.
Probably the earliest fossils of the Crepicephalus zone collected in
the area are those from near the base of the lower limestone member
occurring in the vicinity of Rogersville (collections cnk/1, cnk/3).
The species include:
*Blountia alexas
Blountia montanensis
*Coosella planicauda
Coosella, sp. undet.
*Crepicephalus convergens
Dresbachia amata
*Kingstonia inflata
Maryvillia arion
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 29
*M eteoraspis brevispinosa
Tricrepicephalus thoosa
Undetermined cranidium No. 2
Most of these species are represented in higher beds except Blountia
alexas and Meteoraspis brevispinosa, which were not found in the
highly fossiliferous, higher portions of the same limestone unit. Mary-
villia arion is very rare in the above faunule, whereas it becomes
abundant in higher beds.
A rather large faunule was collected near Rogersville, a short dis-
tance from locality cnk/1, in beds approximately 45 feet below the top
of the lower limestone unit of the Nolichucky, hence about 90 feet
above the beds cnk/1. At other localities no fossils were observed at
this horizon. The faunule (collection cnm/2) includes:
Blountia arcuosa
Blountia montanensts
Coosella planicauda
Coosia alethes
Coosina amage
Coosina ariston
Dresbachia amata
Kingstonia inflata
Llanoaspis walcotti
Madarocephalus laetus
Maryvillia arion
Meteoraspis mutica
Tricrepicephalus thoosa
Finally, the youngest faunule of the Crepicephalus zone is well rep-
resented at numerous localities. It occurs either near the top of the
massive lower limestone unit of the Nolichucky, or in thin limestone
beds near the base of the overlying shale. The transition between the
Crepicephalus and Aphelaspis zones may occur either within the upper
portion of the limestone unit, or within the lower part of the overlying
shale. In some sections, such as at Big Creek, it is possible that the
faunizone boundary coincides with the lithologic contact. The species
observed at localities cnn/1, cnn/2, cnn/3, cnn/4, cnn/5, cnn/14,
enn/15, cnn/16, cnn/17, cnn/19, and cnm’/20 are listed below. These
collections are lumped together, since age differences between them
appear insignificant.
Amiaspis erratica
*Amiaspis obsolescens
*Blountia arcuosa
Blountia lata
Blountia montanensis
Blountiella, sp. undet.
Coosella, sp. undet.
30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
*Coosia alethes
Coosia robusta
Coosia, sp. undet.
Coosina ariston
Coosina, sp. undet.
Crepicephalus buttst
Crepicephalus cf. convergens
Crepicephalus cf. scissilis
Crepicephalus, sp. undet. No. 1
Crepicephalus, sp. undet. No. 2
Kingstonia inflata
Llanoaspis walcotti
*Maryvillia arion
Meteoraspis mutica
Meteoraspis, sp. undet.
Pemphigaspis, sp. undet.
Terranovella dorsalis
*Tricrepicephalus thoosa
Undet. cranidium No. 1
Fossils from the U.S.N.M. localities 24m, 104, 121a, 123b, 125 and
125a were certainly all collected in the Rogersville area from the
lower limestone member of the Nolichucky formation, hence from the
horizons here designated cnk, cnm, and cnn.
FAUNA OF THE APHELASPIS ZONE
The faunal succession in the Aphelaspis zone is particularly well
developed in Tennessee and was studied in great detail in several
sections.
At some of the localities there is no gap in fossiliferous beds between
the Crepicephalus and Aphelaspis zones, hence the change from one
fauna to the other could be thoroughly investigated. It was shown in
the preceding section that the latest Crepicephalus zone faunule is
characterized by species of Coosia, Crepicephalus, Tricrepicephalus,
Blountia, and Kingstonia, in addition to Maryvillia arion and Terra-
novella dorsalis. Other genera, such as Amiaspis and Llanoaspis, are
occasionally present. At Russell Gap, a faunule that is considered to
belong in the Aphelaspis zone appears about 3 feet above the typical
Crepicephalus fauna, in a succession of massive limestone beds of
uniform lithology. This basal Aphelaspis zone faunule (loc. cno/14)
yielded several species of trilobites representing a holdover of Cre-
picephalus zone forms with the addition of new elements, which had
certainly evolved elsewhere since no possible immediate ancestors
occur in the local Crepicephalus fauna. The Crepicephalus zone genera
Tricrepicephalus, represented by an undetermined species, and
Coosella, represented by Coosella perplexa, are associated with the
typical Aphelaspis zone forms A phelaspis cf. A. lata and Cheilocephalus
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI Sil
brevilobus. Further members of the faunule are Blountia bristolensis
and Glaphyraspis parva. Blountia bristolensis was not found in the
Crepicephalus zone but is there represented by the very similar
Blountia montanensis. Glaphyraspis was not found in Tennessee below
the Aphelaspis zone. However, the author collected cranidia attributed
to G. parva in a late Crepicephalus zone faunule from northeastern
Virginia (Rasetti, 1961).
In the Hurricane Hollow section, also, an interval of a few feet
separates the uppermost Crepicephalus zone faunule from the earliest
A phelaspis zone faunule in a uniform succession of massive limestone
beds. Here, however, the only remnant of the Crepicephalus fauna is
the genus Blountia, represented again by B. bristolensis. It is asso-
ciated with Aphelaspis transversa and Cheilocephalus brevilobus.
The transition between the two faunizones is excellently shown in
the Three Springs section. Here the rock at this level is mostly shale
with thin fossiliferous limestone beds and lenses. The earliest A phel-
aspis zone faunule (loc. cno/15) is essentially the same as at Russell
Gap, holding in great abundance Aphelaspis butts: and Glaphyraspis
parva, with rare specimens of Coosella perplexa.
At all these localities, Coosella is absent from higher beds, while
Blountia and Glaphyraspis continue in association with different species
of Aphelaspis. In this portion of the section faunal changes may occur
within a few feet of beds, and very accurate determinations of the rela-
tive positions of beds and lenses are required to avoid mixing forms
that do not occur together. In the field every single lens was labeled
separately and its stratigraphic position carefully recorded. In the
Russell Gap and Three Springs sections, a characteristic faunule (locs.
cnp/14, cnp/15) including innumerable remains of Aphelaspis lata,
a close relative of A. buttsi, occurs a few feet above the faunule de-
scribed above. Associated species are Blountia bristolensis, Cheiloce-
phalus brevilobus, and Glaphyraspis ornata. This faunule is well
represented also in the Washburn section (loc. cnp/20).
In the Three Springs section, in a thin bed 1 foot higher, Aphelaspis
walcotti appears in association with A. lata. This is an unusually early
occurrence of that species which is more common in higher strata.
Still 6 inches higher, another species of Aphelaspsis, A. minor, makes
its appearance in the Three Springs section and is also common in the
equivalent position in the Russell Gap and Hurricane Hollow sections
(locs. cnq/15, cnq/14, cnq/17). Associated forms, as in the under-
lying faunule, are Blountia bristolensis, Cheilocephalus brevilobus, and
Glaphyraspis ornata.
The next higher faunule, known from a number of sections, is char-
acterized by Aphelaspis walcotti, the type species of the genus. The
32 SMITHSONIAN MISCELLANEOUS COLLECTIONS voL. 148
stratigraphic position of the type collection from Saltville, Va., is un-
known, but in Tennessee the species was found to occur always in the
same relative position to other forms of Aphelaspis, excepting the un-
usually early occurrence mentioned above. It was collected at Three
Springs (cnr/15), Smith Hollow (cnq/16, cnr/16), Lost Creek
(cnq/4), Hurricane Hollow (cnr/17 = Oder’s coll. No. 2), and
Washburn (cnq/20). Associated species are Glaphyraspis declivis,
G. oderi, and Blountia mimula, the last found only at Hurricane Hol-
low.
This is the latest known occurrence of Blountia in Tennessee. In
view of this fact and other faunal changes, it seems proper to designate
the strata so far discussed as the lower portion of the Aphelaspis zone.
The overlying beds, here assigned to the middle Aphelaspis zone,
hold various faunules characterized by several species of Aphelaspis
and related genera. These assemblages do not appear exactly in the
same order in the different sections, hence we may assume that they
are essentially of the same age. In the Washburn section, the earliest
of these faunules (collection cnq’/20) consists of Aphelaspis wash-
burnensis and Glaphyraspis declivis. This is followed by an assem-
blage of Aphelaspis camiro, A. laxa, and A. quadrata, recognized at
several localities (U.S.N.M. locality 120, Shields Ridge; cns/15,
cns’/15, Three Springs; cns/16 (= Oder’s collection No. 13), Smith
Hollow ; enr/20, enr’/20, Washburn). The Washburn section yields
from somewhat higher beds (cns/20) a very characteristic assemblage
of Aphelaspidella macropyge, Aphelaspis arses, A. rotundata, and
Paraphelaspis vigilans.
However, at Lost Creek we encounter in ascending order a bed with
rare Aphelaspis cf. laxa (cnq’/4), followed by one with A. rotundata
(cnq’/4). Above the latter are limestone beds (cnr/4, cnr’/4) with
an abundance of Aphelaspidella macropyge, accompanied by Aphelaspis
arses, Aphelaspis cf. lata, Chetlocephalus sp., and Paraphelaspis vigi-
lans. The still higher beds cns/4 yielded rare Aphelaspis camiro and
A. laxa, in addition to other species to be mentioned later. In the Three
Springs section, above a bed (cnr’/15) with Aphelaspis laxa, collec-
tion cns/15 yielded Aphelaspis camiro, A. laxa, A. quadrata, A. wash-
burnensis, and Aphelaspis, sp. undet. (the last two not associated in
the same stratum with the other three). The still higher beds cns’/15
and cns’”/15 yielded Aphelaspidella macropyge, Aphelaspis arses, A.
rotundata, and Paraphelaspis vigilans. These findings indicate that al-
though the Aphelaspis camiro—laxa—quadrata and the Aphelaspidella
macropyge—A phelaspis rotundata—Paraphelaspis vigilans assemblages
were never observed in the same bed, each may occur either below or
above the other.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 33
An approximate equivalent of the last-mentioned assemblage is the
one collected from Monroe County (U.S.G.S. collection 2970) with
Aphelaspidella macropyge, Aphelaspis arses, A. palmeri, Chetloceph-
alus, sp., Dunderbergia longifrons, Dytremacephalus strictus, and
Paraphelaspis vigilans.
In Jefferson County, lenses at the previously mentioned locality
cns/4 also yield Aphelaspis arses and A. inermis, both also present in
collection cns/2, accompanied by Cheilocephalus sp. and Pseudagnostus
communis.
Above these faunules appears a widespread assemblage characterized
in all sections where it is known by innumerable examples of Aphel-
aspis tumifrons. It was collected from Big Creek (cns/1, cnt/1), Lost
Creek (cnt/4), Shields Ridge (cns/2), Three Springs (cnt/15,
ent’/15), Smith Hollow (Oder’s coll. No. 14), Washburn (cnt/20,
ent’/20), River Ridge (cnt/21), and Purchase Ridge, Va. (cnt/7).
Here should be mentioned the exceptional occurrence at Lost Creek
in the collection cnt/4 of very rare specimens of Dytremacephalus
angulatus, a species that becomes common in strata of the upper
Aphelaspis zone. Normal associates of Aphelaspis tumifrons are in-
stead Aphelaspis arsoides, Cheilocephalus sp., and Pseudagnostus
communis.
The beds above the Aphelaspis tumifrons faunule and up to the top
of the fossiliferous sequence, i.e., to the top of the Nolichucky forma-
tion (or Maynardville limestone), shall be assigned to the upper
Aphelaspis zone. One faunule seems to occupy this interval, covering
in the Big Creek section about 70 feet of strata, and the characteristic
species are Aphelaspis tarda and Dytremacephalus angulatus. Less
frequent and widespread are Aphelaspis punctata, Cheilocephalus
brachyops, Dunderbergia tennesseensis, and the rare Dytremacephalus
sulcifrons. This Aphelaspis tarda faunule was collected at Big Creek
(cnu/1, cnv/1, cnw/1, cnx/1l), Purchase Ridge (cnu/7, cnv/7,
cnv’/7), Russell Gap (cnw/14), Three Springs (cnu/15, cnv/15),
Smith Hollow (Oder’s coll. No. 14A), Washburn (cnw/20, cnx/20),
and River Ridge (cnu/21, cnv/21).
In Tennessee all the higher fossiliferous beds of the Nolichucky, up
to the top of the formation, have been assigned to the Aphelaspis zone,
since the faunules are very homogeneous, being dominated by species
of Aphelaspis. However, the younger of these faunules may be equiva-
lent to faunules attributed by Palmer to post-Aphelaspis zones in the
western sections (see later discussion).
It seems likely that the vertical distribution of genera and species
described above does not mean that each species only lived for the short
time span indicated by the thickness of beds through which it was
34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
collected. Two examples, the presence of Aphelaspis cf. lata at an un-
usually high horizon in collection cnr/4, and the early occurrence of
Dytremacephalus angulatus in collection cnt/4, probably indicate that
while at a given locality each species was abundant for only a very
limited time, it may have lived at different times at other places. The
inversion of the order of the Aphelaspis camiro and Aphelaspis rotun-
data assemblages, observed in two sections, even though it does not
involve a considerable thickness of strata, is another indication that
the presence or absence of a species at a certain level may have little
time significance, being determined rather by some ecologic factor, or
simply a historical accident.
Even considering these restrictions to its validity, it is clear that
the above-discussed succession of Aphelaspis faunules is the best docu-
mented in the entire Cambrian of the Appalachians and may allow the
stratigrapher to correlate new sections with great precision. As it will
be pointed out in the discussion of Aphelaspis, a species of that genus
may not be identifiable from a single individual, even if perfectly pre-
served, much less from weathered or flattened material. Fortunately,
however, the strata of the Aphelaspis zone, and especially thin, crystal-
line limestone lenses in shale, may be so fossiliferous that a small
sample of rock in many cases supplies sufficient information for the
clear recognition of one of the faunules described herein.
In view of the relatively meager knowledge of the biostratigraphy of
the Aphelaspis zone in North America and of the observed transition
between the Crepicephalus and Aphelaspis faunas, a comparison with
recent findings in other areas is of interest. A detailed study of the
distribution of genera and species of trilobites near and above the
Crepicephalus—A phelaspis zone boundary was made by Palmer (1954,
1962b) in Alabama, central Texas, and Nevada. His main conclusions,
derived from the study of the faunal succession in the Conasauga
formation at Woodstock and Cedar Bluff, Ala., and in the uppermost
part of the Hamburg limestone and the overlying Dunderberg shale at
several localities in Nevada, may be thus summarized: (1) There is a
sudden change, often occurring in a few feet of strata, from a faunule
containing trilobite genera of the Crepicephalus zone (“Crepicephalid
biofacies”) to a faunule with Aphelaspis and other trilobites of the
Aphelaspis zone (“Pterocephaliid biofacies’”). (2) This change in Ne-
vada coincides with the contact between the relatively pure, massive
Hamburg limestone and the interstratified siltstone and silty limestone
beds of the overlying Dunderberg formation. (3) Notwithstanding
the great faunal change, no appreciable hiatus is believed to be in-
volved. (4) The replacement of the Crepicephalid biofacies with the
Pterocephaliid biofacies is believed not to have been synchronous every-
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 35
where, but to have taken place earlier in the geosynclinal areas and to
have spread later toward the interior of the continental shelf. Hence
the use of the term “biofacies” rather than faunizones. (5) The upper-
most faunule attributed to the Crepicephalid biofacies at McGill, Nev.,
and a similar faunule collected at Woodstock, Ala., include Cedaria
prolifica, the type species, or related forms of Cedaria. If the inter-
pretation is correct, the type species of Cedaria would be a trilobite of
the Crepicephalus rather than the Cedaria zone.
In a second, more extensive paper on the Upper Cambrian faunas
of Nevada, Palmer (1965)? recognizes in ascending order the Aphel-
aspis, Dicanthopyge, Prehousia, Dunderbergia, and Elvinia zones, all
belonging to a Pterocephaliid “biomere.”’ The validity of some of these
zones may be limited to the Great Basin.
The observations in Tennessee show several features in common
with the faunal development in Nevada. The change from the Crepi-
cephalus to the Aphelaspts fauna is equally sudden, and the writer has
already expressed agreement with Palmer’s conclusion that most of
the trilobites of the Aphelaspis fauna have no immediate ancestors in
the Crepicephalus fauna ; hence the change occurred by immigration of
a new fauna that had been evolving elsewhere, presumably in geosyn-
clinal areas. In Tennessee the faunal change may occur either within
the lower, massive limestone member of the Nolichucky formation, or
coincide with the contact between this limestone unit and the over-
lying shale with interbedded, thin limestone beds and lenses; or it may
occur within the latter lithologic unit. In any case there is no evidence
whatever that the faunal change is associated with a hiatus.
The earliest Aphelaspis faunule observed in Tennessee has species
identical with or closely related to some of the earliest species of the
Pterocephaliid biofacies found by Palmer in Nevada. In particular,
Aphelaspis buttsi is the earliest species of the genus appearing both at
McGill, Nev., and in the Three Springs section in Tennessee. Instead,
no very close relationship appears between the youngest faunules of
the Crepicephalid biofacies observed in Nevada and Tennessee; only
the genus Coosia seems common to both. This fact might be indicative
of the presence of a hiatus in the Nevada sections.
It becomes more difficult to correlate younger faunules from Ten-
nessee with those of the Nevada sections. Several Aphelaspis species
described from Nevada, A. brachyphasis, haguei, subditus, and longts-
pina, all closely resemble species from Tennessee, but in view of the
fact that in either region species of Aphelaspis of rather different ages
* The writer is indebted to Dr. Palmer for reading the manuscript before pub-
lication.
Aphelaspis buttsi
lata
transversa
minor
walcotti
washburnensis
camiro
laxa
quadrata
rotundata
palmeri
arses
inermis
arsoides
tumifrons
tarda
punctata
Aphelaspidella macropyge
Paraphelaspis vigilans
Dytremacephalus angulatus
strictus
sulcifrons
Dunderbergia longifrons
tennesseensis
Cheilocephalus brevilobus
brachyops
sp. undet.
Coosella perplexa
Tricrepicephalus, sp. undet.
Glaphyraspis parva
ornata
declivis
oderi
Blountia bristolensis
mimula
Pseudagnostus communis
Fic. 1.—Range of trilobite species in the Aphelaspis zone of Tennessee.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI a7
may be extremely similar (e.g., in Tennessee the early species A.
walcotti resembles the late species A. tarda), not much time signifi-
cance can be attributed to such similarities. In Nevada, Palmer finds
Tumicephaius (based on a species almost identical with Aphelaspis
tumifrons) in the post-Aphelaspis, Dicanthopyge zone, species of
Dytremacephalus in the still younger Prehousia and Dunderbergia
zones, Cheilocephalus brachyops and various species of Dunderbergia
in the Dunderbergia zone. These findings might be taken to indicate
that part of the middle Aphelaspis zone and all of the upper Aphelaspis
zone of this paper are equivalent to portions of Palmer’s post-Aphel-
aspis zones in Nevada. On the other hand, these latter zones are char-
acterized by a large number of genera of Pterocephaliid trilobites
never observed in Tennessee. Hence it is difficult to decide what fauna
in Nevada is the equivalent of the youngest Aphelaspis faunule from
Tennessee, the Aphelaspis tarda faunule, which occurs in the upper-
most beds of the Nolichucky formation. Perhaps the evidence favors
equivalence to part of the Prehousia or Dunderbergia zones in Nevada.
Even in the lower part of the Aphelaspis zone several genera present
in the early Aphelaspis fauna in Alabama and Nevada were not found
in Tennessee. Conspicuous among these are Glyptagnostus and other
agnostid genera, and the Pterocephaliid genus Olenaspella, indistin-
guishable from Aphelaspis in the cranidial features but characterized
by the development of one or more pairs of marginal pygidial spines.
Apparently these trilobites are more characteristic of the geosynclinal
facies and never migrated far enough within the continental shelf to
reach northeastern Tennessee. Absence of trilobites of the geosynclinal
facies is a feature of both the Crepicephalus and Aphelaspis faunas.
The observations in Tennessee bear no evidence on the question
whether the replacement of the Crepicephalus fauna with the Aphel-
aspis fauna was simultaneous or not in different areas, since the locali-
ties studied are all within a narrow belt parallel to the margin of the
geosyncline.
In Tennessee no occurrence of Cedaria or other genera of the
Cedaria zone close to the base of the Aphelaspis zone, or even a few
hundred feet below this level, was ever observed. This fact may again
be related to the “cratonic” rather than geosynclinal environment pre-
vailing through the entire Upper Cambrian in Tennessee.
PART I SYSTEMATIC PALEONTOLOGY
GENERAL STATEMENT
Not all the species of trilobites described from the Upper Cambrian
of Tennessee are treated in this paper. With few exceptions, only those
collected by the author from measured sections and hence contributing
to the knowledge of the faunal succession are discussed herein.
Type catalog numbers and type localities for previously described
species are given only when the types are from the southern Appala-
chians.
Unless otherwise stated, all the described and illustrated specimens
are preserved in limestone, and show the outer surface of the test, on
which the description is based.
The author’s localities are often given only by their numbers in this
descriptive part; their topographic position may be readily identified
from the locality list, the stratigraphic position from the descriptions
of the sections.
All the types and other figured specimens collected by the writer
were deposited in the U.S. National Museum collections. All the Mu-
seum numbers beyond 144000 are listed in Paleozoic catalog No. 30.
DESCRIPTIONS OF TRILOBITE GENERA AND SPECIES
Order AGNOSTIDA
Family AGNOSTIDAE McCoy, 1849
Genus KORMAGNOSTUS Resser, 1938
Type species —Kormagnostus simplex Resser.
KORMAGNOSTUS SIMPLEX Resser
Plate 1, figures 8, 9
Kormagnostus simplex Resser, 1938a, p. 49, pl. 9, figs. 11-13.
Kormagnostus harlanensis Resser, 1938a, p. 49, pl. 10, figs. 11, 12.
Kormagnostus simplex Resser, PALMER, 1954, p. 718, pl. 76, figs. 8-12 (includes
complete synonymy).
Kormagnostus simplex Resser, LocHMAN and Hu, 1960, p. 822, pl. 99, figs. 5-31.
Common almost everywhere in the fossiliferous beds at the top of
the Maryville limestone and the overlying basal Nolichucky shale
(Cedaria zone).
Occurrence.—Type locality for K. simplex is U.S.N.M. 27d (=
author’s locality cnd/1) ; red beds at the base of the Nolichucky E.
of Rogersville. Type locality for K. harlanensis is U.S.N.M. locality
38
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 39
124, presumably near the top of the Maryville limestone and identical
with one of the author’s localities, cnc/2 to cnc/5. Collected by the
author at localities cnc/5, cnc/6, cnd/1, cnd/2, cne/1, cne/2, cnb/10,
end/10, cne/10, cne/13.
Types —Cotypes of K. simplex: U.S.N.M. 94842. Cotypes of K.
harlanensis: U.S.N.M. 94863. Plesiotypes figured herein: U.S.N.M.
144546.
Genus PPEUDAGNOSTUS Jaekel, 1909
Type spectes——Agnostus cyclopyge Tullberg.
PSEUDAGNOSTUS COMMUNIS (Hall & Whitfield )
Plate 10, figures 23-25
Agnostus communis Hatt and WHITFIELD, 1877, p. 228, pl. 1, figs. 28, 29.
Agnostus neon Hatt and WHITFIELD, 1877, p. 229, pl. 1, figs. 26, 27.
Pseudagnostus communis (Hall and Whitfield) Patmer, 1955, p. 94, pl. 19, figs.
16, 19-21; pl. 20, figs. 4-11, 14; 1960, p. 61, pl. 4, figs. 3, 4.
Pseudagnostus communis (Hall and Whitfield) Rasettt, 1961, p. 109, pl. 23, figs.
13-17.
A Pseudagnostus that occurs at several localities in beds of the
A phelaspis zone does not differ in any observable features from topo-
type material illustrated by Palmer. The latter is from the Dunder-
bergia zone of Nevada. The author (Rasetti, 1961) figured specimens
from the Dunderbergia zone of Maryland.
Occurrence.—Collected at localities cnt/1, cns/2, cns/4, cnt/4, cnt/7,
ens/15, cnt/15. All these collections are from the middle portion of the
Aphelaspis zone.
Types.—Plesiotypes: U.S.N.M. 144547.
Order CORYNEXOCHIDA
Family DORYPYGIDAE Kobayashi, 1935
Genus OLENOIDES Meek, 1877
Type spectes.—Paradoxides nevadensis Meek.
OLENOIDES, species undetermined
Plate 5, figures 12, 13
Available material—T wo fragmentary pygidia.
Description.—Pygidium fully typical of the genus, of the four-spined
group. Axis not preserved except for the terminal portion, almost
reaching the posterior margin. Pleural regions of low convexity. Three
pairs of pleural furrows and as many of interpleural grooves about
equally impressed, regularly curved, all becoming somewhat deeper in
the indefinite border furrow; each interpleural groove approximately
parallel to the preceding furrow but diverging from the following fur-
40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
row. Spines progressively closer to each other ; those of the first two
pairs strong, the last two progressively more slender. Spines of last
pair directed straight backward, their distance greater than between
the third and fourth pairs. Surface of test smooth.
Discussion.—This form, as far as can be ascertained from the frag-
mentary material, does not greatly differ from several Middle Cam-
brian species of the genus, such as O. curticet Walcott, and O. con-
vexus Rasetti, but is readily distinguished by the course of the pleural
furrows and the spacing of the marginal spines. The writer (Rasetti,
1946) described a Dresbachian species of the genus which, however,
has only 3 pairs of marginal spines.
Occurrence.—U.S.G.S. collection 2406 (= author’s collection
cnb/10), Comby Ridge. The species occurs in the same piece of rock
with abundant Ankoura triangularis.
Disposition of material—Figured specimens: U.S.N.M. 144548.
Order PTYCHOPARIIDA
Family LONCHOCEPHALIDAE Hupé, 1953
Genus TERRANOVELLA Lochman, 1938
Type species —Terranovella obscura Lochman.
TERRANOVELLA DORSALIS (Hall)
Plate 6, figure 7
Conocephalites? (Arionellus?) dorsalis Haut, 1863, p. 222.
Ptychoparia dorsalis (Hall) Vocpss, 1890, p. 141.
Lonchocephalus sospita Watcott, 1916a, p. 195, pl. 36, figs. 1, la.
Terranovella buttsi REssER, 1938a, p. 100, pl. 15, figs. 22-26.
Terranovella dorsalis (Hall) RaascH and Locuman, 1943, p. 234, pl. 35, figs.
3-10, 17.
Terranovella dorsalis (Hall) Rasettt, 1961, p. 118, pl. 22, figs. 7-13.
Occurrence.—Type locality for T. buttsi is U.S.N.M. 35s, near
Abingdon, Va. Collected by the author in the uppermost beds of the
lower limestone member of the Nolichucky (Crepicephalus zone) at
localities cnn/1, cnn/14, enn/15, cnn/19, and cnn/20.
Types.—Holotype of T. butisi: U.S.N.M. 94984. Plesiotype:
U.S.N.M. 144549.
Genus GLAPHYRASPIS Resser, 1937
Type species —Liostracus parvus Walcott.
GLAPHYRASPIS PARVA (Walcott)
Plate 10, figures 9-17
Liostracus parvus Waucortt, 1899, p. 463, pl. 65, fig. 6.
Glaphyraspis parva (Walcott) Ressrr, 1937, p. 12.
Raaschella occidentalis Lochman, in Locuman and Duncan, 1944, pl. 43, pl. 4,
figs. 1-5.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 41
Glaphyraspis parva (Walcott) Rasettt, 1961, p. 112, pl. 22, figs. 14-17.
Glaphyraspis parva (Walcott) LocHMAN and Hu, 1962b, p. 438, pl. 68, figs. 7-52.
A form that occurs in the transition beds between the Crepicephalus
and Aphelaspis zones is referred to the species. The cranidia are some-
what variable both in shape and ornamentation. The glabella is typically
parallel-sided, but in some individuals it is slightly tapered and pro-
portionately shorter and wider. The depth of the glabellar furrows is
also variable. The ornamentation of the type material from Yellow-
stone National Park consists of a dense, extremely fine granulation
plus scattered, larger granules. Some of the individuals from Tennessee
match this type of ornamentation; others show granules of one size,
while some are almost smooth. All these features may be found in
specimens from a single piece of rock, hence they must be ascribed to
intraspecific variability.
Occurrence.—The illustrated material is from locality cno/15,
Three Springs. Also collected at locality cno/14, Russell Gap. At both
localities it occurs below the beds yielding other species of Glaphy-
raspis.
Types.—Plesiotypes: U.S.N.M. 144550.
GLAPHYRASPIS ORNATA (Lochman)
Plate 10, figure 8; plate 11, figures 13, 14
Raaschella ornata LocHMAN, 1938, p. 82, pl. 18, figs. 6-10.
Raaschella ornata Lochman, PALMER, 1954, p. 767, pl. 98, figs. 7-9.
Glaphyraspis ornata (Lochman) RaseEtt1, 1961, p. 112.
The species is not rare in the basal beds of the Aphelaspis zone.
Complete specimens in shale collected by Dr. Oder, one of which is
illustrated herein, show that the thorax has 8 segments. The axial rings
have no nodes or spines. The pleurae are flat, straight, and uniformly
furrowed for most of their course. Near the distal end they bend back-
ward and downward and possess the peculiar ridges previously ob-
served in the pygidium.
Occurrence.—Author’s localities cnp/14, cnq/14, cng/15, cnq/16,
enr/16, cnq/17. Also in Oder’s collection No. 3 at Hurricane Hollow
and U.S.G.S. collection 2804 on Shields Ridge.
Types.—Plesiotypes: U.S.N.M. 144551-2.
GLAPHYRASPIS ODERI Rasetti, new species
Plate 10, figures 18-22
Available material—Numerous cranidia, free cheeks, and pygidia
well preserved in limestone.
Description.—Glabella of same shape as in G. ornata; glabellar
furrows of usual pattern but exceedingly shallow on outer surface.
42 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Occipital furrow well impressed; occipital ring expanded medially,
rounded. Fixed cheeks convex, rising somewhat above axial furrow,
then downsloping. Frontal area short, about one-fifth the glabellar
length; border narrow and poorly defined by a shallow border furrow.
Ocular ridges faint, transverse in direction ; palpebral lobes narrow and
short, in advance of glabellar midpoint. Posterior area as in type
species, steeply downsloping, well furrowed. Free check with border
well defined anteriorly, poorly marked posteriorly; genal angle
rounded.
Pygidium with long axis, showing about 4 distinct rings, reaching
the posterior margin. Pleural platforms flat; border downsloping.
Pleural and interpleural furrows both well marked. Each segment has
the characteristic distal ridge as in other species.
Surface of cranidium in most of the specimens from the type locality
with scattered tubercles only in certain areas, more apparent on the
posterior portion of the fixed cheeks, almost lacking on the glabella.
Some of the cranidia appear entirely smooth, particularly among those
from collection cnq/20, and especially from the higher collection
cnr’/20. However, smooth and granulated cranidia occur on the same
piece of rock, and there are all intermediate forms.
Length of largest cranidium 3.0 mm. ; length of largest pygidium 1.8
mm.
Discussion.—This species resembles both G. parva, from which it
differs in the somewhat wider and shorter glabella, and G. ornata, from
which it can be separated by the much weaker ornamentation.
Occurrence.—The types are from Oder’s collection No. 2 at Hurri-
cane Hollow, in beds immediately overlying those with G. ornata. Also
present in collections enr/15, enp’/20, cnq/20, and cnr’/20. The spe-
cies ranges through an appreciable thickness of beds, appearing in the
Aphelaspis minor, A. walcotti, and the A. camiro, A. laxa, and A.
quadrata assemblages.
Types.—Holotype: U.S.N.M. 144553. Paratypes: U.S.N.M.
144554.
GLAPHYRASPIS DECLIVIS Rasetti, new species
Plate 14, figures 20-24
Available material—Numerous cranidia and free cheeks well pre-
served in limestone.
Description —Glabella subovate, slightly tapered, rounded in front,
rising well above the cheeks. Posterior glabellar furrows of same shape
as in G. ornata, very shallow; other pairs indistinct. Occipital furrow
moderately impressed ; occipital ring widely subtriangular, bearing an
indistinct node. Cheeks sloping down steeply from axial furrow ; frontal
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 43
area about one-fourth the glabellar length, slightly convex, barely
divided by a trace of a border furrow; anterior outline somewhat
pointed medially. Ocular ridges faint ; palpebral area about one-fourth
the glabellar width ; palpebral lobes very small, at level of anterior third
of glabella. Anterior section of facial suture convergent immediately in
front of palpebral lobes; posterior section slightly convex outward,
gradually curving backward and inward to produce broad, well-
rounded posterior area. Furrow on posterior area broad and shallow.
Free cheek rounded at genal angle; border narrow but fairly distinct
anteriorly, becoming indistinct posteriorly. Surface of test smooth.
Length of largest cranidium 2.4 mm.
Discussion.—The pygidium has not been identified. The cranidium
of G. declivis differs from other species of the genus in the steeply
downsloping palpebral area and the tendency to obsolescence of all the
furrows ; however, its close relationship to the more typical forms is un-
mistakable.
Occurrence.—The type is from Oder’s collection No. 2, Hurricane
Hollow. Also present in collections cnr/15, Three Springs, and cnr/16,
Smith Hollow. In all these occurrences it is associated with Aphelaspis
walcottt. Rare specimens were collected at locality cnq’/20, Washburn,
in somewhat higher beds.
Types——Holotype: U.S.N.M. 144556. Paratypes: U.S.N.M. 144-
57:
Genus AMIASPIS Lochman, 1944
Type species —Amuaspis erratica Lochman.
AMIASPIS ERRATICA Lochman
Plate 5, figure 20
Amiaspis erratica Lochman, in LocHMAN and Duncan, 1944, p. 68, pl. 8, figs.
41-46.
A few cranidia do not appear to differ appreciably from topotype
material from Montana.
Occurrence.—Locality cnn/16, Smith Hollow.
Type.—Plesiotype: U.S.N.M. 144558.
AMIASPIS OBSOLESCENS Rasetti, new species
Plate 5, figures 21-24
Available material—tThe holotype, a good cranidium, is the only
specimen from the type locality. Several fragmentary cranidia from
another locality are also available.
Description—Glabella large, somewhat tapered, widely rounded in
front, unfurrowed, barely defined on the outer surface by a very shallow
44 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
axial furrow, almost merging with the general convexity of the cepha-
lon. Occipital furrow very shallow ; occipital ring extended into a long,
slender, almost horizontal spine. Fixed cheeks convex and down-
sloping ; frontal area short (sag.), not differentiated into preglabellar
field and border. Ocular ridges barely indicated ; palpebral lobes almost
indistinct, at level of the anterior fourth of glabella. Posterior area
broad, strongly downsloping, rounded distally, deeply furrowed in con-
trast to the shallowness of all other furrows. Margin of posterior border
showing a geniculation close to the axial furrow. Surface of test com-
pletely smooth. Length of largest cranidium, exclusive of spine, 2.2
mm.
Discussion—The species differs from the type, with which it is
associated, in the obsolescence of the axial furrow and the proportion-
ately larger and unfurrowed glabella.
Occurrence.—The type locality is cnm’/20, Washburn. Also in col-
lection cnn/16, Smith Hollow. The stratigraphic position is in the up-
per Crepicephalus zone.
Types——Holotype: U.S.N.M. 144559. Paratypes: U.S.N.M. 144-
560.
Family CATILLICEPHALIDAE Raymond, 1938
Genus PEMPHIGASPIS Hall, 1863
Type species —Pemphigaspis bullata Hall.
PEMPHIGASPIS, species undetermined
Plate 7, figures 23-25
A few cranidia and pygidia of Pemphigaspis, the latter fragmentary,
may be identical with the type species but are not sufficient for a satis-
factory identification.
Occurrence.—Uppermost beds of lower limestone member of the
Nolichucky (Crepicephalus zone) at locality cnn/3.
Disposition of material—Figured specimens: U.S.N.M. 144562.
Genus MADAROCEPHALUS Resser, 1938
Type species —Madarocephalus laetus Resser.
MADAROCEPHALUS LAETUS Resser
Plate 8, figure 20
Madarocephalus laetus REssEr, 1938a, p. 87, pl. 10, figs. 51-53.
A single cranidium agrees with the types, and proves that the species
belongs to the Crepicephalus zone.
Occurrence.—Type locality is U.S.N.M. 56v, near McCalla, Ala.
The author collected the specimen in the upper part of the lower lime-
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 45
stone member of the Nolichucky (Crepicephalus zone) at locality
cnm/2.
Types.—Cotypes: U.S.N.M. 94885. Plesiotype: U.S.N.M. 144563.
Family CREPICEPHALIDAE Kobayashi, 1935
Genus CREPICEPHALUS Owen, 1852
Type species —Dikelocephalus ? iowensis Owen.
CREPICEPHALUS cf. C. SCISSILIS Resser
Plate 8, figure 30
Crepicephalus scissilis RESSER, 1938a, p. 72, pl. 11, figs. 34, 35.
Crepicephalus greendalensis RESSER, 1938a, p. 73, pl. 11, figs. 46, 47.
A few, exfoliated pygidia resemble this species in the general shape,
differing in the following minor features. The outline between the
spines is slightly concave rather than straight; the median profile of
the pleural region behind the axis is somewhat concave, instead of
convex as it appears in Resser’s specimens. Possibly these differences
should be attributed specific value when better-preserved and more
complete material can be found.
Occurrence.—Type locality for C. scissilis is U.S.N.M. 124a, 4 miles
NE. of Rogersville. Type locality for C. greendalensis is U.S.N.M.
36u, near Greendale, Va. The author’s material was collected from the
uppermost beds of the lower limestone member of the Nolichucky
(Crepicephalus zone) at locality cnn/3.
Disposition of material—Figured specimen: U.S.N.M. 144564.
CREPICEPHALUS BUTTSI Resser
Plate 6, figures 5, 6
Crepicephalus buttsi Ressrr, 1938a, p. 72, pl. 11, figs. 28, 29, 49, 50.
Crepicephalus expansus REssER, 1938a, p. 73, pl. 11, fig. 36.
Crepicephalus buttst is represented by cranidia and pygidia poorly
preserved and somewhat flattened in shale, while C. expansus is based
on a limestone pygidium. No observable differences separate the pygi-
dia bearing the two names. A form collected by the author and repre-
sented only by pygidia is identified with this species. The individual
specimens vary to some extent in possessing straight or somewhat in-
ward curved spines. Since both types occur in the same bed, these slight
differences are not attributed specific significance.
Occurrence.—The type locality of C. buttsi is U.S.N.M. 26s, near
Cleveland, Va. The type locality of C. expansus is U.S.N.M. 105, near
Sneedville, Hancock County, Tenn. The specimens figured herein are
from locality cnn/19.
46 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Types.—Holotype of C. buttsi (pygidium) : U.S.N.M. 94907. Para-
types: U.S.N.M. 94908. Holotype of C. expansus: U.S.N.M. 94910.
Plesiotypes: U.S.N.M. 144565.
CREPICEPHALUS CONVERGENS Rasetti, new species
Plate 8, figures 5-8
Available material—Several pygidia and cranidia, the former of
small size, mostly preserving the test.
Description —Cranidium fully typical of the genus. Glabella tapered,
rounded in front, showing 2 pairs of shallow furrows even on the outer
surface ; occipital furrow straight, occipital ring rounded. Frontal area
divided into preglabellar field and border of about equal widths (sag.) ;
border slightly convex. Palpebral area and lobes as in other species of
the genus ; posterior area not preserved.
Pygidium represented by better specimens than the cranidium. Axis
occupying two-thirds of the length, somewhat tapered, extended into
a short postaxial ridge which reaches the wide, indistinct border fur-
row. About 2 rings distinct, 1 or 2 more barely indicated. Pleural lobes
with rounded anterior angles, fairly straight sides converging toward
the rear, and concave posterior margin between the spines. Pleural
platforms relatively small, with 3 short, well-marked furrows, no
interpleural grooves; slope dropping rather steeply to border furrow
and wide, flat border. Spines rapidly tapered, flat, relatively short.
Surface finely granulate. Length of largest pygidium 6.5 mm., width
10.5 mm.
Discussion.—This form is chiefly characterized by the pygidium,
which differs in outline, form of the spines, and relative length of axis
from described species.
Occurrence.—Lower portion of lower limestone member of the
Nolichucky (Crepicephalus zone) at locality cnk/1.
Types—Holotype (pygidium): U.S.N.M. 144566. Paratypes:
U.S.N.M. 144567.
CREPICEPHALUS cf. C. CONVERGENS Rasetti
Plate 8, figures 9-11
Several pygidia collected in strata higher than those yielding the types
of the species differ consistently in several features aside from the
different manner of preservation (these pygidia are exfoliated). The
sides are even more strongly convergent than in C. convergens, thus
bringing the spines closer together; these are also shorter and more
obtuse in shape, and the margin between them more definitely notched.
Occurrence—Uppermost beds of the lower limestone member
(Crepicephalus zone) of the Nolichucky (loc. cnn/1, enn/3).
Dispostion of material_—Figured specimens: U.S.N.M. 144568-9.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 47
CREPICEPHALUS, species undetermined No. 1
Plate 8, figures 17, 18
Available material—Represented by incomplete, exfoliated pygidia
and one poorly preserved cranidium that may belong to the same
species.
DescriptionPygidium twice as wide as long. Axis occupying
about five-sixths of the length, somewhat tapered, showing 3 rings and
a terminal section. Pleural lobes extended into a pair of broad-based,
strongly outward-directed, and presumably very long spines. Pleural
platforms relatively short, with 3 pairs of pleural furrows. Border
furrow indistinct.
Discussion—This form cannot be identified with any described
species on account of the character of the pleural spines.
Occurrence-—Uppermost beds of the lower limestone member
(Crepicephalus zone) of the Nolichucky (loc. cnn/4).
Disposition of material—Figured specimens: U.S.N.M. 144570.
CREPICEPHALUS? species undetermined No. 2
Plate 8, figures 12, 13
Available material—A few cranidia and pygidia tentatively assigned
to one species, preserved in limestone as internal impressions.
Description—Glabella rather strongly convex in both directions,
straight-sided, tapered, rounded in front, unfurrowed. Occipital furrow
well impressed, straight; occipital ring lacking node or spine. Pre-
glabellar field very short; border sharply elevated, convex, somewhat
arched transversely ; border furrow lacking depressions. Palpebral area
slightly upsloping, about 0.25 times glabellar width; palpebral lobes
small, curved, opposite glabellar midpoint ; ocular ridges faintly indi-
cated. Anterior facial sutures slightly divergent; anterior angles of
cranidium narrowly rounded. Posterior area not preserved.
Associated pygidium of the Crepicephalus type, twice as wide as the
midlength. Axis long, showing 3 rings and a terminal section, extended
into a short postaxial ridge that reaches the margin. Pleural platforms
convex and downsloping, with 3 pairs of deep, wide furrows, ending
at wide, shallow border furrow. Spines continue the straight, slightly
convergent outline of pygidial sides and are sharply pointed without
attaining great length; margin between spines forming a broad curve.
Length of largest cranidium 16 mm. ; of pygidium 7 mm., width 14 mm.
Discussion.—The pygidium seems definitely to belong in the genus;
the cranidium, however, is unusual in the strongly elevated anterior
border and slightly upsloping palpebral area. The first of these char-
acters would rather suggest Meteoraspis, but in that genus the pal-
pebral area rises above the axial furrow and then slopes downward in
characteristic fashion.
48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Occurrence-—Uppermost beds of the lower limestone member of
the Nolichucky (Crepicephalus zone) ; locality cnn/3.
Disposition of material—Figured specimens: U.S.N.M. 144571.
Genus COOSELLA Lochman, 1936
Type species —Coosella prolifica Lochman.
COOSELLA ANDREAS ( Walcott)
Plate 1, figures 14
Blountia andreas Watcort, 1916b, p. 398, pl. 64, fig. 2.
Coosella andreas (Walcott) REsseEr, 1938a, p. 70, pl. 13, fig. 11.
Available material—tThe holotype is a cranidium. Two cranidia and
two associated pygidia collected by the author allow a more complete
description. The cranidia differ from the holotype in the slightly less
downsloping attitude of the anterior border, but such differences are
common in obviously conspecific populations.
Description —tThe pygidium has a very prominent, tapered, rounded
axis reaching more than two-thirds of the pygidial midlength ; it shows
3 rings and a terminal section extended into a low, broad postaxial
ridge. Pleural lobes with unusually strong convexity, sloping down
steeply to a narrow, poorly defined, concave border. Pleural platforms
furrowed for a short distance, with 2 pairs of furrows and 1 pair of
interpleural grooves indicated, all ending on the line that marks the
inner edge of the doublure. Posterior margin in dorsal view showing a
narrow notch between rounded lobes, in posterior view strongly raised
medially. Surface of test smooth. The strong convexity of the pygidium
distinguishes the species from all others attributed to the genus.
Occurrence-—Uppermost beds of Maryville limestone (Cedaria
zone). Type locality is U.S.N.M. 102a, east of Rogersville. Collected
by the author at locality cnc/2.
Types——Holotype: U.S.N.M. 62823. Plesiotypes: U.S.N.M.
144572.
COOSELLA RESSERI Rasetti, new name
Plate 1, figures 5-7
Uncaspis tennesseensis RESSER (part), 1938a, p. 105, pl. 9, fig. 20 (only).
Available material—The pygidium, holotype of Uncaspis tennes-
seensis, and 2 additional pygidia, all preserved in limestone but ex-
foliated.
Description.—Pygidial axis slightly tapered, very prominent, show-
ing 3 rings plus a terminal section, extended into a low postaxial ridge.
Pleural platforms convex and strongly downsloping, showing several
pairs of shallow furrows and interpleural grooves, all curving back-
ward. Pleural region extended into a pair of slightly concave, horizon-
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 49
tal, somewhat falcate lobes separated by a wide, rounded notch. Mid-
length of pygidium 5 mm., width 10 mm.
Discussion.—The cranidium referred by Resser to Uncaspis tennes-
seensis is an example of Modocia dubia, as mentioned in the synonymy
of that species. The holotype pygidium is certainly not an Uncaspis,
whatever the characters of this poorly understood genus may be, and
seems definitely referable to Coosella. This assignment requires a
change in the trivial name, because the binomial combination Coosella
tennesseensis was used by Resser for another species. The pygidium
has fundamentally the same structure as Coosella andreas, but is more
strongly bilobate, and the notch between the lobes is much wider.
Occurrence.—Red beds at the base of the Nolichucky (Cedaria
zone) at U.S.N.M. locality 27d, where it was also collected by the
author (loc. cnd/1).
Types.—Holotype: U.S.N.M. 94846. Plesiotype: U.S.N.M.
144573.
COOSELLA PLANICAUDA Rasetti, new species
Plate 7, figures 1-5
Available material_—A few cranidia and numerous pygidia.
Description.—Glabella of usual shape, with traces of lateral furrows;
occipital furrow deep and straight, occipital ring bearing a low node.
Preglabellar field and border of about equal width (sag.) ; border
strongly convex, with terrace lines. Palpebral lobes narrow, half the
glabellar length; width of palpebral area about 0.3 times the glabellar
width. Midpoint of palpebral lobes somewhat in advance of glabellar
midpoint.
Pygidium with very little overall relief. Axis moderately convex,
little more than half the pygidial length, moderately tapered, showing
2 or 3 rings and an unfurrowed terminal section, extended into a brief
postaxial ridge. Pleural lobes almost flat, showing faint furrows in the
narrow triangular portions anterior to the inner margin of the wide
doublure, smooth in the remainder of the broad, slightly concave area;
posterior outline well rounded except for a shallow median notch
between the pair of wide lobes. Surface of test smooth. Length of
largest pygidium 7.5 mm., width 11 mm.
Discussion—This species possibly resembles Coosia more than
Coosella in the shape of the pygidium, but the cranidial features rather
indicate the present generic assignment.
Occurrence-—Lower and middle portions of the lower limestone
member of the Nolichucky (Crepicephalus zone). Localities cnk/2,
cnm/2.
Types.—Holotype: U.S.N.M. 144574. Paratypes: U.S.N.M.
144575-6.
50 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
COOSELLA PERPLEXA (Palmer)
Plate 15, figures 19-26
Crepicephalus? perplexus PALMER, 1954, p. 733, pl. 77, figs. 1, 2, 4.
Represented in the collections by numerous cranidia and pygidia
and a few free cheeks. Careful comparison with topotype specimens
and further material from Nevada identified by Palmer (private com-
munication) failed to disclose any significant difference, hence the
identification seems highly reliable.
Palmer tentatively referred the species to Crepicephalus rather than
Coosella because of the stratigraphic position rather than morphology.
The cranidia of the two genera are indistinguishable, and it has been
customary to refer to Crepicephalus the forms with pygidia extended
into a pair of lateral spines, to Coosella those with a pair of rounded
lobes more or less separated by a median notch. Hence the reference
to Coosella seems indicated in the present case. Other species of Coo-
sella, e.g., C. planicauda, occur in the upper Crepicephalus zone, hence
there is no stratigraphic discontinuity in the distribution of the genus.
Occurrence.—Basal beds of the Aphelaspis zone in collections cno/
14, Russell Gap, and cno/15, Three Springs.
Types.—Plesiotypes: U.S.N.M. 144577-8.
COOSELLA, species undetermined
Plate 6, figure 19
A single pygidium was collected. It has a short axis and wide, flat
pleural lobes with a slight median notch in the posterior margin. The
axis is extended into a long, narrow postaxial ridge. This specimen
resembles a pygidium of an unnamed species of Coosella figured by
Palmer (1954, p. 730, pl. 79, fig. 1) but the sides are straighter and
the posterior angles not so widely rounded.
Occurrence.—Lower portion of lower limestone member of the
Nolichucky (Crepicephalus zone) at locality cnk/1.
Disposition of material.—Figured specimen: U.S.N.M. 144579.
Genus COOSINA Rasetti, 1956
Type spectes—Maryvillia ariston Walcott (part).
COOSINA AMAGE (Walcott)
Plate 7, figures 14-22
Blountia amage Watcott, 1916b, p. 398, pl. 64, figs. 3, 3a.
Blountia alethes Watcortt (part), 1916b, p. 397, pl. 64, figs. 1b, 1c (only).
Coosella amage (Walcott) ReEsseEr, 1938a, p. 70, pl. 13, figs. 12, 13.
Available material—Blountia amage was based on a proper com-
bination of cranidium and pygidium, both represented by specimens
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 51
preserving the test. Blountia alethes was described on a cranidium of
Coosia illegitimately combined with an exfoliated pygidium of the pre-
ceding species. Since Walcott designated the cranidium as the holotype,
the name alethes belongs to the species of Coosia, as used by Resser.
The present generic assignment seems the proper one for Blountia
amage. This species was found to be exceedingly common at one local-
ity, and the numerous and better preserved material allows a more
complete description.
Description.—Glabella defined by a fairly deep axial furrow, strongly
tapered, rounded in front ; glabellar furrows obsolete on outer surface,
faint on impression of interior. Occipital furrow wide, occipital ring
simple. Frontal area as in type species except for the greater distinct-
ness of the border furrow and border. Palpebral area approximately
horizontal, about 0.4 times the glabellar width; palpebral lobes about
0.4 times the glabellar length. Posterior area somewhat more slender
and more deeply furrowed than in type species.
Pygidium 1.4 times as wide as long. Axis elevated, slightly tapered,
occupying 0.8 of the pygidial length, extended into a brief postaxial
ridge, with about 5 distinct rings and a terminal section. Pleural lobes
convex, downsloping to moderately wide concave border. Anterior
marginal furrow deep and wide, three other pairs of furrows shallow
even on interior casts, traces of interpleural furrows also visible; all
furrows end sharply at a line that corresponds to the inner edge of the
doublure on the ventral side. The lateral and posterior margin with
almost even curvature, except for a slight indication of flattening
medially. Surface of test smooth. Length of largest cranidium 14 mm.,
of largest pygidium 10 mm.
Occurrence.—The type locality is U.S.N.M. 107, 11 miles NW. of
Knoxville. Type locality for Blountia alethes, U.S.N.M. 123b, near
Rogersville. Illustrated plesiotypes from the middle portion of the
lower limestone member of the Nolichucky (Crepicephalus zone) at
locality cnm/2.
Types.—Holotype: U.S.N.M. 62824. Paratype: U.S.N.M. 62825.
Paratype pygidium of Blountia alethes assigned to the species:
U.S.N.M. 62822. Plesiotypes: U.S.N.M. 144580, 144561.
COOSINA ARISTON ( Walcott)
Plate 7, figure 27
Maryvillia ariston Watcott (part), 1916b, p. 401, pl. 64, figs. 5, 5’ (not fig. 5a).
Coosina ariston (Walcott) Rasett1, 1956, p. 1267 (includes complete syn-
onymy) ; 1961, p. 111, pl. 21, figs. 12, 13.
Several pygidia seem identical with this species. The cranidium was
not identified ; it would be difficult to distinguish from that of the far
more common associated species C. amage.
52 SMITHSONIAN MISCELLANEOUS COLLECTIONS VoL. 148
Occurrence——Type locality is U.S.N.M. 120, on Shields Ridge,
New Market quadrangle. Collected by the writer in the middle portion
of the lower limestone member of the Nolichucky (Crepicephalus zone)
at locality cnm/2.
Types.—Holotype: U.S.N.M. 62829. Plesiotype: U.S.N.M. 144581.
Genus COOSIA Walcott, 1911
Type species ——Coosia superba Walcott.
COOSIA ALETHES (Walcott)
Plate 6, figures 15-18; plate 7, figures 6-13
Blountia alethes Waucott (part), 1916b, p. 397, pl. 64, figs. 1, la (only).
Coosia alethes (Walcott) Resser, 1938a, p. 71.
Available material—Abundant new specimens show that Walcott’s
type cranidium is an immature individual of a species of Coosia that
attains large dimensions and is common everywhere in the upper
Crepicephalus zone of the Nolichucky.
Description.—Glabella well defined by the axial furrow, unfurrowed,
not changing much in shape in cranidia from 2.3 to 18 mm. in length,
except for a gradual decrease of the convexity. Occipital furrow
straight, well impressed, occipital ring simple. Frontal area increasing
in length relative to the entire cranidium from 0.30 to 0.37 in the above-
mentioned size range. Border furrow becoming gradually wider and
shallower ; midlength of preglabellar field about equal to border width
(sag.) in small cranidia, decreasing to about half of border in adults.
Palpebral area decreasing in relative width with size; palpebral lobes
regularly curved in early stages, becoming somewhat angular later.
Entire thorax preserved in an immature specimen that may represent
a holaspid and has 12 segments. The pygidium in this individual has a
long axis and the pleural lobes show 3 or 4 distinct pairs of furrows.
In larger pygidia the axis becomes shorter, equaling only half or less
of the pygidial length, and extends into a postaxial ridge. It is com-
posed of 3 rings and a terminal section distinct even on the outer
surface. The pleural lobes are slightly downsloping and furrowed in
a limited area near the axis, then flatten out into a wide, smooth, some-
what concave area that corresponds to the extent of the doublure.
The anterior marginal furrow is the only one that extends almost to
the lateral margin. The largest fairly complete cranidium is 18 mm.
long, but fragments indicate larger individuals. A large, incomplete
pygidium has a length of 22 mm. and a width of 44 mm. Surface of test
smooth except for wavy terrace lines on cranidial and pygidial borders.
Discussion—lIt may be questioned whether forms of Coosia de-
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 53
scribed under various names from other areas, such as C. dakotensis
Resser, C. albertensis Resser, C. modesta Lochman, C. grandis Loch-
man are distinct from the present species. In any case, the trivial name
alethes would be the proper one for the species from Tennessee since
it has priority.
Occurrence.—Type locality is U.S.N.M. 123b, near Rogersville.
Common in the uppermost beds of the lower limestone member of the
Nolichucky (Crepicephalus zone). Localities cnn/1 to cnn/4, cnn/19,
and cnn/16; rare in somewhat lower beds (loc. cnm/2).
Types—Holotype: U.S.N.M. 62821. Plesiotypes: U.S.N.M.
144582-6.
COOSIA ROBUSTA Walcott
Plate 7, figure 26
Coosia robusta Watcott, 1911, p. 97, pl. 16, figs. 2, 2a.
Coosia robusta Walcott, RESSER, 1938a, p. 70, pl. 11, figs. 12, 13.
Several pygidia associated with the preceding species seem identical
with the types ; however, no cranidia could be identified. The pygidium
differs from that of C. alethes in the longer axis and almost entirely
convex surface. The largest pygidium found is 25 mm. long and 40
mm. wide.
Occurrence.—Type locality is U.S.N.M. 107, NW. of Knoxville.
Collected from the uppermost beds of the lower limestone member of
the Nolichucky (Crepicephalus zone) at localities cnn/1, cnn/2.
Types.—Cotypes: U.S.N.M. 57590, 57591. Plesiotype: U.S.N.M.
144587.
COOSIA, species undetermined
Plate 5, figure 19
Known from a single pygidium. Axis stout, prominent, slightly
tapered, rounded posteriorly, somewhat over half the pygidial length,
extended into a short postaxial ridge. Pleural regions flat, with straight
anterior and posterior outlines that give the entire pygidium a rec-
tangular appearance. Pleural furrows, except the first pair, almost
indistinct, curving backward. Surface of posterior portion of pleural
regions with transverse wrinkles. Length 3.0 mm., width 8.0 mm.
This pygidium differs from the associated species of Coosia in its
subquadrate shape.
Occurrence.—Upper portion of lower limestone member of the
Nolichucky (Crepicephalus zone) at locality cenn/1.
Disposition of material—Figured specimen: U.S.N.M. 144588.
54 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Family TRICREPICEPHALIDAE Palmer, 1954
Genus TRICREPICEPHALUS Kobayashi, 1935
Type species —Arionellus (Bathyurus) texanus Shumard.
TRICREPICEPHALUS THOOSA (Walcott)
Plate 6, figures 14
Crepicephalus thoosa Watcott, 1916a, p. 214, pl. 31, figs. 1, la—k.
Paracrepicephalus walcotti LocoMAN, 1936, p. 39, pl. 9, figs. 29, 31, 33.
Tricrepicephalus walcotti (Lochman) REsser, 1938a, p. 102, pl. 11, fig. 54.
Tricrepicephalus thoosa (Walcott) ReEsseEr, 1938a, p. 101, pl. 14, fig. 8.
Tricrepicephalus coria (Walcott) PALMER (part), 1954, p. 755 (includes syn-
onymy).
Palmer placed a number of described forms of Tricrepicephalus in
the synonymy of Tricrepicephalus coria (Walcott), the type of which
is from the House Range, Utah. He pointed out that the species con-
strued in this broad sense includes a considerable amount of variation.
Since the material from the type locality for T. coria is rather poorly
preserved, the writer prefers to adopt for the southern Appalachians
form a name based on specimens from that area, and as new material
was collected from the type locality for T. thoosa, this is the name here
used. The differences between the type specimens of T. thoosa and
T. walcotti fall well within the range of variation in cranidial and
pygidial features observed in individuals from a single bed, hence
Lochman’s name is placed in synonymy. It was also included by Palmer
in the list of synonyms of T. coria.
Occurrence.—Type locality for T. thoosa is U.S.N.M. 125a, 4 miles
NE. of Rogersville (presumably identical with author’s locality
cnn/1). Type locality for T. walcotti is U.S.N.M. 119, S. of Morris-
town. Collected by the author at localities cnk/1, cnm/2, cnn/1 to
cnn/5. The species ranges throughout the lower limestone member
(Crepicephalus zone) of the Nolichucky formation.
Types——Holotype of T. thoosa: U.S.N.M. 61654. Holotype and
paratype of T. walcotit: U.S.N.M. 61655, 61658. Plesiotypes:
U.S.N.M. 144589-91.
Genus METEORASPIS Resser, 1935
Type species —Ptychoparia metra Walcott.
METEORASPIS MUTICA Rasetti
Plate 6, figures 13, 14
Meteoraspis mutica RAsETTI, 1961, p. 116, pl. 21, figs. 25-29.
The assignment of cranidium and pygidium to the same species is
made certain by the frequent association in the same bed observed
in Tennessee. The largest cranidium observed has a length of 11 mm.,
the largest pygidium a length of 5 mm. and a width of 9 mm.
Occurrence.—The types are from the Conococheague formation
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 55
near Winchester, Va. Plesiotypes from localities cnm/2 and cnn/1,
in the upper portion of the lower limestone member of the Nolichucky
(Crepicephalus zone).
Types.—Plesiotypes : U.S.N.M. 144592-3.
METEORASPIS BREVISPINOSA Rasetti, new species
Plate 6, figures 9-12
Available material —Several cranidia and pygidia preserved in lime-
stone, the larger ones lacking the test.
Description.—Glabella of usual shape and convexity, unfurrowed,
defined by a deep axial furrow all around. Occipital furrow deep, occip-
ital ring rounded, bearing a low node. Preglabellar field and palpebral
area narrow, convex, downsloping; border elevated, convex, defined
by a deep border furrow; the latter with a pair of shallow depressions.
Posterior area deeply furrowed.
Pygidium subrectangular, about as wide as long. Axis very promi-
nent, large, somewhat tapered, rounded posteriorly, almost reaching
posterior margin ; 3 rings and a terminal section defined by deep fur-
rows. Pleural lobes steeply downsloping, with fairly straight sides
slightly convergent backward, extended into a pair of blunt spines;
margin between spines straight for a considerable length. A few broad
and shallow pleural furrows indicated on internal impression; border
furrow and border indistinct. On the outer surface the pleural lobes
would probably appear almost entirely smooth, except for the an-
terior marginal furrow. Length of largest cranidium 11 mm., of
largest pygidium 11 mm.
Discussion —The cranidium differs little from M. metra and other
described species, but the pygidium is characteristic, lacking the long
spines of other species. The pygidium of M. mutica lacks spines but is
quite different in other respects.
Occurrence——Lower portion of lower limestone member of the
Nolichucky (Crepicephalus zone) at locality cnk/1.
Types.——Holotype (pygidium): U.S.N.M. 144594. Paratypes:
U.S.N.M. 144595.
Family ASAPHISCIDAE Raymond, 1924
Genus BLOUNTIA Walcott, 1916
Type species —Blountia mimula Walcott.
BLOUNTIA ARCUOSA Resser
Plate 9, figures 1-8
Blountia arcuosa REsseEr, 1938a, p. 64, pl. 12, fig. 25.
Available material—The hypodigm contains only cranidia. Excel-
lent additional material allows a more complete description of the
species.
56 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Description.—Glabella very slightly expanding forward in the pos-
terior half, well rounded anteriorly, exceedingly convex in the anterior
portion, overhanging the frontal area; occipital furrow exceedingly
faint on outer surface, occipital ring very short (sag.) ; glabellar fur-
rows lacking. Preglabellar field vertical; border about as wide (sag.)
as the preglabellar field, convex, with terrace lines. Anterior sections of
facial sutures parallel; posterior section with gentle curvature, defining
slender, sharply pointed, faintly furrowed posterior area. Palpebral
lobes small and faintly elevated; palpebral area about 0.2 times the
glabellar width.
Pygidium almost twice as wide as long. Axis long, not rising above
the general convexity ; axial furrow shallow. Pleural lobes with con-
vexity increasing toward the margin, lacking distinct border furrow
and border, sharply downrolled especially in the posterior portion.
Furrows obsolete on outer surface; on interior cast, 6 or 7 rings are
distinguishable on the axis and 3 faint pairs of furrows on the pleural
lobes. Surface smooth.
Occurrence.—Type locality is U.S.N.M. 12la, 4 miles NE. of
Rogersville. The species is not rare in the upper part of the lower
limestone member of the Nolichucky formation (Crepicephalus zone)
in the Rogersville area (localities cnm/1, cnm/2, cnn/2, cnn/3).
Types.—Holotype: U.S.N.M. 94960. Plesiotypes: U.S.N.M.
144555.
BLOUNTIA ALEXAS Walcott
Plate 9, figures 9-12
Blountia alexas Watcott, 1916b, p. 398, pl. 61, figs. 5, 5a.
Blountia alexas Walcott, REsSER, 1938a, p. 65, pl. 12, fig. 27.
Available material—The hypodigm consists of the holotype crani-
dium. Additional cranidia and pygidia allow a more complete descrip-
tion.
Description—Glabella of moderate convexity, straight-sided,
slightly tapered, rounded in front, unfurrowed. Occipital furrow al-
most indistinct on outer surface, occipital ring very short (sag.).
Preglabellar field on the average somewhat shorter (sag.) than border,
the ratio varying somewhat in different individuals; border slightly
convex, wide (sag.), set off from preglabellar field by its upturned
position. Palpebral area about 0.3 times the width of glabella at same
level. Anterior facial sutures divergent, anterior angles of cranidium
well rounded ; posterior section of facial suture with gentle curvature;
posterior area falcate, extending farther backward than occipital ring,
with faint furrow in proximal portion only.
Pygidium with little convexity. Length 0.6 times width. Axis ta-
pered, occupying two-thirds of length; axial furrow shallow laterally,
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 57
almost obsolete posteriorly. Pleural lobes with faint border furrow
and wide border. Only traces of segmentation on outer surface. Sur-
face smooth.
Occurrence.—Type locality is U.S.N.M. 125, 4 miles NE. of Rogers-
ville. Plesiotypes from the lower portion of the lower limestone mem-
ber (Crepicephalus zone) of the Nolichucky formation (loc. cnk/1,
cnk/3, the latter presumably identical with type locality).
Types.—Holotype: U.S.N.M. 62785. Plesiotypes: U.S.N.M.
144596, 144701.
BLOUNTIA LATA (Resser )
Plate 9, figure 21
Blountiella lata REssEr, 1938a, p. 65, pl. 12, fig. 37.
Blountia rogersvillensis REsSER, 1938a, p. 64, pl. 12, figs. 29, 30.
The species was described under the two names on the basis of
cranidia preserving the test or not, respectively, as recognized by
Lochman and Duncan (1944). This trilobite was found as a rare
member of the faunule of the upper portion of the lower limestone
member of the Nolichucky. The previous descriptions and the illus-
trations supply the available information about the species.
Occurrence.—The type locality for Blountiella lata is U.S.N.M. 125
and that for Blountia rogersvillensis is U.S.N.M. 121a, both 4 miles
NE. of Rogersville. The author collected the species from the upper-
most beds of the lower limestone member of the Nolichucky (Crepi-
cephalus zone) at locality cnn/3.
Types.—Holotype: U.S.N.M. 94961. Holotype of Blountia rogers-
villensis: U.S.N.M. 94959. Plesiotype: U.S.N.M. 144597.
BLOUNTIA MONTANENSIS Duncan
Plate 9, figures 13-20
Blountia montanensis Duncan, in LocHMAN and Duncavy, 1944, p. 53, pl. 8, figs.
29-34.
This species, described from Montana, is common in the Crepi-
cephalus zone in Tennessee. There is some variation in the length of
the preglabellar field, elevation of the anterior border and depth of the
axial furrow on the cranidium, but since all intermediate forms occur
in the same beds, these features should be interpreted as intraspecific
variability.
Occurrence.—Localities cnk/1, enm/2, cnn/1, cnn/3. The species
is more common in the lower portion of the lower limestone member
of the Nolichucky (Crepicephalus zone) but ranges throughout this
limestone.
Types.—Plesiotypes: U.S.N.M. 1445989.
58 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
BLOUNTIA BRISTOLENSIS Resser
Plate 10, figures 1, 2; plate 11, figures 9-12
Blountia bristolensis RESSER, 1938a, p. 65, pl. 12, fig. 24.
Maryvillia bristolensis RESSER, 1938a, p. 87, pl. 12, fig. 38.
Blountia nixonensis Lochman, in LocHMAN and Duncan, 1944, p. 43, pl. 4, figs.
7-12.
Available material—The hypodigm of B. bristolensis includes the
holotype pygidium. Maryvillia bristolensis is based on a cranidium
from the same collection. Blountia nixonensis was described from
numerous cranidia and pygidia. The author’s collections include nu-
merous fragments and one articulated shield. The latter allows a de-
scription of the thorax.
Description—Entire exoskeleton ovate; pygidium as large as ceph-
alon. Thorax of 7 segments, not tapered, as wide as cephalon and
pygidium. In the specimen, evidently an exuvia as it lacks the free
cheeks, the cranidium was pushed over the thorax, concealing
the entire first and part of the second thoracic segment. The entire
thorax was exposed during preparation when the cranidium broke off.
In the illustration the cranidium is shown restored. Thoracic axis
slightly tapered, at much lesser rate than pygidial axis. Axial furrows
on thorax rather deep. Pleurae unfurrowed, flat and horizontal in
proximal two-thirds, presenting sharp geniculation and showing an-
terior facet that allowed enrollment of the animal. Termination of
pleurae narrowly rounded, sharper in anterior pleurae. Length of exo-
skeleton, allowing for displacement of cranidium, 17.4 mm., of which
7.0 belong to the cephalon, 4.4 to the thorax, and 6.0 to the pygidium.
The individual corresponds almost to the largest size of cranidia and
pygidia in the author’s collections.
Discussion.—A species of Blountia common in the basal beds of the
Aphelaspis zone in Tennessee is identified with B. bristolensis. This
and Maryvillia bristolensis, from the same collection, obviously are
conspecific. Careful comparison of the author’s material with B. nix-
onensis from Montana failed to reveal any differences.
The species, like B. mimula, has 7 thoracic segments. In the present
case one may be certain that the individual is a holaspid. However, it
should not be inferred that all species of Blountia have 7 segments.
An undescribed Blountia from the Murphy’s Creek formation of the
Gaspé Peninsula of Quebec, collected by the author, has 9 thoracic
segments. This Blountia occurs in association with Cedaria and Crepi-
cephalus and is therefore considerably older.
Occurrence.—Type locality for Blountia bristolensis and Maryvillia
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 59
bristolensis is U.S.N.M. 36v, near Bristol, Va. Collected by the author
at localities cnp/17 (complete specimen), cnp/14, and cngq/14.
Types.—Holotype of Blountia bristolensis: U.S.N.M. 94942. Holo-
type of Maryvillia bristolensis: U.S.N.M. 94963. Plesiotypes:
U.S.N.M. 144600-1.
BLOUNTIA MIMULA Walcott
Plate 10, figures 3-7
Blountia mimula W atcott, 1916b, p. 399, pl. 61, figs. 4, 4a-c.
Blountia mimula Walcott, REssEr, 1938a, p. 63, pl. 12, figs. 18, 19.
As far as can be determined, a species of Blountia collected from the
lower Aphelaspis zone seems identifiable with the species. The holo-
type is an articulated exoskeleton of very small size and is the only
specimen in the hypodigm that comes from the type locality. The para-
types are from a different locality and appear conspecific with the
holotype as far as one can compare immature individuals. The cranidia
and pygidia illustrated herein are larger than any of the types and
differ only in the shallower axial furrow around the glabella, a modi-
fication gradually acquired during the growth of these trilobites.
Occurrence.—The holotype is from U.S.N.M. locality 120 on Shields
Ridge. Under this label trilobites from both the Crepicephalus and
Aphelaspis zones are mixed. The paratypes are from U.S.N.M. locality
107c, NW. of Knoxville. The specimens illustrated herein are from
Oder’s collection No. 2 in the Hurricane Hollow section, in association
with Aphelaspis walcotti, in beds higher than those holding Blountia
bristolensis.
Types.—Holotype: U.S.N.M. 62781. Paratypes: U.S.N.M.
627824. Plesiotypes: U.S.N.M. 144602.
Genus MARYVILLIA Walcott, 1916
Type species —Maryuvillia arion Walcott.
MARYVILLIA ARION Walcott
Plate 9, figures 22-26
Maryvillia arion Waucott, 1916b, p. 400, pl. 64, figs. 4-4.
Maryvillia arion Walcott, Rasetti, 1956, p. 1267 (includes complete synonymy) ;
1961, p. 116, pl. 21, figs. 14, 15.
Occurrence.—Type locality is U.S.N.M. 123b, % mile E. of Rogers-
ville (probably identical with author’s locality cnn/2). A common
and diagnostic fossil of the upper part of the Crepicephalus zone.
Collected at localities cnk/1 (very rare), cnm/2, cnn/1, cnn/2, cnn/3,
enn/4, cnn/14.
60 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Types——Holotype: U.S.N.M. 62826. Plesiotypes: U.S.N.M.
1446034.
Family KINGSTONIIDAE Kobayashi, 1933
Genus KINGSTONIA Walcott, 1924
Type species —Kingstonia apion Walcott.
KINGSTONIA INFLATA Resser
Plate 8, figures 21-28
Kingstonia inflata Resser, 1938a, p. 84, pl. 12, figs. 5, 6.
Kingstonia rotundata ResseEr, 1938a, p. 83, pl. 12, figs. 9-10.
Available material—The two names represent the same species,
described from the appearance of the outer surface and from internal
impressions respectively. Abundant material of this exceedingly com-
mon form allows a more complete description.
Description—Cranidium very convex in both directions, barely
showing a trace of the axial furrow on outer surface. Glabella defined
on internal impressions, straight-sided, slightly tapered, very wide in
proportion to cranidial width. Anterior border indicated only by its
terraced surface, without change in slope from glabella and preglabellar
field. Palpebral lobes almost indistinct; facial suture showing little
change of direction before and after palpebral lobes in dorsal view;
anterior sections strongly convergent; posterior section gently convex
outward, defining a stout posterior area; posterior angles of cranidium
obtuse. Posterior outline rounded in axial portion, with indentations
corresponding to the axial furrow; convex along the margin of the
posterior area.
Pygidium with axis occupying less than one-third of the maximum
width, well defined anteriorly but merging with the pleural region
posteriorly, not tapered. Pleural lobes increasingly convex toward the
margin. Facet at anterior angles very distinct. Five axial rings and
3 or 4 broad, shallow pleural furrows visible on interior impressions.
Length of largest cranidia 4.5 mm.
Several cranidia, one of which is figured, show through the dark
surface of the test a regular pattern of yellow stains that presumably
represent muscle attachments on the inner surface.
Occurrence.—Type localities for K. inflata are U.S.N.M. 121a, 125,
4 miles NE. of Rogersville. Type locality for K. rotundata is U.S.N.M.
123b, near Rogersville. Found by the writer throughout the lower
limestone member of the Nolichucky (Crepicephalus zone) in the
Rogersville area (locs. enk/1, cnk/3, cnm/2, cnm/3, cnn/1, cnn/3).
Types.—Cotypes of K. inflata: U.S.N.M. 94934, 94953. Cotypes
K. rotundata: U.S.N.M. 94935. Plesiotypes: U.S.N.M. 144605-7.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 61
Genus ANKOURA Resser, 1938
Type species —Ankoura triangularis Resser.
ANKOURA TRIANGULARIS Resser
Plate 3, figures 15-21
Ankoura triangularis REsseEr, 1938a, p. 58, pl. 9, fig. 33.
Available material—Although the pygidia are quite common at the
type locality, the much more fragile cranidia are difficult to obtain.
Resser figured a fragmentary cranidium, from which the precise char-
acters were not clearly understood. Lochman (1940) attributed to
the species good limestone material from the Bonneterre dolomite;
however, her form belongs to a different species. Hence a brief descrip-
tion of the cranidium of Ankoura triangularis is in order. This descrip-
tion is based on exfoliated topotype material, plus specimens preserving
the test from another locality.
Description—Glabella parallel-sided, rounded in front, well defined
on internal impressions but barely indicated on the outer surface.
Occipital furrow almost obsolete on outer surface; occipital ring very
short, lacking a spine. Frontal area convex and downsloping; border
barely represented on outer surface by a narrow striated band as in
many species of Kingstonia. On internal impressions there is a shallow
border furrow. Furrow on posterior area almost obsolete on outer
surface.
Discussion—The species differs from the material identified by
Lochman in two important characters: the simple occipital ring and
the absence of a flat border.
Occurrence.—The type locality is U.S.N.M. 27d; red beds at the
base of the Nolichucky (Cedaria zone) E. of Rogersville. The speci-
mens figured herein are partly from the type locality, partly from a
limestone lens at an unspecified level near the base of the Nolichucky
on Comby Ridge, Howard Quarter quadrangle (author’s locality cnb/
10).
Types—Cotypes: U.S.N.M. 94851. Plesiotypes: U.S.N.M.
144608-9, 144702.
Family MENOMONIIDAE Walcott, 1916
Genus DRESBACHIA Walcott, 1916
Type species —Dresbachia amata Walcott.
DRESBACHIA AMATA Walcott
Plate 8, figures 14
Dresbachia amata WatcotT, 1916a, p. 167, pl. 26, figs. 5, 5a—c.
Dresbachia appalachia REsseEr, 1938, p. 74, pl. 10, figs. 32-34.
Dresbachia amata Walcott, LocHMAN, 1950, p. 338, pl. 48, figs. 11-14.
62 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
A few cranidia and more numerous free cheeks were collected from
the lower limestone member of the Nolichucky (Crepicephalus zone)
at localities cnk/1, cnk/3, cnm/2.
Types.—Holotype of D. appalachia (from loc. U.S.N.M. 22z, near
Greendale, Va.) : U.S.N.M. 94875. Plesiotypes: U.S.N.M. 144694.
Genus MENOMONIA Walcoit, 1916
Type species —Conocephalites calymenoides Whitfield.
MENOMONIA PROMINENS Resser
Plate 5, figures 14-17
Menomonia prominens REssER, 1938a, p. 88, pl. 9, figs. 42, 43.
Dresbachia speciosa RESSER, 1938a, p. 75, pl. 9, figs. 28, 29.
Available material—Resser’s two names were based on the cranidia
and free cheeks of the same species. Additional material allows a more
complete description.
Description—Glabella straight-sided, tapered, rounded in front,
with 2 pairs of short lateral furrows; occipital furrow well impressed,
occipital ring rounded. Preglabellar field slightly arched transversely,
fairly long (sag.) ; border upturned, arched transversely. Palpebral
lobes with their midpoint at the level of the anterior end of the glabella,
strongly upsloping, rising higher than glabella. Posterior area tapered,
large, strongly downsloping and hence giving strong relief to the
cranidium, deeply furrowed ; posterior cranidial margin curving back-
ward. Free cheek with border well defined only anteriorly, almost
parallel-sided, well rounded at the genal angle. The surface characters
are described as they appear on internal impressions, as none of the
specimens preserve the test. Large tubercles on the glabella are ar-
ranged more or less regularly in 4-5 pairs. Tubercles of the same size
are irregularly scattered on the fixed cheeks, decreasing in number
toward the distal end of the posterior area. The tubercles are more
crowded on the anterior border. The free cheeks have larger granules
near the eye and finer granules distally. The largest cranidium has a
length of 4.8 mm.
Occurrence.—Type locality is U.S.N.M. 27d; red beds at the base
of the Nolichucky E. of Rogersville (Cedaria zone). Collected by the
author at the same lecality (cnd/1).
Types.—Holotype and paratypes: U.S.N.M. 94857. Plesiotypes:
U.S.N.M. 144695.
MENOMONIA TUBERCULATA Rasetti, new species
Plate 2, figures 19-24
Available material—Several cranidia and free cheeks in limestone.
Description.—Glabella and occipital ring similar to preceding spe-
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 63
cies. Preglabellar field about as long (sag.) as border width (sag.) ;
border elevated, arched transversely. Palpebral area almost as wide as
anterior portion of glabella, less upsloping than in M. prominens; pal-
pebral lobe moderately upsloping, not extending much farther forward
than the anterior end of the glabella. Posterior area much less tapered
than in M. prominens, more rounded distally, bearing a deep, wide
furrow. Posterior outline of cranidium transverse; posterolateral
angles not extending farther backward than occipital ring.
Free cheek almost subtriangular. Border distinct for more than half
the length of the margin. Anterior section of facial suture much longer
than in M. prominens, corresponding to the more posterior position
of the eye. Posterior section with slight sigmoidal curvature, cutting
posterior margin closer to genal angle than in preceding species. Ele-
vated portions of surface covered with coarse tubercles, possibly repre-
senting the base of broken spines, those on the glabella being arranged
more or less regularly in several rows. Length of largest cranidium
5 mm.
Discussion.—The present species resembles M. calymenoides rather
than M. prominens, the differences from the latter having been already
pointed out in the description. An accurate comparison with topotypes
of M. calymenoides is not very significant because of the poor preser-
vation of these small trilobites as internal casts in the Eau Claire sand-
stone. One definite difference seems to be that in M. calymenoides the
anterior border has almost even width, whereas in the present species
it tapers at the sides. The palpebral area seems to be proportionately
wider.
Occurrence.—Uppermost beds of the Maryville limestone (Cedaria
zone) at localities cnc/1 to cnc/6.
Types——Holotype: U.S.N.M. 144696. Paratypes: U.S.N.M.
144697-8.
MENOMONIA, species undetermined
Plate 2, figures 25-27
A few incomplete cranidia and several free cheeks apparently repre-
sent a form of Menomonia different from the two previously discussed
species.
Most of the cranidial features agree with M. tuberculata, except in
the somewhat more anterior position of the eyes, narrower palpebral
area, and lack of tubercles on the posterior area, where the surface is
finely wrinkled. The free cheek resembles more closely that of M.
prominens in general shape and also shows a wrinkled surface with,
in addition, a few tubercles on the anterior part of the border.
64 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Occurrence.—Uppermost beds of the Maryville limestone (Cedaria
zone) at localities cnc/4, cnc/6.
Disposition of material—Figured specimens: U.S.N.M. 144699-
700.
Family NORWOODIIDAE Walcott, 1916
Genus NORWOODIA Walcott, 1916
Type species—N orwoodia gracilis Walcott.
NORWOODIA ROGERSVILLENSIS Resser
Plate 4, figures 25, 26
Norwoodia rogersvillensis REssER, 1938a, p. 91, pl. 9, figs. 25, 26.
Norwoodia harlanensis REssEr, 1938a, p. 91, pl. 9, fig. 31.
Available material—The hypodigms consist of cranidia from the
same locality. In addition to further cranidia, pygidia occur in the
author’s collection.
Description—Glabella tapered, rounded in front, rather convex,
defined by a well-impressed axial furrow. Glabellar furrows probably
obsolete cn outer surface. Occipital furrow shallow ; occipital ring ex-
tended into a large, horizontal spine longer than the glabella. Frontal
area as long as glabella, mostly consisting of downsloping preglabellar
field; border wide (sag.), upturned. Palpebral area about half the
glabellar width; ocular ridges distinct. Anterior sections of facial
sutures very slightly divergent; posterior section directed outward
and somewhat forward, reaching the margin well in advance of genal
angle. Posterior area slightly expanding distally, well furrowed, ex-
tended into a slender and moderately long genal spine.
The pygidia are attributed to the species because of the close simi-
larity to N. gracilis and other closely related species. Pygidium twice
as wide as long, convex. Axis defined laterally, merging with the
pleural region posteriorly, of 3 distinct rings. Pleural lobes convex,
with 3 pairs of shallow furrows; border narrow but distinct. All the
described cranidial and pygidial features refer to the impression of the
interior since none of the specimens preserves the test.
Discussion—Among the species of the southern Appalachians, the
present one resembles N. gracilis Walcott, differing mainly in the
proportionately wider and shorter glabella, shorter occipital spine, and
different shape of the posterior area and genal spine.
Occurrence——Found only in the red beds (Cedaria zone) at the
base of the Nolichucky. Type locality is U.S.N.M. 27d, the same as
the author’s locality cnd/1.
Types.—Holotype: U.S.N.M. 94847. Holotype of N. harlanensis:
U.S.N.M. 94850. Plesiotypes: U.S.N.M. 144610.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 65
NORWOODIA, species undetermined
Plate 4, figure 24
Cranidia of Norwoodia, too incomplete for specific identification but
certainly very close to the preceding species, are present in the upper-
most beds of the Maryville limestone in the Rogersville area.
Occurrence.—Maryville limestone (Cedaria zone) ; localities cnc/2,
cnc/4, cnc/6.
Disposition of material—Figured specimen: U.S.N.M. 144611.
Genus NORWOODELLA Besser, 1938
Type species —N orwoodia saffordi Walcott.
NORWOODELLA SAFFORDI ( Walcott)
Plate 3, figures 1-6
Norwoodia saffordi W Atcott, 1916a, p. 171, pl. 27, figs. 1-1.
Norwoodella saffordi (Walcott) Ressrr, 1938a, p. 89, pl. 10, figs. 40, 41, 49, 50.
This species is readily distinguished from all others of the genus
by the depth of the axial furrow and the fixed cheeks which rise above
the furrow itself instead of sloping down from it. Limestone specimens
are figured, in addition to the complete holotype exoskeleton flattened
in shale. The thorax of this individual seemingly has 9 segments, not
8 as stated by Walcott. The material from Missouri attributed to this
species by Lochman (1940) was incorrectly identified.
Occurrence.—Type locality is U.S.N.M. 103, near Rogersville. The
species is common in the basal beds of the Nolichucky shale and inter-
stratified limestone lenses (Cedaria zone). Collected at localities cnd/1,
cne/1, cne/2.
Types——Lectotype (herein designated): U.S.N.M. 61595. Para-
types: U.S.N.M. 61596-600. Plesiotypes: U.S.N.M. 144612-3.
NORWOODELLA ROTUNDICOLLIS Rasetti, new species
Plate 4, figures 1-7
Available material—Numerous cranidia and a few free cheeks and
pygidia, preserved in limestone but mostly lacking the test.
Description—Glabella tapered, straight-sided, rounded in front,
fairly convex, rising above the cheeks, unfurrowed on outer surface.
Axial furrow on outer surface impressed laterally but obsolete in front ;
on interior impressions well defined all around. Occipital furrow im-
pressed throughout ; occipital ring subtriangular but rounded, lacking
a spine. Frontal area convex and downsloping, somewhat over one-
third the glabellar length, undivided by a border furrow even on inter-
nal impressions. Palpebral area downsloping, about 0.3 times the
glabellar width; ocular ridges faint. Posterior area wide (exsag.),
66 SMITHSONIAN MISCELLANEOUS COLLECTIONS VoL. 148
parallel-sided, with a distinct furrow even on outer surface. Genal
spine slightly curved, of moderate length. Free cheek as in other
species of the genus. Surface of test perfectly smooth; internal impres-
sions show fine anastomosing lines on frontal area and free cheeks.
Length of largest cranidium 8 mm.
The pygidia attributed to the species are so similar to N. saffordi,
which occurs in the same beds, that some doubt remains concerning
their assignment. Pygidium somewhat fan-shaped, with regularly
curved pleurae and anterior margin. Axis prominent, long, tapered,
showing 3 rings plus a terminal section. Pleurae poorly fused, with 3
pairs of wide furrows and as many narrow interpleural grooves, all
furrows and grooves extending to the margin, where the separate
endings of the pleurae form a wavy outline. Border furrow and border
lacking.
Discussion.—The cranidium resembles N. declivis Resser, which
also appears to lack an occipital spine. However, this condition in the
type material in shale may be due to imperfect preservation, and there-
fore it was deemed preferable not to attempt identification with that
species. The pygidium resembles, besides N. saffordi, pygidia associ-
ated with the type cranidia of N. kingstonensis Resser. All these py-
gidia strongly differ from those of other species of the genus, such as
N. walcotti and N. halli illustrated herein, which have well-fused
pleural regions, a smooth posterior margin, and a border furrow, much
like pygidia of Norwoodia.
Occurrence.—Red beds at the base of the Nolichucky (Cedaria
zone) at locality cnd/1 (= U.S.N.M. loc. 27d).
Types——Holotype: U.S.N.M. 144614. Paratypes: U.S.N.M.
144615.
NORWOODELLA WALCOTTI Resser
Plate 4, figures 16-23
Norwoodella walcotti REsssEr, 1938a, p. 89, pl. 10, figs. 42, 54.
Available material—The hypodigm consists of cranidia flattened
in shale. Good cranidia, free checks, and pygidia in limestone occur in
the U.S.G.S. and author’s collections.
Description —Glabella entirely undefined on upper surface, except
for a faint indication of its anterior boundary. Occipital furrow obso-
lete ; occipital ring extended into a slender, horizontal spine. Frontal
area undifferentiated, somewhat downsloping. Palpebral area, as de-
terminable on exfoliated specimens, very narrow. Palpebral lobes
small, somewhat elevated. Anterior sections of facial suture convergent,
making the frontal portion of the cranidium very narrow, well rounded.
Posterior section directed almost straight outward from palpebral lobe,
NO. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 67
almost parallel to posterior cranidial margin, sharply curving back-
ward, cutting margin near base of genal spine. Genal spine slender, of
moderate length. Furrow on posterior area obsolete on outer surface,
impressed on interior cast. Free cheek completely lacking border fur-
row on outer surface, entirely convex, extended into a short, slender
strip that simulates a genal spine, but actually contributes to the
cephalic margin in a region in advance of the base of the genal spine
borne by the cranidium. Visual surface of eye convex, bean-shaped ;
facets indistinguishable.
Pygidium approximately semicircular, twice as wide as long. Facets
well developed. Posterior outline with uniform curvature. Axis well
defined anteriorly but merging with the pleural lobes posteriorly,
showing 2 rings plus a terminal indistinctly segmented section. Pleural
lobes entirely convex, lacking any furrows, showing barely a trace of
differentiated border. Surface of cranidium and free cheeks perfectly
smooth. Pleural lobes of pygidium with very fine, transverse terrace
lines only visible under conditions of perfect preservation.
Discussion.—This species is quite distinctive in the lack of all
furrows on the outer surface, and especially the narrowing of the
cranidium in front of the eyes. The pygidium is much like Norwoodia
gracilis and N. rogersvillensis and unlike Norwoodella saffordi, N.
kingstonensis, and N. rotundicollis. This fact would perhaps justify
redistributing the species hitherto referred to Norwoodia and Nor-
woodella on the basis of the pygidia, rather than the questionable
character of the structure of the frontal area. This revision should only
be undertaken when the pygidia of most species of this group are
known with certainty. For the present species the assignment is cer-
tain, since only one species of the Norwoodiidae occurred in the beds
yielding the material illustrated herein.
Occurrence.—Basal portion of the Nolichucky (Cedaria zone).
The type locality is U.S.N.M. 107a, NW. of Knoxville. The specimens
illustrated are from the collections cne/10, Comby Ridge (= U.S.G.S.
collection 2407), and cne/12 near Heiskell (the latter presumably
close to or identical with the type locality).
Types——Holotype and paratypes: U.S.N.M. 94880. Plesiotypes:
U.S.N.M. 144616-8.
NORWOODELLA HALLI Resser
Plate 4, figures 8-15
Norwoodella halli ResseEr, 1938a, p. 90, pl. 10, figs. 45, 46.
Norwoodella halli Resser, LocHMAN, 1940, p. 47, pl. 5, figs. 31-36.
The types are cranidia preserved in shale. Lochman gave a detailed
description of the species and figured unflattened limestone material
68 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
from Missouri, including the pygidium. The assignment of the two
parts of the shield is confirmed by the specimens illustrated herein.
Occurrence.—The type locality is U.S.N.M. 22t in the Thorn Hill
section, in the interval 45-133 feet above the base of the formation.
Also in author’s collection cnd/10, Comby Ridge.
Types.—Holotype and paratypes: U.S.N.M. 94883. Plesiotypes:
U.S.N.M. 144619.
Genus HOLCACEPHALUS Resser, 1939
Type species.—Holcacephalus granulatus Resser.
HOLCACEPHALUS GRANULATUS Resser
Plate 3, figures 12-14
Holcacephalus granulatus ResseEr, 1938a, p. 81, pl. 9, figs. 15-17.
Available material—tThe species, quite common at the type locality,
was not found elsewhere. All the available specimens lack the test.
Description.—Glabella definitely tapered, defined by a deep axial
furrow, with two pairs of short, but deep lateral furrows, and another
pair less distinct. Occipital furrow deep, occipital ring long (sag.),
bearing a short, very slender spine. Preglabellar field downsloping,
border narrow, well defined by the border furrow. Ocular ridges trans-
verse; palpebral lobes at level of anterior third of glabella; palpebral
area almost as wide as anterior portion of glabella. Posterior area
slender, slightly expanded distally, bearing a genal spine that is broken
off in almost all available specimens. Surface covered with relatively
large granules.
Pygidium twice as wide as long, subelliptical ; with posterior outline
slightly indented medially. Axis occupying almost entire length, with
4 prominent rings. Pleural lobes slightly convex, lacking border furrow
or border. Three pairs of pleurae are clearly separated by interpleural
grooves; each pleura is furrowed and the posterior band bears a row
of tubercles like those on the cranidium.
Discussion.—This species differs considerably from all others hith-
erto attributed to the genus in the tapered, deeply furrowed glabella.
Occurrence.—Red limestone beds at the base of the Nolichucky
(Cedaria zone) at U.S.N.M. locality 27d (= author’s locality cnd/1).
Types.—Cotypes: U.S.N.M. 94844. Plesiotypes: U.S.N.M. 144620.
HOLCACEPHALUS PRAECURSOR Rasetti, new species
Plate 3, figures 10, 11
Available material—Several cranidia and pygidia.
Description—Owing to the similarity to the preceding species, it is
sufficient to point out the differences. The anterior border is somewhat
wider and flat instead of convex ; the ocular ridges are more prominent ;
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 69
the cranidial surface has fewer and smaller granules than H. granu-
latus; these are barely apparent on the glabella and frontal area, being
more conspicuous on the palpebral and posterior areas. The pygidium
has the same structure as in H. granulatus, but here again the granules
are indistinct. The species attains a larger size, with cranidia 3-4 mm.
in length. This form may be ancestral to H. granulatus.
Occurrence.—Uppermost beds of Maryville limestone (Cedaria
zone) at locality cnc/1.
Types——Holotype: U.S.N.M. 144621. Paratypes: U.S.N.M.
144622.
Family CEDARIIDAE Raymond, 1937
Genus CEDARIA Walcoit, 1924
Type species —Cedaria prolifica Walcott.
CEDARIA TENNESSEENSIS Walcott
Plate 5, figures 4-8
Cedaria tennesseensis WAtcott, 1925, p. 79, pl. 17, figs. 22-25.
Cedaria tennesseensis Walcott, REssER, 1938a, p. 68, pl. 11, figs. 3-5.
Available material—The types are cranidia, free cheeks, and py-
gidia flattened in shale. Fragmentary material in limestone was col-
lected by the writer.
Description—Cranidium of moderate convexity. Glabella as in other
species of the genus. Frontal area sharply divided into preglabellar
field and border by a narrow border furrow; border flat, its sagittal
length more than half the length of the preglabellar field. Palpebral
area and lobe without specific features. Posterior area broad (exsag.),
the posterior section of the facial suture running outward and slightly
forward ; border furrow on posterior area turning forward for a con-
siderable distance. Anterior sections of facial suture less divergent
than in most other species of the genus. Free cheek with ocular plat-
form and border of about equal widths, separated by sharp border
furrow. Genal spine long and strong as in other species of Cedaria.
Pygidium 1.6 times as wide as long, almost elliptical, with anterior
angles widely rounded. Axis short, in larger individuals not exceeding
half of the pygidial length, showing about 3 rings plus a terminal sec-
tion. Pleural regions almost flat, wide, with 3 pairs of broad, shallow
furrows and a trace of a fourth, and indistinct interpleural grooves.
The furrows run straight through the pleural platform, change to a
more backward direction in passing onto the wide, slightly concave
border, and almost reach the pygidial margin. Pygidial doublure very
wide, its anterior margin well visible as an impression on the dorsal
side. Pygidial border with very fine, wavy lines.
Discussion—This species differs considerably from the type species,
70 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
C. prolifica, in the lesser divergence of the anterior section of the facial
suture, wider cephalic border, broader (exsag.) posterior area, py-
gidium more transverse, with shorter axis, fewer pleural segments,
and much wider border and doublure.
Occurrence.—The type locality is U.S.N.M. 107a, Copper Ridge,
NW. of Knoxville (very close to author’s locality cne/12). Collected
by the writer at localities cne/10, cne/12, cne/13. All the limestone
material is fragmentary, especially the cranidia.
Types.—Lectotype (designated herein): U.S.N.M. 70270. Para-
types: U.S.N.M. 70271-3. Plesiotypes: U.S.N.M. 144623.
Genus CEDARINA Lochman, 1940
Type species —Cedarina vale Lochman.
CEDARINA, species undetermined
Plate 5, figure 18
Available material—aA few pygidia, all lacking the test.
Description—Pygidium almost 3 times as wide as long. Axis ele-
vated, tapered, composed of 3 rings plus a terminal section, almost
reaching the posterior pygidial margin. Anterior outline of pleural
lobes slightly curved, anterior angles sharp, posterior margin with
shallow, rounded median notch. Three pairs of pleural furrows well
impressed, shallow interpleural grooves distinct near border. Border
furrow indistinct, border flat, narrow. Length of largest pygidium
3.3 mm., width 9.2 mm.
Discussion.—The pygidium closely resembles that of Cedarina vale
Lochman from Missouri. The pygidia of other species of the genus
described by Lochman from the West are all proportionately longer.
No definite identification can be made without the cranidium.
Occurrence.—Rare in the red beds at the base of the Nolichucky
(Cedaria zone) at locality cnd/1.
Disposition of material_—Figured specimen: U.S.N.M. 144624.
Genus LLANOASPIS Lochman, 1938
Type species —Llanoaspis modesta Lochman.
LLANOASPIS WALCOTTI (Resser )
Plate 8, figures 14-16
Genevievella walcotti RessEr, 1938a, p. 77, pl. 15, figs. 3-5.
Genevievella rogersvillensis REsSER, 1938a, p. 78, pl. 15, figs. 16-18.
Rogersvillia rogersvillensis (Resser) Huré, 1953, p. 182, fig. 159.
Palmer (1954) placed a number of described species of the genus,
including walcotti, in the synonymy of the type species. While the
writer agrees that not all the described forms are distinguishable, he
believes that the one here discussed is readily separable by the shape
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 71
of the pygidium, which completely lacks the lateral expansion of the
posterior border clearly apparent in the specimens of L. modesta fig-
ured by Lochman (1938) and Palmer (1954).
The type specimens of walcotti are preserved in limestone, while
those of rogersvillensis are flattened in shale, but there seems to be no
specific difference between the two.
Occurrence.—Type locality for L. rogersvillensis is U.S.N.M. 24m,
near Rogersville. Type locality for L. walcotti is U.S.N.M. 107, NW.
of Knoxville. The figured specimens are from the uppermost beds of
the lower limestone member of the Nolichucky (Crepicephalus zone)
at locality cnn/3.
Types.—Holotype and paratypes of L. rogersvillensis: U.S.N.M.
94974-5. Holotype and paratypes of L. walcotti: U.S.N.M. 94970-1.
Plesiotypes: U.S.N.M. 144625.
Genus GENEVIEVELLA Lochman, 1936
Type species—Genevievella neunia Lochman.
GENEVIEVELLA, species undetermined
Plate 5, figures 9-11
Known from several cranidia. The shape and convexity of glabella,
frontal area and posterior area are about the same as in the type spe-
cies. However, the present form lacks the strong elevation of the
palpebral area and palpebral lobes present in G. neunia. As the material
is scarce, imperfectly preserved, and from different localities, it does
not warrant naming a new species.
Occurrence.—A large cranidium was collected from locality cnc/4,
and another from locality cnc/2, both in the uppermost Maryville
limestone. Further material was collected in limestone beds or lenses
at the base of the Nolichucky (localities cnd/1, cne/2). All these beds
belong in the Cedaria zone.
Disposition of material—Figured specimens: U.S.N.M. 144626-7.
Family ELVINIIDAE Kobayashi, 1935
Genus DUNDERBERGIA Walcott, 1924
Type species —Crepicephalus (Loganellus)nitidus Hall and Whit-
field.
DUNDERBERGIA TENNESSEENSIS Rasetti, new species
Plate 15, figures 1-12
Available material—Several cranidia and free cheeks, two pygidia,
and one tentatively assigned hypostome.
Description—Glabella of fairly strong convexity, straight-sided,
tapered, somewhat truncate in front, defined by deep axial furrows
laterally, shallower furrow in front. Three pairs of lateral furrows;
TL, SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
posterior pair very oblique, moderately deep; third pair shorter and
shallower, directed slightly backward; second pair very short and
shallow, directed slightly forward. Occipital furrow deep, occipital ring
bearing a node. Preglabellar field slightly convex longitudinally and
more or less downsloping in different individuals. Border furrow well
impressed, in some cranidia showing an indication of the median angle
more marked in several other species of the genus. Border somewhat
convex, not greatly tapered laterally ; midlength (sag.) of border about
half the length of preglabellar field. In anterior view the border appears
fairly arched transversely in some cranidia, especially the larger ones,
rather flat in smaller individuals. It was considered whether this might
be a specific distinction ; however, since the two kinds are mixed in the
collections from both localities where the species was found, it was
thought more likely that the differences are due either to growth
stages, to intraspecific variability, or both. Palpebral area somewhat
convex, on average horizontal, half as wide as glabella. Ocular ridges
straight, slanted backward, more strongly so in the larger cranidia.
Palpebral lobe defined by deep furrow even on upper surface, narrow,
strongly curved, somewhat convex transversely, 0.20 to 0.25 times as
long as glabella; distance from posterior margin greater than length
of lobe. Anterior section of facial suture as divergent as in an average
Aphelaspis. Posterior area slender, somewhat narrower (tr.) than
occipital ring. Ocular platform moderately convex. Border on free
cheek of uniform width, almost flat, defined by shallow furrow; genal
spine strong, of moderate length.
All portions of the cranidial surface except in the furrows covered
with granules, usually of two sizes, although in some of the cranidia
only the larger granules are distinct. The border of the free cheek has,
in addition to dense, fine granules, a few scattered, somewhat larger
granules. Length of largest (holotype) cranidium 15 mm.
Pygidium twice as wide as long. Axis large, wider than the pleural
lobe, elevated, subcylindrical, rounded at the extremity, extended into
a short postaxial ridge reaching the posterior margin. First two axial
rings well defined, the rest merging into a terminal section. Pleural
platforms without much relief, with 2 pairs of broad, rather indefinite
furrows. Border rather narrow, flat, poorly defined. In posterior view
the posterior margin appears elevated medially. Surface finely granu-
late.
Discussion—The cranidium seems definitely referable to Dunder-
bergia and shows most similarity to D. bigranulosa Palmer (1960)
and D. anytus (Hall and Whitfield), both from Nevada. The pygidium
also closely agrees with pygidia of Dunderbergia figured by Palmer.
D. bigranulosa is from the Dunderbergia zone, while the stratigraphic
position of D. anytus does not seem to be known with certainty.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 73
Occurrence-—Uppermost Aphelaspis zone, in association with
Aphelaspis tarda. The type locality is cnw/14, Shields Ridge. Also in
collections cnw/20, Washburn, and cnu/7, Purchase Ridge, Scott
County, Va.
Types.—Holotype: U.S.N.M. 144628. Paratypes: U.S.N.M.
144629-31.
DUNDERBERGIA LONGIFRONS Rasetti, new species
Plate 15, figures 13-18
Available material—sSeveral cranidia and one pygidium.
Description —Glabella strongly convex transversely and fairly con-
vex longitudinally, slightly tapered, rounded in front, with 2 pairs of
shallow lateral furrows. Occipital furrow deep, occipital ring lacking a
distinct node. Frontal area relatively short; preglabellar field steeply
downsloping ; border convex, elevated. Palpebral area convex trans-
versely, on the average horizontal; ocular ridges low and broad; pal-
pebral lobes well defined by furrow even on outer surface, slightly more
anterior with respect to the glabella than in the preceding species.
Anterior section of facial suture weakly divergent; posterior section
and posterior area not entirely preserved.
Pygidial axis broad, elevated, showing two very distinct rings and
a terminal section with a third shallow ring furrow ; axis extended into
a broad postaxial ridge. Pleural regions with 3 distinct pairs of broad
furrows; interpleural grooves lacking. Border furrow broad, border
narrow, poorly defined. The posterior outline shows a faint median
notch in dorsal view and is elevated medially in posterior view.
Surface of both shields covered with moderately elevated granules.
Length of largest (holotype) cranidium 6 mm. Length of pygidium
1.3 mm., width 2.4 mm.
Discussion.—The species differs from D. tennesseensis and most
other forms of the genus in the proportionately longer glabella relative
to the entire cranidium.
Occurrence.—U.S.G.S. collection 2970, Monroe County. The asso-
ciation of species at that locality indicates the middle Aphelaspis zone.
Types.—Holotype: U.S.N.M. 144632. Paratypes: U.S.N.M.
144633.
Family PTEROCEPHALIIDAE Kobayashi, 1935
Genus APHELASPIS Resser, 1935
Type species —A phelaspis walcotti Resser.
The study of the species of Aphelaspis from the southern Appala-
chians presents such taxonomic problems as may be expected when
thousands of individuals from numerous localities and slightly differ-
74 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
ent horizons are available. Each thin limestone bed or lens, where the
well-preserved material occurs, shows a population with a certain
range of variability, but often statistically distinguishable from those
occurring in lower or higher beds. In certain cases the range of varia-
tion within a population is such that extreme individuals overlap in
several features those of different populations. Nevertheless, as mate-
rial from a larger number of localities was studied, 17 well-character-
ized species emerged. Most of these could be found at a number of
different localities in the same stratigraphic order, hence are valuable
for correlation.
A favorable factor in the study of this difficult genus was offered
by the frequent occurrence in a single bed or lens of a coquina of
fragments of a single species. Hence the various parts could be
assigned unequivocally for all the species described herein. Less fre-
quently 2 species occurred in the same bed, and only 1 association of 3
species (A. camiro, laxa, and quadrata) was observed.
Difficulties in identification resulted from the presence in some beds
of only immature forms of species that occur in much larger sizes
at other localities. Cranidia less than 4 or 5 mm. in length are often
indeterminable. Exfoliated specimens are difficult to compare accu-
rately with individuals preserving the test; the latter were chosen
almost exclusively for the descriptions and illustrations. Material pre-
served in shale or siltstone can seldom be specifically identified.
Virtually all the specimens collected could be assigned to the species
discussed herein. However, it is to be expected that future collections
from new localities will yield further new species, owing to the fact
that fossiliferous limestone beds in shale may occur at slightly different
horizons at different places.
In agreement with Palmer (1962b), Proaulacopleura Kobayashi,
1936, Clevelandella Resser, 1938, and Labiostria Palmer, 1954, are
here considered subjective synonyms of Aphelaspis.
The characters of the genus have been described in great detail by
Palmer (1954, 1962b). Only one point concerning ornamentation will
be mentioned here. The upper surface of the test in the southern Ap-
palachian species is either perfectly smooth, or finely punctate, in
some species only in the furrows (A. inermis, A. arsoides, A. pal-
merit). The inner surface is invariably very finely granulate, and the
internal impression therefore finely and densely pitted. Lack of com-
ment on ornamentation in the specific descriptions means that the
outer surface is entirely smooth.
The characters most frequently used for specific discrimination are
the following.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI IAS
(1) The width of the palpebral area relative to the glabellar width
at the same level.
(2) The sagittal length of the frontal area relative to the length
of glabella, including the occipital ring.
(3) The relative sagittal lengths of preglabellar field and border.
This ratio and the preceding one, although of undoubted statistical
significance, were found variable within a population for some of the
species (e.g., A tarda, A. camiro). Such variations appeared uncor-
related with either stratigraphic position or size of the cranidia.
(4) The (exsagittal) length of the palpebral lobes relative to the
length of glabella inclusive of occipital ring.
(5) The (exsagittal) length of the palpebral lobe relative to the
exsagittal distance between the posterior end of the palpebral lobe
and the posterior cranidial margin.
(6) The (transverse) width of the posterior area relative to the
width of the occipital ring.
(7) The angle of divergence of the anterior sections of the facial
suture and the more or less sharp change of direction of the suture
in crossing the anterior border furrow. The posterior section of the
facial suture has the same course in all species.
(8) The slope of the palpebral area, also a somewhat variable
feature within a population.
(9) The slope and convexity of the preglabellar field and the
more or less sharp angle formed by the border with respect to the pre-
glabellar field. These features show large intraspecific variability,
e.g.,in A. laxa and A. tarda.
(10) The free cheeks in some cases offered useful characteristics
in the features of the border and genal spine.
(11) The pygidia may be virtually indistinguishable for several
species. In other cases species whose cranidia are very similar may
show quite different pygidia.
All the species previously described from Virginia and Tennessee
by Walcott (1916a) and Resser (1938a) could be found again, repre-
sented by more abundant and better preserved material, and with
three exceptions are discussed herein. Saratogia aruno Walcott and
Clevelandella nitida Resser are specifically undetermined forms of
Aphelaspis possessing an occipital spine, presumably identical with
either A. arses or A. arsoides. Aphelaspis hamblenensis is based on a
complete exoskeleton flattened and weathered in shale; since individ-
uals so preserved do not preserve the specific features, the name should
be restricted to the holotype. In these three cases the stratigraphic
position of the type specimens is unknown.
76 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
APHELASPIS WALCOTTI Resser
Plate 18, figures 10-20
Aphelaspis walcotti REssER, 1938a, p. 59, pl. 13, fig. 14.
Aphelaspis walcotti Resser, PALMER, 1962b, p. 33, pl. 4, figs. 24, 28, 33.
Aphelaspis simulans REssER, 1938a, p. 59, pl. 13, figs. 19-21.
Available material—The hypodigm of A. walcotti consists of sev-
eral cranidia, free cheeks, and pygidia, moderately well preserved and
exfoliated. The types of A. simulans also include cranidia, free cheeks,
and pygidia. Abundant material from the author’s collections at various
localities is also available.
Description —Cranidium with less relief than average in the genus.
Glabella defined by a shallow axial furrow on outer surface, weakly
convex. Preglabellar field moderately downsloping and somewhat
convex. Border flat, forming sharp angle with preglabellar field.
Frontal area on average 0.6 times the length of glabella plus occipital
ring. Sagittal length of border averaging slightly less than the length
of preglabellar field. Palpebral area of average width, from slightly
upsloping to horizontal. Ocular ridges very faint, almost transverse
to slightly slanted backward. Palpebral lobe averaging somewhat more
than one-third the length of glabella plus occipital ring; distance from
posterior end of palpebral lobe to posterior margin greater than length
of palpebral lobe. Anterior section of facial suture with average diver-
gence ; anterior angles of cranidium more widely rounded than in most
species. Width (tr.) of posterior area less than width of occipital ring.
Free cheek with ocular platform of low convexity. Border slightly
concave, upturned, not defined by furrow or sharp change in slope.
Genal spine flat on upper side, of less than average length, rather
rapidly tapered.
Pygidium 3 times as wide as long. Anterior margin almost straight ;
anterior angles sharp. Axis short, showing 2 or 3 rings plus a terminal
section. Pleural lobes flat, with furrows and interpleural grooves,
almost indistinct on outer surface, well marked on internal impression.
Border flat, very narrow medially.
Length of largest cranidium collected 15 mm.
Discussion —Careful examination of the types of Aphelaspis simu-
Jans and additional topotype material preserved in the U.S. National
Museum indicates that the species may be definitely synonymized
with A. walcotit. Aphelaspis simulans is based on a population show-
ing a slightly greater relief of the cranidial parts than the average in
A. walcotti, in particular, definitely upsloping palpebral area ; however,
the differences are not consistent among individual cranidia and fall
within the range of variability observed within a single population.
The pygidium also fully agrees with that of typical A. walcotti.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 77
The species is closest to A. bridget, A. quadrata, and A. tarda. The
differences will be discussed in describing these species.
Palmer (1954) assigned to Aphelaspis walcotti material from Texas
which seems to include excessive variation to represent a single spe-
cies. The Texas pygidia differ considerably from the Tennessee forms,
hence it appears doubtful that the species exists in Texas. Cranidia
from Wyoming illustrated by Shaw (1956) certainly do not belong
to the species.
Occurrence.—The type locality is U.S.N.M. 10u, near Saltville, Va.
The type locality for A. simulans is U.S.N.M. 117d, near Washburn,
Grainger County. Collected by the author at localities cnq/4, cnr/15,
enr/16, cnq/16, cnr’/17, and cnq/20.
Types.—Holotype and paratypes: U.S.N.M. 94923. Holotype and
paratypes of Aphelaspis simulans: U.S.N.M. 94925-6. Plesiotypes:
U.S.N.M. 14463244.
APHELASPIS BRIDGET Rasetti, new species
Plate 13, figures 1-7
Available material—lLarge numbers of cranidia and less numerous
free cheeks and pygidia well preserved in limestone.
Description—Glabella defined by a shallow axial furrow, of usual
shape. Occipital furrow shallow, occipital ring bearing a small node.
Frontal area about 0.55 times as long as glabella. Preglabellar field
somewhat convex longitudinally; border sharply defined by border
furrow and change in slope, slightly convex, approximately horizon-
tal; sagittal length of border almost equaling preglabellar field. Pal-
pebral area slightly downsloping, 0.4 times as wide as glabella. Aver-
age exsagittal length of palpebral lobe 0.34 times length of glabella
plus occipital ring and 0.84 times distance from posterior end of
palpebral lobe to posterior cranidial margin. Ocular ridges faint,
somewhat slanted backward. Width (tr.) of posterior area 0.8 times
the width of the occipital ring.
Free cheek with flat border defined by shallow border furrow; genal
spine flat on upper side, of moderate length.
Pygidium about 2.8 times as wide as long. Axis tapered, showing
2 or 3 well-defined rings and a terminal section. Anterior outline of
pleural region almost straight, without apparent geniculation. Anterior
angles rounded, posterior margin regularly curved. Three pairs of
pleural furrows very distinct ; interpleural grooves faint. Furrows and
grooves not extending to narrow, flat border.
Surface of all parts of test smooth. Length of large cranidium
10 mm. Length of largest pygidium 4.3 mm., width 12 mm.
Discussion.—This species is very close to A. walcotti, from which
78 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
it may be distinguished, at least statistically, by the slightly down-
sloping palpebral area, flat rather than concave border of the free
cheeks, and more deeply furrowed pygidium. In some respects the
species is transitional between A. lata and A. walcottt.
Occurrence.—U.S.G.S. collection 2804, from N. slope of Shields
Ridge on New Market—Piedmont road, in upper part of lower lime-
stone unit of the Nolichucky. The association with Blountia bristolen-
sis and Glaphyraspis ornata shows that the species belongs to the
lower portion of the Aphelaspis zone. The author was unable to
collect fossils from this portion of the zone at the locality. The nearby
locality at Russell Gap yielded fossils of the basal Aphelaspis zone,
including, in ascending order, Aphelaspis lata and A. minor. The
present species presumably occurs in higher beds, but lower than
those which yielded Aphelaspis camiro, A. laxa, and A. quadrata at
their type locality, U.S.N.M. 120, which is also on the New Market-
Piedmont road.
Types——Holotype: U.S.N.M. 144635. Paratypes: U.S.N.M.
144636.
APHELASPIS QUADRATA Resser
Plate 18, figures 1-9
Aphelaspis quadrata REsSER, 1938a, p. 59, pl. 13, figs. 16-17.
Available material_—The holotype is a large, somewhat incomplete
cranidium. The collection from the type locality includes several
cranidia and pygidia, from which a clear picture of the specific char-
acters can be gathered. The species was collected by Dr. Oder and the
writer from the Three Springs, Washburn, and Smith Hollow sec-
tions. Free cheek and pygidium were unequivocally identified.
Description—Glabella of average shape and convexity, defined by
a well-impressed axial furrow. Preglabellar field downsloping, of
moderate and fairly uniform convexity. Border averaging two-thirds
of the sagittal length of preglabellar field, upturned and hence forming
a sharp angle with the preglabellar field, almost flat; border furrow
uniformly curved. Frontal area on average 0.50 times as long as
glabella inclusive of occipital ring. Palpebral area slightly convex,
horizontal to slightly upsloping. Ocular ridges definitely slanted back-
ward. Length of palpebral lobe 0.25 times length of glabella plus
occipital ring, and 0.7 times distance from posterior end of palpebral
lobe to posterior margin. Anterior section of facial suture with average
divergence. Width (tr.) of posterior area equals width of occipital
ring.
Free cheek with fairly convex ocular platform. Border flat, up-
turned. Genal spine relatively short, rapidly tapered.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 79
Pygidium 2.3 times as wide as long. Anterior margin definitely
curving backward. Axis elevated, tapered, showing 3 rings plus a
terminal section. Pleural lobes with distinct furrows and shallower
interpleural grooves even on outer surface. Border flat, narrower
medially ; margin with slight median inbend.
Length of largest cranidium about 15 mm.
Discussion.—This species may be compared with A. laxa and A.
walcotti. From laxa it differs consistently in the somewhat more con-
vex glabella, less bulging preglabellar field, more posterior position
of the eyes, and shorter (tr.) posterior area. The pygidium is propor-
tionately narrower and more strongly furrowed. Compared with A.
walcotti, A. quadrata has a cranidium with greater relief, lesser rela-
tive sagittal length of border relative to preglabellar field, and the
pygidium has a more curved anterior margin.
Occurrence.—The type locality is U.S.N.M. 120, Shields Ridge.
Although material under this label includes collections from different
horizons, the association of the species with A. camiro and A. laxa is
proved by the occurrence of the three species on the same piece of
rock. Also collected by the author at localities cns/15, cns/16, cnr/20
and enr’/20, in association with the equally common A. camiro and
rare specimens of A. laxa.
Types.—Holotype and paratypes: U.S.N.M. 94924. Plesiotypes:
U.S.N.M. 144637-8.
APHELASPIS TARDA Rasetti, new species
Plate 20, figures 1-18
Available material—Large numbers of cranidia, free cheeks, and
pygidia from several localities, both preserving the test and exfoliated.
Description—Glabella of average shape and convexity; occipital
ring bearing a median node. Frontal area averaging 0.65 times the
glabellar length, but showing wide variation in this ratio, uncorrelated
with size, locality, or horizon. Preglabellar field more or less convex
longitudinally ; border flat, forming sharp angle with preglabellar field.
Sagittal length of border on average half of that of preglabellar field;
this ratio is also highly variable. Palpebral area and lobe always more
or less upsloping; palpebral area from 0.3 to 0.4 times as wide as
glabella. Ocular ridges transverse to slightly slanted backward. Length
of palpebral lobe about 0.4 times glabellar length and equal to distance
to posterior margin. Width (tr.) of posterior area 0.8 times the width
of occipital ring.
Free cheeks with border furrow distinct and border of variable
width, flat to somewhat convex. Genal spine subcylindrical, rather flat
on upper side, wide at the base, of moderate length.
80 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Pygidium 2.5 times as wide as long. Axis showing 2 or 3 distinct
rings on outer surface. Anterior outline of pleural lobes gradually
curving backward without sharp geniculation, anterior angles more
or less rounded. Pleural platforms with very faint furrows on outer
surface ; border furrow and border indefinite.
Length of largest cranidium 18 mm. Length of largest pygidium
4 mm., width 10 mm.
Discussion—The numerous populations of this species observed
show individual variability, especially in the relative proportions of
border, preglabellar field, and glabellar length. Single cranidia with
short preglabellar field and long border may be confused with A. wal-
cotti and possibly other species. However, statistically the species is
fairly well defined. The considerable length of the preglabellar field
in most individuals, the upsloping palpebral area, definite flat border
and border furrow on the free cheeks, and the characteristic pygidium
with well-rounded anterior angles clearly distinguish a population of
A. tarda from one of A. walcottt. The two species are rather widely
separated stratigraphically, and no transition forms were observed in
intermediate beds.
Occurrence-——Common at every locality where fossiliferous beds
of the upper Aphelaspis zone are developed. The type locality is
cnw/20, Washburn. Also present in collections cnu/1, cnv/1, cnw/1,
enw/14, cnu/15, cnv/15, cnx/20, cnu/21, cnv/21 and Oder’s collec-
tion No. 14A. The species is also common in beds cnu/7, cnv/7 and
cnv’/7 in the Purchase Ridge section, Scott County, Va.
Types.—Holotype: U.S.N.M. 144639. Paratypes: U.S.N.M.
144640-2.
APHELASPIS LAXA Resser
Plate 12, figures 18-21; plate 13, figures 8-15
Aphelaspis laxa REssER, 1938a, p. 60, pl. 13, fig. 18.
Available material—The holotype is an exfoliated cranidium lack-
ing the palpebral lobes and part of the anterior border. Several para-
type cranidia are much better preserved, and further topotype material
exists in the U.S. National Museum collections. The species also
occurs in several of the author’s collections, represented by cranidia,
free cheeks, and pygidia.
Description —Glabella of low convexity, rising little above the level
of the cheeks, but defined at least laterally by a rather deep axial
furrow. Frontal area about 0.6 times the glabellar length. Preglabellar
field strongly convex longitudinally, hence sloping down steeply to
border furrow. Border almost flat, horizontal ; sagittal length of border
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 81
more than half the length of preglabellar field. Palpebral area 0.4
times as wide as glabella, approximately horizontal; ocular ridges
faint, with transverse course. Sagittal length of palpebral lobe 0.3
times the glabellar length, and about 0.6 times the distance from pos-
terior end of palpebral lobe to posterior margin. Width (tr.) of
posterior area 1.1 times the width of occipital ring.
Free cheek with relatively convex ocular platform, and wide, flat
border upturned with respect to platform. Genal spine broad at base,
rather rapidly tapered, flat on upper side, in most specimens somewhat
curving upward. Depression at end of posterior border furrow deeper
than in most species of the genus.
Pygidium definitely identified from collections where the species
occurs alone. Pygidium about 3 times as wide as long; anterior margin
fairly straight, anterior angles narrowly rounded. Axis tapered, show-
ing 2 and sometimes 3 rings plus a terminal section. Two or three
pairs of broad, shallow pleural furrows usually visible; some speci-
mens also show a trace of interpleural grooves.
Length of largest cranidia 16 mm. Length of largest pygidium 5
mm., width 15 mm.
Discussion—The species is well distinguished, at least statistically,
by the low glabella, strongly convex preglabellar field, anterior posi-
tion of the eyes, and considerable width (tr.) of the posterior area.
However, single cranidia, especially if incompletely preserved, may
be confused with such species as A. walcotti, A. quadrata, and A.
tarda. The pygidium resembles those of A. walcotti and A. bridget.
Occurrence.—The type locality is U.S.N.M. 120 on Shields Ridge;
beds holding this species are not now exposed at that locality. The
stratigraphic position of the species is well established by its occur-
rence in the author’s collections cns/4, cns/15, cns/16, cns’/15,
enr/20, and cnr’/20.
Types.—Holotype and paratypes: U.S.N.M. 94929. Plesiotypes:
U.S.N.M. 144643-5.
APHELASPIS PALMERI Rasetti, new species
Plate 14, figures 13-19
Available material—Several cranidia, free cheeks, hypostomes, and
pygidia.
Description—Glabella of average shape and convexity; occipital
ring bearing a small node. Preglabellar field convex longitudinally,
steeply downsloping in anterior portion, forming sharp angle with
horizontal, slightly convex border. Preglabellar field about one and
one-half times as long (sag.) as border; entire frontal area about
82 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
three-fourths the length of glabella plus occipital ring. Border furrow
showing in most specimens a slight median inbend. Palpebral area
half of the glabellar width, slightly upsloping ; ocular ridge transverse.
Palpebral lobe 0.4 times the length of glabella plus occipital ring;
distance to posterior cranidial margin slightly greater than length of
palpebral lobe. Anterior facial sutures slightly more divergent than
the average in the genus; anterior angles of cranidium more widely
rounded than in most species. Posterior area as wide (tr.) as occipital
ring. Free cheek with wide border well defined anteriorly, the border
furrow fading out posteriorly; genal spine convex on upper face,
rather long, somewhat curving inward.
Pygidium somewhat more than twice as wide as long. Axis occupy-
ing somewhat less than a third of the width, tapered, showing at least
on internal impression 3 rings plus a terminal section, extended into
a broad, low postaxial ridge. Anterior outline of pleural lobes and
furrows curving backward, producing well-rounded anterior angles.
Doublure fairly wide laterally, reduced medially. Posterior margin
rather straight in median portion, with suggestion of a slight median
notch.
Surface of cranidium and free cheeks punctate in the furrows,
especially in the anterior border furrow where the puncta are larger.
Length of largest (holotype) cranidium 20 mm. Length of pygidium
2.6 mm., width 5.5 mm.
Discussion.—The cranidium is somewhat similar to A. laxa in the
longitudinal profile of the frontal area, differing from that species in
the proportionately longer (sag.) border, more widely rounded anter-
ior angles, longer palpebral lobe, lesser distance from palpebral lobe
to posterior margin, narrower (tr.) posterior area, and punctate sur-
face. The pygidium is unlike A. Jaxa and much more like A. tarda in
the lesser relative width and rounded sides. The rather strong diver-
gence of the anterior facial sutures and median inbend of the border
furrow give the cranidia of this species some resemblance to Aphelaspi-
della macropyge, but the pygidium is definitely of the Aphelaspis type.
Occurrence.—The type locality is U.S.G.S. 2970, Monroe County,
where it occurs in association with Aphelaspidella macropyge, Aphe-
laspis arses, and Paraphelaspis vigilans. These species indicate the
lower portion of the middle Aphelaspis zone. A few, imperfect cranidia
in the collection cnq’/4 from the Lost Creek section may belong to
this species, but, especially in the absence of the pygidia, cannot be
distinguished with certainty from A. lara. The stratigraphic position
would confirm the assignment indicated above.
Types—Holotype: U.S.N.M. 144646. Paratypes: U.S.N.M.
144647.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 83
APHELASPIS CAMIRO ( Walcott)
Plate 12, figures 1-17
Crepicephalus camiro Watcott (part), 1916a, p. 205, pl. 32, figs. 2, 2’.
Uncaspis camiro (Walcott) Kopayasut, 1935, p. 279.
Aphelaspis camiro (Walcott) REsseEr, 1938a, p. 60, pl. 13, fig. 27.
Available material—Resser properly restricted the name to Wal-
cott’s holotype cranidium, excluding the pygidium which not only does
not belong to the species, but probably is a trilobite of the Crepiceph-
alus zone. The hypodigm includes a number of paratype cranidia well
preserved in limestone. The species was collected at other localities
by Dr. Oder and the author. From these collections the proper free
cheek and pygidium could be identified unequivocally. Many of these
pygidia were then discovered in the collection from the type locality
in the U.S. National Museum.
Description——Glabella somewhat smaller in proportion to the cra-
nidium than in other species of the genus. Occipital ring bearing a
small node near the posterior margin. Frontal area unusually long,
averaging 0.8 times the glabellar length; as in other species, however,
this ratio varies considerably among the individuals from one bed.
Anterior sections of facial sutures diverging at average angle, making
the cranidium very wide between the anterior angles. Border furrow
better impressed than usual in the genus. Border slightly convex, its
sagittal length averaging two-thirds the length of preglabellar field;
border furrow showing in most, but not all, specimens a definite
median inbend, and generally pitted on the outer surface. Preglabellar
field as a whole rather flat, showing a low median boss. Palpebral area
upsloping, about half the glabellar width. Ocular ridges transverse
to slightly slanted backward. Palpebral lobe averaging 0.3 times the
glabellar length, and about 0.5 times the distance from posterior end
of palpebral lobe to posterior margin. Posterior area at least as wide
(tr). as occipital ring. Length of largest observed cranidium 22 mm.
Free cheek with distinct, flat border set off by definite furrow,
deeper in anterior portion, and long, slowly tapered genal spine, flat
on the upper side.
Pygidium on average 1.75 times as wide as long, with a somewhat
pointed shape. Axis relatively large, prominent, tapered, rounded pos-
teriorly, showing 3 very distinct rings plus a terminal section. Anterior
outline of pleural lobes after a short transverse course turning back-
ward like the first pair of pleural furrows. Two other pairs of furrows
may be faintly indicated. Border furrow and border poorly defined.
Length of largest pygidium 3.8 mm., width 6.8 mm.
Discussion.—This is one of the most distinctive species of Aphe-
laspis. Larger cranidia may be distinguished by the long frontal area.
84 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
upsloping palpebral area, flat preglabellar field with a more or less
distinct preglabellar boss, and anterior position of the eyes. The
pygidium is unique in its relatively long and narrow shape and well-
rounded sides. Immature cranidia, however, are not always easily
distinguishable from those of associated species.
Occurrence.—The type locality is U.S.N.M. 120, Shields Ridge
(see discussion of A. quadrata and A. laxa). Also collected by the
author at localities cns/4, cens/15, cns/16, enr/20, and cnr’/20.
Types.—Holotype and paratypes: U.S.N.M. 61672. Plesiotypes:
U.S.N.M. 144648-51.
APHELASPIS ROTUNDATA Rasetti, new species
Plate 14, figures 1-12
Available material—Numerous cranidia, free cheeks, and pygidia,
and a few hypostomes. Most of the specimens lack the test.
Description —Cranidium with low relief. Glabella and occipital
ring without distinctive features. Preglabellar field slightly down-
sloping, with little convexity; border furrow better defined than in
most species; border elevated, somewhat convex. Total length (sag.)
of frontal area averaging 0.6 times the length of glabella plus occipital
ring; midlength (sag.) of border about 0.3 times the midlength of
preglabellar field. Palpebral area averaging somewhat less than half
the glabellar width, upsloping ; palpebral lobe also upsloping, defined
by shallow furrow even on outer surface. Exsagittal length of pal-
pebral lobe about 0.4 times the length of glabella plus occipital ring;
exsagittal distance to posterior margin equal to length of palpebral
lobe. Posterior area slender, about as wide (tr.) as occipital ring.
Anterior sections of facial suture on the average more divergent than
in most species, but there is considerable variability in this character
among the population from a single thin bed. Free cheek with well-
defined, flat border; genal spine flat dorsally at least in basal part,
very long.
Pygidium twice as wide as long. Outline oval, lacking definite
geniculation on anterior margin, widely rounded laterally, not notched
but elevated medially. Axis stout, composed of 3 rings plus a terminal
section, extended into a broad postaxial ridge that reaches the margin.
Pleural platforms downsloping, giving pygidium considerable relief
compared to other species. Pleural furrows and grooves shallow, the
first furrow curving backward to follow the curvature of the margin.
Border flat, poorly defined ; doublure wide laterally, tapering medially.
Surface of test smooth, except for the genal coeca showing faintly
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 85
on outer surface on preglabellar field and ocular platform, well marked
on internal impression. Length of largest cranidium 21 mm.; length
of largest pygidium 7 mm., width 14 mm.
Discussion.—This is a large species, whose cranidia somewhat re-
semble A. camiro. They differ in the narrower and more elevated
anterior border, proportionately longer palpebral lobes, and lesser
width (tr.) of the posterior area. The free cheek and genal spine are
also very similar to that species. The pygidium is quite distinctive,
with a proportionately narrower axis and regularly oval rather than
subtrapezoidal outline.
Unless careful attention is paid to the divergence of the anterior
sections of the facial suture, cranidia of Aphelaspis rotundata may be
confused with those of the associated species Aphelaspidella macro-
pyge. Even though there is some variability in the divergence of the
sutures in either species, usually well-preserved cranidia can be classi-
fied on this character alone. The pygidia are immediately distinguish-
able, although the pygidium of Aphelaspis rotundata, with its doublure
wider than in most species of the genus, approaches in shape the
pygidium of Aphelaspidella.
Occurrence-—Medial portion of the Aphelaspis zone, in association
with Aphelaspis arses, Aphelaspidella macropyge, and Paraphelaspis
vigilans. The type locality is cns/20, Washburn. Also present in col-
lections cns/20a, Washburn, cnq”/4, Lost Creek, and cns’/15, cns”/
15, Three Springs.
Types—Holotype: U.S.N.M. 144652. Paratypes: U.S.N.M.
1446534.
APHELASPIS WASHBURNENSIS Rasetti, new species
Plate 17, figures 15-23
Available material—Several cranidia, free cheeks, and pygidia.
Description ——Glabella relatively small in proportion to cranidium,
of low convexity but defined by a fairly deep axial furrow. Frontal
area averaging 0.75 times the length of glabella plus occipital ring.
Preglabellar field tumid, strongly downsloping in anterior portion ;
border well defined by sharp change in slope, about half as long (sag.)
as preglabellar field. Palpebral area somewhat upsloping, unusually
wide (somewhat more than half the glabellar width) ; ocular ridges
transverse ; palpebral lobes about 0.3 times the length of glabella plus
occipital ring; distance from posterior end of palpebral lobe to pos-
terior margin about equaling length of palpebral lobe. Anterior section
of facial suture diverging at average angle; anterior angles of cra-
86 SMITHSONIAN MISCELLANEOUS COLLECTIONS VoL. 148
nidium fairly sharp. Posterior area slender, considerably wider (tr.)
than occipital ring.
Free check with relatively narrow and well-defined border; border
furrow becoming obsolete along posterior portion of lateral margin.
Genal spine rather broad-based, flat on dorsal side, of average length.
Pygidium slightly more than twice as wide as long; axis prominent,
showing 2 rings plus a terminal, indistinctly segmented section, oc-
cupying more than two-thirds of pygidial length. Pleural regions with
2 pairs of broad pleural furrows and traces of interpleural grooves;
border flat, fairly wide.
Surface of test smooth except for more or less distinct puncta in
the depressions, especially the anterior border furrow. Length of holo-
type cranidium 15 mm.
Discussion.—The combination of cranidium and pygidium forms a
distinctive species. The cranidium differs from most of the known
species of Aphelaspis in the relative width of the palpebral area; other
species that have a wide palpebral area (A. lata, A. buttsi) are quite
different in other cranidial features. The low glabella and tumid pre-
glabellar field recall A. laxa, in which, however, the palpebral area is
narrow and the palpebral lobes are more anteriorly situated. The
pygidium resembles none of the above-mentioned species, being simi-
lar to A. rotundata and A. palmeri.
As far as can be ascertained from the scarce and mostly fragmentary
material, the species is rather variable in most of its features. At both
localities where it was collected, A. washburnensis occurs in associa-
tion with another species of Aphelaspis, possibly the same in both
cases. This second species seems somewhat intermediate between A.
walcotti and A. quadrata, but the material was deemed insufficient
to decide whether it should be identified with either of these two
species or described as a new one. Therefore this form appears as
Aphelaspis sp. undet. in the faunal lists.
Occurrence.—The type locality is enq’/20, Washburn. In this sec-
tion the species occurs in association with Aphelaspidella macropyge
and Glaphyraspis declivis, above the strata holding A. walcotti and
below those with A. camiro, A. laxa, and A. quadrata. In the Three
Springs section, a limestone lens holding Aphelaspis washburnensis
and possibly Aphelaspidella macropyge was collected at the same level
(cns/15) as beds yielding Aphelaspis camiro, A. laxa, and A. quad-
rata, but the latter 3 species were not associated with A. washburnensis
in the same lens. From this evidence it is clear that A. washburnensis
occurs near the base of the middle Aphelaspis zone.
Types—Holotype: U.S.N.M. 144655. Paratypes: U.S.N.M.
144656-7.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 87
APHELASPIS BUTTSI (Kobayashi)
Plate 16, figures 1-7
Olenus cf. truncatus (Briinnich) Burts, 1926, pl. 9, figs. 6, 7.
Proaulacopleura buttst KopAYASHI, 1936, p. 93, pl. 15, fig. 6.
Proaulacopleura buttsi Kobayashi, REssEr, 1938a, p. 95, pl. 16, fig. 18.
Aphelaspis buttsi (Kobayashi) PALMER, 1962b, p. 35, pl. 4, figs. 23, 26, 31, 32;
pl. 6, fig. 15.
Large numbers of specimens, many of them complete exoskeletons
like the holotype, are available from the type locality in Alabama.
This material is all flattened in shale, hence identification with lime-
stone specimens inevitably leaves some uncertainty. However, all the
features of cranidium, free cheek, and pygidium, excepting the con-
vexity that cannot be compared, match so perfectly that reference of
the Tennessee material to the species seems justified. Palmer (1962b)
referred to A. buttsi, his excellent limestone specimens from Nevada,
which are identical in all respects with those from the writer’s collec-
tions.
Occurrence.—The species is very abundant in collection cno/15,
Three Springs, from beds containing a mixture of genera of the Crepi-
cephalus and Aphelaspis zones. Cranidia of an Aphelaspis collected
from the essentially equivalent beds cno/14 at Russell Gap may belong
to the species, but they cannot be distinguished with certainty from
A. lata in the absence of associated pygidia. This is the oldest Aphe-
laspis species found in Tennessee. The type locality is U.S.N.M. 9lo,
near Center, Ala.
Types—Holotype: U.S.N.M. 93048. Plesiotypes: U.S.N.M.
144658.
APHELASPIS LATA Rasetti, new species
Plate 16, figures 8-20
Available material—Large numbers of cranidia and several free
cheeks and pygidia, both preserving the test and exfoliated.
Description.—Cranidium proportionately wide and short, its sagit-
tal length equaling the width between the palpebral lobes, which is
slightly greater than the width between the anterior angles. Glabella
somewhat wider and shorter than in most species, of moderate con-
vexity. Fixed cheeks not rising above the level of the axial furrow.
Preglabellar field of moderate, uniform longitudinal convexity ; border
somewhat convex, defined by change in slope and shallow border
furrow. Length of frontal area 0.6 times the length of glabella;
sagittal length of border slightly less than half the length of pre-
glabellar field. Border furrow somewhat angular on midline. Pal-
pebral area horizontal to slightly downsloping, wider than in most
88 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
species, half as wide as glabella. Ocular ridges transverse or even
slightly slanted forward. Palpebral lobe averaging 0.4 times the gla-
bellar length. Distance from posterior end of palpebral lobe to posterior
margin equal to length of palpebral lobe. Anterior section of facial
suture of average divergence. Posterior area as wide (tr.) as occipital
ring.
Free cheek with slightly convex border like the cranidium; genal
spine flat, of average length.
Pygidium somewhat less than 3 times as wide as long, transversely
subelliptical. Axis relatively long, showing 2 or 3 rings plus a ter-
minal section, well defined on outer surface. Pleural lobes with well-
impressed furrows and very shallow interpleural grooves visible on
outer surface. Posterior margin slightly indented medially.
Length of largest cranidium collected 8 mm. Length of largest pygi-
dium 3.6 mm., width 10 mm.
Discussion.—The cranidium of this species is almost indistinguish-
able from A. buttsi except for the shallower glabellar and axial fur-
rows. Even this difference can be determined statistically only when
numerous well-preserved specimens in limestone are available. The
pygidium, however, is markedly distinct in possessing one less seg-
ment both in the axis and pleural lobes, and in its posterior outline
which is slightly notched medially, like A. walcotti and several other
species, rather than somewhat pointed as in A. buttsi. The interpleural
grooves are less distinct than in that species.
Occurrence——The type locality is cnp/14, Shields Ridge. Also
collected at localities cnp/15, Three Springs, and cnp/20, Washburn.
A few, small cranidia apparently identical with topotypes of the same
size were recovered from considerably higher beds at locality cnr/4,
Lost Creek. Since several species of Aphelaspis are distinguishable
only from the pygidia, the identification must be considered tentative.
Types—Holotype: U.S.N.M. 144659. Paratypes: U.S.N.M.
144660-2, 144734.
APHELASPIS TRANSVERSA Rasetti, new species
Plate 16, figures 21-27
Description—Cranidium wide and short, of the same general
proportions as in A. lata. Glabella of considerable transverse con-
vexity, defined by a rather deep axial furrow at the sides, a shallower
furrow in front, truncate. Occipital furrow deeper than usual in the
genus; occipital ring bearing a small node. Preglabellar field with
considerable convexity on midline; border furrow straight at the sides,
forming a rounded, obtuse angle medially. Border sharply upturned
from preglabellar field, almost flat; sagittal border length two-thirds
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 89
of length of preglabellar field. Frontal area averaging slightly over 0.6
times the glabellar length. Palpebral area rising above the axial fur-
row, somewhat convex, on average somewhat upsloping, half as wide
as glabella. Ocular ridges stronger than in most species, transverse
to slightly slanted forward. Palpebral lobes 0.4 times the glabellar
length; distance from posterior end of palpebral lobe to posterior
margin equal to length of palpebral lobe. Posterior area as wide (tr.)
as occipital ring. Free cheek with flat genal spine of average rate of
tapering.
Pygidium about 3 times as wide as long. Axis with 2 rings plus a
terminal section. Pleural lobes showing only 1 distinct pair of pleural
furrows.
Length of largest cranidium observed 7 mm.
Discussion—tThis species resembles A. lata but is clearly distin-
guished by the depth of the axial furrow, convexity of the palpebral
area, wider anterior border, and smoother pygidium.
Occurrence.—Locality cnp/17, Hurricane Hollow, in the basal bed
of the Aphelaspis zone, a few feet above strata with typical Crepi-
cephalus fauna.
Types——Holotype: U.S.N.M. 144663. Paratypes: U.S.N.M.
144664.
APHELASPIS MINOR Rasetti, new species
Plate 19, figures 18-25
Available material—tLarge numbers of cranidia and free cheeks,
and a few pygidia.
Description.—Glabella of average shape and convexity; occipital
furrow fairly well impressed, occipital ring bearing a low node. Pre-
glabellar field moderately convex longitudinally; border furrow well
impressed, slightly angular on midline; border convex, its midlength
(sag.) less than the length of preglabellar field. Length of frontal area
averaging 0.50 times length of glabella plus occipital ring. Palpebral
area upsloping ; palpebral lobes slightly elevated above palpebral area,
set off by shallow furrow, half the length of glabella plus occipital ring.
Distance from posterior end of palpebral lobe to posterior cranidial
margin less than length of palpebral lobe. Ocular ridges transverse.
Anterior sections of facial suture with average divergence. Posterior
area about as wide (tr.) as occipital ring. Free cheek with rather flat
border defined by sharp change in slope. Genal spine relatively long,
rather flat on dorsal side.
Pygidium exactly 3 times as wide as long. Axis well tapered,
rounded posteriorly, showing 2 rings plus a terminal section, reaching
the border furrow. Pleural platforms rather convex, faintly furrowed.
90 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Anterior outline without definite geniculation. Border and doublure
very narrow throughout.
Length of largest of hundreds of cranidia observed, 7 mm. Length
of largest pygidium 2.5 mm., width 7.5 mm.
Discussion.—The cranidia may not be easy to distinguish from
immature examples of some of the larger species, but the combination
of cranidium and pygidium characterizes the species as definitely dis-
tinct from all others. The cranidium is extremely similar to that of
A. inermis, the distinguishing features being pointed out in the de-
scription of that species. The pygidium instead is very much like
A. walcotti and A. bridget.
Occurrence.—Lower part of the Aphelaspis zone, above the beds
with A. lata and below those carrying A. walcotti. Type locality is
eng/17, Hurricane Hollow. Also in collections cnq/14, Shields Ridge,
enq/15, Three Springs, and cnp’/20, Washburn.
Types.—Holotype: U.S.N.M. 144665. Paratypes: U.S.N.M.
144666-8.
APHELASPIS INERMIS Rasetti, new species
Plate 19, figures 8-17
Available material—Numerous cranidia and free cheeks, and a few
tentatively assigned pygidia.
Description—Glabella of average shape and convexity; occipital
furrow shallow; occipital ring bearing a node, lacking spine. Frontal
area averaging slightly less than half the glabellar length. Preglabellar
field somewhat convex longitudinally especially on midline. Border
defined by shallow furrow and change in slope, slightly convex, rather
narrow for the genus. Anterior section of facial suture moderately
divergent, straight to border furrow. Palpebral area slightly upsloping,
about 0.3 times the glabellar width. Palpebral lobes set off by very
shallow furrow, somewhat elevated, averaging 0.3 times the glabellar
length and somewhat less than distance from posterior margin. Width
(tr.) of posterior area equal to width of occipital ring. Free cheek
with slightly convex border defined by shallow furrow. Genal spine
oval in cross section, rather thick and long.
Pygidia associated with the cranidia in more than one collection are
transversely subelliptical, about 2.5 times as wide as long. Axis very
prominent, equally long and wide, rounded posteriorly, with 1 distinct
ring. Pleural lobes with 2 pairs of furrows and indistinct interpleural
grooves, all ending in flat border which is wider laterally than medially.
Surface of test pitted in furrows of cranidium and free cheek, but
not as coarsely as in A. arsoides. Length of unusually large cranidium
9mm. Most of the specimens do not exceed 6 mm.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 91
Discussion—This species is very similar to A. arsoides in all pro-
portions. Apart from lack of an occipital spine, it may be distinguished
at least statistically by the lesser divergence of the anterior section of
the facial suture, greater convexity of the preglabellar field, slightly
upsloping palpebral area, and convex instead of flat genal spine. It is
also very similar to A. minor, with which it had been confused before
large collections were made. It may be distinguished from that species
by the usually slanted instead of transverse course of the ocular ridge,
sharper anterior angles of the cranidium, slightly smaller palpebral
lobe, and lesser average slope of the palpebral area. The pygidia are
quite different, the one of A. minor being proportionately shorter and
wider, with narrower border and furrows extending almost to the
margin. The pygidium of A. inermis is more like that of A. arses.
The present species and A. minor occupy different stratigraphic posi-
tions, and no transition forms are known from intermediate beds.
Occurrence.—The type locality is cns/2, Shields Ridge. Also present
in collections cnr/4, cns/4 and cnt/4. It occurs in association with A.
tumifrons or A. arsoides.
Types.—Holotype: U.S.N.M. 144669. Paratypes: U.S.N.M.
144670-1.
APHELASPIS TUMIFRONS Resser
Plate 19, figures 1-7
Aphelaspis tumifrons REsseEr, 1938a, p. 60, pl. 13, fig. 15.
Available material—The hypodigm includes the holotype and sev-
eral other cranidia in fair state of preservation. Abundant and well-
preserved new specimens from various localities allow a more complete
description.
Description—Glabella poorly defined on upper surface by a very
shallow axial furrow. Occipital furrow shallow; occipital ring bearing
a node. Frontal area averaging 0.45 times the glabellar length. Pre-
glabellar field with definite median boss. Border defined by somewhat
gradual change in slope, of average width medially, almost vanishing
at the sides. Anterior cranidial margin slightly pointed medially. Pal-
pebral area approximately horizontal, about 0.3 times the glabellar
width ; palpebral lobe more or less upsloping, not defined by palpebral
furrow on outer surface. Average exsagittal length of palpebral lobe
0.4 times the glabellar length and 0.8 times the distance to posterior
margin. Ocular ridges wide, almost undefined on outer surface, some-
what slanted backward. Transverse width of posterior area 0.8 times
width of occipital ring. Free cheek with somewhat convex ocular plat-
form, broad and vaguely defined border furrow, and fairly long,
cylindrical genal spine.
92 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Pygidium more than twice as wide as long. Axis strongly tapered,
usually showing 1 distinct ring plus a terminal unsegmented section,
almost reaching posterior margin. Anterior outline of pleural lobe
with sharp geniculation situated about midway from axial furrow to
anterior angle. Two pairs of broad pleural furrows and somewhat
indistinct pleural grooves are visible on upper surface. Border narrow
all along posterior margin, poorly defined by shallow border furrow.
In some specimens fine puncta are present in the furrows on cra-
nidium and free cheeks. Length of largest cranidium observed among
several hundred specimens 10 mm. The overwhelming majority of the
cranidia do not exceed 7 mm. Length of largest pygidium 1.6 mm.,
width 4.0 mm.
Discussion.—This is a distinctive species, that can seldom be con-
fused with other forms of Aphelaspis even if only a small sample is
available. The main characteristics are the shallowness of the axial
furrow, the tumid preglabellar field, the poorly defined anterior border,
and the relatively anterior position of the eyes.
Occurrence.—The species is usually extremely abundant when
present, and represents an excellent index fossil for the upper portion
of the middle Aphelaspis zone. The type locality is U.S.N.M. 119,
S. of Morristown, Hamblen County. Present in the author’s collec-
tions cns/1, ent/1, cns/2, cnt/4, cnt/7, cns/15, ent/15, ent’/15, cnt/20,
ent/21, and in Oder’s collection No. 14.
Types.—Holotype: U.S.N.M. 94927. Plesiotypes: U.S.N.M.
144672.
APHELASPIS PUNCTATA Rasetti, new species
Plate 18, figures 21-29
Available material—Numerous cranidia and free cheeks and a few
pygidia.
Description—Glabella of usual shape and convexity; axial furrow
with deep pits at anterior corners of glabella. Frontal area markedly
convex in front of glabella; border furrow well impressed, forming
rounded angle on midline; border convex, averaging in midlength
(sag.) one-third of length of preglabellar field. Entire frontal area
over half the length of glabella plus occipital ring. Palpebral area
somewhat upsloping; palpebral lobes elevated above palpebral area,
half the glabellar length, defined by distinct furrow. Distance from
posterior end of palpebral lobe to posterior cranidial margin less than
length of palpebral lobe. Anterior sections of facial suture with aver-
age divergence; anterior angles of cranidium very sharp. Posterior
area equal in width (tr.) to occipital ring. Free cheek with narrow,
convex border. Genal spine rapidly tapered, fairly flat on dorsal side;
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 93
posterior border furrow with shallow extension on proximal portion
of genal spine.
Associated pygidium with large axis, wider than pleural lobes, ele-
vated, rounded at the extremity, showing 3 poorly defined rings plus
a terminal section. Anterior outline of pleural lobes showing genicula-
tion not far from axial furrow, then bending backward rather sharply ;
posterior margin with maximum curvature on midline. One pair of
pleural furrows well impressed, two other pairs shallow and rather
indistinct. Border narrow, poorly defined by border furrow.
Surface of cranidium and free cheeks almost entirely covered with
fine, dense puncta. Surface of pygidium also punctate. Length of
largest cranidium 8 mm. Length of pygidium 2.1 mm., width 3.7 mm.
Discussion.—The cranidium of this species would be distinctive
even without the unique feature of the punctate surface because of
the deep pits in the axial furrow, the roll in front of the glabella, and
the elevated palpebral lobes. All these features tend to give the species
an aspect approaching Dytremacephalus angulatus. The pygidium is
also distinctive in shape, having a proportionately larger axis than
other species of Aphelaspis.
Occurrence-—Uppermost beds of the Aphelaspis zone, in associa-
tion with Aphelaspis tarda. The type locality is cnw/14, Shields Ridge,
but the species is less rare at locality cnw/20, Washburn.
Types.—Holotype: U.S.N.M. 144673. Paratypes: U.S.N.M.
144674-5.
APHELASPIS ARSES (Walcott)
Plate 13, figures 16-23
Saratogia arses WAucortt, 1916a, p. 196, pl. 35, figs. 44b.
Clevelandella arses (Walcott) ReEsseEr, 1938a, p. 69, pl. 13, fig. 22.
Available material—tThe hypodigm consists exclusively of the holo-
type, a good cranidium in limestone. Collections by the author sup-
plied numerous cranidia and free cheeks and a few pygidia.
Description.—Glabella of average shape and convexity. Occipital
furrow well defined throughout, deeper than in most species of the
genus. Occipital ring bearing a small node and, in addition, a long,
slender, somewhat upturned spine. Frontal area averaging half the
length of glabella (exclusive of spine). Preglabellar field slightly con-
vex longitudinally. Border narrow, defined by shallow furrow and
change in slope, in most specimens definitely convex. Anterior sections
of facial suture quite straight from palpebral lobe to border furrow.
Palpebral area slightly convex, horizontal to slightly upsloping, aver-
aging 0.3 times the glabellar width. Ocular ridges broad but distinct,
slanted backward. Palpebral lobes set off by distinct furrow on upper
94 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
surface, relatively narrow, about 0.3 times the glabellar length and
equaling the distance to posterior cranidial margin. Posterior area
about as wide (tr.) as occipital ring. Free cheek with slightly convex
border defined by shallow furrow; genal spine oval in cross section,
fairly long, tapering to sharp point.
Pygidium associated with the cranidia transversely subelliptical,
twice as wide as long. Axis prominent, showing 2 rings plus a termi-
nal section, almost reaching margin. Pleural lobes with 2 more or less
distinct pairs of broad furrows and very weak interpleural grooves.
Anterior outline regularly curved, anterior angles rounded. Border
furrow and border undefined.
Surface of test smooth. Length of largest cranidium (exclusive of
spine) 7 mm. Length of pygidium 2 mm., width 4 mm.
Discussion.—The assignment of the species to Aphelaspis was justi-
fied in the discussion of the genus. Aphelaspis arses may be distin-
guished from most species of the genus, apart from the occipital spine,
by the better than average definition of the occipital ring and palpebral
lobe. The closest relatives are two species described herein, A. arsoides
and A. inermis; the differences are mentioned in their discussion.
Occurrence.—The type locality is U.S.N.M. 173, near Maryville.
The exposures in that area were very poor and may now be concealed
in built-up areas. The author’s material was collected from localities
cnr/4 and cns/4, Lost Creek, cns/20, Washburn, and cns’/15, Three
Springs.
Types.—Holotype: U.S.N.M. 61617. Plesiotypes: U.S.N.M.
144676, 144733.
APHELASPIS ARSOIDES Rasetti, new species
Plate 11, figures 15-21; plate 12, figure 22
Available material—Large numbers of cranidia and free cheeks
from several localities, and a few pygidia.
Description.—Glabella rather flat, defined by shallow axial furrow.
Occipital furrow shallow; occipital ring extended into long, slender,
almost horizontal spine, not bearing a node. Frontal area from 0.5 to
0.7 times the glabellar length. Preglabellar field with very slight longi-
tudinal convexity; border of average width, defined by furrow and
change in slope, more or less convex. Anterior sections of facial suture
straight to border furrow, diverging at somewhat greater angle than
in most species, including A. arses. Palpebral area horizontal to
slightly downsloping, about 0.3 times the glabellar width. Ocular
ridges distinct, slanted backward. Palpebral lobe almost undefined by
furrow on upper surface, about 0.3 times the glabellar length, and
equaling the distance to posterior margin. Posterior area somewhat
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 95
narrower (tr.) than occipital ring. Free cheek with flat border well
defined by lateral border furrow, which, however, becomes indistinct
before meeting posterior border furrow, as in all species of Aphelaspis.
Genal spine flat, of average length. Facial suture cutting posterior
margin somewhat farther from genal angle than in A. arses.
Surface distinctly pitted in furrows on cranidium and free cheeks,
especially in border furrow. Length of unusually large cranidium
exclusive of spine, 13 mm.; the majority do not exceed 8 mm.
Pygidium transversely ovate, two and one-half times as wide as
long. Axis stout, showing 2 rings and a terminal section, almost reach-
ing the margin. Pleural lobes almost flat and horizontal. Anterior and
posterior outlines slightly and regularly curved, lateral angles well
rounded. Anterior pleural furrow distinct, distally curving backward
to parallel the margin; another pair of furrows indistinct. The surface
in the depressions in some specimens is pitted as in the cranidium and
free cheeks. Length of largest pygidium 3.5 mm., width 8.5 mm.
Discussion—This species can be distinguished from the closely
related A. arses by the shallower axial furrow, almost horizontal pal-
pebral area, indistinct palpebral furrow, the characteristic pitted sur-
face in the depressions of the test, and somewhat different shape and
flat border of the free cheek.
Occurrence.—This species occupies a somewhat higher stratigraphic
position than A. arses and is frequently associated with A. tumifrons.
The type locality is cns/2. Also present in collections cns/1, cnt/1,
ent/4, cns/15, cnt/15, ent’/15, cnt/20, ent’/20, cnt/21, and Oder’s
collection No. 14.
Types.—Holotype: U.S.N.M. 144677. Paratypes: U.S.N.M.
144678-80.
Genus APHELASPIDELLA Rasetti, new genus
Description—Cranidium similar to Aphelaspis, except in the very
strong divergence of the anterior sections of the facial suture. Free
cheek as in Aphelaspis, with long genal spine. Pygidium proportion-
ately much larger than in Aphelaspis. Axis occupying less than half
the length, extended into a postaxial ridge. Pleural lobes wide, with
little relief, with shallow furrows and grooves and a wide, concave
border ; doublure very wide.
Discussion—The very close relationship to Aphelaspis is obvious.
However, the different course of the anterior section of the facial
suture and the pygidial characters are important enough to deserve
generic recognition.
Type species —A phelaspidella macropyge Rasetti, n. sp.
Occurrence.—A phelaspis zone of the southern Appalachians.
96 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
APHELASPIDELLA MACROPYGE Rasetti, new species
Plate 11, figures 1-8
Available material—Numerous cranidia, free cheeks, and pygidia
excellently preserved in limestone.
Description—Cranidium of low general convexity. Glabella
straight-sided, subtruncate in front, of low convexity, defined by a
shallow axial furrow. Glabellar furrows barely indicated on outer
surface; occipital furrow shallow, occipital ring short (sag.) and
simple. Frontal area 0.8 times the glabellar length; preglabellar field
convex, slightly downsloping; border furrow deep, with a median
inbend; border somewhat convex, wide medially, tapering in width
at the sides. Palpebral area half as wide as the glabella, slightly up-
sloping. Ocular ridges faint, transverse. Palpebral lobes 0.3 times the
length of glabella plus occipital ring, defined by a very shallow pal-
pebral furrow. Anterior sections of facial suture forming an angle of
almost 60° with the median line; anterior angles of cranidium more
widely rounded than in any species of Aphelaspis ; marginal portion of
suture about one-third the length of anterior cranidial margin, as in
most Aphelaspis species. Posterior section of facial suture first directed
backward, curving outward, then again somewhat backward, defining
slender posterior area identical with that of most Aphelaspis species.
Free cheek with well-defined lateral border.
Pygidium twice as wide as long, subelliptical. Axis rapidly tapered,
showing 3 rings and a terminal section, less than half the pygidial
length, extended into a long postaxial ridge. Three pairs of increas-
ingly shallow pleural furrows and less distinct interpleural grooves
are visible ; the furrows extend, very broad and shallow, even across
the wide, concave border. The inner edge of the doublure is clearly
apparent on the upper surface.
Surface of test smooth, except for a dense row of puncta in the
anterior border furrow. Length of largest cranidium 18 mm. Length
of largest pygidium 9 mm., width 18 mm.
Occurrence.—The type locality is author’s locality cnr/4, Lost
Creek. Also common in collections cns/20, cns/20a, Washburn, and
present in collections cns’”/15, Three Springs, and U.S.G.S. 2970. In
the U.S. National Museum there is a collection of cranidia and pygidia
of the species from locality 173, marked “Maryville, Tenn.” which
is also the type locality for Aphelaspis arses.
Types—Holotype: U.S.N.M. 144681. Paratypes: U.S.N.M.
144682. ,
Genus PARAPHELASPIS Rasetti, new genus
Description.—Cranidium with considerable relief. Glabella well ta-
pered, truncate in front, fairly convex transversely, defined by a deep
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 97
axial furrow laterally. Occipital furrow and ring as in Aphelaspis.
Frontal area less than half the glabellar length, downsloping. Pregla-
bellar field slightly convex; border narrow, elevated. Palpebral area
narrow, upsloping; palpebral lobe elevated, opposite anterior third of
glabella. Posterior area narrower (tr.) than occipital ring, broadly
triangular, rather strongly downsloping. Anterior section of facial
suture as in Aphelaspis. Free cheek wide, steeply downsloping ; ocular
platform somewhat convex ; border narrow. Facial suture cutting pos-
terior margin rather far from genal angle; genal spine short and
slender. Size small. Surface smooth except for puncta in the depres-
sions.
Discussion.—The close affinity with Aphelaspis is obvious. Never-
theless the genus appears to deserve recognition because of the greater
relief of the cranidial parts, in particular the elevation of the palpebral
area and lobe and the downsloping attitude of the free cheek and
posterior area. Another distinguishing feature is the anterior position
of the eyes. The cranidia of Paraphelaspis resemble immature cranidia
of Aphelaspis rather than adult individuals of that genus. Possibly
we have a case of paedogenesis, Paraphelaspis representing an offshoot
of the Aphelaspis stock preserving immature features in sexually ma-
ture individuals.
One should also mention the resemblance of the genus to Kujandas-
pis Ivshin (type species: Kujandaspis kujandensis Ivshin, 1956),
which seems also to represent another close relative of Aphelaspis. In
Kujandaspis the glabella is relatively smaller and the eyes do not have
such an anterior position as in Paraphelaspis.
Type species —Paraphelaspis vigilans Rasetti, n. sp.
Occurrence.—A phelaspis zone of the southern Appalachians.
PARAPHELASPIS VIGILANS Rasetti, new species
Plate 21, figures 14-28
Available material—Numerous cranidia and free cheeks.
Description.—Glabella strongly tapered, truncate in front, defined
by a deep axial furrow at the sides, a shallower furrow in front. One
or two shallow pairs of lateral furrows visible even on outer surface,
of the same pattern as in Aphelaspis. Occipital furrow well marked;
occipital ring bearing a node. Frontal area 0.4 to 0.5 times as long as
glabella plus occipital ring, proportionately longer in larger cranidia.
Preglabellar field with a more or less pronounced convexity in front
of the glabella; border furrow regularly curved; border length (sag.)
less than half the preglabellar field; border convex, elevated. Pal-
pebral area very narrow, proportionately wider in larger cranidia,
more or less strongly upsloping; ocular ridges distinct, very short,
directed somewhat forward. Palpebral lobe somewhat less than 0.3
98 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
times as long as glabella plus occipital ring, set off by shallow but
distinct furrow even on outer surface; its anterior end almost at the
level of the front of the glabella, its posterior end slightly anterior to
level of glabellar midpoint. Distance to posterior margin about twice
length of palpebral lobe. Anterior section of facial suture straight to
border furrow, divergent as the average in Aphelaspis; posterior sec-
tion directed straight outward and backward, curving rather sharply
backward before cutting posterior margin at right angle, defining much
longer (exsag.) and narrower (tr.) posterior area than in Aphelaspis
species ; width of posterior area less than width of occipital ring.
Free cheek proportionately wide, evidently steeply sloping. Ocular
platform convex near the eye. Border furrow shallow and broad;
border narrow, convex as in cranidium. Facial suture cutting margin
at considerable distance from short, slender genal spine. The pygidium
has not been identified.
Length of largest among hundreds of cranidia observed 5.5 mm.
Discussion.—It was mentioned in the generic description that Para-
phelaspis resembles immature individuals of Aphelaspis in several
respects. This also agrees with the fact, apparent from the description
and the illustrations, that the similarity to Aphelaspis increases with
increasing size of the cranidia of Paraphelaspis, especially in the fea-
tures of greater relative length of the frontal area and width of the
palpebral area. Nevertheless, there are still considerable differences
between the largest cranidia of Paraphelaspis vigilans and individuals
of the same size of all the known species of Aphelaspis. In particular,
immature cranidia of the two species of Aphelaspis that occur in asso-
ciation with Paraphelaspis are known and are quite different from
Paraphelaspis. Of all species of Aphelaspis, A. inermis is possibly
closest to Paraphelaspis.
Occurrence.—The type locality is cns/20, Washburn. Also present
in collections cens/20a, Washburn, cnr/4, Lost Creek, cns’/15, cns’’/
15, Three Springs, and U.S.G.S. 2970. The species has been found
only in association with Aphelaspidella macropyge.
Types.—Holotype: U.S.N.M. 144683. Paratypes: U.S.N.M.
1446845.
Genus DYTREMACEPHALUS Palmer, 1954
Type species —Dytremacephalus granulosus Palmer.
DYTREMACEPHALUS ANGULATUS Rasetti, new species
Plate 21, figures 1-9
Available material—Large numbers of cranidia, a few free cheeks
and pygidia in excellent state of preservation.
Description.—Glabella tapered, straight-sided, truncate in front, of
moderate convexity, defined by deep axial furrows at the sides, a
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 99
shallow furrow in front. A pair of deep pits in furrow at anterior
corners of glabella. Three shallow pairs of lateral furrows visible on
upper surface. Occipital furrow deep at the sides, shallow medially ;
occipital ring long (sag.), bearing a node. Preglabellar field swollen
in posterior portion, rising above the frontal portion of the axial fur-
row, downsloping in anterior portion; border furrow wide with strong
curvature on midline, giving it an angular aspect. Border about half
as long (sag.) as preglabellar field, upturned, convex, tapering at the
sides. Entire frontal area half as long as glabella inclusive of occipital
ring. Palpebral area slightly more than half as wide as glabella, slightly
convex and upsloping from the axial furrow. Ocular ridges distinct,
moderately slanted backward. Palpebral lobes defined by furrow even
on outer surface, fairly wide, not rising above palpebral area, 0.4 times
as long as glabella. Distance from palpebral lobe to posterior cranidial
margin considerably shorter than palpebral lobe. Anterior sections of
facial suture moderately divergent as in Aphelaspis, straight to border
furrow. Posterior area as in Aphelaspis, narrower (tr.) than occipital
ring. Free cheek with well-defined, convex border and border furrow;
ocular platform more convex than in species of Aphelaspis; genal
spine short, rapidly tapered, flat on upper side.
Thorax preserved in complete exoskeletons in shale. One small
individual appears to have 12 segments; however, the larger thorax
illustrated herein, attached to the pygidium but lacking the cephalon,
shows 13 segments, and this seems to be the number in the holaspid,
as in the species of Aphelaspis where the thorax is known. The pleurae
are straight proximally, curving backward to short falcate extension
distally, and are furrowed through all their length, much as in Aphe-
laspis.
Pygidium with considerable convexity. Axis occupying one-third
of the width, almost reaching margin, strongly elevated, showing 3 to
5 distinct rings plus terminal section, rounded posteriorly. Pleural
platforms steeply downsloping, with strong furrows and distinct inter-
pleural grooves. Border flat, wide at the sides, almost vanishing
medially, as the axis almost attains the margin. Anterior margin curv-
ing backward, almost attaining longitudinal course; angles fairly
sharp; posterior margin straight laterally, forming fairly sharp angle
medially.
Surface of cranidium finely and densely granulate except in the
furrows. Border of cranidium and free cheek with terrace lines. Ocular
platform granulate like the cranidium. Ornamentation of pygidium
indistinct. Length of largest cranidium 6.5 mm. Fragments indicate
that the species attains a somewhat larger size. Length of largest
pygidium 2.4 mm., width 6 mm.
Discussion.—This trilobite, obviously a very close relative of Aphe-
Fic. 2—A, Dytremacephalus angulatus Rasetti, n. sp. Cranidium, pygidium. B,
Aphelaspidella macropyge Rasetti, n. gen., n. sp. Cranidium, free cheek, pygi-
dium. C, Loxoparia obliqua Rasetti, n. gen., n. sp. Frontal, dorsal, and lateral
views of cranidium. D, Hawkinsia minuta Rasetti, n. gen., n. sp. Dorsal, frontal,
and lateral views of cranidium. E, Paraphelaspis vigilans Rasetti, n. gen., n. sp.
Frontal and dorsal views of cranidium.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 101
laspis, seems best referred to Dytremacephalus, although the palpebral
area is wider than in D. granulosus and the palpebral lobe larger and
more posterior in position. The frontal and palpebral areas are more
like D. laevis Palmer (1954). In Nevada, Palmer (1965) finds two
species of Dytremacephalus in the lower part of the Dunderbergia
zone. In view of the somewhat questionable assignment of the present
species to the genus, this fact should not be attributed much signifi-
cance for correlation. Dytremacephalus angulatus differs from all spe-
cies of Aphelaspis in the deep axial furrows, more posterior position
of the eyes, granulate surface, and shortness of the genal spine.
One should also note the considerable similarity of the cranidia of
this trilobite to Acrocephalaspis fidus Ivshin (1956) from Kazakhstan,
where it occurs in association with A phelaspis, and hence may be taken
to be approximately of the same age as the present species. Unfortu-
nately Ivshin’s material includes only cranidia. Ivshin compared Acro-
cephalaspis with Acrocephalites, but, judging from the illustrations,
his new genus seems very close to Aphelaspis. It is also possible that
Aphelaspis and Acrocephalites are closely related.
Occurrence-——Mainly characteristic of the uppermost portion of the
Aphelaspis zone in Tennessee, usually associated with Aphelaspis
tarda. The type locality is cnw/14, Shields Ridge. Also present in col-
lections cnw/1, cnx/1, cnv/15, and U.S.G.S. 2969. A single specimen
was found in the collection cnt/4, from somewhat lower beds here
assigned to the upper portion of the middle Aphelaspis zone.
Types——Holotype: U.S.N.M. 144686. Paratypes: U.S.N.M.
144687-9.
DYTREMACEPHALUS SULCIFRONS Rasetti, new species
Plate 12, figures 23-25
Available material—T wo cranidia from different localities.
Description—Cranidium as a whole and glabella with greater longi-
tudinal convexity than in preceding species. Glabella with 2 fairly deep
pairs of lateral furrows, a third pair very short and shallow, more
rounded anteriorly than in D. angulatus. Shallow portion of axial
furrow shorter than in preceding species. Palpebral area, palpebral
lobes, and course of facial sutures as in D. angulatus. Surface orna-
mentation of the same type. Length of cranidium 6 mm.
Discussion.—The differences from D. angulatus were pointed out
in the description. This may be an extreme case of variation within
that species; however, in the absence of intermediate forms, it is de-
scribed as a representative of an associated, rare species. It resembles
the type species of the genus.
102 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Occurrence.—The holotype is from collection cnw/14, Shields
Ridge; the paratype from collection cnx/1, Big Creek.
Types.——Holotype: U.S.N.M. 144690. Paratype: U.S.N.M.
144691.
DYTREMACEPHALUS STRICTUS Rasetti, new species
Plate 21, figures 10-13
Available material—sSeveral cranidia and one tentatively assigned
pygidium.
Description——Glabella as in D. angulatus, defined by a deeper fur-
row in front. Occipital ring unusually short (sag.), set off by a deep
occipital furrow, bearing a small node. Pits at anterior corners of
glabella marked in some individuals. Preglabellar field convex longi-
tudinally, somewhat shorter than in D. angulatus; border furrow not
distinctly angulate as in that species; border somewhat less elevated.
Palpebral area somewhat convex, upsloping, from one-third to one-
half the glabellar width; ocular ridges slightly slanted backward. Pal-
pebral lobe, posterior area, and facial sutures as in D. angulatus.
Granulation of surface rather indistinct.
The pygidium tentatively assigned to the species is proportionately
shorter and wider than D. angulatus and has fewer segments both in
the axis and the pleural lobes.
Discussion—The species was compared in the description with D.
angulatus, from which the cranidium differs essentially in the propor-
tionately larger glabella. As it appears from the illustrations, consider-
able variation occurs among the specimens, all from one small piece
of rock.
Occurrence.—Locality U.S.G.S. 2970, Vonore quadrangle, Monroe
County, in association with Aphelaspidella macropyge, Aphelaspis
palmeri, and other species.
Types.—Holotype: U.S.N.M. 144692. Paratypes: U.S.N.M.
144693.
PTYCHOPARIIDA OF UNCERTAIN AFFINITIES
Genus BONNETERRINA Lochman, 1936
Type species—Bonneterrina prima Lochman.
BONNETERRINA APPALACHIA ( Walcott)
Plate 2, figures 10-18
Lonchocephalus appalachia Watcott, part, 1916a, p. 190, pl. 35, figs. 6, 6a, 6c.
Lonchocephalus appalachia Walcott, REsSER, 1938a, p. 86, pl. 10, fig. 30.
Bonneterrina appalachia (Walcott) Patmer, 1954, p. 726, pl. 80, fig. 9.
The species is one of the most common and readily recognizable
fossils of the uppermost beds of the Maryville formation in the Rogers-
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 103
ville area. A considerable amount of variability is present in the
cranidia; since the various forms intergrade and occur in the same
bed, it would be improper to split the species, even though the ex-
tremes in the range of variation might suggest such action.
The main variable features are the convexity of the glabella and
the entire cranidium; the depth of the axial furrow; the direction of
the occipital spine, varying from almost horizontal to upturned at 45
degrees; the distinctness of the occipital furrow; the relative width
and convexity of the anterior border. The figured cranidia show some
of these features. The largest cranidium has a length of 15 mm. exclu-
sive of the spine.
The pygidium, although less common than the cranidium, can be
assigned with virtual certainty. It is about twice as wide as long,
regularly rounded posteriorly. Axis occupying almost entire length,
tapered, with 3 prominent rings and a terminal section, bearing a large
upright spine on the first ring. Pleural lobes convex and downsloping,
with 3 pairs of broad pleural furrows and 2 pairs of narrower inter-
pleural grooves, all reaching almost to the margin; border furrow
shallow, border narrow, poorly defined. Length of largest pygidium
9 mm., width 18 mm.
The pygidium closely resembles that of Shickshockia cristata (Ra-
setti, 1946), and the cranidium also has similar features. It is ques-
tionable whether Shickshockia should be maintained as a distinct
genus.
Occurrence-—Uppermost beds of Maryville and basal beds of Noli-
chucky formation (Cedaria zone). Type locality is U.S.N.M. 123a,
4 miles NE. of Rogersville. Collected by the author at localities cnc/1
to cnc/6 in the Maryville limestone and localities cnd/1, cnd/2 in the
red beds of the Nolichucky.
Types——Holotype: U.S.N.M. 61719. Paratypes: U.S.N.M.
61721, 61722. Plesiotypes: U.S.N.M. 144703-6.
Genus CHEILOCEPHALUS Berkey, 1898
Type species—Cheilocephalus stcrotxensis Berkey.
CHEILOCEPHALUS BREVILOBUS (Walcott)
Plate 17, figures 1-5
Lisania? breviloba Wa tcott, 1916b, p. 404, pl. 66, figs. 3-3c.
Pseudolisania breviloba (Walcott) KopayasHt, 1935, p. 162.
Pseudolisania breviloba (Walcott) REssEr, 1938a, p. 96, pl. 16, fig. 17.
Cheilocephalus breviloba (Walcott) Patmer, 1954, p. 759, pl. 88, figs. 1-4 (in-
cludes complete synonymy up to 1954).
Chetlocephalus brevilobus (Walcott) LocHMAN and Hu, 1962b, p. 436, pl. 69,
figs. 1-24.
104 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
The species is common in the basal beds of the Aphelaspis zone in
Tennessee. The largest cranidium observed has a length of 20 mm.
and a width between the tips of the posterior area of 40 mm. The
largest pygidium has a length of 21 mm. and a width of 34 mm.
The free cheek has never been described. Fragments are common
in association with other parts of the exoskeleton, but it is difficult
to prepare good specimens. The free cheek has a concave border not
differentiated from the ocular platform by a furrow. The facial suture
cuts the posterior margin very close to the genal angle. This is ex-
tended into a short, flat, triangular genal spine. Hence the suture does
not have a proparian course, as some authors have conjectured.
Occurrence.—The types are from an unspecified horizon in the
Nolichucky formation at U.S.N.M. locality 118a, near Greeneville,
Greene County. Collected by the author at localities cno/14, cnp/14,
enq/14, cnp/17.
Types.—Holotype: U.S.N.M. 62852. Paratypes: U.S.N.M.
628534. Plesiotypes: U.S.N.M. 144707-8.
CHEILOCEPHALUS BRACHYOPS Palmer
Plate 17, figures 6-11
Cheilocephalus brachyops PALMER, 1965, p. 105, pl. 1, figs. 12-15, 17.
A species of Cheilocephalus that occurs in the upper Aphelaspis
zone fully agrees in all characters of cranidium and pygidium with the
species, described from the Dunderbergia zone in Nevada.
Occurrence.—Collections cnx/1, Big Creek, and cnw/14, Shields
Ridge.
Types.—Plesiotypes: U.S.N.M. 144709-10.
CHEILOCEPHALUS, species undetermined
Plate 17, figures 12-14
Rare specimens of Cheilocephalus that occur in the middle portion
of the Aphelaspis zone possess a frontal area short as in C. brachyops,
but flat and lacking the raised border of that species. The surface
shows indistinct ornamentation. The pygidium is like both C. brevi-
lobus and C. brachyops. A close comparison is made uncertain by the
fact that all the specimens in question are small and obviously imma-
ture. Hence it will be left undecided whether this form should be
assigned to a new species.
Occurrence.—The figured specimens are from locality cnr/4, Lost
Creek. Also present in collections cns/4, cens/2, and U.S.G.S. 2970.
Disposition of material—Figured specimens: U.S.N.M. 144711.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 105
Genus COENASPIS Resser, 1938
Type spectes——Coenaspis spectabilis Resser.
COENASPIS SPECTABILIS Resser
Plate 5, figures 1-3
Coenaspis spectabilis REssER, 1938a, p. 69, pl. 16, fig. 9.
The only new information about this rare trilobite is its stratigraphic
position.
Occurrence.—Beds of the lower Cedaria zone at the top of the
Maryville formation. The type locality is U.S.N.M. 123a, near Rogers-
ville. One cranidium was collected by the writer at locality cnc/3,
close to or identical with the preceding.
Types.—Holotype: U.S.N.M. 94978.
Genus HAWKINSIA Rasetti, new genus
Description—Very small trilobites. Cranidium subtrapezoidal,
rather convex. Glabella moderately convex, defined by deep axial
furrow, tapered, with short, shallow lateral furrows. Occipital furrow
deep, occipital ring simple. Frontal area short (sag.), convex and
downsloping, barely differentiated into preglabellar field and border.
Ocular ridges well marked, subtransverse, curved. Palpebral area
convex, as wide as glabella; palpebral lobes small and inconspicuous,
situated far in advance of glabellar midpoint. Posterior area large,
deeply furrowed. Facial sutures showing little change of direction
between anterior and posterior section in dorsal view; in lateral view
there is a marked angle. Anterior sections convergent, curving inward,
rounding off the anterior cranidial outline. Posterior section first run-
ning outward and backward, gradually curving backward and finally
slightly inward, giving the cranidium a sharp posterolateral angle.
Type species —Hawkinsia minuta Rasetti, n. sp.
Discussion.—Although the known specimens of the type species are
quite small, the fact that they are all about the same size suggests that
they are not immature. In any case, Hawkinsia could not be the im-
mature form of any of the larger trilobites known from the same beds.
No plausible affinities of the genus can be suggested. The name is
derived from Hawkins County, where the type species occurs.
Occurrence-——Upper Cambrian (Cedaria zone) of the southern
Appalachians.
HAWKINSIA MINUTA Rasetti, new species
Plate 3, figures 22-25
Available material_Several cranidia preserved in limestone.
Description—tThe generic description includes most of the known
106 SMITHSONIAN MISCELLANEOUS COLLECTIONS vOoL. 148
characters of the species. The glabella shows 2 pairs of short, rather
shallow lateral furrows; those of the posterior pair show a tendency
to bifurcate. The occipital ring is rounded, lacking spine or node. The
frontal area is divided about equally into preglabellar field and border
by an excessively shallow furrow, which becomes obsolete medially.
The surface of the test is very finely granulate. Length of holotype
cranidium 2.2 mm., width at posterior end 3.3 mm.
Occurrence.—Uppermost beds of the Maryville limestone (Cedaria
zone) at locality cnc/1.
Types.—Holotype: U.S.N.M. 144712. Paratypes: U.S.N.M.
144713.
Genus ITHYCEPHALUS Resser, 1939
Type species.—I thycephalus typicalis Resser.
ITHYCEPHALUS TYPICALIS Resser
Plate 1, figures 10-12
Ithycephalus typicalis ResseEr, 1938a, p. 82, pl. 9, fig. 10.
A perfect cranidium of this rare species is figured.
Occurrence.—Type locality U.S.N.M. 27d; red beds at the base of
the Nolichucky (Cedaria zone) east of Rogersville. The figured speci-
men is from the same beds and locality (author’s locality cnd/1). One
specimen was also collected from the underlying uppermost beds of
the Maryville limestone (loc. cnc/1).
Types.—Holotype: U.S.N.M. 94841. Plesiotype: U.S.N.M.
144714.
Genus MODOCIA Walcott, 1924
Type species——Arionellus (Crepicephalus) oweni Meek and Hay-
den.
Three genera have been considered synonyms of Modocia: Armonia
Walcott, 1924 (type species, Armonia pelops Walcott); Metisia
Resser, 1937 (type species, Ptychoparia metisensis Walcott) ; and
Semnocephalus Resser, 1942 (type species, Solenopleura? weedi
Walcott (part) ).
A question arises concerning the status of the genus Syspacheilus
Resser, 1938 (type species, Syspacheilus typicalis Resser). Palmer
(1954) discussed the problem of assigning a pygidium to Syspacheilus.
He attributed to cranidia identified as Syspacheilus camurus Lochman
pygidia indistinguishable from Coosella. Lochman and Hu (1961)
attributed to S. dunoirensis (Miller) and a new species, Syspacheilus
praecedens, short pygidia of the generalized ptychoparioid type.
The latter assignment seems unquestionable, in view of the abun-
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 107
dance of the material and of the almost identical association of cranidia
and pygidia observed by the author in other areas. Then, if Palmer’s
pygidium is correctly attributed, we must conclude that there are two
genera of trilobites with indistinguishable cranidia and very different
pygidia, not an unusual situation. In that case it would be impossible
at present to decide which one is Syspacheilus, since there is no reliable
assignment of a pygidium to the type species.
Whatever the solution of this problem may be, the author sees no
reason to maintain the use of Syspacheilus for the species with a short
pygidium, typified by Syspacheilus praecedens, which are almost iden-
tical with Metisia metisensis (Rasetti, 1963). If these forms are
sufficiently distinct from Modocia owen to warrant generic recogni-
tion, then they should be referred to Metisia accepted as a valid genus.
Possibly the same arguments apply to Talbotina (at least as repre-
sented by T. juweli Lochman, in Lochman and Duncan, 1944) and
Ithyektyphus Shaw (1956), (Lochman and Hu, 1960).
In conclusion, it seems best at present to restrict the use of Sys-
pacheilus to the type species until the characters of the genus are
clarified.
MODOCIA DUBIA (Resser)
Plate 1, figures 22-26
Asaphiscus? agatho Watcott (part), 1916b, p. 391, pl. 63, fig. 9a (only).
Ehmania dubia REsseEr, 1938a, p. 75, pl. 9, figs. 18, 19.
Uncaspis tennesseensis RESSER, 1938a (part), p. 105, pl. 9, fig. 21 (only).
Three species of Modocia are common in the red beds at the base
of the Nolichucky, and two of them were also collected at various
localities in the underlying beds of the Maryville formation. Through
association in several instances it was possible to obtain an unambigu-
ous assignment of the pygidia to the respective cranidia.
Description—Entire cranidium of moderate convexity. Glabella
moderately convex, proportionately wide and short, strongly tapered,
rounded in front, bearing a trace of furrows on outer surface. Pregla-
bellar field flat; border not greatly elevated or convex, about as wide
(sag.) medially as the preglabellar field. Palpebral area slightly convex
and downsloping; ocular ridges faint; palpebral lobes one-third the
glabellar length, placed about parallel to the axial furrow, defined by
a sharp palpebral furrow, situated well in advance of glabellar mid-
point. Posterior area long (exsag.), deeply furrowed. The anterior
sections of the facial sutures are barely divergent. The surface of the
test is densely and finely granulate. Length of larger cranidia 12 mm.
Pygidium twice as wide as long. Axis stout and prominent, showing
two distinct rings, and in some specimens a less distinct third ring,
108 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
plus a terminal section, almost reaching posterior margin. Pleural re-
gions of low convexity, with almost equally deep pleural furrows and
interpleural grooves, curving back distally and almost reaching the
margin. Border furrow and border almost indistinct. Length of a large
pygidium 6.5 mm., width 13 mm.
Discussion.—This form differs from the type species in many details
of the cranidium, such as the lesser prominence of the glabella, lesser
divergence of the anterior sections of the facial suture, and more
anterior position of the eyes.
Occurrence.—The type locality is U.S.N.M. 27d; red beds at the
base of the Nolichucky (Cedaria zone) near Rogersville. Collected by
the author at the same locality (cnd/1) and also in the uppermost beds
of the underlying Maryville limestone (localities cnc/1 to cnc/6).
Types.—Holotype and paratypes: U.S.N.M. 94845. Paratype of
Asaphiscus ? agatho: U.S.N.M. 62820. Paratype of Uncaspis tennes-
seensis: U.S.N.M. 94846. Plesiotypes figured herein: U.S.N.M.
144715-6.
MODOCIA BIDENTATA Rasetti, new species
Plate 1, figures 13-21
Available material—Numerous cranidia and pygidia in limestone.
Description.—Glabella rather convex, rising above the cheeks, rela-
tively narrow and long, unfurrowed. Occipital furrow well marked;
occipital ring short, simple. Frontal and palpebral areas downsloping ;
preglabellar field longer (sag.) than border width ; border well defined,
slightly convex, tapered in width at the sides. Palpebral area about
half the glabellar width; ocular ridges faint; palpebral lobes located
somewhat in advance of glabellar midpoint. Anterior sections of facial
suture somewhat divergent; posterior section curving backward, pro-
ducing blunt posterior area.
Pygidium of same general proportions as in preceding species, not
greatly convex transversely. Axis as in preceding species. Pleural
regions with pleural furrows and interpleural grooves of progressively
decreasing strength. First pleural segment extended into a pair of
short, backward-directed marginal spines.
Surface of test smooth. Length of largest cranidium 17 mm. Length
of largest pygidium 8.5 mm., width 17 mm.
Discussion.—The cranidial proportions are fully typical of Modocia.
The chief distinguishing feature is the pair of short pygidial spines.
This character is not uncommon in several genera of late Medial Cam-
brian and Dresbachian ptychoparioid trilobites, e.g., in species of
Ehmaniella.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 109
Occurrence-—Red beds at the base of the Nolichucky (Cedaria
zone) E. of Rogersville (locality end/1).
Types——Holotype (pygidium): U.S.N.M. 144717. Paratypes:
144718.
MODOCIA CRASSIMARGINATA Rasetti, new species
Plate 2, figures 1-9
Available material— Numerous cranidia and pygidia well preserved
in limestone.
Description.—Glabella rather plump, defined by a deep axial furrow,
rounded in front, unfurrowed; occipital furrow well impressed, occi-
pital ring simple. Preglabellar field downsloping, short (sag.), on the
average shorter than the border width (sag.), although there is vari-
ability in this character. Border convex, wide (sag.). Ocular ridges
faintly indicated ; palpebral lobes narrow, defined by a shallow palpe-
bral furrow, about 0.3 times the glabellar length, somewhat in advance
of level of glabellar midpoint. Palpebral area convex, on average down-
sloping, 0.4 times the glabellar width. Anterior sections of facial suture
somewhat divergent, curving inward after crossing the border furrow,
rounding off the anterior cranidial angles. Posterior section first di-
rected outward, curving backward, rounding off the extremity of the
posterior area which is deeply furrowed.
Pygidium with a stout, barely tapered, well-rounded axis showing
3 rings and a terminal section, not reaching the margin. Pleural re-
gions transversely downsloping and convex longitudinally, showing 3
pairs of well-impressed furrows and 2 pairs of slightly shallower inter-
pleural grooves, all fading out toward the margin without the presence
of any defined border furrow or border.
Surface of test with inconspicuous ornamentation. Some of the
cranidia show a punctate surface, the puncta being small and so dense
as to produce the effect of a fine granulation ; other cranidia appear al-
most smooth. Pygidia where the test is preserved show a very fine
granulation.
Length of the largest cranidia 17mm. Length of largest pygidium
6.5 mm., width 14 mm.
Discussion.—Species of this type were assigned to Syspacheilus (see
discussion of Modocia) ; for example, the present form does not seem
to differ greatly from Syspacheitlus camurus Lochman (1940), S.
dunoirensis (Miller), as figured by Lochman and Hu (1961), and S.
praecedens Lochman and Hu (1961). From the latter two forms,
where the pygidium is known, the present species differs in the more
deeply furrowed pleural lobes. Armonia pelops Walcott is also close to
110 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
the present species, but an accurate comparison is difficult since all the
type material is more or less flattened. It would seem that Armonia
pelops has a proportionately narrower glabella and a more nearly tri-
angular pygidium. Metisia metisensis (Walcott) is almost identical in
the proportions and convexity of all the cranidial parts, but the surface
ornamentation is coarser, and the pygidium has a definite border and
is not turned down marginally as in the present form.
Occurrence.—Uppermost beds of Maryville limestone (Cedaria
zone). Type locality cnc/2; also common at localities cnc/1, cnce/3 to
cnc/6. Also occurring in the red beds at the base of the Nolichucky at
locality cnd/1.
Types.—Holotype: U.S.N.M. 144719. Paratypes: U.S.N.M. 144-
720-23.
MODOCIA ? AGATHO ( Walcott)
Plate 1, figures 27-30
Asaphiscus? agatho Watcott (part), 1916b, p. 391, pl. 63, fig. 9 (only).
Ehmania? agatho (Walcott) REssEr, 1938b, p. 29.
Available material—Walcott based the species on the holotype
cranidium and assigned to it a pygidium on the same piece of limestone.
The author’s collections, however, indicate that the pygidium belongs
to the more common, associated species Modocia dubia. A pygidium
believed to belong to the species is present in the collection from the
type locality. The author collected several cranidia and one pygidium.
Description.—Glabella of moderate convexity, fairly straight-sided,
moderately tapered, rounded in front, with a bare trace of lateral fur-
rows on outer surface. Occipital furrow well marked; occipital ring
subtriangular, rounded. Frontal area downsloping, rather flat, divided
into preglabellar field and border by a shallow furrow, not accom-
panied by much change in slope. Ocular ridges present ; palpebral area
convex, on average horizontal, one-third the glabellar width. Palpebral
lobes 0.3 times the glabellar length, narrow, defined by shallow palpe-
bral furrow, situated at the level of glabellar midpoint and hence more
posterior in position than in the 3 preceding species. Anterior sections
of facial suture definitely divergent ; posterior section directed outward
from palpebral lobe, curving backward distally ; posterior area almost
parallel-sided, rounded distally, deeply furrowed ; surface smooth.
Pygidium tentatively assigned to the species 2.2 times as wide as
long. Anterior margin fairly straight. Axis stout, not greatly tapered,
showing 2 rings plus a terminal section. Pleural regions with little con-
vexity, almost horizontal, showing several pairs of furrows and inter-
pleural grooves; only the first pair of furrows fairly deep. All furrows
and grooves extend to a shallow border furrow that sets off a slightly
elevated border. Surface very finely granulate.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 111
Length of largest cranidium 6 mm. Length of pygidium 3.5 mm.,
width 7.5 mm.
Discussion—tThis species cannot be given a satisfactory generic
assignment. The cranidium differs from typical Modocia in the lack of
a convex anterior border, horizontal rather than downsloping palpe-
bral area, more posterior position of the eyes, and parallel-sided rather
than tapered posterior area. In all these features it closely resembles
cranidia of Marjumia typa. However, if the pygidium is correctly as-
signed, it is rather indicative of Modocia; spinose pygidia of the Mar-
jumia type were not recovered from the Maryville formation.
Occurrence.—The type locality is U.S.N.M. 123a, near Rogersville.
Also collected by the author in the same area at localities cnc/2 to
cnc/5. The species belongs to the lower Cedaria zone faunule of the
uppermost Maryville limestone.
Types——Holotype: U.S.N.M. 62819. Plesiotypes: U.S.N.M. 144-
724-6.
Genus LOXOPARIA Rasetti, new genus
Description —Cranidium subtrapezoidal, moderately convex. Gla-
bella moderately convex, unfurrowed, rising above the cheeks, with
slightly concave side outline, subtruncate in front, reaching the border.
Occipital furrow well marked; occipital ring extended into spine.
Frontal area flat, consisting only of border; border furrow present at
the sides, merging with axial furrow medially. Palpebral area some-
what over half the glabellar width, convex, downsloping ; ocular ridges
barely distinct, strongly slanted ; palpebral lobes short and narrow, in-
conspicuous, situated in advance of glabellar midpoint. Anterior sec-
tions of facial sutures directed forward from palpebral lobes, curving
inward; anterior angles of cranidium widely rounded. Posterior sec-
tion of facial suture directed outward and backward, fairly straight for
half its course, then curving backward and finally somewhat inward.
Posterior area of fixed cheeks large, downsloping, extending back-
ward much farther than glabella, sharply pointed. Furrow on posterior
area deep, first directed outward and then curving forward; posterior
margin of posterior area straight, strongly slanted outward and back-
ward.
Type species —Loxoparia obliqua Rasetti, n. sp.
Discussion.—The shape of the glabella and frontal area are sug-
gestive of Llanoaspis and related forms; however, the characters of
the palpebral area, palpebral lobes, and course of the posterior section
of the facial sutures are radically different. The affinities of this tri-
lobite are obscure.
Occurrence-—Upper Cambrian (Cedaria zone) of the southern Ap-
palachians.
kale SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
LOXOPARIA OBLIQUA Rasetti, new species
Plate 3, figures 7-9
Available material—Three cranidia preserved in limestone.
Description——tThe generic description and the illustrations present
all the observable characters of the species. The axial and border fur-
rows are shallow on the outer surface. The occipital ring has a subtri-
angular shape, extending into a broad-based, short spine. Surface of
test perfectly smooth. Length of largest cranidium 7 mm.
Occurrence.—Red beds at the base of the Nolichucky (Cedaria
zone) at locality cnd/1.
Types.—Holotype: U.S.N.M. 144727. Paratypes: U.S.N.M. 144-
F2e:
UNDETERMINED TRILOBITES
UNDETERMINED CRANIDIUM No. 1
Plate 8, figure 29
Known from a single, incomplete specimen. Glabella large, rising
well above the cheeks, almost straight-sided, strongly tapered, rounded
in front. Occipital furrow deep and straight ; occipital ring short (sag.),
extended into an uptilted spine of unknown length. Posterior glabellar
furrows fairly deep, bifurcated, with the shorter anterior branch trans-
verse, the longer posterior branch turning backward. Two other pairs
of lateral furrows short, the anteriormost one very shallow. Preglabel-
lar field almost vanishing medially ; border slightly convex, not greatly
arched transversely. Palpebral area and lobe not preserved. Incom-
plete posterior area deeply furrowed, the furrow turning forward in
the distal part. Surface covered with medium-sized granules. Length
of cranidium, exclusive of occipital spine, 4 mm.
Although this trilobite cannot be referred to any described genus,
the incomplete material does not warrant a new name. Possibly the
nearest known forms are certain species of Genevievella.
Occurrence.—Uppermost beds of the lower limestone member of
Nolichucky (Crepicephalus zone) at locality cnn/3.
Disposition of material—Figured specimen: U.S.N.M. 144729.
UNDETERMINED CRANIDIUM No. 2
Plate 8, figure 19
Known from a single, incomplete specimen. Glabella very convex,
defined by a deep axial furrow, strongly tapered to a pointed anterior
end which is somewhat truncate. Surface of glabella mostly broken off ;
lateral furrows, if present, must have been very shallow. Occipital fur-
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI IS:
row broad and deep; occipital ring short (sag.), but extended into a
very long, uptilted spine. Frontal area consisting of convex, down-
sloping, preglabellar field and elevated, convex, transversely arched
border. Ocular ridges wide and fairly prominent, directed slightly
forward from the glabella, curving slightly to assume a transverse di-
rection. Palpebral area somewhat wider than glabella, rising above the
axial furrow and strongly convex transversely. Palpebral lobes and
posterior area not preserved. Surface of glabella and fixed cheeks cov-
ered with granules of different sizes. Length of cranidium 4.2 mm.
exclusive of occipital spine.
This cranidium, remarkable for the pointed glabella, wide palpebral
area, and forward-directed ocular ridges, cannot be assigned to any
described genus. No affinities can be suggested, beyond its inclusion in
the great ptychoparioid group.
Occurrence.—Lower portion of lower limestone member of the Noli-
chucky (Crepicephalus zone) at locality cnk/1.
Disposition of material—Figured specimen: U.S.N.M. 144730.
UNDETERMINED Pycip1um No. 1
Plate 6, figure 8
Known from a single example. Pygidium 2.5 times as wide as long.
Axis prominent, tapered, showing 3 rings plus a terminal section,
reaching the border furrow. Pleural region with a straight anterior
outline, rounded anterior angles, and posterior margin fairly straight
on either side, slightly pointed medially. Three pairs of rather deep
pleural furrows and shallow interpleural grooves are present. Border
furrow shallow, border very narrow.
This pygidium somewhat resembles the pygidia of Lianoaspis, dif-
fering in its shortness and small number of pleural furrows. No cran-
idium to which it may be assigned was collected from the same beds.
Occurrence.—Lower portion of lower limestone member of the Noli-
chucky (Crepicephalus zone) at locality cnk/1.
Disposition of material—Figured specimen: U.S.N.M. 144731.
UNDETERMINED Pycip1um No. 2
Plate 6, figures 20, 21
Known from several examples. Pygidium of low convexity, 1.75
times as wide as long. Axis long, tapered, straight-sided, extended into
a sharp postaxial ridge that reaches the posterior margin. Seven or
eight axial rings separated by shallow furrows are distinguishable.
Pleural regions with straight anterior outline, well-rounded anterior
angles, and regularly semicircular posterior margin except for a shal-
114 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
low median notch. Five pairs of shallow, broad pleural furrows end
very sharply on the line corresponding to the margin of the doublure.
The remaining portion of the pleural regions is smooth and flat or
slightly concave. Surface of test smooth. Length of largest pygidium
6 mm., width 10.7 mm.
This pygidium may belong to Coosia or a related trilobite. It differs
from the usual pygidia of Coosia in the great relative length of the axis.
No corresponding cranidium was collected.
Occurrence.—Upper portion of lower limestone member of the Noli-
chucky (Crepicephalus zone) at locality cnm/2. One specimen was col-
lected from the lower portion of the same limestone at locality cnk/1.
Disposition of material—Figured specimens: U.S.N.M. 144732.
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EXPLANATION OF PLATES
PLATE 1
Bigs: 1-4) Coosella andreas (Walcott) © oc <)<i0:s ays <6;0 csals alien emer al eee
1, Cranidium, x4. 2-4, Dorsal, lateral, and posterior views of pygidium,
4 (coll. enc/2) ; U.S.N.M. 144572, plesiotypes.
Figs. 5-7. Cooscila-resseri Rasetti, New NAME. 22 <0.s.0.0% c.cemn swine cokes ene
5-7, Lateral, posterior, and dorsal views of pygidium lacking test, x2
(coll. cnd/1) ; U.S.N.M. 144573, plesiotype.
Figs. 8, 9. Kormagnosius sumplex ReSSELr. ....060600 0 vices ss nas we nna cwainee sie
8, Cephalon, x5. 9, Pygidium, x5 (coll. cnc/5); U.S.N.M. 144546,
plesiotypes.
Figs. 10-12) dthycephalus typicalis RESSEP coe. so <ase oc teers no a sarenen crete
10-12, Dorsal, lateral, and anterior views of cranidium, x5 (coll.
end/1) ; U.S.N.M. 144714, plesiotype.
Kies: 13-2). Modoria Didentata Rasetti, 1. SP: 2 <0; «<< <0 <n0:0rore, es eee
14-16, Dorsal, lateral, and posterior views of pygidium, x2 (coll.
end/1) ; U.S.N.M. 144717, holotype. 13, Cranidium, «1.5. 17, Pygid-
ium, <2. 18, Cranidium, <2. 19-21, Dorsal, frontal, and lateral views
of cranidium, x2 (coll. cnd/1); U.S.N.M. 144718, paratypes. All
specimens lacking test.
Bigs 22-20) Modocta dubia *(RESSEP)) (s.1s.0.0 ecssis. cere. © wiereis evs sre otieles tent eer
22, 23, Dorsal and lateral views of cranidium, x2. 24, Free cheek, x2.
26, Pygidium, x2 (coll. cnc/5); U.S.N.M. 144715, plesiotypes. 25,
Exfoliated cranidium, x2 (coll. cnd/1) ; U.S.N.M. 144716, plesiotype.
Figs. 27-30: ModoctaZagatho (Walcott) Fec.s.ts om cie een cls once ore ieee
27, 28, Lateral and dorsal views of cranidium, «4 (coll. cnc/5) ; U.S.-
N.M. 144724, plesiotype. 29, Pygidium, x3 (coll. cnc/2) ; U.S.N.M.
144725, plesiotype. 30, Cranidium, x4 (coll. cnc/4); U.S.N.M.
144726, plesiotype.
PrArE 2
Figs. 1-9. Modocia crassimarginata Rasetti, n. sp. ........0000.. se eeeccees
1-3, Dorsal, lateral, and frontal views of cranidium, x2 (coll. cnc/2) ;
U.S.N.M. 144719, holotype. 4, 5, Exfoliated cranidia, 2 (coll.
enc/1) ; U.S.N.M. 144721, paratypes. 6, 7, Dorsal and posterior views
of pygidium, x2 (coll..cnc/3) ; U.S.N.M. 144722, paratype. 9, Ex-
foliated pygidium, x2 (coll. cnd/1); U.S.N.M. 144723, paratype.
8, Partly exfoliated cranidium, <2 (coll. cnd/1) ; U.S.N.M. 144723,
paratype.
Figs. 10-18. Bonneterrina appalachia (Walcott) ........seececccccccccces
10, Large cranidium, 1.5 (coll. cnc/6); U.S.N.M. 144703, plesio-
type. 11, 12, Dorsal and lateral views of cranidium with strong relief,
2 (coll. cnc/5) ; U.S.N.M. 144704, plesiotype. 13, Free cheek, x2
(coll. cnc/5) ; U.S.N.M. 144704, plesiotype. 14, 15, Dorsal and lateral
views of pygidium, x4 (coll. cnc/1) ; U.S.N.M. 144705, plesiotype.
16, 17, Lateral and dorsal views of cranidium with weak relief and
shallow occipital furrow, x2 (coll. cnd/1) ; U.S.N.M. 144706, plesio-
118
108
109
102
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 119
Page
type. 18, Exfoliated pygidium, x2 (coll. cnd/1) ; U.S.N.M. 144706,
plesiotype.
Figs. 19-24. Menomonia tuberculata Rasetti, n. sp. ..........eee eee cceeeee 62
19-21, Dorsal, lateral, and frontal views of cranidium, 5 (coll. cnc/2) ;
U.S.N.M. 144696, holotype. 22, Free cheek, 5 (coll. cnc/2); U.S.-
N.M. 144697, paratype. 23, 24, Lateral and dorsal views of cranidium
with somewhat shorter preglabellar field, «5 (coll. cnc/5) ; U.S.N.M.
144698, paratype.
isg25—e/Vecnomonia. Sit Undet! cuore sos te oe ed foe a tee Wa eens Ne dcioree 63
25, 26, Dorsal and lateral views of cranidium, «5 (coll. cnc/4) ; U.S.-
N.M. 144699. 27, Free cheek, <5 (coll. cnc/6) ; U.S.N.M. 144700.
PLATE 3
lay Sos Narada alin aiiach (NEN esta) so one oocoodenocudpeodoansansec 65
1, Artificial cast of counterpart of holotype, X3 (U.S.N.M. coll. 103) ;
U.S.N.M. 61595. 2, 3, Exfoliated cranidia, «5 (coll. cnd/1); U.S.-
N.M. 144612, plesiotypes. 4, Cranidium, <5. 5, 6, Pygidia, X7.5 (coll.
cne/2) ; U.S.N.M. 144613, plesiotypes.
Figs. 7-9. Loxoparia obliqua Rasetti, n. gem., n. Sp. ......ccccecccccccceees 112
Dorsal, frontal, and lateral views of cranidium, x5 (coll. cnd/1);
U.S.N.M. 144727, holotype.
Figs. 10, 11. Holcacephalus praecursor Rasetti, mn. sp. ...2.......seeceecees 68
10, Partly exfoliated cranidium, 7.5 (coll. enc/1) ; U.S.N.M. 144621,
holotype. 11, Exfoliated pygidium, 10 (coll. enc/1); U.S.N.M.
144622, paratype.
Bigs, 12-14: Holcacephalus granulatus Resser ... 3.60.0) 06 6 cose ces cece nse on 68
12, 13, Exfoliated cranidia, x10. 14, Exfoliated pygidium, «10 (coll.
cnd/1) ; U.S.N.M. 144620, plesiotypes.
Bigs, 15-21 tAnkoure trtangularts ReSSer 2. otixcas sow ciedds cl cece Coesdbes 61
15, 16, Dorsal and lateral views of exfoliated pygidium, 7.5. 17, Ex-
foliated pygidium, 7.5 (coll. U.S.N.M. 27d); U.S.N.M. 144702,
plesiotypes. 18, 19, Lateral and dorsal views of exfoliated cranidium,
7.5 (coll. U.S.N.M. 27d) ; U.S.N.M. 144608, plesiotype. 20, Incom-
plete cranidium preserving test, 7.5. 21, Pygidium, «7.5 (coll. cnb/
10) ; U.S.N.M. 144609, plesiotypes.
Pigs. 22-25. Hawkinsia minuta Rasetti, n.. gen: fl. sp) .5. 0.62 s0c. sec ccccces 105
22, Cranidium, X10 (coll. cnc/1) ; U.S.N.M. 144713, paratype. 23-25,
Frontal, lateral, and dorsal views of cranidium, X10 (coll. cnc/1) ;
U.S.N.M. 144712, holotype.
PLATE 4
Figs. 1-7. Norwoodella rotundicollis Rasetti, n. sp. .........00.. cc ccceceee 65
1, 2, Dorsal and lateral views of exfoliated cranidium, x3 (coll. end/1) ;
U.S.N.M. 144614, holotype. 3, Exfoliated cranidia, x3. 4, Free check,
<5. 5, Cranidium, x5. 6, Exfoliated pygidium, 10. 7, Exfoliated py-
gidium, <8 (coll. cnd/1) ; U.S.N.M. 144615, paratypes.
BS 815.) Vor OOM EH, RElGIRESSER 1s. Srel./i4s Goo hrat eva s he ctoichciaii.e Gases = 67
8-10, Frontal, lateral, and dorsal views of cranidium, 7.5. 11, 12, Free
cheeks, <5. 13-15, Pygidia, 7.5 (coll. cnd/10) ; U.S.N.M. 144619,
plesiotypes.
120 SMITHSONIAN MISCELLANEOUS COLLECTIONS voL. 148
BigswG-25) WNorwoodellaiwalcotit MResser (eee eee eee eee eee
16-18, Dorsal, lateral, and frontal views of cranidium, «4. 19, 20, Py-
gidia, <5. 21, Free cheek, x5 (coll. cne/10); U.S.N.M. 144616,
plesiotypes. 22, Free cheek, 5 (coll. cne/12); U.S.N.M. 144617,
plesiotype. 23, Cranidium, x4 (coll. U.S.G.S. 2407); U.S.N.M.
144618, plesiotype.
Bip /24. WN orwoodra, Sp. witidet. 5 sos 3s sd epee ae BR ee Ses Nee ae
Incomplete, exfoliated cranidium, «4 (coll. cnc/4) ; U.S.N.M. 144611.
Bigs.) 20" Zo: Niorwoodia nogersuullensts INeCSSCL eee eels eee eee ene
25, Exfoliated cranidium, x5. 26, Exfoliated pygidium, 10 (coll.
cnd/1) ; U.S.N.M. 144610, plesiotypes.
PLATE 5
Biesil—3Coenaspis spectauilts, KESSEL ecient caine seen eee
Dorsal, frontal, and dorsolateral views of rubber reproduction of par-
tially exfoliated holotype cranidium, x4 (coll. U.S.N.M. 123a) ;
U.S.N.M. 94978.
Pugs; 4=8: (Gedaria tennesscensts Walcott’ 5 .ci5.0 oe cic see Wises cers cae See eee
4, 5, Cranidia flattened in shale, x2 (coll. U.S.N.M. 107a) ; U.S.N.M.
70273, paratypes. 6, Free cheek, X3. 7, Exfoliated pygidium, x2. 8,
Pygidium, <3 (coll. cne/10) ; U.S.N.M. 144623, plesiotypes.
Rigs Ol nGenewevellasspuundety wae cemocaecetecieeee och ae eeneeee
9, 10, Dorsal and lateral views of cranidium, «3 (coll. cnc/4); U.S.-
N.M. 144626. 11, Exfoliated cranidium, <5 (coll. cnd/1) ; U.S.N.M.
144627.
Bigs 12.3" Olenoides:/ Spwtttdets aon ck eer eee ies Oh oe ee er Oeeee
Pygidia, 4 (coll. U.S.G.S. 2406) ; U.S.N.M. 144548.
Figs. 14-17. Menomonia prominens Resser .........0. 00 cesses cceecces
14, Exfoliated cranidium, <5. 15, 16, Lateral and posterior views of
cranidium, <5. 17, Free cheek, x5 (coll. cnd/1) ; U.S.N.M. 144695,
plesiotypes.
Fig, &8.\Gedarmia, ispundet.n 2). on. sash) mince oa chee Sonate se eee ae
Exfoliated pygidium, <3 (coll. cnd/1) ; U.S.N.M. 144624.
Fig: 19iCoostas spe undetieus, aah yats a cle on Aotearoa eee or Rn ee
Pygidium, <5 (coll. cnn/1) ; U.S.N.M. 144588.
Big. 20: Amtaspis errattca Lochman: <0). 2 sean ean aie ea eee
Cranidium, x10 (coll. cnn/16) ; U.S.N.M. 144558, plesiotype.
Figs. 21-24. Amiaspts obsolescens Rasetti, ni/sp. 3.20.24 2\)-tin soo des ees
21-23, Dorsal, lateral, and frontal views of cranidium, «8 (coll. cnm’/
20) ; U.S.N.M. 144559, holotype. 24, Cranidium, x8 (coll. cnn/16) ;
U.S.N.M. 144560, paratype.
PLATE 6
Bigs. 1-4) Tricrepicephalus thoosa’ (Walcott) ..-s ac tase ee ee eee
1, Exfoliated cranidium, 1.5, coll. cnn/3); U.S.N.M. 144589, plesio-
type. 2, Exfoliated pygidium, «2.2 (coll. cnn/3) ; U.S.N.M. 144589,
plesiotype. 3, Cranidium, <2 (coll. cnn/14) ; U.S.N.M. 144590, plesio-
type. 4, pygidium preserving unusually smooth test on pleural regions,
2.2 (coll. cnm/2) ; U.S.N.M. 144591, plesiotype.
Bigs: 5:6) Creprcephalus butts Resser 45) oie eeeeekoet. Maueee eee
5, Exfoliated pygidium, <1. 6, Exfoliated pygidium, 1.5 (coll. cnn/19) ;
U.S.N.M. 144565, plesiotypes.
65
105
69
71
39
62
70
53
43
43
54
45
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI P2T
Page
Hig.if. Lerranavetia: dorsalys:\(Elall) ius iele te citeactaieisiaiwrale dials cals wsiaiesec 40
Cranidium, 10 (coll. cnn/19) ; U.S.N.M. 144549, plesiotype.
Bis: 6. Undetermined py cidmita INGOs Uji alclataials oa leyec'elalwiolerevelasaidis Bole i's eae 113
Pygidium, <5 (coll. cnk/1) ; U.S.N.M. 144731.
Figs. 9-12. Meteoraspis brevispinosa Rasetti, n. Sp. ......-.cceee cece cc eecs 55
9, 10, Lateral and dorsal views of exfoliated pygidium, X2 (coll. cnk/1) ;
U.S.N.M. 144594, holotype. 11, Small cranidium, <5. 12, Exfoliated
cranidium, x2 (coll. cnk/1) ; U.S.N.M. 144595, paratypes.
Rigs plow. Mereoraspis mutica KRASettiicaiieiacicie ceisseticlere ciclo oe oiele: sleicle. ie 54
13, Cast of impression of cranidium, x3. 14, Exfoliated pygidium, x3
(coll. cnm/2) ; U.S.N.M. 144592-3, plesiotypes.
Higsalo—1l Oh GoosianaletnesiiGWwalcotts) sreierrsteciaroeeieciiecsisteiei clove terete os hele 52
15, Exfoliated cranidium, x2. 16, 17, Exfoliated hypostomes, x2. 18,
Pygidium, <3 (coll. cnn/16); U.S.N.M. 144582, plesiotypes. (See
also pl. 7.)
Bie lov GEoosella tsp yunaetsuciet isis rete edhe Oa ors oie wie ak aferenstovere alee ve eters 50
Partly exfoliated pygidium, x2 (coll. cnk/1) ; U.S.N.M. 144579.
Biss Z0e2leuOndetenmined py. eiditmm NO wa ciieascisle eistels fl clio seiereieve cieie sie 113
20, Pygidium, <5. 21, Exfoliated pygidium, <3 (coll. cnm/2); U.S.-
N.M. 144732.
PLATE 7
Pres; 15. Cooscila plamcauda Rasety Ae Spe sions ie Woes cas tS ee wees 49
1, Cranidium, x3. 2, Cranidium, <5 (coll. cnk/1) ; U.S.N.M. 144576,
paratypes. 3, Exfoliated pygidium, x2. 4, Pygidium, x3 (coll. cnm/
2); U.S.N.M. 144575, paratype. 5, Pygidium, x4 (coll. cnm/2) ;
U.S.N.M. 144574, holotype.
Bigs 6-13) Coosa aicines (Walcott)... ao. fees eos coes oe tone oboe eenes 52
6, Internal rubber cast of pygidium, 1.5 (coll. cnn/1l); U.S.N.M.
144583, plesiotype. 7, Exfoliated cranidium, 1.5 (coll. cnn/4) ; U.S.-
N.M. 144584, plesiotype. 8, Small, exfoliated cranidium, <5. 9, Ex-
foliated cranidium, 1.5. 10, Internal rubber cast of cranidium, X1.5.
11, Exfoliated pygidium, x2 (coll. cnn/3); U.S.N.M. 144585, ple-
siotypes. 12, 13, Two views of immature, partially enrolled exoskeleton
lacking only the free cheeks, «10 (coll. cnm/2); U.S.N.M. 144586,
plesiotype.
Pics. 14-22: Coosina amage (Walcott) \yaisSiys sen Sassi nie here tikdas aeveee 50
14-16, Dorsal, lateral, and frontal views of exfoliated cranidium, x2.
17, Cranidium, x3. 19-21, Dorsal, lateral, and posterior views of py-
gidium, <2. 22, Internal rubber cast of pygidium, 2 (coll. cnm/2) ;
U.S.N.M. 144580, plesiotypes. 18, Pygidium, x2 (coll. cnm/3) ;
U.S.N.M. 144561, plesiotype.
BHES.( 20-254 e CINPHIGUSPIS: Spe UNGEE. (sis Scare atele quiaiele eteyclantardaerieieicee ae cares 44
23, 24, Lateral and dorsal views of cranidium, <5. 25, Ventral view of
pygidium, <5 (coll. cnn/3) ; U.S.N.M. 144562.
ie 120. Coosia fo0Uusta WWaAlCOtt. Sc.) visi 0 ocsrarmieysie Wiaictea siavsiaetea els Binite ah o,ahia-s 53
Rubber cast of interior surface of pygidium, 1.5 (coll. cnn/1); U.S.-
N.M. 144587, plesiotype.
i277. COOSING GTUSEOM UNV AICOLE)) voice wisn afeieysitiaie om nioisin b OutelwalSeaieihercrcriels 51
Exfoliated pygidium, <2 (coll. cnm/2) ; U.S.N.M. 144581, plesiotype.
PLATE 8
gnc nl 4: re sDACHta GINala) VW AlCOLED sic ce save bani oe sis aie Bee sisacetion ee oe 61
122 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Page
1, 2, Lateral and dorsal views of incomplete cranidium, <4. 3, 4, Free
cheeks, x4 (coll. cnk/1) ; U.S.N.M. 144694, plesiotypes.
Figs. 5-8. Crepicephalus convergens Rasetti, n. Sp. ........ cece cece cece ccs 46
5, Pygidium, x2 (coll. cnk/1) ; U.S.N.M. 144567, paratype. 6, Pygid-
ium, <2 (coll. cnk/1); U.S.N.M. 144566, holotype. 7, Exfoliated
cranidium, <5. 8, Portion of cranidium showing ornamentation, 5
(coll. cnk/1) ; U.S.N.M. 144567, paratypes.
Figs. 9-11. Crepicephalus cf. convergens Rasetti ........e0ceeeeueccaccsecs 46
9, 11, Exfoliated pygidia, x2 (coll. cnn/3) ; U.S.N.M. 144568. 10, Ex-
foliated pygidium, <2 (coll. cnn/1) ; U.S.N.M. 144569.
Bigs, 12, 13Crepicephalus 2 sp. undet: No. 201. cco. ese ce ser ie tees 47
12, Rubber cast of internal surface of cranidium, X2. 13, Exfoliated
pygidium, x2 (coll. cnn/3) ; U.S.N.M. 144571.
lara WAS, IL remy ao CaleorrO, INCITS Gonoocoucadccacoucouensouaccs scout 70
14, Rubber cast of external impression of cranidium, 5. 15, 16, Py-
gidia, X5 (coll. cnn/3) ; U.S.N.M. 144625, plesiotypes.
Figs. 17; 18aGrepicephalus, sp. widet. No. 1. 35. sas sone doce eon eee 47
17, Rubber cast of internal surface of pygidium, x2. 18, Exfoliated py-
gidium, X2 (coll. cnn/4) ; U.S.N.M. 144570.
Bie iOeWndeterminedicraniditimmNOwZese sec cioeeciine eee eee: 12
Cranidium, <5 (coll. enk/1) ; U.S.N.M. 144730.
Big: 20; Madarocephalus actus. Ressery < o.:cicts ccays Ge statis ian ein tpt 44
Cranidium, X10 (coll. cnm/2) ; U.S.N.M. 144563, plesiotype.
Bigs, 21-28. kangstoniaunplatasResseranen oeeeece eee a oee ree eee 60
21, 22, Lateral and dorsal views of pygidium, <5. 25, Pygidium, x5.
26, Photograph of cranidium taken under water, <5, showing lighter
stains probably corresponding to muscle attachments on interior sur-
face (coll. cnm/2) ; U.S.N.M. 144605, plesiotypes. 23, Exfoliated py-
gidium, <5 (coll. cnn/1) ; U.S.N.M. 144606, plesiotype. 24, 28, Lateral
and dorsal views of cranidium, «5. 27, Cranidium, 5 (coll. cnk/1) ;
U.S.N.M. 144607, plesiotype.
Bie29 Undetermined cranidiame Nos Wea ee eerie eeeeeretnia 112
Cranidium, «5 (coll. cnn/3) ; U.S.N.M. 144729.
Fig: 30) Crepicephalus ck scesstlisiResser si. ..22. 4s see ae fee oe ee 45
Exfoliated pygidium, X2 (coll. cnn/3) ; U.S.N.M. 144564.
PLATE 9
Figs. 1-8. Blountia arcuosa Ressery... souw acid ae salsiae see ee ee ee 55
1, 2, Dorsal and frontal views of cranidium, <5. 3, 4, Dorsal and lateral
views of cranidium, <5. 5, Pygidium, <4. 6, Exfoliated pygidium,
<5. 7, 8, Dorsal and lateral views of pygidium, <5 (coll. cnm/3) ;
U.S.N.M. 144555, plesiotypes.
Bigs) 9-25 Blountiaaleras Walcot eee eee eee cee eee eee 56
9, Cranidium, <5. 10, 11, Dorsal and lateral views of cranidium, «5
(coll. cnk/1); U.S.N.M. 144596, plesiotypes. 12, Pygidium, x5
(coll. cnk/3) ; U.S.N.M. 144701, plesiotype.
Figs. 13-20. Blountia montanensts Duncan .........500ecc0cectceeccceccee 57
13, 16, Dorsal and lateral views of cranidium, x5. 14, Free cheek, <5.
15, Pygidium, <5 (coll. cnk/1); U.S.N.M. 144598, plesiotypes. 17,
Lateral view of large cranidium, x3. 18, Pygidium, x5. 19, Ex-
foliated pygidium, <2. 20, Cranidium, «5 (coll. cnm/2) ; U.S.N.M.
144599, plesiotypes.
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 123
ine, a ee OUNMEIELE CINESSEE Gers bid aeisiilc wralsiaiais ec ciueialeeldares widialee ease la ocd 57
Rubber impression of internal surface of cranidium, <5 (coll. cnn/3) ;
U.S.N.M. 144597, plesiotype.
Bane peenlO/ Maryotliisiariow NValcOtth ciao sb aciseileslsiae.s & ots eae WS os 59
22, 23, Dorsal and lateral views of exfoliated cranidium, x2. 24, Py-
gidium, 1.5. 25, Exfoliated pygidium, 1.5 (coll. cnm/2); U.S.-
N.M. 144603, plesiotypes. 26, Partly exfoliated pygidium, x2 (coll.
cenn/1) ; U.S.N.M. 144604, plesiotype.
Pate 10
Figs, 1, 2. Blountiavbrisiolensts Resser:.. 2.25505 Sh cai sist sata cada a vee os 58
1, 2, Dorsal and lateral views of exoskeleton lacking free cheeks, x4
(coll. cenp/17) ; U.S.N.M. 144600, plesiotype. (See also pl. 11.)
gS Onde LOUNGE AIMUIE” WW AICOEE «5 2 <)- atcsolsle cian v cJai eine Osta e iele sia soc oe os 59
3, Cranidium, X3. 4, 5, Dorsal and lateral views of cranidium, 3. 6,
Exfoliated pygidium, <3. 7, Pygidium, X3 (coll. Oder No. 2) ; U.S.-
N.M. 144602, plesiotypes.
Pigve. Glapwyraspis ornata Clochinatl) side). ocd slo cei nde ccs cs dete ceva 41
Rubber cast of external impression of exoskeleton in shale, 10 (coll.
Oder No. 3) ; U.S.N.M. 144551, plesiotype. (See also pl. 11.)
Riss: 9-17-Glaphyraspis parva -(CWalcott)” sciois sccklet eeekids we ce la caetes 40
9-12, 14, Cranidia, X7.5. 13, Free cheek, X5. 15-17, pygidia, X5 (coll.
cno/15) ; U.S.N.M. 144550, plesiotypes.
Rigs. 18-22. Glaphyraspis odert Rasetti, 1. SP) .cccic.siga ce sees nena eeae wads 41
18, Cranidia, the one at left being the holotype, 7.5, U.S.N.M. 144553.
19, Lateral view of holotype cranidium. 20, Cranidium, 7.5. 21, Free
cheek, x 7.5. 22, Pygidium 7.5 (all specimens from coll. Oder No. 2;
U.S.N.M. 144554, paratypes.
Figs. 23-25. Pseudagnostus communis (Hall and Whitfield) .............. 39
23, Exfoliated cephalon, «4. 24, 25, Exfoliated pygidia, «4 (coll. cns/
2) ; U.S.N.M. 144547, plesiotypes.
PLATE 11
Figs. 1-8. Aphelaspidella macropyge Rasetti, n. gen., n. sp. ..........2.0058 96
7, 8, Dorsal and frontal views of cranidium, <3 (coll. cnr/4) ; U.S.N.M.
144681, holotype. 1, 2, Cranidia, «3. 3, 4, Pygidia, x2. 5, 6, Free
cheeks, X2 (coll. cnr/4) ; U.S.N.M. 144682, paratypes.
nies: 9-12, Blountia bristolensts RESSET «.2'..¢ fo ok oe crnnielon visual te elo aa chads 58
9, 11, Cranidia, x4. 10, 12, Pygidia. <4 (coll. cnp/14); U.S.N.M.
144601, plesiotypes. (See also pl. 10.)
igs. 13) 14. Glaphyraspts ornata: (Lochman))\.)) 40. /scndoe cose ee ieaaeee ss 41
13, Pygidium, <7.5. 14, Cranidium, x7.5 (U.S.G.S. coll. 2804) ; U.S.-
N.M. 144552, plesiotypes. (See also pl. 10.)
Bags: 15-21. Aphelaspis arsotdes Rasetti, m) ‘spy. c/ffo) svioccte cise sea gies act ols 94
15-17, Dorsal, frontal, and lateral views of cranidium, <4 (coll. cns/2) ;
U.S.N.M. 144677, holotype. 18, 19, Cranidia, 4 (coll. cns/2) ; U.S.-
N.M. 144678, paratypes. 20, 21, Free cheeks, <4 (coll. cnt/4) ; U.S.-
N.M. 144679, paratypes. (See also pl. 12.)
PLaTE 12
Mics. 117. A phelaspis camiro: (Walcott W0e. so cscas ldo oe vee Salen cee 83
1, 2, Dorsal and frontal views of cranidium, <3. 3-5, Dorsal, lateral,
124 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Page
and frontal views of cranidium, x2. 6-8, Pygidia, x4 (U.S.N.M. coll.
120) ; U.S.N.M. 144648, plesiotypes. 9, Cranidium, 2.5. 10, Free
cheek, X2 (coll. cnr’/20) ; U.S.N.M. 144649, plesiotypes. 11, Hypos-
tome, <3 (coll. cnr/15) ; U.S.N.M. 144650, plesiotype. 12, 13, Dorsal
and frontal views of cranidium, <4. 14, Free cheek, «4. 15, Hypos-
tome, <4. 16, Cranidium, x2. 17, Exfoliated cranidium, <2 (coll.
cns/16) ; U.S.N.M. 144651, plesiotypes.
Pies, 18-21, Abhelaspys lawa Resser: i 42a ici int ees cide inaitione creas 80
18, Exfoliated free cheek, «1.5. 19, Cranidium, 4 (coll. cns/16) ; U.S.-
N.M. 144643, plesiotypes. 20, Free cheek, 1.5. 21, Pygidium, x4
(coll. enr’/20) ; U.S.N.M. 144644, plesiotypes. (See also pl. 13.)
Bie 22. .Apheiaspis arsodes Rasetti; nivsp. 22 Hobe. tise dow es oe soe 94
Pygidium, <3 (coll. cnt/20) ; U.S.N.M. 144680, paratype. (See also pl.
TH.)
Figs. 23-25. Dytremacephalus sulcifrons Rasetti, mn. sp. ......02..ceeeceeees 101
Dorsal, lateral, and frontal views of cranidium, <4 (coll. cnw/14) ;
U.S.N.M. 144690, holotype.
PLATE 13
Kigs) 1-7. Aphelaspis bridges Rasetti,.n. Sp. 6 oii.ds- ese boc occasion eee a7
1-3, Dorsal, frontal, and lateral views of cranidium, <3 (coll. U.S.G.S.
2804) ; U.S.N.M. 144635, holotype. 4, Cranidium, <3. 5, Free cheek,
<3. 6, 7, Pygidia, x3 (coll. U.S.G.S. 2804) ; U.S.N.M. 144636, para-
types.
Figs.i8=15,Aphelaspes lata Ressers)... sc straws Genes ers eieisio 0 we aoe oreeue ae 80
8, Cranidium, x3. 9-11, Dorsal, frontal, and lateral views of cranidium,
<4. 13, 15, Pygidia, «2. 14, Lateral view of cranidium, X2 (coll.
U.S.N.M. 120); U.S.N.M. 144645, plesiotypes. 12, Free cheek, x2
(coll. enr’/20) ; U.S.N.M. 144644, plesiotype. (See also pl. 12.)
Bigs! 16-235 Aphelaspisiarsess (NV alcott) = acme ekiaaeaeiieeec eee 93
16-18, Dorsal, frontal, and lateral views of cranidium, «4. 19, Cranid-
ium, <4. 20, Pygidium, x4. 21, Free cheek, x4. 22, Free cheek and
pygidium, <4 (coll. cns/4) ; U.S.N.M. 144676, plesiotypes. 23, Cran-
idium, <4 (coll. cnr/4) ; U.S.N.M. 144733, plesiotype.
PLATE 14
Figs. 1-12: Aphelaspis rotundata, Raseti; a:'sp: ¢...% ) <-> inte ee oe ees cr 84
1-3, Dorsal, lateral, and frontal views of partly exfoliated cranidium,
2.8 (coll. cns/20); U.S.N.M. 144652, holotype. 5, 6, Exfoliated
cranidia, 1.5. 4, Exfoliated hypostome, x4. 7, Free cheek, x3. 8,
Exfoliated free cheek, x3. 9, Exfoliated pygidium, x2. 10, 11, Lateral
and dorsal views of exfoliated pygidium, 2.5 (coll. cns/20) ; U.S.-
N.M. 144653, paratypes. 12, Pygidium attributed to the species, x3
(coll. cnq’’/4) ; U.S.N.M. 144654, paratype.
Figs. 13-19. Aphelaspts palmert Rasetti; 1. Spiv.se ss. s).,25 2 sna ne eee eee. 81
13-15, Dorsal, lateral, and frontal views of cranidium, <2 (coll. U.S.-
G.S. 2970) ; U.S.N.M. 144646, holotype. 16, Free cheek, 3. 17, Partly
exfoliated cranidium, «4. 18, 19, Exfoliated pygidia, x4 (coll. U.S.-
G.S. 2970) ; U.S.N.M. 144647, paratypes.
Figs, 20-24. Glaphyraspis dechiuts IRasettiy my Sp. toes cae ceeis = cee ene ee 42
20-22, Lateral, dorsal, and frontal views of cranidium, 7.5 (coll. Oder
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 125
Page
No. 2); U.S.N.M. 144556, holotype. 23, Cranidium, 7.5. 24, Free
cheek, 7.5 (coll. Oder No. 2) ; U.S.N.M. 144557, paratypes.
Prate 15
Figs. 1-12. Dunderbergia tennesseensis Rasetti, n. sp. ...... 2.022... cece eeee 71
1-3, Dorsal, lateral, and frontal views of cranidium, X2 (coll. cnw/14) ;
U.S.N.M. 144628, holotype. 4, Cranidium, x3. 5, Cranidium, x5. 6,
Free cheek, x2 (coll. cnw/14); U.S.N.M. 144629, paratypes. 7,
Hypostome tentatively attributed to the species, x10. 8, Cranidium,
<5. 9, 10, Dorsal and posterior views of pygidium, <3. 11, Pygidium,
<5 (coll. cnw/20) ; U.S.N.M. 144630, paratypes. 12, Free cheek, x3
(coll. cnu/7) ; U.S.N.M. 144631, paratype.
Figs. 13-18. Dunderbergia longifrons Rasetti, n. sp. ......0....ccceccccces 73
13-15, Dorsal, frontal, and lateral views of cranidium, <5 (coll. U.S.-
G.S. 2970) ; U.S.N.M. 144632, holotype. 16, Cranidium, x5. 17, Ex-
foliated cranidium, <4. 18, Pygidium, x10 (coll. U.S.G.S. 2970) ;
U.S.N.M. 144633, paratypes.
Bigs. 19-26; Cooscila perpleza’ (Palmer) >.) i.e 4s vieediee ls wi elelela Sasi oa c's 6 50
19-21, Dorsal, lateral, and frontal views of cranidium, <3. 22, 23, Py-
gidia, X3 (coll. cno/14) ; U.S.N.M. 144577, plesiotypes. 24, Exfoliated
pygidium, 1.5. 25, Free cheek, <3. 26, Exfoliated cranidium, x3
(coll. cno/15) ; U.S.N.M. 144578, plesiotypes.
PLATE 16
Bigs, 1-7. Aphelashis buttsy (Kobayashi) c.cs csc <ea-s-ccoewlatacls ¢ aclaecieelnces 87
1, 6, 7, Cranidia, «4. 2, 4, Pygidia, x2. 3, Pygidium, «4. 5, Free cheek,
<4 (coll. cno/15) ; U.S.N.M. 144658, plesiotypes.
BGs O20: 4 PCLES HES MATER ASCELI» fl. \SPs) tbe d.a:cvsiw)o'a tiara ld eveleisies ea BLS Ree 87
8-10, Dorsal, frontal, and lateral views of cranidium, <4 (coll. cnp/14) ;
U.S.N.M. 144659, holotype. 11, Free cheek, «4. 12-14, Pygidia, x4
(coll. cnp/14) ; U.S.N.M. 144660, paratypes. 15, Cranidium, x3. 16,
Exfoliated cranidium, x3. 17, Pygidium, «4 (coll. cnp/20); U.S.-
N.M. 144661, paratypes. 18, Pygidium, x4 (coll. cnp/15) ; U.S.N.M.
144662, paratype. 19, 20, Cranidia tentatively attributed to the species,
<4 (coll. cnr/4) ; U.S.N.M. 144734, paratypes.
Figs, 21-27. Aphelaspis transverse Rasetti, ni sp. oo. ss oe oe dscns ne cs 88
21-23, Lateral, frontal, and dorsal views of cranidium, x4 (coll. cnp/
17) ; U.S.N.M. 144663, holotype. 24, Exfoliated free cheek, 2. 25, 27,
Cranidia, <3. 26, Pygidium, x4 (coll. cnp/17) ; U.S.N.M. 144664,
paratypes.
PLATE 17
Figs. 1-5. Chetlocephalus brevilobus (Walcott) ...............cccceeenees 103
1, Pygidium, <2. 2, Small cranidium, x5. 4, Free cheek, X3 (coll. cnq/
14) ; U.S.N.M. 144707, plesiotypes. 3, Small cranidium, with pygidium
of Blountia bristolensis, X3 (coll. cnp/17) ; U.S.N.M. 144708, plesio-
type. 5, Small pygidium, «3 (coll. cno/14) ; U.S.N.M. 144735, plesio-
type.
Bigs, 6—)lt Chedlocephalusbrachyops Palmer as.) s saoeecie s ese else he ceene 104
6, Cranidium, <5. 7, Pygidium, 3. 8, Cranidium, x3 (coll. cnw/14) ;
U.S.N.M. 144709, plesiotypes. 9, Hypostome, <5. 10, Pygidium, x5.
11, Cranidium, <5 (coll. cnx/1) ; U.S.N.M. 414710, plesiotypes.
126 SMITHSONIAN MISCELLANEOUS COLLECTIONS VoL. 148
Page
Figs 12-14) Cheilocephalus: sp. undet, @.i4e. 5. btebaeecestue on ben hae eee 104
12, Cranidium, x4. 13, 14, Pygidia, x4 (coll. cnr/4) ; U.S.N.M. 144711.
Figs. 15-23. Aphelaspis washburnensis Rasetti, n. Sp. .......00..eecccecees
15-17, Dolsal, lateral, and frontal views of cranidium, x2 (coll. cnq’/
20) ; U.S.N.M. 144655, holotype. 18, Cranidium, 1.5. 19, Free cheek,
4. 20, Pygidium, x2 (coll. cnq’/20) ; U.S.N.M. 144656, paratypes.
21, 22, Partly exfoliated cranidium, <3. 23, Pygidium, «3 (coll. cns/
15) ; U.S.N.M. 144657, paratypes.
Pate 18
Bigs:1-9. Aphelaspis. quadrata Resser ot vcsischeiieie vse caaeuen Mee oR
1-3, Small cranidium, <4. 4, Exfoliated free cheek, X2. 5, Free cheek,
X2. 6, 7, Exfoliated pygidia, X3. 8, Pygidium, x4 (coll. cns/16) ;
U.S.N.M. 144637, plesiotypes. 9, Pygidium, x4 (coll. U.S.N.M. 120;
U.S.N.M. 144638, plesiotype.
Pags10-20) Abhelaspis walcottt Resser nics o<.64c.cy sence a nlose eee
10, Cranidium, <3. 11, Free cheek and partly exfoliated cranidium, x 4.
12, Exfoliated pygidium, 2. 16, Cranidium, «4 (coll. cng/16) ; U.S.-
N.M. 144632, plesiotypes. 13-15, Lateral, frontal, and dorsal views of
cranidium, X2. 20, Pygidium, <3 (coll. cnq/20) ; U.S.N.M. 144633,
plesiotypes. 17, Free cheek, x3. 18, Pygidium, <4. 19, Free cheek,
<2 (coll. cnr/15) ; U.S.N.M. 144634, plesiotypes.
Figs. 21-29, Aphelaspis punctata Rasettt; m: Sp.).0c. cos os owien co been eee
21, 22, 24, Frontal, dorsal, and lateral views of cranidium, <4 (coll.
cnw/14) ; U.S.N.M. 144673, holotype. 23, Cranidium, x4 (coll. cnw/
14) ; U.S.N.M. 144674, paratype. 25, 29, Free cheeks, x4. 26, cranid-
ium, X3. 27, Cranidium, «4. 28, Pygidium, <5 (coll. cnw/20) ; U.S.-
N.M. 144675, paratypes.
PLaTeE 19
Figs. J=7.-A phelaspts tumsfrons Resser \..2 <ce.iseis soc eae bees eee
1, 2, Dorsal and frontal views of cranidium, <4. 3, 4, Lateral and dorsal
views of cranidium, x4. 5, Free cheek, <4. 6, 7, Pygidia, x4 (coll.
cnt/4) ; U.S.N.M. 144672, plesiotypes.
Figs. 8-1/7, Aphelaspis tnermis Rasettt, ni Sp.o ue. co oe she sesiccone) ae en ee
8, 9, Frontal and dorsal views of cranidium, «4 (coll. cns/2) ; U.S.N.M.
144669, holotype. 10-12, Dorsal, lateral, and frontal views of cranidium,
<4. 13, Frontal view of large, partly exfoliated cranidium, x2. 14,
Dorsal view of the same specimen, <3. 15, Free cheek, 3 (coll. cns/
2); U.S.N.M. 144670, paratypes. 16, Pygidium, x4. 17, Cranidium,
2 (coll. cns/4) ; U.S.N.M. 144671, paratypes.
Pigs. 18-25. Aphelaspis minor Rasetti, mn. Sp... 2...004+ s+ s0+ asus snase en
18-20, Dorsal, frontal, and lateral views of cranidium, 4 (coll. cnq/
17) ; U.S.N.M. 144665, holotype. 21, Cranidium, <4. 22, 23, Frontal
and dorsal views of cranidium, *4. 24, Pygidium, x4 (coll. cng/14) ;
U.S.N.M. 144667, paratypes. 25, Free cheek, 4 (coll. cnq/15) ; U.S.-
N.M. 144668, paratype.
PLATE 20
Rigs. d-18: Aphelaspis tarda Rasettijm. sp. 4. henseenee eee eee ee
5, Several cranidia, the one at left preserving one free cheek being the
holotype, X3. 6, Cranidium, X5; U.S.N.M. 144639, holotype. 1, Num-
85
78
76
91
90
89
79
No. 3 UPPER CAMBRIAN TRILOBITE FAUNAS—RASETTI 127
Page
erous meraspid cranidia in various stages, X7.5. 2, 3, Dorsal and
frontal views of cranidium, x3. 4, Cranidium, x4. 7, Free cheek, x2.
8, 17, Free cheeks, x3. 9, Hypostome, x5. 10-12, Pygidia, x4 (all
above specimens from collection cnw/20); U.S.N.M. 144640, para-
types. 13-15, Dorsal, lateral, and frontal views of cranidium, x2 (coll.
cnu/1) ; U.S.N.M. 144641, paratype. 16, Pygidium, x3 (coll. cnu/7) ;
U.S.N.M. 144642, paratype. 18, Pygidium, x3 (coll. cnv/7); U.S.-
N.M. 144642, paratype.
PLATE 21
Figs. 1-9. Dytremacephalus angulatus Rasetti, n. sp. ........... cee cee eens 98
1-3, Dorsal, lateral, and frontal views of cranidium, <5 (coll. cnw/14) ;
U.S.N.M. 144686, holotype. 4, Cranidium, «5. 7, Pygidium, 5 (coll.
cnw/14) ; U.S.N.M. 144687, paratypes. 5, Free cheek, x5. 6, 8, Py-
gidia, <5 (coll. cnx/1) ; U.S.N.M. 144688, paratypes. 9, Rubber cast
of impression of thorax and pygidium, x4 (coll. U.S.G.S. 2969) ;
U.S.N.M. 144689, paratype.
Figs. 10-13. Dytremacephalus strictus Rasetti, n. sp. .......2...ce eee eeceee 102
10, Cranidium, x5 (coll. U.S.G.S. 2970) ; U.S.N.M. 144692, holotype.
11-12, Cranidia, <5. 13, Exfoliated cranidium, <5 (coll. U.S.GS.
2970) ; U.S.N.M. 144693, paratypes.
Figs. 14-28. Paraphelaspis vigilans Rasetti, n. gen., n. sp. 2... 2.0... eee eee 97
14-16, Dorsal, lateral, and frontal views of cranidium, 6 (coll. cns/
20) ; U.S.N.M. 144683, holotype. 17, Exfoliated free cheek, x4. 18,
19, Frontal and dorsal views of cranidium, 7.5. 20, 21, Dorsal and
frontal views of cranidium, <5. 22, Cranidium, 7.5. 23, Exfoliated
cranidium, <5. 24, 25, Free cheeks, X5 (coll. cns/20); U.S.N.M.
144684, paratypes. 26, 27, Lateral and dorsal views of cranidium, x 7.5.
27, Cranidium, <4 (coll. cnr/4) ; U.S.N.M. 144685, paratypes.
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THSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. 1
TRILOBITES OF THE CEDARIA ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. |
TRILOBITES OF THE CEDARIA ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
ITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. 3
TRILOBITES OF THE CEDARIA ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3. PL. y
TRILOBITES OF THE CEDARIA ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
MITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3
TRILOBITES OF THE CEDARIA AND CREPICEPHALUS ZONES
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. 6
TRILOBITES OF THE CREPICEPHALUS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.) |
VOL. 148, NO. 3, PL. 7
MITHSONIAN MISCELLANEOUS COLLECTIONS
TRILOBITES OF THE CREPICEPHALUS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
ONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. 8
TRILOBITES OF THE CREPICEPHALUS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
ITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. 9
TRILOBITES OF THE CREPICEPHALUS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. 1
TRILOBITES OF THE APHELASPIS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
ITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. 11
ae
he Te
TRILOBITES OF THE APHELASPIS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. 1)
TRILOBITES OF THE APHELASPIS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
‘MITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. 13
8 9 pone PI —_
y [EOP ty, A:
ae a SAY > a
TRILOBITES OF THE APHELASPIS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3. PL. 14
[gs get Net
ae
TRILOBITES OF THE APHELASPIS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
ITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. 15
ie Tog
te vet ae
on ;
TRILOBITES OF THE APHELASPIS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. 1
TRILOBITES OF THE APHELASPIS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
ITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. 17
es
ee
2)
|
M6 SN
t ha
TRILOBITES OF THE APHELASPIS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. ff
TRILOBITES OF THE APHELASPIS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
MITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. 19
TRILOBITES OF THE APHELASPIS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. 2
OZ
TRILOBITES OF THE APHELASPIS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
THSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 3, PL. 21
TRILOBITES OF THE APHELASPIS ZONE.
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
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SMITHSONIAN MISCELLANEOUS COLLECTIONS
# VOLUME 148, NUMBER 4
ws pre
Charles DB. and Mary Waux Walcott
Research Fund. uf
PLANKTONIC FORAMINIFERA FROM
THE WESTERN NORTH ATLANTIC ©
(Wire Nine Puates)
By
RICHARD CIFELLI
U. S. National Museum
Smithsonian Institution
CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
FEBRUARY 23, 1965
SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 148, NUMBER 4
Charles BD. and Mary Waux TA alcott
Research Fund
PLANKTONIC FORAMINIFERA FROM
Tee WESTERN NORTH ATLANTIC
(WitH Nine PiateEs)
By
RICHARD CIFELLI
U. S. National Museum
Smithsonian Institution
(PusLicaTion 4599)
CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
FEBRUARY 23, 1965
PORT CITY PRESS, INC.
BALTIMORE, MD., U. S. A.
Charles B. and Mary Waux Talcott
Research Fund
PLANKTONIC FORAMINIFERA FROM THE
WESTERN NORTH ATLANTIC
By RICHARD CIFELLI
U. S. National Museum, Smithsonian Institution
(With NINE PLATEs)
INTRODUCTION
The present paper describes and records the distribution of Fo-
raminifera collected in plankton tows from four seasonal traverses
between Cape Cod and Bermuda. Plankton stations were occupied
in the shelf waters, slope waters, Gulf Stream and Sargasso Sea (see
Appendix for details). The Gulf Stream stations, except for the fall
traverse, were determined by bathythermograph at the times of collec-
tion and were encountered at approximately longitude 69° W. In this
part of the North Atlantic the Gulf Stream is an important hydro-
graphic boundary, separating the temperate slope waters from the
subtropical Sargasso Sea. The chief purpose of this study was to
determine the influence of this boundary on the distribution of
planktonic Foraminifera.
The four seasonal cruises were made in 1960 and 1961 aboard the
Woods Hole Oceanographic Institution vessels Chain and Crawford;
the position of the stations are shown in figure 1. The summer and
winter stations are the ones that have been regularly occupied by the
Woods Hole Oceanographic Institution over a period of years in a
continuing program to study the biology and chemistry of the western
North Atlantic. The distribution of epizooplankton from those sta-
tions has been reported on by Grice and Hart (1962).
The collections were obtained in oblique tows with a No. 10
plankton net having a 3-meter open-mouth diameter. At shallow sta-
tions the net was lowered as close as possible to the bottom, and
beyond the shelf it was lowered to 200 meters. The ship’s speed during
SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 148, NO. 4
45°
40°
35°
2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
80° 75° 70° 65° 60°
UNITED STATES
i
7 ae
CAPE HATTERAS 3?
00
& BERMUDA
© SUMMER-WINTER, AUGUST 2-7, 1960- JANUARY 9-14, 1961
© FALL, OCTOBER 26-27, 1960
© SPRING, MAY 15-16, 1961
80° tS "Oe 69" 60°
Fic. 1—Location of stations.
towing was approximately 2 knots. The samples were preserved in
5-percent formalin, buffered with hexamethylenamine.
Acknowledgments.—Travel, ship-time, and facilities for this work
were provided by the Woods Hole Oceanographic Institution, sup-
ported variously by the Office of Naval Research under contract
Nonr-2196 and the Atomic Energy Commission under grant AT
(30-1)-1918. I am grateful to the Woods Hole Oceanographic In-
stitution staff for making this study possible, for their assistance
aboard ship, and for the collateral data that they made available. This
is Woods Hole Oceanographic Institution Contributions No. 1498.
HYDROGRAPHIC SETTING
Between Cape Cod and Bermuda the subtropical waters of the
Sargasso Sea are in close proximity to the temperate shelf and slope
45°
40°
NO. 4 PLANKTONIC FORAMINIFERA—CIFELLI 3
waters of the North Atlantic. Separating these water bodies is the
Gulf Stream, a well-defined band of currents originating in the straits
of Florida that moves clockwise and can be traced as far north and
east as the Grand Banks. Significant short- and long-period variations
occur in the velocity and position of the Gulf Stream, but throughout
the year it forms a sharp pressure gradient between the slope waters
and the Sargasso Sea (Iselin, 1936). Because of this pressure
gradient the slope waters and the Sargasso Sea maintain their more or
less unique hydrographic properties.
The waters in the Sargasso Sea are warm, and surface temperatures
remain relatively uniform throughout the year, ranging from about
19° C. to 27° C. In contrast, the surface temperatures of the shelf and
slope waters range from about 12° C. in March, the coldest month,
to about 26° C. in September, the warmest month (Stommel, 1958,
fig. 5). During the warmer months there is a pronounced stratified
surficial layer in the Sargasso Sea with a summer thermocline de-
veloping between 40 and 70 meters (Cifelli, 1962, figs. 3,6). In the
slope and shelf waters the summer thermocline develops between 10
and 40 meters, but there is relatively little surficial stratification. The
summer warming affects mostly the upper 100 meters; below that
depth there is little change, and at 200 meters the temperature remains
relatively constant throughout the year, which is generally between
9° and 12° C. in the slope waters and between 19° and 21° C-. in the
Sargasso Sea. Lateral variations in temperature are more common
in the slope waters than in the Sargasso Sea and, moreover, subsur-
face temperature inversions occur in the former (Grice and Hart,
1962, p. 289).
The Sargasso Sea is more saline than the shelf and slope waters.
In the Sargasso Sea salinities are between 36-37 0/oo, while those in
the slope waters normally range between 34-36 o/oo. The shelf waters
tend to be even less saline, with salinities as low as 25-31 o/oo having
been recorded at the location of the inshore shelf stations (Grice and
Hart, 1962, p. 289).
The hydrographic differences between the shelf slope waters and
the Sargasso Sea are reflected in the composition of their planktonic
foraminiferal faunas. In the vicinity of the Gulf Stream is located
the boundary between the temperate and the subtropical faunas.
DISTRIBUTION
Tables 1-4 show the percentage of total population at the stations
sampled expressed in number of specimens per half-hour tow.
The principal features of the distribution and the faunal changes
observed in the traverses studied as ascertained from these tables
4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
have been discussed in a previous paper (Cifelli, 1962). Briefly, these
features may be summarized as follows:
Abundance.—Considerable areal variation in numerical abundance
of specimens was observed, even between nearby stations. Some of
this variation is probably more apparent than real, since, in the
absence of a current meter, the actual amount of water filtered at the
towing stations is unknown, and the length of towing time is an inexact
and variable expression of this quantity. For the most part, however,
the differences in abundances between stations in the same water body
reflect the patchiness of distribution, a phenomenon that has long
been known to be characteristic of planktonic organisms. Patchiness
of distribution among planktonic Foraminifera has been recognized
in the Pacific by Bradshaw (1959) and Smith (1963). In general,
of the waters sampled the Sargasso Sea was the most uniform in the
abundance of specimens.
The slope waters yielded the richest concentrations of specimens,
whereas the Sargasso Sea was generally impoverished. The shelf
waters were the most variable, and planktonic Foraminifera appear
to be rare and sparsely distributed at the inner part of the shelf.
Seasonaily, the highest concentrations of specimens were obtained in
the fall and in the spring. The poorest concentrations were obtained
in the summer.
Faunal composition—That the Gulf Stream is a boundary of
major biogeographic importance can be seen in the changes in faunal
composition of planktonic Foraminifera along the traverses studied.
On the shelf and inner slope the fauna is distinctly temperate in
character, being composed throughout the year almost exclusively of
species of Globigerina. The dominant species are Globigerina bulloides
and G. pachyderma incompta, but relative frequencies were found
to be variable and G. inflata and G. aff. quinqueloba are also common.
To the south Globigerina is replaced by a diverse subtropical group of
species that characterize the Sargasso Sea. The dominant subtropical
species are Globigerinoides ruber, G. trilobus trilobus, Globigerinella
aequilateralis, Globorotalia truncatulinoides, and Puilleniatina obli-
quiloculata. The relative frequencies of these species, however, were
inconstant along the traverses and varied considerably throughout the
year. The position of the boundary between the temperate and sub-
tropical faunas also changed throughout the year but was always
observed on the north side of the Gulf Stream. It was closest inshore
in the fall and farthest offshore between winter and spring. Insofar
as could be observed, the Gulf Stream contained no endemic elements,
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NO. 4 PLANKTONIC FORAMINIFERA—CIFELLI 9
and its fauna was identical with that of the Sargasso Sea. The
boundary is transitional in faunal character and contains a mixture of
Globigerina and subtropical species. The mixed character of the as-
semblage strongly suggests that mixing of surficial waters occurs
across the Gulf Stream and that the subtropical species occurring
with Globigerina in the slope waters are expatriates.
Seasonal changes in faunal composition.—Clearly, seasonal cycles
cannot be described, nor, even, can the fact be established that such
cycles exist on the basis of only four seasonal traverses. However,
some marked changes were observed in composition of the subtropical
fauna from traverse to traverse and there can be no doubt that some
species of that fauna undergo considerable changes in relative fre-
quencies throughout the year. The most remarkable change noted
was the sharp increase of Globorotalia truncatulinoides in the winter.
Mostly rare or absent in the spring and summer stations, that species
showed some increase in the fall and was dominant in the winter when,
at one station (II), it occurred at a frequency of 55 percent. This
winter increase in Globorotalia truncatulinoides was mainly at the
expense of Globigerinoides species (mostly G. ruber and G. trilobus
trilobus), which were relatively rare then but were dominant or im-
portant elements of the subtropical fauna at the other seasons. Pul-
lentatina obliquiloculata also showed a considerable increase in the
winter. Globigerinella aequilateralis attained its highest frequency in
the spring (60 percent at station 2) but remained fairly common
through all the seasons.
It is more difficult to determine whether changes in frequencies of
species occur throughout the year within the temperate Globigerina
fauna because of the considerable lateral changes in frequencies that
occur from station to station and also, possibly, because of the
morphologic variation of the Globigerina species, which are sometimes
difficult to separate. The indications are that the relative frequencies
of the Globigerina species are fairly stable throughout the year except
for Globigerina aft. quinqueloba, which appears to increase appreciably
in the winter.
SYSTEMATICS
Since the primary purpose of this work was to determine the dis-
tribution of planktonic Foraminifera in a limited sector of the North
Atlantic, no attempt is made to treat the species monographically.
Only the original and a few pertinent references are given in the
synonymies. Extensive synonymies can be found in the works of
Cushman, Todd, Parker, and others.
Io SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
In a group as highly variable as the planktonic Foraminifera it is
perhaps inevitable that opinions will vary as to the morphologic limits
of species. Some workers will tend to split more finely than others,
and in the absence of quantitative treatments of population structures
and the lack of data on the biology of the animal, judgments on the
limits of species are bound to be subjective. The policy here has been
to group together in a single species those forms that occur together
with intermediaries among which no line of demarcation could be
perceived. Admittedly, further taxonomic refinements are possible,
but it is believed that with the morphologic limits recognized here, an
internal consistency in identification has for the most part been main-
tained and further refinements would not significantly change the
distributional patterns presented. The specimens used for illustration
were chosen to show the range of forms included in the species, and
the descriptive remarks under the species refer to the specimens
actually examined, with the emphasis on those characters that were
found particularly useful for identification.
Generic as well as specific characters are variable in the planktonic
Foraminifera, and some species include end forms showing close af-
finities to species placed in other genera. In fact, Globigerina inflata
shows a transition from Globigerina to Globorotalia. Such continuous
variability across established generic boundaries suggests that the Re-
cent planktonic Foraminifera comprise a closely related group. There-
fore, they are included here in a single family, the Globigerinidae.
The species are grouped into eight commonly recognized genera,
though, admittedly, the genera serve in some cases, owing to a lack
of exclusive characters, more as conveniences than as representations
of genetic affinities.
In the use of specific names an attempt has been made to conform
with the present Code of Zoological Nomenclature (1961). As pointed
out by Todd (1961, 1963) this code now limits the application of
priority in the naming of species. However, it is not clear from the
provision of conservation (article 23b) what these limitations are,
and, in fact, there is some question as to whether that provision can
actually be interpreted. Therefore, it would appear that the code
serves as a guide rather than a “‘cook book,” and the individual is not
relieved of the responsibility of exercising individual judgment in
serving the interests of nomenclatural stability. As a result, some
arbitrary decisions were found necessary in the choice of names, and
these are discussed under the species concerned.
NO. 4 PLANKTONIC FORAMINIFERA—CIFELLI Il
Family GLOBIGERINIDAE Carpenter, Parker, and Jones, 1862
Genus GLOBIGERINA d’Orbigny, 1826
Globigerina bulloides d’Orbigny
Plate 1; figures 1-3, 5
Globigerina bulloides D’OrBiGNy, 1826, Ann. Sci. Nat., vol. 7, p. 777, Nos. 76,
17.—BrapsHAw, 1959, Contr. Cushman Found. Foram. Res., vol. 10, pt. 2,
p. 33, pl. 6, figs. 1-4.—B&, 1959, Micropaleontol., vol. 5, No. 1, pl. 1, figs.
15-17—BaNnNER and Biow, 1960, Contr. Cushman Found. Foram. Res.,
vol. 11, pt. 1, p. 3, figs. 1, 4—Parker, 1962, Micropaleontol., vol. 8, No. 2,
p. 221, pl. 1, figs. 1-8.
Most of the specimens have bulbous chambers and broad, rounded
apertures that join in the center of the ventral side to form a large,
open umbilicus. The species, however, shows continuous gradation to
small compact forms with restricted apertures and reduced umbilical
areas (pl. 1, fig. 2b). These latter forms are relatively scarce but are
included in G. bulloides because of the continuous gradation.
The final chamber in Globigerina bulloides and other species of
Globigerinidae shows considerable variation and, as noted by Parker
(1962, p. 246), sometimes covers the umbilicus and is reduced in size.
I agree with Parker that a bulla is often nothing more than a much-
reduced final chamber covering the umbilicus. A specimen of G.
bulloides with a well-defined bulla is figured here (pl. 1, fig. 5b).
Other specimens with the final chamber covering the umbilicus and
grading from bulla size to normal size were also observed. An effect
of the final chamber covering the umbilicus is that the aperture is
reduced to a narrow slit or is completely absent.
Distribution.—Overall, Globigerina bulloides was observed to be
the dominant species in the shelf and slope waters. The highest fre-
quency was 70 percent at winter shelf station C. Along with other
species of Globigerina it diminishes in importance in the vicinity of
the Gulf Stream and was found to be rare or absent in most of the
Gulf Stream and Sargasso Sea stations.
GLOBIGERINA PACHYDERMA INCOMPTA Cifelli
Plate 1, figures 4, 6
Globigerina incompta C1FeEttt, 1961, Contr. Cushman Found. Foram. Res., vol. 12,
pt. 3, p. 84, pl. 4, figs. 1-7.
This problematic form, which is characterized mainly by its sim-
plicity and paucity of distinctive characters, varies in the amount of
12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
inflation of the test and in nature of the final chamber. As in G.
bulloides, the test is sometimes compact, and the final chamber oc-
casionally deviates from the axis of coiling and partially covers the
umbilicus. Also, the last chamber is often reduced in size. Specimens
with a compact test and a reduced final chamber covering the umbilicus
are identical with G. pachyderma. Several such specimens have been
observed in a few of the samples studied, and two are figured here.
These specimens show that G. incompta grades into G. pachyderma.
However, they are of rare occurrence in the region studied, and it is
useful to retain G. incompta as a subspecies. Parker (1962, p. 224)
has shown that in Recent Pacific bottom sediments G. incompta
grades into G. pachyderma, with G. pachyderma dominating in the
high latitudes. The transition is further shown by Smith (1963) from
northeastern Pacific plankton tows. The form that Smith figures (pl.
1, figs. 12-14) as a Globigerina pachyderma-eggeri intergrade is
identical with G. pachyderma incompta. The relationships, however,
with G. eggeri (=G. dutertrei) are not yet completely clear.
Distribution.—Globigerina pachyderma incompta is next in domi-
nance to G. bulloides in the shelf and slope waters. The highest fre-
quencies were observed in the summer (50 percent at stations B and
FE) and the fall (63 percent at station 2).
GLOBIGERINA DUTERTREI d’Orbigny
Plate 2, figures 1, 2
Globigerina eggeri RHUMBLER, 1900, Nordische Plankton, pt. 14, Foraminiferen,
p. 19, text figs. 20a-c.
Globigerina eggeri BrapsHaw, 1959 (part), Contr. Cushman Found. Foram.
Res., vol. 10, pt. 2, p. 35, figs. 5, 10 only —B£, 1959, Micropaleontol., vol. 5,
No. 1, pl. 2, figs. 1-3.
Globigerina dutertrei p’OrBIGNY, 1839—BANNER and Bow, 1960, Contr. Cush-
man Found. Foram. Res., vol. 11, pt. 1, p. 11, pl. 2, fig. 1.
This species closely resembles both Globigerina pachyderma in-
compta and the early stages of Pulleniatina obliquiloculata. G.
dutertret is distinguishable from G. pachyderma incompta by its rela-
tively high trochoid spire and its broad, open umbilicus. The differ-
ences are slight, however (Cifelli, 1961), and future studies of addi-
tional material, particularly from the warmer waters, may show that
G. dutertrei belongs to the G. pachyderma species group.
The coiling in G. dutertrei is trochoid throughout except, occasion-
ally, for the last chamber, which, like other Globigerina species, tends
to deviate toward the umbilicus. Thus, in the last whorl the chambers
NO. 4 PLANKTONIC FORAMINIFERA—CIFELLI 13
tend to wrap around the umbilicus, rather than overlap it as they do
in Pullentatina obliquiloculata.
In view of the close morphologic affinities of G. dutertrei to G.
pachyderma incompta and Pulleniatina obliquiloculata, I disagree with
Parker (1962, pp. 221, 242) in removing G. dutertrei from the genus
Globigerina and placing it in the genus Globoguadrina, family
Globorotaliidae. At least, I can find no consistent difference in wall
surface between G. dutertrei and other species of Globigerina. Nor
can a separation be made by the presence or absence of spines, since,
as Parker points out (Parker, 1962, p. 224), Globigerina pachyderma
only sometimes has spines. The fact that spines may be present or
absent in a single species weakens considerably the argument that
spines are a character of sufficient importance to separate otherwise
similar species into different families.
Distribution.—Globigerina dutertrei appears to be relatively rare
among the Globigerina in the northwestern part of the Atlantic. In
the summer, the maximum frequency was 5 percent (station HH’)
and in the fall, 9 percent (station 6). It was not recorded in the
winter, and in the spring the maximum frequency was only 2 percent
(station 3).
GLOBIGERINA aff. G. QUINQUELOBA Natland
Plate 2, figures 3, 4
Globigerina cf. quinqueloba Topp and BronniMan, 1957, Cushman Found.
Foram. Res. Spec. Publ. No. 3, p. 40, pl. 12, fig. 2.
Globigerina aff. quinqueloba Bk, 1959, Micropaleontol., vol. 5, No. 1, pl. 1, figs.
Zl. 22.
The test is small, and there are 4 to 6 chambers visible on the
ventral side. The periphery is lobulate, and the final chamber deviates
slightly from the trochoid spiral, projecting over the umbilicus. The
wall is thin and translucent. The aperture is a rounded umbilical
opening that is sometimes partially obscured by a thin, weakly de-
veloped chamber. The coiling is both sinistral and dextral, but the
sinistral mode is dominant.
The specimens included here and those in the figures cited closely
resemble G. quinqueloba but differ in having a thinner wall and a less
developed lip.
The present specimens also resemble in general form and outline
Globigerina concinna Reuss and G. diplostoma Reuss (which appears
to be identical with G. concinna) as originally figured. Those figures,
however, are lacking in diagnostic detail, and G. concinna and G.
14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
diplostoma have been interpreted in so many different ways that they
include a mixed bag of specimens ranging in age from Lower Tertiary
to Recent. Clarification of these species is needed before the form
designated here as Globigerina aff. G. quinqueloba can be definitely
assigned taxonomically.
Distribution—This species appears to be relatively scarce in the
summer (a maximum of 4 percent at station G) but common or
abundant at other times of the year. A maximum frequency of 57
percent was recorded at winter station D.
GLOBIGERINA INFLATA @’Orbigny
Plate 4, figures 1-3
Globigerina inflata p’'OrBIGNY, 1839, in Barker-Webb and Berthelot, Hist. Nat.
Tes Canaries, vol. 2, pt. 2, Foraminiféres, p. 134, pl. 2, figs. 7-9 —BrapsHAw,
1959, Contr. Cushman Found. Foram. Res., vol. 10, pt. 2, p. 36, pl. 6,
figs. 16-18.—Bé&, 1959, Micropaleontol., vol. 5, No. 1, pl. 1, figs. 12-14.
Globorotalia inflata (d’Orbigny) PARKER, 1962, Micropaleontol., vol. 8, No. 2,
p. 236, pl. 5, figs. 6-9.
This is an interesting species as it bridges the morphologic gap
between Globigerina and Globorotalia. Suites of specimens range
from a globigerine form with highly inflated chambers, a rounded
periphery and a large umbilical aperture to a globorotalid form with
compressed chambers, an angular periphery and a relatively low,
elongate, extra-umbilical aperture. The surface of the wall is also
variable, ranging from smooth to rough, with blunt spines. Radiating
spines, however, are absent.
Since this species is transitional between Globigerina and
Globorotalia, the generic assignment becomes somewhat arbitrary.
The species has been referred to both genera, but most commonly to
Globigerina. In the samples studied the globigerine form appears to
be dominant, and the species has a distribution like that of the
Globigerina species.
The angular, globorotalid form of Globigerina inflata closely ap-
proaches Globorotalia punctulata, which is distinguishable by its
lower, slitlike aperture and its sharper, more angular periphery. These
characters, however, are variable and end forms are sometimes dif-
ficult to distinguish.
Distribution.—Globigerina inflata is common in the shelf and slope
waters but apparently is not one of the dominant temperate species.
The highest frequency recorded was 38 percent, at fall station 4. In
NO. 4 PLANKTONIC FORAMINIFERA—CIFELLI T5
the winter it was recorded in the Sargasso Sea as far south as station
OO with a frequency of 2 percent.
GLOBIGERINA sp.
Plate 2, figures 5, 6
The test is small and relatively high trochospirally. In the last
whorl the final 1 or 2 chambers tend to bend over the umbilicus. In
some specimens the umbilicus is covered with a small bubblelike
chamber with a narrow aperture at the margin. The surface of the
test is spinose.
In general form this species resembles Globigerinita glutinata, but
the surface is spinose and the chambers are more inflated.
Distribution —This form was recorded in frequencies of less than 1
percent at summer stations HH”, MM; fall stations 4, 9; spring sta-
tion 2.
Genus PULLENIATINA Cushman, 1927
PULLENIATINA OBLIQUILOCULATA (Parker and Jones)
Plate 3, figures 1, 3; text figure 2
Pullenia sphaeroides (d’Orbigny) var. obliquiloculata PARKER and Jones, 1865,
Philos. Trans. Roy. Soc. London, vol. 155, pp. 365, 368, pl. 19, figs. 4a-b.
Pulleniatina obliquiloculata (Parker and Jones) BrapsHAw, 1959, Contr. Cush-
man Found. Foram. Res., vol. 10, pt. 2, p. 49, pl. 8, figs. 19, 20.—BE, 1959,
Micropaleontol., vol. 5, No. 1, pl. 2, figs. 4-6.
Pullenia sphaeroides (d’Orbigny) var. obliquiloculata BANNER and Brow, 1960,
Contr. Cushman Found. Foram. Res., vol. 11, pt. 1, p. 25, pl. 7, figs. 4a-c.
In this species the coiling changes during growth from trochospiral
to streptospiral (Bolli, Loeblich, and Tappan, 1957, p. 39). The
change in the axis of coiling becomes apparent at about the end of the
second whorl, and the last 2 or 3 chambers overlap the umbilical
area. Some of the stages in development are shown in figure 2.
Stages 1-4 comprise the majority of forms, and stages 5-7, which are
like the typical form, make up only about 20 percent of the present
total populations in this species. Stages 5-7 appear to represent varia-
tions in the degree of overlap of the final chamber over the umbilicus
rather than successive periods of development. In stage 7, the
umbilicus is completely covered and the aperture is an extra-umbilical,
crescent-shaped arch. The highly polished surface occurs only in the
final 1 or 2 chambers, in stages 6-7. In the earlier stages the surface
is hispid, but no spines were observed.
16 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
In its early stages this species closely resembles Globigerina
dutertret in having a broad, open umbilicus and a large umbilical
aperture. However, at about the end of the second whorl the
streptospiral coiling of Pulleniaiina obliquiloculata becomes apparent
and the chambers in the final whorl can be seen to deviate from the
axis of coiling of the earlier chambers when the test is viewed from
the dorsal side. Also, the later chambers of P. obliquiloculata tend to
be elongate in their axis of coiling.
PEOS
Voy
Fic. 2—Some developmental stages in Pulleniatina obliquiloculata,
Distribution.—This species was recorded mostly from the southern
stations and was most common in the winter, when it reached a
maximum frequency of 34 percent at station II. It was extremely
scarce in the summer and was recorded at only two stations (LL and
JJ) with frequencies of 1 and less than 1 percent respectively.
Genus GLOBIGERINITA Bronnimann, 1951
GLOBIGERINITA GLUTINATA (Egger)
Plate 3, figures 2, 4, 5
Globigerina glutinata Eccrr, 1893, Abhandl. K. Wiss. Miinchen, Cl. II, vol. 18,
p. 371, pl. 13, figs. 19-21.
Globigerinita glutinata BrapsHaw, 1959, Contr. Cushman Found. Foram. Res.,
vol. 10, pt. 2, p. 40, pl. 7, figs. 7, 8—Bzé, 1959, Micropaleontol., vol. 5, No. 1,
pl. 1, figs. 25-26—Parker, 1962, Micropaleontol., vol. 8, No. 2, p. 246,
pl. 9, figs. 1-16.
Globigerinita glutinata is distinguishable mainly by its smoothly
polished surface and low umbilical aperture. The bulla and dorsal
NO. 4 PLANKTONIC FORAMINIFERA-—CIFELLI 7
aperture, characters diagnostic of the genus Globigerinita, are poorly
developed in the studied assemblages of this species, and neither
character appeared on more than about 1 percent of the specimens. No
single specimen was observed that combined both bulla and dorsal
aperture.
To me, the relationship of Globigerinita with the Globigerinidae
seems clear enough, and I see no need in placing that genus in Incertae
Familiae (Parker, 1962, p. 244). The test of Globigerinita is distinctly
globigerine in form, and there is not a known character in its species
that is not found in the Globigerinidae. The bulla, or modified last
chamber, occurs in variants of both Globigerina and Globigerinoides
species, and the dorsal aperture is a diagnostic feature of Globig-
ertnoides. Nor is the nonspinose, smooth, finely perforate wall hard
to come by in the Globigerinidae, as Pulleniatina obliquiloculata lacks
spines and, in its final stage, has a smooth wall, comparable to that of
Globigerinita glutinata.
Distribution —Globigerinita glutinata appears to be a euryopic
species. In the traverses studied, this species ranged from the shelf
waters to the Sargasso Sea in about equal abundances. Frequencies
were low to moderate, the highest being 16 percent at the winter shelf
station F. In the summer a maximum frequency of 12 percent was
recorded at both shelf station B and Sargasso Sea station MM.
Genus ORBULINA d’Orbigny, 1839
ORBULINA UNIVERSA d@’Orbigny
Plate 3, figures 6, 7
Orbulina universa v’ORBIGNY, 1839, in De la Sagra, Hist. Phys. Pol. Nat. Cuba,
Foraminiféres, p. 3, pl. 1, fig. 1—BrapsHaw, 1959, Contr. Cushman Found.
Foram. Res., vol. 10, pt. 2, p. 49, pl. 8, figs. 17, 18—B&, 1959, Micropaleon-
tol., vol. 5, No. 1, pl. 2, fig. 18.
The test is highly porous, with the pores being of two sizes
evenly scattered throughout the surface. The wall of the inner
globigerine stage is highly fragile and was seldom found preserved
in the material studied. Mostly all that was visible of this early stage
was protoplasm roughly retaining the shape of the chambers and
some spiny remnants of the wall. The globigerine stage is highly
spinose, and the spines radiate out into the outer chamber, sometimes
penetrating through the wall.
The wall of the outer chamber is variable in thickness and almost
always single layered. However, on a few specimens the wall was
18 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
observed to be double layered, with the layers loosely attached like
the concentric rings of an onion. On these specimens the outer layer
could easily be separated from the inner one with a dissecting needle.
The bichambered form, Biorbulina bilobata of some authors, is
regarded here as a variant form of Orbulina universa. It is very
rare and was observed at only one station (Sargasso Sea, summer
station KK).
Distribution—This species occurs mostly in the Sargasso Sea and
Gulf Stream in low to moderately high frequencies. The lowest fre-
quencies were recorded in the winter, with less than 2 percent at all
stations. The summer traverse yielded the highest frequencies, reach-
ing 18 percent at station KK.
Genus GLOBOROTALIA Cushman, 1927
GLOBOROTALIA PUNCTULATA (d’Orbigny)
Plate 4, figure 4; plate 5, figure 1
Globigerina punctulata p'OrBicny, 1826, Ann. Sci. Nat., vol. 7, p. 277, No. 8.—
ForNASINI, 1898, Paleontol., Ital., vol. 4, p. 210, text fig. 5.
Globorotalia punctulata Phleger, PARKER and Petrson, 1953, Rep. Swedish
Deep-Sea Exped., vol. 7, No. 1, p. 20, pl. 4, figs. 8-12—Bz8, 1959, Micro-
paleontol., vol. 5, No. 1, pl. 1, figs. 9-12.
Globorotalia crassaformis (Galloway and Wissler, 1927). PARKER, 1962, Micro-
paleontol., vol. 8, No. 2, p. 35, pl. 4, figs. 17-18, 20-21.
The test of this species is characterized by its flattened dorsal side
and its relatively high spire. The periphery is angular and, occasion-
ally, thinly keeled. The aperture is slitlike and extends from the
umbilicus to the vicinity of the periphery. On some specimens there
is a thin lip above the aperture.
The close morphologic affinities between Globorotalia punctulata
and Globigerina inflata were mentioned under the latter. It is pos-
sible that somewhere in their geographic and stratigraphic ranges
these forms intergrade, and they may eventually prove to be con-
specific subspecies.
There has been considerable confusion concerning the rightful name
of this species, but no attempt is made here to resolve this complicated
legal problem which has been dealt with by Parker (1958, p. 281;
1962, p. 235) and Banner and Blow (1960, p. 15). Suffice it to say
that the present specimens are identical with G. punctulata as figured
by Fornasini. However, they are not identical with the single lecto-
type for both G. puncticulata and G. punctulata designated by Banner
and Blow. That lectotype clearly is not the same specimen figured by
NO. 4 PLANKTONIC FORAMINIFERA—CIFELLI 19
Fornasini as G. punctulata and in fact, as figured, appears referable
to G. inflata. Therefore, the lectotype is a potential source of taxo-
nomic confusion. With G. punctuculata as the senior synonym of G.
punctulata and G. inflata, the past records of two commonly occurring,
related species having different distributional patterns would become
virtually uninterpretable.
Distribution.—This species occurred mostly in the southern sta-
tions. Frequencies were low throughout the year. A maximum fre-
quency of 4 percent was recorded in the summer at station MM in
the Sargasso Sea and in the winter at station NN, also in the
Sargasso Sea. The fall maximum was 3 percent (station 5, slope
waters), and the spring maximum was 1 percent (station 6, slope
waters).
GLOBOROTALIA HIRSUTA (d’Orbigny)
Plate 5, figures 2, 3
Rotalina hirsuta p’Orsicny, 1939, in Barker-Webb and Berthelot, Hist. Nat.
Iles Canaries, vol. 2, pt. 2, Foraminiféres, p. 131, pl. 1, figs. 37-39.
Globorotalia hirsuta BrapsHAw, 1959, Contr. Cushman Found. Foram. Res.,
vol lOM pie 2..p.44,.plecwiigss henc.
This species is convex on the dorsal side and flattened on the
ventral side. The periphery is subacute and slightly keeled. The
aperture is a narrow opening extending beyond the umbilicus and
sometimes reaching the periphery. The surface of the test is coarsely,
but irregularly, spinose and punctate, closely resembling the surface
of G. truncatulinoides, G. punctulata, and some representatives of
Globigerina inflata.
The spire of Globorotalia hirsuta is much compressed, and the test
has the appearance of a G. punctulata that has been flattened on the
ventral side and expanded somewhat on the dorsal side.
Distribution.—This species was observed to occur rarely and was
found only in the stations south of the Gulf Stream. It was most
abundant in the winter at station OO, where the frequency was 4
percent.
GLOBOROTALIA MENARDII (d’Orbigny)
Plate 6, figures 3, 4
Rotalia menardii v’Orsicny, 1826, Ann. Sci. Nat., vol. 7, p. 273, No. 26; Mo-
déles, No. 10.
Globorotalia menarditi BrapsHAW, 1959, Contr. Cushman Found. Foram. Res.,
vol. 10, pt. 2, p. 44, pl. 8, figs. 3, 4.—-Bé, 1959, Micropaleontol., vol. 5, No. 1,
pl. 1, figs. 1-3.
20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Globorotalia cultrata (d’Orbigny, 1839) Parker, 1962, Micropaleontol., vol. 8,
No. 2, p. 235, pl. 5, figs. 3-5.
The present specimens were compared with representatives of this
species from plankton tows collected in the Lesser Antilles region of
the Caribbean. Although the present Central Atlantic forms are
clearly identical with Caribbean forms, some small general differences
were noted, as follows:
1, The Central Atlantic form, on the average, appears to be of
smaller size.
2, In the Central Atlantic form the test is smooth with few or no
pustules on the surface. In the Caribbean form the test ranges from
smooth to rough, with many pustules or, occasionally, an additional
coating of calcite on the surface.
3, The keel of the Central Atlantic form is thin and smooth with
little or no denticulation. In the Caribbean form the keel is more
variable and includes forms with thickened and crenulate keels.
In general, the Central Atlantic form is simpler and shows less
variation than the Caribbean form.
Distribution.—This species was observed mostly in the Sargasso
Sea stations. The highest frequency was recorded in the summer at
station KK (7 percent). However, most of the records were 1 percent
or less, suggesting that the stations occupied are beyond the optimum
range of G. menardu. It was particularly scarce in the stations from
the winter and spring traverses.
GLOBOROTALIA TRUNCATULINOIDES (d’Orbigny)
Plate 6, figures 1, 2; text figure 3
Rotalina truncatulinoides p’'OrBicny, 1939, in Barker-Webb and Berthelot, Hist.
Nat. Iles Canaries, vol. 2, pt. 2, Foraminiféres, p. 132, pl. 2, figs. 25-27.
Globorotalia truncatulinoides BrapsHAW, 1959, Contr. Cushman Found. Foram.
Res., vol. 10, pt. 2, p. 44, pl. 8, figs. 7, 8-—Bf£, 1959, Micropaleontol., vol. 5,
No. 1, pl. 1, figs. 5-7.
Globorotalia truncatulinoides is a distinctive and easily recognizable
species. In the adult form the test is high spired and has the shape of
a truncated cone, flattened on the dorsal side and with 5 chambers
visible on the ventral side. The periphery is subrounded in side view,
slightly keeled and denticulate. The aperture is a narrow, basal slit
that extends to a deep, narrow umbilicus; above the aperture there
is a well-defined lip. The projections of the lips of apertures on the
chambers surrounding the umbilicus form weak umbilical teeth.
NO. 4 PLANKTONIC FORAMINIFERA—CIFELLI 21
Pustules or blunt spines are distributed over the entire surface but
are concentrated mostly beneath the aperture of the final chamber.
The young form of this species does not have an umbilicus, and
the ventral cone is much lower than in the adult form. The truncated
conical shape of the test with an umbilicus is achieved during the
ontogeny, at about the end of the second whorl, where there is a
sudden relative increase in size of the lateral dimensions of the
chamber. The lateral slope at this stage is less acute than in the early
stage and tends to flare out with respect to the axial dimension of
the chamber (fig. 3).
<—— LATERAL SLOPE ————-
Fic. 3.—Relative increase in lateral slope of Globorotalia truncatulinoides.
Left, mature form. Right, immature form.
In the material studied, this species showed a decided preference
for sinistral coiling. However, specimens were not available in suf-
ficient numbers from the summer and fall traverses to determine
possible seasonal differences in coiling ratios.
Distribution—Globorotalia truncatulinoides was the dominant
species in the southern stations (JJ through OO) in the winter. The
highest frequency was 55 percent at station JJ. At other seasons this
species was rare or absent at most stations, the highest frequency
being 3 percent in the fall at station 5.
Genus CANDEINA d’Orbigny, 1839
CANDEINA NITIDA @’Orbigny
Plate 5, figure 4
Candeina nitida D’OrBIGNY, 1839, in De la Sagra, Hist. Phys. Pol. Nat. Cuba,
Foraminifeéres, p. 108, pl. 2, figs. 27-28.—BrapsHaw, 1959, Contr. Cushman
‘Found. Foram. Res., vol. 10, pt. 2, p. 32, pl. 7, fig. 19—B#, 1959, Micro-
paleontol., vol. 5, No. 1, pl. 2, figs. 19, 20.
to
to
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Candeina nitida is a very distinctive species, having 3 large, highly
inflated final chambers that envelop most of the previous part of
the test. Pores are distributed along the sutures of the last 3 chambers.
Distribution.—This species is very rare in the northwestern part of
the Atlantic and was recorded only in the Sargasso Sea, at summer
station KK and spring station 3. At both stations the frequencies were
less than 1 percent.
Genus GLOBIGERINELLA Cushman, 1927
GLOBIGERINELLA AEQUILATERALIS (Brady)
Plate 7, figures 3-5
Globigerina aequilateralis Brapy, 1884, Rep. Voy. Challenger, Zool., vol. 9,
p. 605, pl. 80, figs. 18-21.
Globigerinella aequilateralis BRApsHAW, 1959, Contr. Cushman Found. Foram.
Res., vol. 10, pt. 2, p. 38, pl. 7, figs. 1, 2—B#£, 1959. Micropaleontol., vol. 5,
No. 1, pl. 1, figs. 19, 20, 27.
Globigerinella siphonifera (d’Orbigny, 1839) Parker, 1962, Micropaleontol.,
vol. 8, No. 2, p. 228, pl. 2, figs. 22-28.
In its early stages this species is distinctly trochospiral and evolute.
As growth proceeds the coiling becomes planispiral and the test
partially involute with the later chambers overlapping and sometimes
obscuring the trochospiral portion of the test. The large, inflated
forms, however, are variable in coil and some tend to uncoil and
grow erratically, with the final 1 or 2 chambers sometimes being
added on either the dorsal or ventral side.
The wall is lacking in the axial region of the chambers so that the
sides of the chambers in the later stages do not touch the previous
whorl. Asa result the aperture is usually a basal slit but is variable in
size and extends entirely around the final chamber. It is often visible
around the margins of the previous 1 or 2 chambers. In the larger
forms that are partially uncoiled, the axial regions of the last few
chambers are entirely exposed.
Banner and Blow (1960, p. 22) have resurrected the name H.
siphonifera (d’Orbigny) for this species. However, this unnecessary
name change is based on an uncertain type specimen (Todd, 1963,
p. 110) and is contrary to the present principle of conservation of the
International Code of Zoological Nomenclature.
Distribution.—Globigerinella aequilateralis is one of the dominant
species of the subtropical assemblages. In the spring it reached a
maximum frequency of 60 percent in the Sargasso Sea at station 2.
In the summer the maximum frequency was 28 percent at station
NO. 4 PLANKTONIC FORAMINIFERA—CIFELLI 23
LL. The percentages dropped in the fall, when the maximum was
only 9 percent (station 9, in the Sargasso Sea) but increased in the
winter, when the maximum was 17 percent (Sargasso Sea station
MM).
Genus HASTIGERINA Thompson, 1876
HASTIGERINA PELAGICA (d’Orbigny)
Plate 7, figures 1, 2
Nontonina pelagica D’OrBIGNY, 1838, Foram. Amér. Meérid., p. 27, pl. 3, figs.
13, 1%
Hastigerina murrayi Thompson, 1876, Botti, LoesticH, and Tappan, 1957,
U. S. Nat. Mus. Bull. 215, p. 29, pl. 3, figs. 1-3b.
Hastigerina pelagica BrapsHAW, 1959, Contr. Cushman Found. Foram. Res.,
vol. 10, pt. 2, p. 47, pl. 8, figs. 14, 15—Bré, 1959, Micropaleontol., vol. 5,
No. 1, pl. 2, figs. 21-22——BANNER and Biow, 1960, Micropaleontol., vol. 6,
p. 20, text fig. 1.
The test consists of a highly involute, biumbilicate planispiral coil
of inflated chambers that is sometimes compressed laterally. A
trochoid stage was not observed. The aperture is an equatorial open-
ing at the base of the last chamber that varies in size from a slit to a
broad arch. Above the aperture is a thin lip. The wall of the test is
very thin and extremely fragile, and specimens are often in a poor
state of preservation, even from plankton tows. The spines are few
in number but are coarse and triradiate (Banner and Blow, 1960,
p. 21). The spines extend into, and even through, the walls of the
chambers from the previous whorl.
Hastigerina pelagica is one of the most distinctive and easily
recognizable Recent planktonic species. It is most readily comparable
with Globigerinella aequilaterlalis, but I agree with Parker (1962, p.
228) in retaining these two species in separate genera. As Parker
states, a much better case can be made for combining H. pelagica with
Hastigerinella digitata, as these two latter species are unique in their
spinosity.
Distribution.—This species reached a maximum frequency of 24
percent in the summer at Sargasso Sea station (LL) but otherwise
occurred mostly in low percentages. The winter maximum was 13
percent (Sargasso Sea station KK), but the fall maximum was only
3 percent and the spring maximum only 1 percent.
Genus GLOBIGERINOIDES Cushman, 1927
The genus Globigerinoides includes a distinctive group of species
with peculiar chamber arrangements that tend to deviate considerably
24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
from the trochospiral coil as seen in Globigerina. The chamber ar-
rangements, though sometimes difficult to express geometrically, are
useful in distinguishing the species of Globigerinoides. Illustrations
of chamber arrangements in Recent species of Globigerinoides are
shown in figure 4.
Fic. 4—Chamber arrangements and positions of primary apertures in some
species of Globigerinoides. 4a, G. ruber, ventral view. 4b, G. conglobatus, im-
mature form, ventral view. 4c, G. conglobatus, mature form, ventral view.
4d, G. trilobus trilobus, edge view. 4e, G. trilobus trilobus, ventral view.
In Globigerinoides conglobatus the chambers are coiled in a fashion
similar to that in Pulleniatina obliquiloculata, with the early chambers
added in a trochoid spiral and the final chambers added streptospirally,
overlapping the umbilicus. In the final stage of development the last
chamber completely covers the umbilicus.
In Globigerinoides ruber there is a pronounced shift in the axis of
the chambers as they are added; in fact, it is somewhat difficult to
think of the chambers actually forming a coil. Each chamber is added
directly above the aperture of the earlier chamber. The aperture of
the new chamber is 90 degrees apart from the aperture of the pre-
NO. 4 PLANKTONIC FORAMINIFERA—CIFELLI 25
vious chamber. This arrangement of chambers might possibly be
thought of as an extreme streptospiral coil, with the coil changing 90
degrees in direction with the addition of each chamber. The test is
nonumbilicate, as in the mature G. conglobatus. The chamber ar-
rangement of G. elongatus is identical with that of G. ruber.
The chamber arrangement in Globigerinoides trilobus is more ob-
scure. In edge view the test is rather flattened and the chambers ap-
pear to adhere to the trochospiral coil as in Globigerina. At the same
time, however, portions of the new chambers overlap the ventral side
of the test considerably, so that the umbilicus is almost obscured and
the aperture is low and elongate. In overall appearance G. trilobus
is similar to G. ruber when viewed from the ventral side, where 3
chambers are visible with 1 larger chamber set above 2 smaller, earlier
chambers. However, in G. ruber the primary aperture is symmetrical
above the 2 earlier chambers, while in G. trilobus it is asymmetrical
(Boilt 19573 p.112).
GLOBIGERINOIDES ELONGATUS (d’Orbigny)
Plate 8, figures 1, 4
Globigerina rubra D’OrBIcNyY, 1839, in De la Sagra, Hist. Phys. Pol. Nat. Cuba,
Foraminiféres, p. 82, pl. 4, figs. 12-14—-BANNER and Bow, 1960, Contr.
Cushman Foram. Res., vol. 11, pt. 1, p. 19, pl. 3, figs. 8a, b.
Globigerinoides rubra BrapsHAw, 1959, Contr. Cushman Found. Foram. Res.,
vol. 10, pt. 2, p. 42, pl. 7, figs. 12, 13-——Bé, 1959, Micropaleontol., vol. 5,
No. 1, pl. 2, figs. 16, 17.
This species is nonumbilicate, and each new chamber is added above
the primary aperture of the earlier chamber. The final chamber is
sometimes reduced in size, appearing like a small bubble on the pre-
vious part of the test. The primary aperture is a broad arched open-
ing at the base of the last chamber, which is symmetrically located
above the 2 earlier chambers. There are 2 supplementary apertures
on the side of the chamber opposite to the primary aperture. The
supplementary apertures vary from low slits to broad, rounded
openings; on some of the smaller specimens they are barely per-
ceptible. When well developed, the supplementary apertures can be
seen on the last 2 or 3 chambers.
The color in Globigerinoides ruber ranges from white through
various shades of pink to bright red. Most often, the red or pink
color is confined, appearing only in part, particularly the early part,
of the test. In the summer traverse over 75 percent of the specimens
were red or pink in color, and most of these were bright red. In the
26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
winter traverse the white forms predominated, accounting for over
50 percent of this species. The winter-colored specimens included only
shades of pink, and bright red forms were lacking. In the fall and
spring traverses the colors were intermediate between summer and
winter.
Distribution.—Overall, Globigerinoides ruber is the most abundant
species of Globigerinoides in the traverses studied. It was also one
of the dominant species of the subtropical assemblages. The highest
frequency recorded was 43 percent at the summer slope station HH.
Along with other species of Globigerinoides, the frequency dropped
considerably in the winter, reaching a maximum of only 8 percent
(station IT).
GLOBIGERINOIDES ELONGATUS (d’Orbigny)
Plate 9, figure 5
Globigerina elongata d’Orbigny, 1826, BANNER and Biow, 1960, Contr. Cushman
Found. Foram. Res., vol. 11, pt. 1, p. 12, pl. 3, figs. 10a-c.
This species closely resembles and may turn out to be a variant
form of Globigerinoides ruber. However, the test is more compact
than in G. ruber, and the final chambers are compressed, almost
flattened, as in G. conglobatus.
The primary aperture is symmetrically located above the two earlier
chambers in G. elongatus but is less broad than in G. ruber. The
present specimens agree with the lectotype of G. elongatus as figured
by Banner and Blow.
Distribution —tThis species is rare and was recorded only from
Sargasso Sea stations. In all cases the frequencies were less than 1
percent.
GLOBIGERINOIDES TRILOBUS TRILOBUS (Reuss)
Plate 9, figures 1-3
Globigerina triloba Reuss, 1850, Denkr. K. Akad. Wiss. Wien, vol. 1, p. 374,
pl. 47, fig. 11.
Globigerinoides sacculifer (Brady, 1877), B&, 1959, Micropaleontol., vol. 5, pl. 2,
figs. 13-15.
In this species the final chamber is set above the two preceding ones,
as in Globigerinoides ruber. However, the coiling of G. trilobus
trilobus is essentially trochospiral, and the final chamber does not
completely cover the umbilicus, so that the primary aperture is a
narrow slit at the base of the chamber. On the dorsal side of the
NO. 4 PLANKTONIC FORAMINIFERA—CIFELLI 27
chamber there is a single supplementary aperture, in contrast to G.
ruber in which there are two supplementary apertures on the chamber.
This species shows variation in the size of the supplementary
aperture and in the development of the final saclike chamber. The fol-
lowing forms which are completely transitional were recognized in
the material studied.
1, Supplementary aperture small, saclike final chamber lacking.
2, Supplementary aperture large, saclike final chamber lacking.
3, Supplementary aperture small, saclike final chamber present.
4, Supplementary aperture large, saclike final chamber present.
Form 1 occurs most commonly, but form 2 is also present in
appreciable numbers. Form 3 and particularly form 4 are relatively
scarce. The specimens agree very well and are identical with Miocene
topotypes of Globigerina trilobus Reuss in the U. S. National Museum
collections, which include both forms 1 and 2, with dominance of
form 1. They differ from G. sacculifer Brady in having smaller sup-
plementary apertures and less-developed saclike final chambers. Speci-
mens of G. sacculifer from Recent Pacific bottom sediments studied
for comparison included the same range of forms as G. trilobus but
showed a dominance of forms 3 and 4. Moreover, the Pacific sac-
culifer includes a form with an elongate saclike final chamber (Brady,
1884, pl. 80, fig. 4) that was not observed in the North Atlantic
material.
Thus, G. trilobus and G. sacculifer represent overlapping parts of
a gradational series, a fact noted by several earlier workers, and as
such are distinguishable only at the subspecific level. Although called
subspecies, however, trilobus and sacculifer are not subspecies in the
geographic sense of the neontologist, since G. trilobus sensu lato has
a long, complex fossil record. Additional difficulties in applying the
neontological subspecies concept are introduced by the fact that the
species has a pelagic habitat. The isolating mechanisms in the open
ocean are much less understood than those on land or even on the
ocean bottom.
It would be convenient if the gradational series between trilobus
and sacculifer also represented an evolutionary series, as then it would
be an easy matter to divide the series into vertical subspecies, in the
sense of the paleontologist. Unfortunately, such a simple phyletic
trend does not characterize this lineage. The present North Atlantic
assemblages show a closer morphologic affinity to the Miocene as-
semblages of trilobus than to Recent assemblages of sacculifer. Thus,
G. trilobus will not yield gracefully to a vertical division of subspecies.
28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Vertical subspecies could not be identified without knowing the age
of the assemblage.
There are, in the fossil record, several additional forms that can
be linked to the trilobus—sacculifer gradational series, such as G.
altiapertura and G. immatura. These forms have been treated in
different ways by various authors, but the treatment thus far has been
dominantly typological. As a result, the range of forms in G. trilobus
sensu lato is reasonably well known, but there is still a poor under-
standing of the nature of population structures at the various strati-
graphic levels. Parker (1962, p. 219) pointed out the necessity of
treating assemblages as populations, and it could be added that this
particular problem lends itself to a quantitative analysis, since the
distinctions between the subspecies involve gradational characters. In
order to determine the actual changes that have occurred in G. trilobus
sensu lato since the Miocene, it will be necessary to analyze statistically
the character of many assemblages from widely separated localities
ranging from Miocene to Recent; a formidable task, but only in this
way can a complete and realistic alignment of subspecies be attained.
Thus, any present arrangement of subspecies must be considered
tentative and incomplete. It seems unnecessarily pretentious to force
subspecies into horizontal or vertical straitjackets, and it is much more
compatible with the evidence at hand to recognize subspecies as
dynamic populations in which the range of variation fluctuates through
time and space.
Distribution —Although Globigerinoides trilobus trilobus was not
as common, overall, as G. ruber, the ratio between the two species
varied considerably from station to station, and at a few stations G.
trilobus trilobus was the dominant species of Globigerinoides. Its
highest frequency was 45 percent, which was recorded in the fall at
station 8, in the Sargasso Sea.
GLOBIGERINOIDES CONGLOBATUS (Brady)
Plate 8, figures 2, 3
Globigerina conglobata Brapy, 1884, Rep. Voy. Challenger, Zool., vol. 9, p. 603,
pl. 80, figs. 1-5, pl. 82, fig. 5.
Globigerinoides conglobata BrapsHaAw, 1959, Contr. Cushman Found. Foram.
Res., vol. 10, pt. 2, p. 40, pl. 7, figs. 5, 6—Bz#, 1959, Micropaleontol., vol. 5,
No. 1, pl. 2, figs. 7-12.
Globigerinoides sp. BrapsHAw, 1959, Contr. Cushman Found. Foram. Res.,
vol. 10, pt. 2, pl. 7, figs. 16, 17.
Throughout most of the test the coiling is trochospiral, but in the
last whorl the final 2 chambers overlap the umbilicus. In many
NO. 4 PLANKTONIC FORAMINIFERA—CIFELLI 29
specimens the last chamber completely covers the umbilicus, and the
primary aperture is a small, rounded opening symmetrically located
above 2 earlier chambers. The last chamber is compressed and
flattened in appearance. In the early stages this species has an open
umbilicus and in coiling closely resembles species of Globigerina. The
specimen that Bradshaw (1959, pl. 7, figs. 16, 17) figured as Globig-
erinoides sp. is considered here to be an early stage of G. conglobatus.
The wall of this species is relatively thick for a Globigerinoides and
the surface is coarsely spinose.
Distribution.—This is a characteristic species in the subtropical as-
semblages but was found mostly at frequencies of less than 5 per-
cent. However, at Sargasso Sea summer station KK it was recorded
at a frequency of 15 percent and was the dominant species of
Globigerinoides.
APPENDIX
TABLE 5.—Positions of plankton-collecting stations, summer traverse,
August 1960. Water depths are given for the shelf stations only.
Water : Depth in Latitude N. Longitude W.
body Station meters En uid Om a
Sheltwaters sane ences: AGE Via esi eae 36 40 58 71 49
SP Wehethys iy teddies By insane 4s ite 64 40: 44 71 41
ET Sa ee CUNO ac ones 67 40 31 7135
SS eae ea Dye staersetyok aie HE 40 18 71 28
Pema a ecceaisicteteresche Spa creyspetanelseharete 314 40 00 71 19
Slope waters s see esses F 39 48 7112
SPP t sacs G 39 36 71 06
Sate Pa gobsanate.s HH 38 46 70 12
hat, Al Med eo cea loli!’ 38 39 69 33
Pe Otee oocndee lSUS” 38 12 69 18
Giiltestheaines cee II 38 00 69 32
SHG SEE Sao oposece ai af 12 68 48
yh, Te ae eck KK 36 23 68 04
SEC OS acrclataniatte lel, 35035 67 20
Re eT aslo pea MM 34 47 66 29
TABLE 6.—Positions of plankton-collecting stations, fall traverse,
October 1960. Water depths are given for the shelf stations only.
Water Depth in Latitude N. Longitude W.
body Station meters oes Oe
Shelimawaters sneer aoa dl RS ree 36 41 03 71 29
# Sen CE TE Peerage 65 40 48 7-25
vg SRO RAGIN ORS anus 68 40 28 | ZB
Cie hel) NA Sen ee epee 2 EE RMN PRA Oe 122 40 06 715
Slopenwatersies ee reeieee 39 17 71 03
oy eck) ig aR Nae 6 38 27 70 53
GultaStream_o eee 7 37 38 70 41
Sarsassou Seal eeeeee eee 8 36 58 70 08
cat ae tee AS ht 9 36 14 69 18
* A bathythermograph was not available on this cruise and the position of
Gulf Stream was estimated by the set of the ship.
NO. 4 PLANKTONIC FORAMINIFERA—CIFELLI Sil
TaBLe 7.—Positions of plankton-collecting stations, winter traverse,
January 1961. Water depths are given for the shelf stations only.
Water Depth in Latitude N. Longitude VW.
body Station meters ee a,
SING? SELES NRC toe: an eens 36 40 59 At Sil
mad VID choSirests ees Bb sddeendlisdiss 65 40 44 71 41
ET ats te I fee Oh ats or cee 70 40 31 71 36
de Sea in eee DPR. 77 40 18 71 28
Ce UP ee eae Bene Fe epee ars Peas 342 39 56 71 18
Sloperwatersh «tsi wie F 39 48 TLAZ
Seed Leet ha: G 39 37 71 06
See gt eA CON So Me HH 38 46 70 19
Gulia Streatnia nt seer Il 37 46 69 20
Sateassop Sed) Antec ovate qf 37 10 68 38
PU Oa cari Reet c rion: KK 36 23 68 05
RN 8 oe eee IIE 35735 67 21
a Ee MM 34 43 66 22
LPT PR Wek cg NN 33 56 65 51
SSRN ESOS OO 33 06 65 03
TABLE 8.—Positions of plankton-collecting stations, spring traverse,
May 1961. Water depths are given for the shelf stations only.
Water Depth in Latitude N. Longitude W.
body Station meters oA Si» A
Sitelf waters 00.6. 0. ON. AGEs 52 40 45 70 30
ee A Be ee Le Oi. sere cl otrors 58 40 31 70 20
Slope Waters: .s.0d.cc50s 7 39 51 69 47
LON SN eR shee aa! 6 39 07 69 14
SA FOLIOS IO... eRe 5 38 35 68 50
SF Ph, A AY 4 38 00 68 26
Gilt Stream 1645.00.05 3 37 20 67 51
Sargasso Sea. 2970)0.4 2 36 06 67 06
REFERENCES
Banner, F. T., and Brow, W. H.
1959. The classification and stratigraphical distribution of the Globigerina-
ceae. Pt. 1. Palaeontol. (Paleontol. Assoc. London), vol. 2, pt. 1,
pp. 1-27, pls. 1-3.
1960. Some primary types of species belonging to the superfamily Globig-
erinaceae. Contr. Cushman Found. Foram. Res., vol. 11, pt. 1,
pp. 1-41, pls. 1-8.
1960a. The taxonomy, morphology, and affinities of the genera included in
the subfamily Hastigerininae. Micropaleontol., vol. 6, pp. 19-31,
figs. 1-11.
BE, A. W. H.
1959. Ecology of Recent planktonic foraminifera: Pt. 1, Areal distribution
in the western North Atlantic. Micropaleontol., vol. 5, No. 1, pp. 77-
100, pls. 1-2, text figs. 1-52, tables 1-2.
1960. Ecology of Recent planktonic foraminifera: Pt. 2, Bathymetric and
seasonal distributions in the Sargasso Sea off Bermuda. Micro-
paleontol., vol. 6, No. 4, pp. 373-392, text figs. 1-19, tables 1-6.
Bott, H. M.
1957. Planktonic Foraminifera from the Oligocene-Miocene Cipero and
Lengua formations of Trinidad, B.W.I. U.S. Nat. Mus. Bull. 215,
pp. 97-121, pls. 22-29.
Botut, H. M., Lorsricu, A. R., and Tappan, H.
1957. Planktonic foraminiferal families Hankteninidae, Orbulinidae, Glo-
borotaliidae, and Globotruncanidae. U.S. Nat. Mus. Bull. 215,
pp. 3-50, pls. 1-11, text figs. 1-9.
BRADSHAW, J. S.
1959. Ecology of living planktonic foraminifera of the North and Equa-
torial Pacific Ocean. Contr. Cushman Found. Foram. Res., vol. 10,
pt. 2, pp. 25-63, pls. 6-8.
Brapy, H. B.
1884. Report on the Foraminifera in Report on the scientific results of
H.M.S. Challenger during the years 1873-76. Zoology, vol. 9,
pp. 1-814, pls. 1-115.
CIFELLI, R.
1961. Globigerina incompta, a new species of pelagic Foraminifera from
the North Atlantic. Contr. Cushman Found. Foram. Res., vol. 12,
pt. 3, pp. 83-86, pl. 4.
1962. Some dynamic aspects of the distribution of planktonic Foraminifera
in the western North Atlantic, Sears Found. Journ. Marine Res.,
vol. 20, No. 3, pp. 201-213.
Grice, G. D., and Hart, D. H.
1962. The abundance, seasonal occurrence and distribution of the epizoo-
plankton between New York and Bermuda. Ecological Monogr.,
vol. 32, pp. 287-309.
3a
NO. 4 PLANKTONIC FORAMINIFERA—CIFELLI 33
IsELin, C. O’D.
1936. A study of the circulation of the western North Atlantic. Massachu-
setts Inst. Techn., Woods Hole Oceanogr. Inst., Pap. Phys.
Oceanogr. and Meteorol., vol. 4, No. 4, pp. 1-101.
Parker, F. L.
1958. Eastern Mediterranean Foraminifera. Swedish Deep Sea Exped.
Reps., vol. 8, pp. 219-283, pls. 1-6.
1962. Planktonic foraminiferal species in Pacific sediments. Micropaleontol.,
vol. 8, No. 2, pp. 219-254, pls. 1-10.
Situ, A. B.
1963. Distribution of living planktonic Foraminifera in the northeastern
Pacific. Contr. Cushman Found. Foram. Res., vol. 14, pp. 1-15,
pls. 1-2.
SToMMEL, H.
1958. The Gulf Stream—a physical and dynamical description. California
Univ. Press, 202 pp. Berkeley and Los Angeles.
Topp, R.
1961. On selection of lectotypes and neotypes. Contr. Cushman Found.
Foram. Res., vol. 12, pp. 121-122.
1963. Nomenclature of Foraminifera. Contr. Cushman Found. Foram, Res.,
vol. 14, pp. 109-111.
EXPLANATION OF PLATES
PLATE 1
Fig. 1. Globigerina bulloides d Orbigny. Summer slope station HH”. U.S.N.M.
641307. a, Dorsal view. b, Ventral view. 93.
Fig. 2. Globigerina bulloides d’Orbigny. Fall shelf station 3. U.S.N.M. 641308.
a, Dorsal view. b, Ventral view. 93.
Fig. 3. Globigerina bulloides d’Orbigny. Spring slope station 4. U.S.N.M.
641309. a, Ventral view. b, Dorsal view. 93.
Fig. 4. Globigerina pachyderma incompta Cifelli. Fall slope station 5. U.S.N.M.
641310. a, Ventral view. b, Dorsal view. 148.
Fig. 5. Globigerina bulloides d’Orbigny. Summer slope station F. U.S.N.M.
641311. a, Dorsal view. b, Ventral view. 93.
Fig. 6. Globigerina pachyderma incompta Cifelli. Fall slope station 6. U.S.N.M.
641312. a, Dorsal view. b, Ventral view. 148.
Pate 2
Fig. 1. Globigerina dutertrei d’Orbigny. Summer slope station HH’. U.S.N.M.
641313. a, Dorsal view. b, Ventral view. 65.
Fig. 2. Globigerina dutertrei d Orbigny. Fall slope station 6. U.S.N.M. 641314.
a, Ventral view. b, Dorsal view. 65.
Fig. 3. Globigerina aff. G. quinqueloba Natland. Winter shelf station B.
U.S.N.M. 641315. a, Ventral side. b, Dorsal side. 214.
Fig. 4. Globigerina aff. G. quinqueloba Natland. Winter shelf station B.
U.S.N.M. 641316. a, Ventral side. b, Dorsal side. 214.
Fig. 5. Globigerina sp. Winter shelf station D. U.S.N.M. 641317. a, Ventral
side. b, Dorsal side. 148.
Fig. 6. Globigerina sp. Winter shelf station D. U.S.N.M. 641318. a, Dorsal
side. b, Ventral side. «148.
PLATE 3
Fig. 1. Pulleniatina obliquiloculata (Parker and Jones). Winter slope sta-
tion HH. U.S.N.M. 641319. a, Dorsal view, b, Ventral view. 93.
Fig. 2. Globigerinita glutinata (Egger). Spring Gulf Stream station 3.
U.S.N.M. 641320. a, Ventral view. b, Dorsal view. 148.
Fig. 3. Pulleniatina obliquiloculata (Parker and Jones). Winter slope sta-
tion HH. U.S.N.M. 641321. a, Dorsal view. b, Ventral view. 93.
Fig. 4. Globigerinita glutinata (Egger). Spring slope station 4. U.S.N.M.
641322. a, Ventral view. b, Dorsal view. 148.
Fig. 5. Globigerinita glutinata (Egger). Spring slope station 4. U.S.N.M.
641323. a, Ventral view. b, Dorsal view. «148.
Fig. 6. Orbulina universa d’Orbigny. Summer Sargasso Sea station KK.
U.S.N.M. 641324. Bichambered form. «46.
Fig. 7. Orbulina universa d’Orbigny. Fall Sargasso Sea station 9. U.S.N.M.
641325. «46.
34
NO. 4 PLANKTONIC FORAMINIFERA—CIFELLI 35
PLATE 4
Fig. 1. Globigerina inflata d’Orbigny. Spring slope station 5. U.S.N.M. 641326.
a, Ventral view. b, Edge view. c, Dorsal view. 93.
Fig. 2. Globigerina inflata d’Orbigny. Fall slope station 5. U.S.N.M. 641327.
a, Ventral view. b, Edge view. c, Dorsal view. 93.
Fig. 3. Globigerina inflata d’Orbigny. Fall slope station 6. U.S.N.M. 641328.
a, Ventral view. b, Dorsal view. 93.
Fig. 4. Globorotalia punctulata (d’Orbigny). Summer Sargasso Sea station
KK. U.S.N.M. 641329. a, Ventral view. b, Edge view. c, Dorsal view.
593.
PLATE 5
Fig. 1. Globorotalia punctulata (d’Orbigny). Summer Sargasso Sea station
KK. U.S.N.M. 641330. a, Ventral view. b, Edge view. c, Dorsal view.
x93.
Fig. 2. Globorotalia hirsuta (d’Orbigny). Winter Sargasso Sea station OO.
U.S.N.M. 641331. a, Dorsal view. b, Ventral view. 65.
Fig. 3. Globorotalia hirsuta (d’Orbigny). Spring Sargasso Sea station 2.
U.S.N.M. 641332. a, Dorsal view. b, Edge view. c, Ventral view. 65.
Fig. 4. Candeina nitida d’Orbigny. Summer Sargasso Sea station KK.
U.S.N.M. 641333. a, Ventral view. b, Dorsal view. 93.
PLATE 6
Fig. 1. Globorotalia truncalulinoides (d’Orbigny). Winter Sargasso Sea sta-
tion NN. U.S.N.M. 641334. a, Ventral view. b, Dorsal view. 93.
Fig. 2. Globorotalia truncatulinoides (d’Orbigny). Fall slope station 5.
U.S.N.M. 641335. a, Dorsal view. b, Ventral view. 93.
Fig. 3. Globorotalia menardu (d’Orbigny). Summer Sargasso Sea station LL.
U.S.N.M. 641336. a, Ventral view. b, Dorsal view. 93.
Fig. 4. Globorotalia menardii (d’Orbigny). Fall Sargasso Sea station 9.
U.S.N.M. 641337. a, Ventral view. b, Dorsal view. 93.
PLATE 7
Fig. 1. Hastigerina pelagica (d’Orbigny). Winter Sargasso Sea station MM.
U.S.N.M. 641338. a, Side view. b, Edge view. 65.
Fig. 2. Hastigerina pelagica (d’Orbigny). Summer Sargasso Sea station LL.
U.S.N.M. 641339. a, Edge view. b, Side view. 65.
Fig. 3. Globigerinella aequilateralis (Brady). Winter Sargasso Sea station NN.
U.S.N.M. 641340. a, Ventral view. b, Dorsal view. 65.
Fig. 4. Globigerinella aequilateralis (Brady). Spring Gulf Stream station 3.
U.S.N.M. 641341. a, Dorsal view. b, Ventral view. X65.
Fig. 5. Globigerinella aequilateralis (Brady). Spring Gulf Stream station 3.
U.S.N.M. 641342. a, Dorsal view. b, Ventral view. 65.
PLATE 8
Fig. 1. Globigerinoides ruber (d’Orbigny). Spring Gulf Stream station 3.
U.S.N.M. 641343. a, Ventral view. b, Dorsal view. «93
36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Vig. 2. Globigerinoides conglobatus (Brady). Fall slope station 6. U.S.N.M.
641344. a, Ventral view. b, Dorsal view. 65.
Vig. 3. Globigerinoides conglobatus (Brady). Summer Sargasso Sea station
LL, U.S.N.M. 641345. a, Dorsal view. b, Ventral view. 93.
Fig. 4. Globigerinoides ruber (d’Orbigny). Spring Gulf Stream station 3.
U.S.N.M. 641346. a, Dorsal view. b, Ventral view. «93.
PLATE 9
Fig. 1. Globigerinoides trilobus trilobus (Reus). Fall slope station 6. U.S.N.M.
641347. a, Ventral view. b, Dorsal view. 65.
Fig. 2. Globigerinoides trilobus trilobus (Reus). Summer Sargasso Sea sta-
tion KK. U.S.N.M. 641348. a, Ventral view. b, Dorsal view. 65.
Fig. 3. Globigerinoides trilobus trilobus (Reus). Summer Sargasso Sea sta-
tion KK. U.S.N.M. 641349. a, Ventral view. b, Dorsal view. 65.
Fig. 4. Globigerinoides trilobus trilobus (Reus). Summer slope station HH’.
U.S.N.M. 641350. a, Ventral view. b, Dorsal view. X65.
Fig. 5. Globigerinoides elongatus (d’Orbigny). Winter Sargasso Sea sta-
tion NN. U.S.N.M. 641351. a, Ventral view. b, Dorsal view. 148.
HSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 4, PL
GLOBIGERINA
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148,
GLOBIGERINA
4SONIAN MISCELLANEOUS COLLECTIONS 148, NO. 4,
PULLENIATINA. GLOBIGERINITA, ORBULINA
VOL. 148, NO. 4, P
GLOBIGERINA, GLOBOROTALIA
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GLOBOROTALIA, CANDEINA
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 4,
GLOBOROTALIA
JNIAN MISCELLANEOUS COLLECTIONS
HASTIGERINA, GLOBIGERINELLA
VOL. 148, NO. 4, PL. 7
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 4, PL. 8
GLOBIGERINOIDES
MITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 4, PL. 9
GLOBIGERINOIDES
a
SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 148, NUMBER 5
Charles D. and Mary Waux Talcott
Research F und
HEXAHEDRILES
LIBRARY OF
(Wire Four PLATES) CONGRESS
: SERIAL RECORD
' JUN1 8 1975
By
}
EDWARD P. HENDERSON
U. S. National Museum. }
Smithsonian Institution ?
7 -
CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
JUNE 14, 1965
SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 148, NUMBER 5
Charles D. and Mary Waux Walcott
Research Fund
HEXAHEDRITES
(WitH Four P tates)
By
EDWARD P. HENDERSON
U. S. National Museum
Smithsonian Institution
S220200080°
(PusticaTion 4601)
CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
JUNE 14, 1965
Gift \
Pul lishep
Copy
PORT CITY PRESS, INC.
BALTIMORE, MD., U. S. A.
Charles DB. and Mary Waux Galcott Research Fund
HEXAHEDRITES
By EDWARD P. HENDERSON
U. S. National Museum
Smithsonian Institution
(WitH Four PLATEs)
INTRODUCTION
Hexahedrites are the simplest of the iron meteorites and a com-
paratively easy type to recognize, yet many have been incorrectly
classified. In several places these irons were found distributed in
such a manner that they seem to have fallen as a shower. This
investigation of the worldwide distribution of hexahedrites was made
to determine how general these local concentrations are. In assem-
bling the geographic data, certain characteristics were noted which
could have a bearing on the scatter of these irons.
Acknowledgments.—Because these topics were discussed with
many investigators in diverse disciplines over the years, it is difficult
to credit specific points to the proper source. The author realizes
that some names probably have been overlooked and to them he
offers apologies. The following persons have made substantial con-
tributions to this study: H. J. Axon, University of Manchester,
Manchester, England; Harrison Brown, California Institution of
Technology, Pasadena, Calif.; V. Buchwald, Technical University,
Copenhagen, Denmark; Walter Corvello, National Museum, Rio de
Janeiro, Brazil; Roy S. Clarke, Jr., U. S. National Museum, Washing-
ton, D. C.; M. E. Lipschultz, Goddard Space Flight Center, National
Aeronautics and Space Administration, Washington, D. C.; Brian
Mason, American Museum of Natural History, New York City;
Charles Olivier, formerly of Flower Observatory, University of
Pennsylvania, Philadelphia, Pa.; Sharat Roy (deceased), Chicago
Museum of Natural History, Chicago, [l.; Harold Urey, University
of California, La Jolla, Calif.; H. Wanke, Max Planck Institute,
Mainz, Germany.
SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 148, NO. 5
2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
HEXAHEDRITES AND THE NICKEL-IRON SYSTEM
The three types of iron meteorites, hexahedrites, octahedrites, and
ataxites, are accounted for by the nickel-iron phase diagram, fig. 1;.
however, there are no clearly defined separations between the dif-
900 |
800
TEMPERATURE °C,
400
0) 10 20 30 40 50 60
WT. % NICKEL
Fic. 1—Nickel-iron phase diagram. The hexahedrites and _ nickel-poor
ataxites fall into the same area, i.e., left of the line AB and usually within the
area defined by the two dotted lines. A hexahedrite should consist of one nickel-
iron alloy, kamacite or alpha iron.
ferent types. The hexahedrite group is located to the left of the
line AB in figure 1. These should consist of a single phase, alpha
iron or kamacite. The octahedrites fall in the area between AB and
AC and consist of two phases of nickel-iron alloys, kamacite (alpha
iron) and taenite (gamma iron). The third group, ataxites, should
NO. 5 HEXAHEDRITES—HENDERSON 3
occupy the area to the right of AC and chiefly consist of taenite, but
usually also contain an appreciable quantity of alpha iron, kamacite.
Meteorites lying along the borderlines of groups are difficult to
classify. Thus, any list of hexahedrites compiled by one investi-
gator will contain irons that another compiler might regard as coarse
octahedrites.
The Ni-Fe diagram (fig. 1) shows the conditions under which
kamacite (alpha iron), the sole constituent of a hexahedrite, forms.
The two dotted vertical lines at 5.5 and 6.0 percent Ni define the
range within which hexahedrites grade into coarse octahedrites.
Thus, no hexahedrite has a nickel value to the right of these dotted
lines, and most hexahedrites lie either on or slightly to the left of the
5.5 line.
The different classes of meteorites—hexahedrites, nickel-poor
ataxites, octahedrites, and nickel-rich ataxites—do not correspond
to the diagram for 1 atmosphere of pressure, as stated by Uhlig
(1954) and by Henderson and Perry (1954). According to Uhlig,
this is due to the fact that meteorites form under pressures greater
than 1 atmosphere.
If a horizontal line is drawn in figure 1 at 490°C., and if it is as-
sumed that no changes take place below this temperature, the modified
diagram more faithfully depicts the structures in iron meteorites.
Following a 490° line from left to right, the hexahedrites, which
consist of one component, lie to the left of the line AB while the
octahedrites and nickel-rich ataxites lie between AB and AC.
The chemical composition reported for the hexahedrites and
nickel-poor ataxites only represents an average composition of the
area selected for analysis and not the entire meteorite. Since the
Ni values of hexahedrites range from about 4 to 6 percent, there is
no valid chemical reason for continuing the use of the term nickel-
poor ataxite. This term should be dropped.
The available analyses of the nickel-rich ataxites, hereafter referred
to as ataxites, show nickel values which can be located on the 490°
line to the left of where it crosses the AC line. Actually most of the
Ni percentages lie nearer to the AB than the AC line. Thus,
kamacite should be a common constituent in ataxites, and indeed,
kamacite spindles are recognizable in these meteorites. The struc-
tures of ataxites are more confused than the structures in the
octahedrites and hexahedrites.
An interesting relationship was noted in the range of Ni percentages
of the three groups of meteorites. The difference between the
4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
lowest and highest nickel value in the hexahedrites is about 2
percent, in octahedrites the range is about 6 percent, while in ataxites
it is nearer 18 percent.
DESCRIBED HEXAHEDRITES
Table 1 lists all known hexahedrites as of July 1962, together with
their weights and dates of fall or find. Synonyms are not numbered.
TABLE 1.—List of described hexahedrites.
Weight, Date of Date of
Name kilograms discovery fall
Angela (see La Primitiva)
Aragon, Ga. (see Cedartown)
Lm Aswan poy pt ance neat beanies omic ? 1953
2euAuburn® Alani bisieti acest ee cae 3.6 1867
35 Aw Gemllita livassn.. apts custisterecietats serene Ds 12S Mar. 31, 1908
4. Barraba, Australia (Bingara)....... 1.36 unknown
Be bellshankaone itl Cals eeeeerireeeice 38 1950 (?)
Oo mbennet) Coes. aks, 6 tec orcas Neer 89 1934
Jee Bingaras Ne Ss, WaleSe.- ae senis 2 1.1 & 6.4 1880
iBeselnyka, Sis, .osoccnadscc000 199 & 57 Oct. 18, 1916
9. Braunau, Czechoslovakia........... 22 SEF, July 14, 1847
LOM Brno. Canada wa. seo eeyacincceeene 13 1913
Ail, (Cedartown e Gas geet seis oecattintr 11.3 before 1898
eer *Centeal Missourt 1"... eee tees 25 1885
130} Chesterville; Sin . 4 Stak. oc 16.5 1848
14ieChicoy Mountains! Tex. s% 208) ee. 2,000 2 before 1915
15. Chinguetti, French W. Africa....... 228 1920
16. (Cinemnati, sOhio 2 beste. sce. cet unknown 1870
17. (Goahnila, Nlexieo! a. Aedes .ctase ic eos 1,000 1837
18. Corrego do Areado, Brazil......... 32 1925
19% CoyaeNonrte wehiles. .-0e ee ee 17.9 1927
2) mEdmontonyGanadayy.e eee See ee 7.34 1939
El Mocovi (see Otumpa)
21. Filomena, “Chile... os..5 seereg cee 21.1 1941
Fort Duncan (see Coahuila)
22: ‘Forsyth County; INZ*G320.0252. eee 17 1891
Gressk, Russia (see Hressk)
Zar lexe River. iAtnicass Se ee: Cee 60 1882
24. Holland’s. Stores Gas: neue cee 12.27 1887
25s MERESSIC HRUSSIAgt os Sei Soa ee 11.9 1954
26 indian’ Valleys "Ware. 0.8. ese eee 14 1887
Zero Iredell, Texans. 2eeo, ee 15 1898
* Usually this iron is listed as a coarse octahedrite, but Perry (1944) consid-
ered it a granulated hexahedrite. See plate 4.
2 Sample lost, weight unconfirmed.
3 Reported as 100 meters long, 45 meters high. These figures probably were
intended to be centimeters, not meters.
NO. 5 HEXAHEDRITES—HENDERSON 5
TABLE 1.—Continued
Bier ence Nes Nae ec aul S 6.7 1950
Zo) wendall) County. | exe ss dewee sec 21 1887
Mila, Priottivas Chile oc ca sieesdels 3.1, 4, 1.5, 1888
4.3, 9
Sie esc Creek Ne CoN e's balsam aes 1.24 1879
sen Muocuse Grove, Gass ccs scscedodcee 10 1857
So eompard. Mont Weems sa cee cess unknown ?
Apr eeyouat: Nai. certo s saad 16 1950
ao. iMejillones, Chile 2050. 2c. ce ooe8 ce 1875
Meiilones, Chile /iidsjcccsceeeeds cae 14.5 1905
ree UMM ane INS Eo Laraers Ais dia die Seles ays 8 1889
Meee NOV ede oo oan ete a on cart cia one 385 1887
Ome Neaval@, ATIZ.n ctestens siiaiec cele cece 1499 1921-1926
680
9s: Nedagolla, Trdia Ss Oo cca. scwcd ce 4.5 Jan. 23, 1870
mi Wearitlas:: Chile o3scjcid< sic sis eee ei BO before 1936
41. Nenntmannsdorf, Saxony .......... 12.5 1872
are MON CALIR PAGAT ute cic :6 sauisiaie sarees 4.74 Apr. 7, 1904
a3, Opavo,- Czechoslovakia .:...'.0222¢: 7.4, 5.8, 1925
1.0; 0.1
AA Oumapa PATE EMEA Chis ases See cade (15 tons, 1576
est.)
eae bund County, Aciziot.csilacasecntes 0.21 before 1947
Bere ieapora.. Brazil Oe cine vccswie ds C00
AP Usipica nile, coms tecsicclleeeee ss 19 1929
4“A cart would be required for its carriage,” G. A. Daubree, Compt. Rend.,
Acad. Sci. Paris, vol. 81, p. 597, 1875.
5 Although reported as a nickel-poor ataxite, the analyses show 6.2 and 6.1
percent of Ni. These values are above the Ni content of hexahedrites. This
iron, which has exceptionally fine flight markings, obviously fell as an orientated
individual. A cross section through its short dimension shows two well-defined
heat-altered zones about 2.5-3.0 mm. wide. The metal between these thermally
altered zones displays a pattern like that formed when metal is rapidly quenched
(Axon, 1962). This structure is visible at low magnifications (6 to 10X) ;
however, at higher magnifications a granular texture is noticeable. Both struc-
tures existed before this meteorite entered our atmosphere.
All witnessed falls of hexahedrites (table 2) occurred in the morning. Neda-
golla fell at 7 p.m. Meteorites falling in the morning are oncoming ones, thus
enter the atmosphere with higher velocities than those which fall in the afternoon
hours. Hence, the Nedagolla differs from the witnessed hexahedrite falls not
only in its metallography and chemistry, but also in the time of fall.
To combine two interpretations, one from its chemistry and the other from
its metallography, to explain its past history, is difficult. The structure, notice-
able at low magnifications, is that of a metal which solidified quickly, but the
granular texture, visible at higher magnifications, is suggestive of later reheat-
ing to about 800°C. Where and when these events took place is unknown, but
they happened prior to its fall in 1870. From its chemical composition this iron
might represent a melted coarse octahedrite, and it is definitely unlike all other
hexahedrites.
6 The Pirapora, Brazil, iron was reported in private communications from
Dr. Walter Curvello, Museum Nacional, Rio de Janeiro. No additional data
are available.
6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
TABLE 1.—Continued
46) (Oullagua, ‘Chile’ “ephas.. cece scien 78 1938
40™ Richland, Tex. (ok cask ee scnsces deme 15.4 1951
SQ, iio oa, Chiles. hen cc aedeemenen 4 1915
St Sakeuchi Japan © 4. asaees eee 4.18 1913 Apr. 13, 1913
52. San Francisco del Mezquital, before 1868
Mexico’ ey sf 24taee co eet eeess BD
53. San! Martin, Chile:.2 6 cneicwash cats: 29 before 1924
54. Scottsville. (Key: abit id eects 10 1867
55; -Sierray ‘Gorda, Chilese tsi o one sacle 22.0 1898
56. Sikhote Alin, E. Siberia’®.....5.). 0. (many Feb. 12, 1947
tons )
57. Siratiles Waa feasts fay. cjssi sheete ars —9 1716
58.) Smit hostia (Gait. titers ce wigreeleitetes © 70 1940
504 SoneeusO ila pertains 6 arena reso stetaers wont 1938
GOWAS crminittt PAI AN ceive yore arajereissove leicht 1 1890
Ol. Tandil, Arcentitia oie 8 01s ie0: 0 Geto: 0.98 1916-1919
62./' Tocopillar ‘Chile, feed ee. ove.ce ae aeleos.< 75 1927
63. Pombighes,. (ATay eis e's ass us eRe Rees 43 1859-86
645, Unione \Chile (5, 23). gis ga. o = Hels ste ble Ave 22 1930
GS Wyte INS AE a fais apoB co¥S. ope ata’e 6 54 1903
66. Villanueva del Fresno, Spain........ 0.35 11 not given
G7y Walker. ‘County, (Alassio: «melee son's 75 1832
68. Warialda, N. S. Wales (Bingera)...2.8 1919
OOS OWiathena, Means. is: cas oae oscdhe ante 0.56 1939
70. Yarroweyah, Victoria, Australia ....9.5 1903
7Since Kanda (1952) lists the Sakouchi as a hexahedrite, it is included
in this list. The information about this meteorite is incomplete and conflicting.
8 The composition lies along the border between the hexahedrites and the
coarse octahedrites. Because there is an absence of a noticeable octahedral
arrangement in these specimens, this iron is classified as a hexahedrite.
® This meteorite needs restudy. Although a large mass was found, only about
1.7 kg. is known today.
10 When Roy and Wyant (1950) studied the Smithonia, Ga., iron, they found
no Neumann lines, the nickel content below 6 percent, and hence classified it as
a nickel-poor ataxite. In a later cut, which penetrated deeper into the meteorite,
Henderson and Furcron (1957) observed Neumann lines which established this
iron as a normal hexahedrite.
11 Weight not reported, but was calculated from the dimensions.
METEORITES INCORRECTLY IDENTIFIED AND EXCLUDED
FROM THE HEXAHEDRITES
Not included in the foregoing list of hexahedrites are seven
specimens incorrectly listed as hexahedrites. These are:
1. Chihuahua City, Mexico. Although this iron was listed by
Hey (1953) as a brecciated hexahedrite, Nininger (1931) reported
it as having “a fine octahedral crystallization.” Also Nininger
NO. 5 HEXAHEDRITES—HENDERSON 7,
published an analysis by F. C. Hawley which reported 6.96 percent
Ni. Again in 1950 Nininger classified this iron as a brecciated
octahedrite. Goldberg and others (1951) published two nickel
determinations, 6.97 and 6.85 percent. Thus, three analyses report
values in excess of those for a hexahedrite.
2. Dorofeevka, U.S.S.R. Illustrations of this iron published by
Zavaritsky (1954) show both narrow kamacite lamellae and plessite
areas. In the text Zavaritsky mentions that this iron resembles a
nickel-rich ataxite.
3. Granado, Ariz. Nininger and Nininger (1950) reported this
38-gram iron as a hexahedrite, but H. H. Nininger now regards it as a
piece of Canyon Diablo (personal communications).
4. Lake Murray, Carter County, Okla. Classified as a coarse
octahedrite. This specimen, weighing 272.7 kg., was found about
1932 but not excavated and recovered until 1952. La Paz con-
sidered it an intermediate member between the hexahedrites and
octahedrites and proposed the term “hexaoctahedrite.” Plate 1
shows a portion of a cut through the Lake Murray meteorite. In
several areas wide kamacite bands are arranged in an octahedral
pattern. The octahedral structure in other parts of this section is
disrupted by the growth of large skeletons of schreibersite inclusions,
some measuring more than 6 cm. in length and 4 cm. in width.
5. New Mexico. This 130-gram specimen was found in 1923
at approximately 34°31’ N. and 107° W. Nininger and Nininger
(1950) listed it as a hexahedrite and said it had been fashioned into
an ax. Obviously man had something to do with this iron. Since
the Sandia Mountains, N. Mex., iron has kamacite grains of about
this size and shape, H. H. Nininger now regards the New Mexico
specimen as a man-worked fragment of the Sandia Mountains iron
(personal communications).
6. Sulechow, Poland. Although typed as a hexahedrite by
Pokrzywnicki (1959), the Ni value in analysis is within the range of
the octahedrites.
7. Western Arkansas. Merrill (1927) reported an analysis with
a nickel value within the range of the hexahedrites but did not
classify the meteorite. Merrill’s published analysis is inconsistent
with the structure of this specimen. Also the analysis of the mete-
orite with which Merrill compared the analysis of the Western
Arkansas was proved to be inaccurate. The Western Arkansas,
therefore, is definitely not a hexahedrite.
8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
PHENOMENA OF HEXAHEDRITE FALLS
WITNESSED FALLS OF HEXAHEDRITES
The first observed fall of a hexahedrite took place near Braunau,
Czechoslovakia, in 1847. Since then, falls of five other hexahedrites
have been witnessed. Six of the seven meteorites in table 2 fell
north of the Equator in the Eastern Hemisphere, while one (Tandil)
fell in the Western Hemisphere south of the Equator (table 2).
Since the two pieces of the Braunau iron, 22 and 17 kg., fell in
1847, two other hexahedrites have been recovered within 100 miles
of Braunau (see fig. 7). Perhaps, therefore, the 1847 fall was a
shower of hexahedrites.
TasLe 2.—Witnessed falls of hexahedrites arranged chronologically.
(The Nedagolla iron, which is not a true
hexahedrite, is included for comparison.)
Name Country Date of fall and hour Coordinates
Braunatt sera. s Czechoslo- July 14, 1847—3:45am. 566°N. 16.3°E.
vakia
Nedagolla! ...India Jan. 23, 1870—7:00 p.m. 18°41'N. 83°20’ E.
Okano eer Lee Japan Apr. 7, 1904—6:35 a.m. 35°4'N. 135°13’E.
AES iA co acke sate Italy Mar. 31, 1908—8:45 a.m. 46°N. 135°:B,
Boguslavka ... Siberia Oct. 18, 1916—11:47 am. 44°33’'N. 131°38' E.
Mandl cyiecmieere Argentina Between 1916-1919—? 37°17"'S., . 59°65.
Sikhote-Alin .. Siberia Feb. 12, 1947—10:38 a.m. 46°9.6'N. 134°39.2’ E.
1 See footnote 5 to table 1.
Another interesting fact about these witnessed falls is that five
occurred in the morning, with the Boguslavka iron falling only 13
minutes before noon. The Nedagolla, which has structural features
and a chemical composition unlike a hexahedrite, fell in the after-
noon. The time of fall of the Tandil iron was not recorded. The
fact that these irons, with the possible exception of the Tandil
meteorite, fell in the morning may not be a coincidence.
CLUSTERING OF HEXAHEDRITES
The clustered occurrence of hexahedrites was once assumed to be
due to transportation by man. Fletcher (1890) concluded that
because iron meteorites were useful as anvils and for other purposes,
man gathered them for use and later discarded them in places
distant from where they fell. This point of view is no longer popu-
lar either with those who study meteorites or with archeologists.
In the late 19th century local concentrations of hexahedrites
NO. 5 HEXAHEDRITES—HENDERSON 9
prompted the question, “Are these irons related?” Farrington (1915)
said: “Early writers are inclined to group into one fall similar
meteorites, even though separated by thousands of miles of distance,
but later observations have failed to confirm this view.”
Several widely scattered large hexahedrites are known from north-
ern Mexico. Many of these have been sectioned and now are con-
sidered to be parts of the Coahuila meteorite. Thus, names given to
individual masses, such as Sanchez Estate, Hacienda, Potosi, Fort
Duncan, etc., are now relegated to synonomy, and all are collectively
known as the Coahuila meteorite. Farrington (1915) accepted the
Coahuila group as a shower and said, “In the State of Coahuila,
Mexico, numbers of meteoritic irons of a rare class, hexahedrites, are
found one or two hundred miles apart. It hardly seems likely that
separate falls of these rare meteorites would occur within such a
limited area.”
Twenty-five hexahedrites have been found since Farrington wrote
as he did in 1915. A number of these coincide with some of the
geographic groupings noted by earlier writers. Of the new geo-
graphic groups found since Farrington’s time, the most important is
the Chilean group. In general, the places where hexahedrites were
found suggest the probability that they fell as showers.
It is assumed that all the Coahuila meteorites come from latitude
28°40’ N. and longitude 102°50’ W., a midpoint in the scatter of
those specimens in northern Coahuila. Earlier writers even sug-
gested that some hexahedrites from Virginia, Georgia, and Kentucky
were related to the Coahuila irons. Although it is possible that the
hexahedrites from these eastern States are part of the Coahuila
shower, this study lists them as hexahedrites from southeastern
United States (see table 6).
If it is reasonable for Fletcher (1890) to regard the Coahuila irons
as a shower, it would seem equally admissable to include some of
the hexahedrites found slightly north and east of Coahuila in Texas
and toward the Oklahoma border, as part of the same shower.
Since the hexahedrites in this portion of Texas are as closely spaced
as the hexahedrites in other geographic areas, they are grouped
with the irons scattered around Coahuila (see table 5).
MECHANISM FOR SCATTERING METEORITES
The above distribution of hexahedrites would be accounted for if
two or more large hexahedrites approached the earth on essentially
parallel trajectories. Under these circumstances the second or third
IO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
masses to enter our atmosphere and fall would scatter pieces in
different places from those where the first or second one fell. Thus,
the distance between the strewn fields would depend upon the
interval that separated the arrival of the individual masses into the
atmosphere and upon the trajectories along which they were travel-
ing. For meteorites to approach the earth in such a manner prob-
ably would require the fragmentation of a larger object relatively
close to the earth. Any mass fragmenting far out in space would
scatter, and thus few pieces would have parallel orbits.
Many spectacular fireballs have been tracked across North America,
and from some of them meteorites have fallen. Since the distance
traversed by some fireballs exceeds the distance over which clustered
hexahedrites have been found scattered, a few of these events will
be briefly reviewed.
When Smith (1877) described the Rochester fireball of 1876, he
may have considered a mechanism similar to that described above
when he wrote:
The Bolide made its appearance about 9 o’clock p.m., December 21, 1876, and
was of extraordinary magnificence. It passed eastward over the States of
Kansas, Missouri, Illinois, Indiana, Ohio, and parts of Pennsylvania and New
York. Although no observations were made in the last two mentioned states,
still Professor Kirwood is doubtless correct in defining this as its course. At
Bloomington, its elevation was 15 degrees. According to the calculations, the
length of its observed track was from 1000 to 1100 miles, one of the longest on
record. Its height is supposed to have been 38 miles above the place where the
small fragments fell from it.
The Canadian fireball of February 9, 1913, which was named
Cyrillid by O’Keefe (1961), also made an unusually long streak
across the country. Detonations were heard all the way from
Toronto, Ontario, to Towanda, Pa., a distance of 200 miles. If more
observations had been collected immediately after its passage, this
distance possibly would have been extended. O’Keefe quotes ob-
servers as saying, “Before the astonishment aroused by the first
meteor had subsided, other bodies were seen coming from the
northwest, emerging from precisely the same place as the first one.
Onward they moved, at the same deliberate pace, in twos or threes
or fours, with trails streaming behind.”
The Pasamonte meteorite, which fell March 24, 1933, also made
a brilliant display over several states. Nininger (1934) interviewed
observers in the area from near Wichita, Kan., to New Mexico, where
the specimens were recovered. This fireball was seen for approxi-
mately 400 miles, but the objects known to have fallen from it are
confined to a distance of about 4 miles.
NO. 5 HEXAHEDRITES—HENDERSON II
The three foregoing events happened within 57 years, and in two
cases the observed flights extended 1,000 to 1,100 miles and
about 400 miles, respectively. Witnesses of the 1913 fireball re-
ported that more than one object was seen moving through the
sky. Meteorites are usually considered to be single objects when
they enter our atmosphere, but it appears on the basis of the 1913
observation that several objects can enter the atmosphere at slightly
different times and along the same trajectory. If more than one
object was involved in the 1913 fireball, probably some were higher
in the sky than others, although all appeared to be moving on the
same or only slightly different trajectories.
Before leaving the subject of fireballs, some comments seem neces-
sary on recurring meteor showers that appear from year to year.
Elliott (1804) wrote about the November 12, 1799, display as
follows:
November 12, 1799, about three o’clock a.m., I was called up to see the shooting
stars. The phenomenon was grand and awful, the whole heavens appeared as if
illuminated by sky rockets, which disappeared only by the light of the sun after
daybreak. The meteors which appeared at any one instant as numerous as stars,
flew in all possible directions except from the earth towards which they are
inclined more or less, and some of them descended perpendicularly over the
vessel we were in. So that I was in constant expectation of their falling among
us. We were in latitude 25° N. and SE. of Kay Largo near the edge of the
Gulph Stream. I have since been informed that the phenomenon extended over
a large proportion of the West India Islands and as far north of Mary’s in
latitude 30°42’, when it appeared as brilliant as with us off Cape Florida.t
Although it is frequently stated that meteorites do not fall from
reappearing meteor showers, such as the Leonid showers in No-
vember, this may be incorrect, for the records show that from 1800
to the present time (January 1963), 43 meteorites have fallen in
November. The greatest number of meteorites to fall on any day
in November is 5, and this number fell on the 12th day of the month.
Thus, until more information is available, we cannot be sure that
these recurring meteor showers do not bring an occasional meteorite.
However, one phenomenal shower like that observed in 1799 could
have delivered most of these hexahedrites.
Between 1800 and mid-1962, 218 meteorites fell and were
recovered in August, September, October, and November. The
distribution of these falls is shown in figure 2 by listing the year and
the day of the month on which the fall occurred. The Bali, West
1 Humboldt, the German naturalist, who was in South America in 1799, also
observed this meteor display.
2 Seventeen falls were reported by year and month, but the day was not given.
12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
AUGUST
[isis } [i932]
1
12
13
© °O "Oo =~) ww RS Gl 1
Li} 14 | [tess]
k— 15 | [1829]
Lic
O17
18
22
23
24| [1se0]
25
27
28
29 | [1678] [is92]
30
31 | [1872] [iser]
NO DATE : 1610,1826,1637,1858,1949,1950.
SEPTEMBER
irae
NO DATE: 1843,1875, 1907, 1930, 1930, 1933.
Fic. 2A.—Meteorite falls by day of month.
NO. 5 HEXAHEDRITES—-HENDERSON 13
OCTOBER NOVEMBER
2
3 | [eis] [1283]
4
5
6 | [1269]
7 | [iss]
8 | [i803] [1954]
9
10 | [i938]
7
12
13
Ly 4} bezel
is
<[ ic
Q 17
8
I9
20
2)
22
23
24
25
26
27
28
29
30 [is22] [1842] [1850] [i901]
31] [tess] [iss]
NO DATE: 1918, 1930,1951. NO DATE: 1833,1959.
Fic. 2B.—Meteorite falls by day of month (continued).
I4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Africa, meteorite fell in the morning hours of either the 22d or 23d
of November 1907, hence is shown midway between these dates.
An inspection of figure 2 shows the following :
1. The falls are not uniformly dispersed through these 122 days.
Actually, on 32 days no meteorite falls were reported.
2. The longest gap without falls is the 6th to 10th of November,
the interval which precedes the reappearance of the Leonid showers.
3. The greatest number of meteorites to fall on any date is 5,
and this number fell on each of three days—August 5, October 13,
and November 12 (see table 3B for detailed listing).
If the witnessed meteorite falls are grouped into 10-day intervals
between August 1 and November 30 (table 3A), the maximum
number of falls, 23, occurs between August 1 and 9; the minimum
number is 8, between November 1 and 9.
GEOGRAPHICAL ANALYSIS OF HEXAHEDRITES
The next step is to examine the distribution of the hexahedrites
listed in table 1 to determine whether their scatter suggests random
falls or a shower. The hexahedrites from the different continents
have been plotted on maps, and their groupings will be discussed by
geographic areas.
NORTH AMERICA
The irons from this continent group themselves into two or possibly
three areas, with two stragglers located outside the main geographic
concentrations. The stragglers, which occur in western United
States, are discussed at the end of the section on North America.
Western North America.—The four hexahedrites from the north-
western portion of the United States and from part of nearby
Canada are shown in table 4. These irons can be enclosed within
an ellipse 875 miles long. Four is an insufficient number of
specimens from an ellipse of this size to suggest a shower. Yet if the
groupings of hexahedrites in other areas of the world are significant,
this may become a promising area for future hexahedrite discoveries.
Southern United States and northern Mexico.—Table 5 lists the
specimens recovered in this part of the continent. Six were found
in an area extending northeast from Coahuila, Mexico, across Texas
to southern Oklahoma (fig. 3). This area can be enclosed by an
ellipse with a long axis of about 500 miles. This distance, more
than half the long axis of the group of four western hexahedrites
wm
ll
HEXAHEDRITES—-HENDERSON
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16 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Tas_Le 4.—Data on hexahedrites from northern and western areas
of United States and Canada arranged by latitude.
Meteorite Date found Latitude Longitude
Bennett County, S. Dak......... 1934 43° 28’ N. 101° 9’ W.
Heoimbatd. NOt pec nrsaisinaels + ors ? 46° N. 111° 24’ W.
prio. Canada’ as. ccclas sie oes ee 1931 52°46 N. 105° 21’ W.
EidmontonmeGanadamaerrteieei lye 1939 53° 35° N: 113° 30’ W.
(table 4), exceeds the scatter of stony meteorites from most of the
witnessed falls by a factor between 50 and 100. The distance over
which the hexahedrites are dispersed is a most difficult fact to
account for in accepting the apparent clustering of these irons as
evidence of a shower of meteorites.
Only the Chico Mountain, Tex., iron requires further mention
here. Acquired by the U. S. National Museum in 1915 from E. M.
Fic. 3.—Geographic distribution of hexahedrites listed in table 5.
NO. 5 HEXAHEDRITES—HENDERSON WW
Flynn of Alpine, Tex., it was described by Merrill in 1922 as the
Alpine, Brewster County, meteorite. Although it is reported that
the original body weighed nearly 2 tons, the piece accessioned in
the national collections weighs only 212 grams. Apparently the
main mass has vanished.
Merrill’s published picture shows that the specimen probably was
reheated, but how and where this took place is not known. Actu-
ally, the entire surface of the small specimen is granulated, but the
texture of the zone near the surface is finer grained than that of the
central part. There is no indication of either cleavage or Neumann
lines. The chemical analysis Merrill reports is consistent with that
of other hexahedrites, and Merrill suggested the possibility that this
specimen is related to the Coahuila meteorite.
TABLE 5.—Data on hexahedrites from Coahuila, Mexico, and Texas—Oklahoima
arranged by latitude.
Meteorite Date found Latitude Longitude
Coatiulat Mexican. 32 i066. oe 1837 28°40’ N. 102°50' W.
Rendall Gounty,. Text 132... 0.85 1887 29°24’ N. 98°30’ W.
Chico*Mountain, Tex..55.... 056% 1915 29°. N. 103°15'W.
RACINATIGS WOK,» ato sells, pea, belade es 1951 31°59’ N. 96°14’ W.
reMeU BOS.) lows Inde ee dea te 1898 31°58’ N. 97°52’ W.
SOpery Cliklaly cf. nln. Wes Sen's aoe 1938 34°5' N. 95°37’ W.
Southeastern United States——The hexahedrites from this area are
arranged in table 6 according to the increasing latitudes of their
points of discovery. Figure 4 shows the arrangement on a map of
all of these finds with the exception of the Cincinnati iron, the
omission of which is explained below. The distance from the south-
ernmost one, Tombigbee River, Ala., to the northernmost, Mt.
Joy, Pa., is approximately 850 miles. This distance exceeds the
length of the strewn fields of stony meteorite falls by a factor of
nearly 100.
Foote (1899) mentioned that six pieces of the Tombigbee River
meteorite were found in nearly a straight line some 16 km. long,
with the heaviest mass to the north. Similarly, the heaviest mete-
orite in table 6, the Mt. Joy iron, is located in the northeastern end
of the 850-mile ellipse. It is easier to assume that the 6 irons along
a line 16 km. long are related as a shower than that all 19 meteorites
came as a shower. But if the north and south alignment of the
Tombigbee River iron is important, all the 19 meteorites perhaps
should be regrouped into smaller clusters, more or less in a north—
south direction.
18 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Both the Scottsville and Cincinnati irons lie to the north and west
of the oval area enclosing the other hexahedrites found in the zone
lying in a northeast-southwest direction. However, if the north—
south alignment of the six Tombigbee River irons is important, and
if the other hexahedrites are grouped into north and south clus-
ters, then the Scottsville and Cincinnati irons fit better into the
pattern with the other irons.
Taste 6.—Data on the hexahedrites from the southeastern area of the United
States arranged by latitude.
Meteorite Vie Date found Latitude Longitude
Tombigbee River, Ala......... 43.8 1858 32°13 IN. 88°10’ W.
Auburn Ala» 2 Ssaeess canae es SHS 1867 OZ a7 Ni: 85°32’ W.
Reocust 1Groye Gar) buat ienicleo oc 10.0 1857 33°20’ N. 84°38’ W.
Walker County, ‘Atasrunyi sie... 75.0 1832 33°50’ N. 87°15’ W.
Cedartown, (Gail oo 2ie sissies 11 1898 34°0’ N. 85°16’ W.
Saiithonia, (Gas. ) cess tckweleldste 69.8 1940 34°0’ N. 83°11’ W.
Aragon, Ga. (Cedartown) 1.... (5gm.) 1898 34°’ N. 85°3! W,
Suminitenla.: <.i3s da enets oe ees 1 1890 34°15’ N. 86°25’ W.
Hollands) Store, Ga... )..2%.% 125 1887 34°21’ N. 85°23’ W.
Ghesterville, S.C... .cteith. fhe. 16.3 1849 34°43’ N. 81°13’ W.
LickyGreele N.C... 98.0. fe. TA 1899 35°57, IN. 84°2’ W.
Migrplay ain.) Goins. ois Bacal chee he 1.2 1879 35°40’ N. 80°16’ W.
Forsyth ‘County, NovGo.. ods. a. 22.5 1891 36-47 NE 80°2’ W.
Mayodan, NaiCiscud: scat strands 15.4 1920 36°23’ N. 79°52’ W.
Seotisville; Koy. ious scion Ss sane 10.0 1867 36°46’ N. 86°10’ W.
Indian, Valley, Wavs. sence scne 14.2 1887 36°55’ N. 80°30’ W.
Keen=Mountain, Va....05...... 6.6 1950 3/13 Ne 82°0' W.
Cincinnati, ‘Ohio 28.4. o264 28 (250 gm.) 1870 SOP 7h ING 84°30’ W.
Mttifoy~(Paswre} eecadert. act 385 1887 39°47’ N. FZ AS We
1 Synonym.
Little is known about the Scottsville iron except that it was found
in 1878, identified and described by Whitfield in 1887. There is
no reason to suspect that it had been transported and abandoned
by man.
The Cincinnati iron, which was found near a dwelling house in
Cincinnati in 1870, was probably carried there by man from where
it fell. The few specimens of this meteorite that are preserved
suggest that it was small and easily transportable. Henderson and
Perry (1958) found it to be a reheated specimen with a composition
in the range of other hexahedrites. Because of its size and the fact
that it is unlikely to have fallen in Cincinnati, this specimen is
unimportant in this study.
NO. 5 HEXAHEDRITES—-HENDERSON 19
The Keen Mountain, Va., specimen appears to be much younger
than the others. Henderson and Perry (1958) assumed that this
meteorite was a relatively recent fall because it had a fresh-looking
black fusion crust with flight markings. Sections cut through one
end showed numerous small open fractures extending into the interior
920 490) 88°. GG (84-41 82° 80. Fee ek Fee) ez7at roe
Fic. 4—Geographic distribution of hexahedrites in table 6. The Cincinnati
iron is omitted for reasons given on page 18.
only slightly farther than the thermally heated zone around its
surface. Since these fractures contain little brown iron oxide and
since this oxide is poorly consolidated, it was estimated by Gordon
Davis (personal communication) and Henderson and Perry (1958)
that the meteorite may have fallen between 1940 and 1950. Using
Ar*®® measurements, Vilcsek and Wanke (1962) reported the time
of fall to be about 900 years ago.
20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
H. Wanke commented as follows about the Keen Mountain iron
in private communications: “The terrestrial age of this meteorite
according to argon-39 and chlorine-36 measurements is 1100+200
years. I had a little problem with my standards, but this definitely
would not change the value of the terrestrial age more than 200
years. The argon-39 content of this meteorite is so low that it
must have been 3 half-lives of argon (T4=325 years) on the ground.”
A statement based on a measurement should be superior to an opinion
about the time needed to alter a fresh flight crust from black to brown.
However, 900 years seems a long time for fresh flight crust to survive
in a climate as damp as that of Virginia. This iron may be an example
of a hexahedrite falling into a cluster of an old hexahedrite fall.
The Walker County, Ala., iron was found in 1832, which makes
it the first of this group to be discovered. The data on it came from
Farrington’s (1915) translation of Cohen’s discussion in Meteoriten-
kunde (1903): “an iron mass of 75 kg. weight was found in 1832 in
the northeast corner of Walker County, by a hunter living in Morgan
County who preserved it in his house until 1843... . It was of
an irregular oval form, with a smooth exterior covered with a thick
coatme of Fust. 0...
The alteration (rust) on the Walker County iron might mean a
long terrestrial exposure. However, rust could have formed during
the 10 years the specimen was stored in the cabin. Some irons
exposed to high humidities corrode faster than ones remaining out-
doors where the rain washes off the iron chlorides. Hence, the rust
in this instance could represent corrosion products formed within a
few years.
The New Baltimore and the Pittsburgh irons should be mentioned
here even though they are not listed in table 6. These meteorites and
the Mt. Joy iron were found in a straight line across Pennsylvania,
and suggested to R. W. Stone (1932) that they were related. A sub-
sequent investigation by Henderson and Perry (1958) indicates that
these are unrelated meteorites.
The unique feature of the New Baltimore iron is the large inclusion,
about 5 x 6 cm., with an octahedral pattern enclosed by large kamacite
grains. The kamacite grains display well-developed, undisturbed
Neumann lines, indicating that this kamacite was neither heated nor
deformed since these lines formed.
It is difficult to explain the mechanism that produces a meteorite
with two different types of Ni-Fe alloys in contact with each other.
The possibility of the octahedrite colliding with and penetrating a
NO. 5 HEXAHEDRITES—HENDERSON FA
hexahedrite must be considered. However, if a hexahedrite were
struck in space by an oncoming octahedrite, both the target and the
impacting object would probably show deformation resulting from
their collision. In this meteorite, neither part is deformed. Although
collisions between meteorites must have taken place in space, this
specimen lacks the most important features one would expect if one
iron meteorite penetrated another.
Hexahedrite stragglers in western North America.—Three isolated
hexahedrites from the western part of the continent remain to be
considered.
1. The Wathena, Doniphan County, Kans., iron. This 556-gram
iron (Henderson and Perry, 1949) was found in 1939 near Wathena,
Kans., in a locality about 400 miles northeast of the nearest grouping
of hexahedrites. Since no other hexahedrites have been found in the
intermediate area, the Wathena iron is assumed not to be associated
with the foregoing groups.
2. The Pima County, Ariz., iron. This 210-gram mass is reported
as having been found before 1947 near Tucson, Ariz. Nothing is
known of its history except that it was at the University of
Arizona for many years before it was accessioned into the national
collections and described by Henderson and Perry (1949). It has
exceptionally well developed flight surfaces. Although this strange-
looking specimen is small enough to have been easily carried by man,
it is thought probable that it fell where it was found, near Tucson.
3. Chico Mountain, Brewster County, Tex., iron. The 212-gram
specimen in the National Museum apparently is all that remains of
what was reported to be a 2-ton meteorite. So little is known about
the history of this iron, and since it was found west of the area in
which the meteorites listed in table 5 were found, the Chico Mountain
iron is grouped with the stragglers.
SOUTH AMERICA
CHILE
The hexahedrites from Chile are given in table 7, arranged by their
increasing latitudes, and plotted on the map in figure 5. Henderson
(1941) reported that these irons may represent a shower. On the
other hand, the finding of these irons aligned along a railroad could be
due to the fact that the exploration in this region followed the course
of the railroad. Nitrates were hauled to the railroad for shipment, and
the included irons could have been rejected from the ore before
22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
shipment. Also, the coordinates of the Chilean hexahedrites may be
less accurately recorded than those of the American meteorites.
Thirteen hexahedrites are known from between latitudes 20° and
24° S., while twelve octahedrites were recovered between approxi-
mately the same northernmost latitude and 27° S. This is an unusually
high proportion of hexahedrites to octahedrites. No hexahedrites are
reported south of latitude 24° S., whereas four octahedrites were
found there, one of which comes from a point as far south as 33°30! S.
No search has been made for meteorites in the area south of latitude
Dye.
TasBLE 7.—Data on hexahedrites from Chile arranged by latitude.
Weight,
Name kilograms Latitude Longitude
La Primitive (Angela)1......... ZS 19°55’ S. 69°49’ W.
Nepelasn Pais enid. dee deers neat 28.5 207127: 70°10’ W.
RTO Wace Ce ci es "casebe ano tae spatelayens 4.0 21°26’ S. 70°S’ W.
Weiaenta sie at cass cuice crack See eee 78.0 Zt SG: 69°32' W.
Sait WAGE oct coe ce cate tomes bie oie 29.0 2252008: 69°45’ W.
GoyarNorte= sess racer sche ste 17.0 22°20’ S. 69°40’ W.
WHO abet Sethe tenes ee haees 22.0 22°300S: 69°30’ W.
TEocopillay tye*. a sera: Sunciseycteserstertere 75.0 22°40’ S. 69°50’ W.
Siegra WGOnGa ser 's oleswree stasouloe 22.0 22°54’ S. 69°21’ W.
til Omientay terres aeieiee eee ketones 20.7 23°07 1S: 69°24' W.
Mejiliones (Cle75)" <5. ci sicese esse (large) 257 SS: 70°29' W.
Mejillones (C1905) Sieiin cee ae. 14.5 27'S: 70°29’ W.
Puripicage ese Te ae 19.0 23°41’ S. 70°15’ W.
1 Synonym.
Northern Chile is an arid region, while to the south the land is more
suitable for agriculture. In northern Chile, owing to the extensive
niter mining, more of the land surface has been scraped and sorted
than elsewhere. Thus, large, heavy objects, such as iron meteorites,
have a good chance of being recovered.
A comparison of statistics on meteorites from two widely separated
geographic areas may be criticized because climate, topography,
population density, and the uses made of the land have a bearing on
the recovery of meteorites. Nevertheless, an area in the United
States—Georgia and South Carolina—where a noticeable concentra-
tion of hexahedrites occurs, has been compared to northern Chile in
table 8.
Georgia and South Carolina together make an area about 1.5 times
that of northern Chile, yet more than 3 times as many hexahedrites
are reported from Chile as from the larger area in the United States.
NO. 5 HEXAHEDRITES—-HENDERSON 23
ler 105, 68° 66°
18°. 18°
20° 20°
Zee 22°
Ch 24°
26° 26°
28° 28°
30°
30°
32° 32°
Te 70° 68° 66°
Fic. 5.—Geographic distribution of hexahedrites in table 7.
Ten octahedrites are known from northern Chile, but twelve came
from Georgia and South Carolina. The conspicuous difference be-
tween the two areas is in the stony meteorites. All six of the stony
meteorites from this part of the United States were observed falls,
while the one stone from northern Chile was a find. This difference
may be due to the fact that the population density of the Chilean area
is far lower than in our two states, obviously making it easier for a
TABLE 8.—Comparison of areas in which hexahedrites are abundant.
Area in Total Hexa- Octa-
square miles meteorites hedrites hedrites Ataxites Stones
Northern Chile.... 60,000 26 13 10 2, 1
GROERIA: "a0 Has Gaines 59,000 17 3 9 1 4
South Carolina.... 31,000 6 1 3 0 2
24. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
meteorite to fall unnoticed in Chile. How these two localities would
compare if both were as effectively prospected is problematic.
The arid climate of northern Chile favors preservation of mete-
orites. Stony meteorites from there should be less contaminated than
those recovered from more humid areas because, without water,
contamination is less likely to penetrate a meteorite. However,
exposed meteorites in arid places can suffer from another type of
weathering—wind ablation, which, in time, could be an effective way
of obliterating a meteorite. Some irons from arid regions have
sculptured surfaces that demonstrate how one constituent is ablated
faster than another. Wind ablation is relatively rapid compared with
chemical weathering in arid areas. The products of mechanical
ablation might be confused with meteoritic dust, because undoubtedly
some of the metallic iron is removed and accumulates in the wind-
blown silt.
Many years ago the author called to C. A. Bauer’s attention the
possible identity of the northern Chilean hexahedrites and later
furnished him with specimens for study. These specimens apparently
were later turned over to Signer and Nier (1962), whose measure-
ments are presented in tables 9 and 10, although in a somewhat
different order so as to arrange the meteorites in their order of
increasing latitude.
Signer and Nier (1962), in discussing the possibility of these
Chilean irons being a common fall, said:
Due to the low concentration of cosmogenic rare gases in these samples, the rela-
tive errors in these measurements may be somewhat higher than the 5% found
for most other measurements; unfortunately, the samples available were so small
that only a single analysis was possible and therefore, no check of reproducibility
could be made. With this reservation, it seems possible that the Tocopilla, Coya
Norte and Rio Loa belong to the same fall. Negrillos, however, appears to
belong to a different fall. It should be mentioned that by nature of the inter-
pretation two meteorites could by coincidence appear to belong to the same fall.
The converse does not appear possible.
The overall scatter of the Chilean hexahedrites extends from about
20° to 24° S. latitude, while the three irons that Signer and Nier
suspected of being related lie between 21°26’ and 22°40’ S. latitude.
Thus, the Rio Loa, Coya Norte, and Tocopilla are confined within
about 70 miles of the overall spread of about 240 miles for these
Chilean hexahedrites.
HEXAHEDRITES—-HENDERSON
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26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
ARGENTINA
Only two hexahedrites, the Otumpa and the Tandil, are recorded
from Argentina. A field investigation recently was made in the area
of the Otumpa meteorite (Campo del Cielo) by the Lamont Geo-
logical Observatory under the leadership of Dr. William A. Cassidy.
Dr. Daniel J. Milton of the U. S. Geological Survey, associated with
Dr. Cassidy in the meteorite studies in Argentina, reports the follow-
ing: Seven impact craters have been identified distributed along a
single line about 18 km. long trending N. 60° E.,S. 60° W. Careful
search in one area near the middle of this line indicates that a zone of
abundant meteorites (many thousands per square kilometer) have the
same ENE-WSW orientation and a width of about 3 kilometers. .. .
In addition, a hexahedrite of 7 kg. has been found 65 kilometers N.
60° E. of the northeasternmost crater. The intervening distance has
not yet been investigated. Locating this on a map, the middle of the
crater line is about 27°35’ S. and 61°40’ W. with the westernmost
crater in the Province of Santiago del Estero. The isolated iron comes
from approximately 27°23’ S.,61°5’ W.”
The Tandil iron is reported as a witnessed fall, although the details
about this fall and its discovery are not satisfactorily documented.
If this iron was seen to fall, its geographic relationship with the
Otumpa specimens is accidental.
AUSTRALIA
Four of the five Australian hexahedrites listed in table 11 and
plotted on the map in figure 6 show a narrow geographic grouping.
These irons were found along a north and south line about 35 miles
long—the direction in which the Tombigbee River (Alabama) and
Chilean irons were aligned. However, in Chile, it would be impossible
to align that many meteorites in any direction other than north and
south.
TaBLe 11.—Data on Australian hexahedrites.
Meteorite Date found foe Coordinates
Bingataedls) 5 y...csetie amore 1880 (240.7 gms.) 29°53’ S. 150°34' E.
BingarawZa serene oe aoe 1924 6.4 9 miles north of No. 1
Bingarawso. (oanraba) eeneee unknown 1.34 30725''S: 150°37’ E.
Bingara 4 (Warialda)..... 1919 25 29°34’ S. 150°35' E.
Varoweyaly varie «eocitae ner 1903 9.5 35°59':S: 145°35’ E.
1 The spelling of Bingara varies, in some places appearing as Bingera.
NO. 5 HEXAHEDRITES—HENDERSON 27
Although the Yarroweyah iron was found a long way from the
other four Australian hexahedrites, all five can be enclosed within
an ellipse approximately 450 miles long. There would be no reason
to associate the Yarroweyah iron with the Bingara group were it not
for the fact that the hexahedrite grouping in the other parts of the
world extends a similar distance. Disregarding the Yarroweyah iron,
the distribution of the four Bingara specimens shows that they must
be related. However, the ellipse enclosing all the Australian hexa-
120° 130° 140° 150°
20°
30°
10° 120° 130° 140° 150
Fic. 6.—Geographic distribution of hexahedrites in table 11.
hedrites exceeds the area in which fragments are scattered in observed
falls of meteorites.
EUROPE
Since man used iron much earlier in Europe than in the Americas,
Australia, or Africa, one might suspect that many of the European
meteorites were transplanted or consumed by the early peoples. If
this is true, the listing of the specimens in table 12 and the plotting of
these on the map in figure 7 may not be reliable.
Two hexahedrites, Opava and Nenntmannsdorf, were found ap-
proximately 100 miles apart and close to where the Braunau mete-
orite fell in 1847. Since these three hexahedrites were found so close
together, it seems likely that they fell as a shower.
28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Generally speaking, all the hexahedrites found in central Europe,
Spain, and Russia follow a pattern of alignment which is also
characteristic of those found from Mexico to Oklahoma and from
Alabama to Pennsylvania and is also evident in those discoveries in
TasLe 12.—Data on European hexahedrites.
Weight,
Meteorite Date found kilograms Coordinates
Opava, Czechoslovakia.... 1925 14.3 49°58'N. 17°54’ E.
Nenntmannsdorf, Saxony. 1872 12.5 5025S Ne Seo 7
Braunau, Czechoslovakia. 1847 (observed 39. 50°36’ N. 16°18’ E.
fall)
ElresslowRaissta\in ai aerate 1954 11.9 53°14 N.) 27°208' E:
Villanueva del Fresno,
SeV IR GE wipe cise aadacdeae Not given (Not given) 38°24 N. 3°26’ W.
Fic. 7.—Geographic distribution of hexahedrites in table 12.
Argentina and Australia. This agreement—alignment in a north-
east-southwest direction—would not seem to be merely coincidence.
AFRICA
Although only six African hexahedrites are known (table 13; fig.
8), two pairs occur sufficiently close together to suggest that they fell
as separate showers. These are the Bellsbank and Hex River irons
in South Africa and the Chinguetti and Siratik in northwest Africa.
NO. 5 HEXAHEDRITES—HENDERSON 29
TABLE 13.—Data on African hexahedrites.
Weight,
Meteorite Date found _ kilograms Coordinates
AS Wall ovipe aeioce css eualeues 1955 12 23°59’ N. aa ida 2
Chinguetti, French West Africa. 1920 ? 20°15’ N. 12°41’ W.
Siratik, French West Africa... 1716 1 NY 14° N. 11° W.
Mrwer, Nigeria yo vcs ames seas ais 1903 54 5°17, N; 8°15’ E.
Bellsbank, South Africa....... 1955 38 28°18’ S. 24°15" E.
Hex River, South Africa...... 1882 60 33° 19"S: 19937":
10° o° 10° 2Or 30 40°
pena
Be
ingle gh ala a
| LPN a’
ou
Fic. 8—Geographic distribution of hexahedrites in table 13.
A YET UNEXPLAINED DISTRIBUTION PATTERN
If a line is drawn on a globe, extending northeasterly from where
the Tandil, Argentina iron was found through the places listed in
Table 14, it forms an arc which extends almost one quarter the
30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
distance of a great circle, and it passes through Braunau, Czechoslo-
vakia, where a hexahedrite fell in 1847.
For what significance it may have, attention is called to two other
pairs of hexahedrites, Uwet, Nigeria and Aswan, Egypt, and the Hex
River and Bellsbank irons in South Africa, which if connected in
this order form two lines which are essentially parallel to the one pass-
ing through the places in Table 14 where the 10 hexahedrites were
found.
Tas_e 14.—A Vet Unexplained Distribution Pattern.
Meteorite Coordinates
Randi Arcentina (5.00. ene meee eter 37 ASUS: 59°10’ W.
Orumpay Argentina: 5.15.02 tvs vas degew Oeewoee ahs 27° 2a S. 60°35’ W.
Conreco de Arede | Brazile pecs sens cmos tees 18°35’ S, 46°30’ W.
Siratus. Mauretania, Africas... f0)nccm csv sates 1a VN: 1h ag W.
Chingtiette, dMauretaniay Africa. !),..: fee 20 4'esh oe 20°15’ N. 12°41 WW.
Villanueva del Fresne, Soain..:0¢ css cee ons oar 38°24’ N. O20 | £:
Opava, Czechoslovalaa.< cnct+ econ avactrelontes svn pmbiee 49°58’ N. 17°54".
Braunan, ‘Czechoslovakia £2240 shoacces ome seas 50°36’ N. Woes. 1H
Wenntmannsdotty Saxony... seeks ees eee 50°58’ N. Ws es gee
icessic;W.S.50Ine ....5 Nsheave.s bodes as Mabe goto boc la’ IN; 27°20.5' EE.
ROLE OF EARLY MAN IN THE DISTRIBUTION OF
HEXAHEDRITES
Few iron meteorites other than witnessed falls are known from
India and Spain. The reason may be that man found and used them.
As stated previously, man used iron in Asia and Europe long before
he did in America, Australia, and Africa, yet early North American
man is known to have fashioned some things from iron meteorites
and to have transported pieces of others from where they fell to his
campsites. Previously it was mentioned that the distribution of the
Coahuila meteorite is attributed to man. If some meteorites were
scattered in this way, man may have effected the distribution of some
of the other hexahedrites listed in table 5.
The fact that the hexahedrites ranging from Texas northeastward
to Oklahoma are located in an oval provides good reason to believe
that man had little to do with them. In this region, there are no
natural barriers to prevent him from moving in a north-south or east—
west direction any more than in the direction these hexahedrites are
scattered. Furthermore, archeological studies in Texas (Shum and
Krieger, 1954) show no relationship between the oval area enclosing
the places where the hexahedrites were found and the culture pattern
of early man in Texas.
NO. 5 HEXAHEDRITES—HENDERSON 31
Recent archeological work in northern Mexico has demonstrated
that the cultural relationships of Chihuahua, Coahuila, eastern Texas,
New Mexico, and Arizona are directly connected to influences out of
the high culture area of the Valley of Mexico, and that relationships
of Mexico and the southeastern part of the United States are along
the Gulf Coast and up the Mississippi and its southern tributary, the
Red River. From an archeological standpoint, the evidence suggests
that man could not have distributed the hexahedrites in Texas over
their oval pattern.®
American Indians chipped fragments from some large meteorites
prior to the time modern man discovered the specimens. The Hope-
well Mound Builders apparently transported small pieces of several
different types of meteorites considerable distances. At some of the
Ohio Mounds, several different types of meteorites have been identi-
fied, and at Havana, IIl., meteoritic iron was found fashioned into
beads. The Casas Grandes, Mexico, iron, which was excavated from
the ruins of a temple, was incased in wrappings similar to those sur-
rounding the bodies found in neighboring graves.
To cite more meteorites which man obviously has transported seems
unnecessary, as this study is limited to hexahedrites and only a small
proportion of these irons seems to have been disturbed by man (see
page 5). Furthermore, since many of the hexahedrites come from
limited geographic areas, transportation by man would seem to have
been negligible. If man was a factor, why would he concentrate these
irons rather than disperse them? To argue that man moved these
meteorites outward from a central spot strengthens the point that
hexahedrites have a peculiar worldwide distribution.
THE PROBABLE GEOGRAPHIC ABUNDANCE OF
HEXAHEDRITES
It can be argued that hexahedrites are equally abundant everywhere
and that chance recovery is responsible for the pattern indicating
fallout from showers. The best counterargument is the worldwide
scatter of hexahedrites, which indicates that they frequently are con-
centrated into limited areas.
It can also be argued that possibly in certain localities we are dealing
with a hexahedrite shower along with one or two single hexahedrite
falls. Until the terrestrial ages of meteorites are better understood,
it is impossible to assess the validity of such an assumption.
3 Personal communications from Dr. Clifford Evans, Jr., curator of the
division of archeology, U. S. National Museum.
32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Six hexahedrites were seen to fall in the last 115 years. Relating
this figure to an assumption that perhaps the known meteorites are
those which fell in the past 10,000 years, by extrapolation, between
500 and 550 hexahedrites should have accumulated in this period. If
this assumption is valid, less than 20 percent of all the hexahedrites
have been found.
Although the area of the surface of the earth is slightly less than
200,000,000 square miles, only about 57,510,000 square miles of this
is land. No consideration has been given to the hexahedrites which
possibly fell into the water nor to the fact that only a small percentage
of the land surface is effectively observed for meteorite showers. The
above figures were obtained, assuming just 6 hexahedrites fell in the
last 115 years, and surely there were more.
If 550 hexahedrites have fallen, and if these were equally scattered
over the land surface, there would be one to about every 100,000
square miles of land surface. When the area of the places shown in
table 8 is compared with this figure (100,000), or if the areas of the
localities where hexahedrites seem to be concentrated are compared
to this figure, the conclusion is that these particular meteorites are far
from being in random distribution.
INTERFERENCE OF PHOSPHORUS WITH METEORITE
STRUCTURES
Iron meteorites that contain considerable amounts of phosphorus
often have strange structures. When the schreibersite develops a
skeleton structure, such as that shown in the Lake Murray and other
similar meteorites, the kamacite grains enclosing the phosphide body
become large and equidimensional. Such kamacite grains interfere
with the normal development of the structure in the meteorite. Four
meteorites with large phosphide inclusions are shown in plates 1-4.
Tombigbee River and Bellsbank are hexahedrites, and Santa Luzia,
Sao Juliao de Moreira, and Lake Murray are coarse octahedrites.
Apparently no chemical analysis is available for the Lake Murray
iron, and erratic nickel values will be obtained if the samples selected
for study come from certain parts of the iron. In an area adjacent
to the large schreibersite bodies, the nickel will be lower than in the
kamacite some distance from these phosphide bodies.
The nickel values in the kamacite around the schreibersite in the
Tombigbee River iron are lower than the kamacite more remote from
the phosphide bodies (Henderson and Perry, 1958). Similar results
NO. 5 HEXAHEDRITES—HENDERSON 33
were obtained in some unpublished work on other meteorites at the
U.S. National Museum.
The Lake Murray, Okla., iron (pl. 1), shows an octahedral pattern
with kamacite bands more than 1 cm. wide, but where the large
skeletal growths of schreibersite form, the octahedral structure in the
matrix is disrupted. The dark square areas are patches applied to
protect troilite from being attacked by the etchant. Modern etching
techniques have found this precaution unnecessary.
The Bellsbank, South Africa, iron (pl. 2), is a hexahedrite with
large schreibersite inclusions. The thin lamellae at the left intersect
each other at a variety of angles and are filled with an alteration
product. The Neumann lines in the kamacite extend to the breaks,
then continue on the other side of the lamellae without a change of
direction. Along these lamellae the kamacite is clear, compared with
the kamacite more remote from them.
The kamacite surrounding the schreibersite in the Bellsbank iron
also is slightly lighter in color than the kamacite remote from the
phosphide bodies. If iron is rejected from schreibersite as the
temperature falls, of if nickel from the surrounding kamacite enters
the phosphide in preference to iron, this may explain the clear
kamacite.
The Santa Luzia, Brazil, meteorite (pl. 3), like the Lake Murray,
Okla., iron, is a coarse octahedrite with wide kamacite bands, some
about 1 cm. wide. However, when schreibersite forms a skeletal
habit, the enclosing kamacite becomes equidimensional, and such
kamacite bodies disrupt the octahedral pattern. Since the slice
illustrated is 0.5 cm. thick, and this schreibersite body is about
equally large on both sides of the slice, it probably continued into
adjoining slices, thus some conception of its size can be made.
The dark triangular area in the central phosphide body is troilite.
In places, the troilite makes a direct contact with the schreibersite ;
elsewhere, it is in direct contact with the kamacite. Schreibersite more
commonly occurs surrounding the troilite.
The Central Missouri iron (pl. 4) was found between 1850 and
1860, but the chemical analysis given by Preston (1900) does not
appear to be reliable. After Perry (1944) reexamined this iron, he
considered it to be a granular hexahedrite and placed it in the
transitional zone between coarse octahedrites and hexahedrites. The
Central Missouri iron resembles very closely the Ainsworth, Nebr.,
meteorite. Both contain large skeletal schreibersites and some
alteration products in the fractures separating the coarse kamacite
34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
grains. Howell (1908) reports that the 10.64-kg. Ainsworth iron was
found beside a creek in Brown County, Nebr., about 6 miles north-
west of Ainsworth. His analysis gave 6.49 percent Ni, which, although
high for a hexahedrite, may be essentially correct because meteorites
with these phosphide inclusions can give a wide range of nickel values
depending upon the area selected for study.
PHYSICAL CHARACTERISTICS RELATIVE TO THE FALLS
OF HEXAHEDRITES
CLEAVAGE IN HEXAHEDRITES
The cubical cleavage in hexahedrites may have an important
bearing on their geographical distribution. Two pieces of the Bogus-
slavka, Siberia, iron were found about 1,700 feet apart, yet they
fitted together, Thus, this hexahedrite was split, near the end of its
high-velocity flight, comparatively close to the earth while falling
nearly vertically.
Any large piece produced by fragmentation of a larger hexahedrite
mass will be covered with cleavage surfaces. Also, it will have large
open cleavages and numerous small ones extending inward from its
surface. While such an irregularly shaped body is in space, the
poorly bonded pieces remain attached, but upon entry into our
atmosphere, conditions change. When the mass meets appreciable
atmospheric resistance, chunks cleave off. Small pieces will decelerate
quickly and may fall unnoticed, while the large mass may blaze its
way across the sky for hundreds of miles before falling to earth.
Hence, many of the cleavages in a hexahedrite approaching the earth
will part, causing fragments to separate. Because of this, more pieces
may break off from a hexahedrite than from a stony meteorite or
from other types of irons. It is said that an iron meteorite is more
likely to survive its flight in the atmosphere than a stony meteorite,
and conversely, that a stony meteorite is more likely to break in
flight than an iron. Because of the cleavages in hexahedrites, there
is some doubt about the survival of hexahedrites in flight. Thus,
cleavages in this group of irons may account for their geographic
distribution.
SIZE DISTRIBUTION OF HEXAHEDRITES
Data on the masses of hexahedrites have been summarized in table
15. Most of the large hexahedrites were never weighed; therefore
the weight estimates reported may be inaccurate. Ten of these irons
are said to have exceeded 100 kgs., but none of the 10 is as large as
NO. 5
HEXAHEDRITES—-HENDERSON 35
the giants in the octahedrite and ataxite groups. Surely, hexahedrites
are neither easier nor harder to find than other types of irons.
Possibly the limited range in their chemical composition restricted
their number; nevertheless, if chemical composition limited their
number, it could have no effect on their distribution.
TaseE 15.—Hexahedrites arranged according to their weights.
Weights of more than 1000 kg. :
Chico 1
Coahuila 2
Navajo
Otumpa 3
Weights between 500 and 100 kg. :
Boguslavka
Mt. Joy
Weights between 100 and 50 kg. :
Bennett County
Hex River
Quillagua
Weights less than 50 kg. :
Auburn
Aswan
Avce
Barraba
Bellsbank
Bingara
Braunau
Bruno
Cedartown
Central Missouri
(Nedagolla?)
Negrillos
Nenntmannsdori
Okano
Opava
Pima County
Pirapora
Puripica
Smithonia
Tocopilla
Uwet
Chesterville
Cincinnati
Corrego do Areado
Coya Norte
Edmonton
Filomena
Forsyth County
Holland’s Store
Hressk (Gressk)
Indian Valley
Richland
Rio Loa
San Francisco del
Mezquital
San Martin
Scottsville
Sierro Gorda
Soper
Summitt
1 Said to weigh about 2 tons. : f
2 Several masses larger than 1000 kg. and many smaller pieces in excess of
00 kg.
3 Many individuals, total weight in excess of 15 tons.
4 Many tons.
ANGLE OF APPROACH
Sikhote Alin 4
Walker County
Iredell
Keen Mountain
Kendall County
La Primitiva
Lick Creek
Locust Grove
Lombard
Mayodan
Mejillones (1905) (1875)
Murphy
Tandil
Tombigbee River
Union
Villaneuva del Fresno
Warialda
Wathena
Yarroweyah
If a hexahedrite entered our atmosphere at a low angle, the
fractured material on its surface would separate, and the fragments
36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
that survive the passage through the atmosphere would fall far short
of the main mass. The large body would go much farther into our
atmosphere before further breaking up or would fall to the ground
intact. The widely scattered geographic groups of hexahedrites must
be explained by some process that brings one large mass or a cluster
of separate similar irons along a trajectory that has a low angle of
approach to the earth. Chance recovery of hexahedrites does not
explain the distribution of these meteorites.
INCLUSIONS
As far as we know, hexahedrites have the same metallic inclusions
as octahedrites with the exception of cohenite, which is relatively
abundant in octahedrites but quite rare in hexahedrites. The reason
being that iron carbide is more soluble in gamma iron (taenite) than
in alpha iron (kamacite), the chief constituent of hexahedrites.
The absence of any appreciable silicate inclusions also may be
significant. Although the Spanish meteorite Colomera was classified
as a hexahedrite with silicate inclusions, a restudy showed it to have
an octahedral pattern and a composition in the octahedrite range.
Since the included silicate is olivine, the Colomera iron may be a
pallasite, but the 151-gram sample in the U. S. National Museum is
too small to be useful in typing a meteorite weighing 134 kg.
RADIATION AGES OF HEXAHEDRITES AND OCTAHEDRITES
AND TIME OF DAY OF FALLS
Wanke (1960) noted that by plotting the log Nye against radius,
all meteorites with the same radiation age lie on a straight line.
Wanke’s plot shows that nearly all the octahedrites lie in a narrow
band and thus may have the same radiation age, but that the hexa-
hedrites and ataxites lie definitely lower and thus may have a different
history.
Wanke also observed that octahedrites fell between 12 and 24
hours of the day, whereas hexahedrites fell between 2 and 12 hours,
or during the morning.
SUMMARY
Seventy hexahedrites are considered in this study. Some of those
listed in the Prior-Hey (1952) catalog were omitted because they
were incorrectly classified in their original descriptions. When speci-
mens were unavailable for study, it was necessary to rely either upon
the author’s notes made during visits to other collections, upon
NO. 5 HEXAHEDRITES—HENDERSON BY;
published analyses, or upon an interpretation of pictures showing the
metallography of the meteorites. When a seemingly reliable analysis
reported more than 6 percent nickel, or when a picture showed either
plessite or taenite in abundance, the meteorite was no longer con-
sidered to be a hexahedrite. If neither a picture nor an analysis of the
iron was available, the Prior—Hey classification or the original descrip-
tion was accepted.
Obviously the hexahedrites are not scattered at random over the
world. Unfortunately, at this time we do not know how other types
of meteorites are distributed. Formerly it was assumed that a shower
of iron meteorites would scatter like the stony ones. However, the
evidence here presented suggests that hexahedrites have a different
fallout pattern from that of stony meteorites, but for reasons not yet
known.
Because the four hexahedrites located in Canada and our adjacent
northern States are so widely separated that they do not make a
convincing case for a meteorite shower, they were not counted. Table
16 gives the number of hexahedrites in each of the areas where
evidence exists that a shower of hexahedrites occurred. The hexa-
hedrites from Chile, southeastern United States, Europe, two places
in Africa, and Argentina seem to be geographically grouped in a
fallout pattern.
Table 16 shows the numbers of hexahedrites which, by grouping,
Tas_e 16.—The numbers of hexahedrites from the different geographic areas
which may be related.
I) Mexico—Nexas Olklahomary cman toon deck soe able 6
Pm SOUtheast enti Ways: ecterter sls shtersxes ousparcioyelete «fares iaiste chiens iets 18
5} A CUGTS oaiis As Beaming arte eaty ots rte che PRSbin a icEsto rarer cca eiactreEs Siete 12
ANGE EE MEE OE et IMAP ars g sic caleiciele =< Spel ddare ene aread ereptainrante tare 5
By, LED(P RG [ty eR Se RGR a Dp ARs oa ot tage ay 5
GUATIICA a Sete seers one eect nie a ote Mitis mre ga ates cae eee 4
RRGEAIN EE re tee Whe arc Barts.) Mania, aOR See Benes 50
Witnessed falls (excluding the Nedagolla1!).................. 6
Number accounted: tor as) possible fallss. «a... ose. soe 56, or 80 percent
ibtaxahedgites scattered. at, random. v0 saya «cd se siorerersereue aetate 14, or 20 percent
1 See page 8.
appear to have fallen in showers. If, to these 50 cases, the 6 which
were seen to fall are added, we have 56 hexahedrites out of a total of
70. This means that approximately 80 percent of these irons either
38 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
fit into fallout patterns or were witnessed falls. Such a percentage
can hardly be a coincidence.
The fact that hexahedrites are chemically simple and apparently
without silicate inclusions raises the possibility that hexahedrites may
represent fragments from the core of a larger body. Most theorists
agree that the core should be essentially free from silicates, and from
a standpoint of quantity, core material should be less abundant than
material from the surrounding shells. The hexahedrites meet these
two rather basic requirements of core material.
Many of these topics have been presented before societies and
symposia since 1950. Critical comments generally can be divided
into two types: (1) Meteoritic statistics are too limited to support
these groupings; (2) Conditions necessary to accomplish these
selected fallout groupings of hexahedrites are difficult to reconcile
with basic concepts of astrophysics.
Perhaps some of these criticisms are still valid, but new finds of
hexahedrites, as well as investigations of other scientists, have pro-
duced more facts to support these proposals than to disprove them.
Thus, more investigators seem to agree with the theme here proposed
than to disagree with it.
Many assume that meteorites are equally distributed over the earth
but because they are discovered by accident, their recovery is limited
to fairly settled regions of the surface of the earth. However, these
70 hexahedrites are not uniformly scattered over the area from which
meteorites have been recovered. About 70 percent of them are con-
centrated into 6 geographic areas, and the points of fall or discovery
within these areas suggest that they fell as a shower.
The long axes of these strewn fields exceed those of the observed
falls of any meteorite, yet are about equal to the paths of several
observed fireballs and some of the witnessed displays of falling
meteorites. The long axes of the scatter of the individuals in the
different geographic areas lie in essentially a northeast-southwest
direction.
LITERATURE CITED
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1962. Dendritic structure in the Nedagolla ataxite. Nature, No. 4854,
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40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
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SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 148, NUMBER 6
Charles D. and Mary Waux Walcott
Research Fund
MIDDLE AND LATE TURONIAN OYSTERS
Oe iHe LOPMA LUGUBRIS: GROUP
(Wirt Ercut Piates)
By
ERLE G. KAUFFMAN
U. S. National Museum
Smithsonian Institution
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SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 148, NUMBER 6
Charles D. and Mary Waux THalcott
Research Fund
MIDDLE AND LATE TURONIAN OYSTERS
OF- THE LOPHA»LUGUBRIS GROUP,
(Wirt Ercut PLATES)
By
ERLE G, KAUFFMAN
U. S. National Museum
Smithsonian Institution
(PusticaTion 4602)
CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
OCTOBER 6, 1965
PORT CITY PRESS, INC.
BALTIMORE, MD., U. S. A.
Charles D. and Mary Waux Walcott Research Fund
MIDDLE AND sLATE TURONIAN, OYSTERS OF
THe LOPHA *LUGUBRIS*:GROUP
By ERLE G. KAUFFMAN
U. S. National Museum
Smithsonian Institution
(Wir Ercut PLAtTEs)
INTRODUCTION
Fossil oysters are among the most common and well preserved
faunal elements in Cretaceous sediments. With few exceptions, how-
ever, they have been ignored in evolutionary studies and biostra-
tigraphy. Although countless species have been described, the tax-
onomy of the group is confusing and inconsistent. It seems ironic,
therefore, that they are one of the groups most suited to modern
population systematics. The present investigation attempts to demon-
strate the feasibility of detailed systematic and evolutionary study,
faunal zonation, and regional correlation based on oysters. It employs
simple biometric analysis of large collections, from numerous locali-
ties, distinct stratigraphic levels, and diverse sediment types. I have
chosen for this purpose a typical lophid species group centered around
Lopha lugubris (Conrad), and including L. bellaplicata bellaplicata
(Shumard), L. bellaplicata novamexicana n. subsp., and varieties of
these forms.
The Lopha lugubris lineage is the predominant ostreid species
group in Middle and Upper Turonian (Upper Cretaceous) sediments
of the Western Interior and western Gulf Coast. These plicate
oysters are abundant and well preserved at various stratigraphic
levels in the upper Eagle Ford Shale of Texas, the Mancos Shale of
New Mexico, and the Carlile Shale of Colorado, New Mexico, and,
rarely, Kansas. They are ideally suited for a modern systematic
study because the structural complexity of lophid oysters is greater
than in many other ostreid types. Detailed analysis of this group
provides a good test for the systematic, taxonomic, and evolutionary
SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 148, NO. 6
2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
utility of morphologic features not previously considered by many
ostreid workers.
Oysters of the Lopha lugubris group characteristically have a
rounded, subovate, or subquadrate outline, asymmetrical prosocline
shells with curved, opisthogyrate beaks and umbones (exogyroid in
some forms), and coarse, bifurcating, radial plicae originating at the
umbone on left valves, but variably developed on right valves. The
shell is lamellate and moderately inequivalve, with the right (upper)
valve flatter and slightly smaller than the left (lower, attached)
valve. The valves are denticulate, with small cardinal areas, and a
subcentral, comma-shaped muscle impression.
The lineage first appears in Western Interior and Gulf Coast
sediments during the late Middle Turonian (zone of Collignoniceras
hyatti Stanton). The youngest known representatives occur in middle
Upper Turonian sediments (zone of Prionocyclus wyomingensis
elegans Haas). It may range into even younger Carlile strata in the
Western Interior, as indicated by scattered reports of small plicate
oysters (indeterminate) in uppermost Turonian beds.
The Lopha lugubris lineage appears to have had a Gulf Coast
origin, or center of dispersal, in the United States, and reached its
maximum development in abundance and size in these southern
waters. Its immediate ancestor is unknown. Possibly, the lineage
arose from the European group of L. syphax (Coquand) (Early
Cenomanian) or from some Early Cretaceous lophid stock, such as
Lopha marcoui (Bose). There is a distinct gap, however, in our knowl-
edge of the evolution of Lopha in sediments of Cenomanian age
where representatives of this genus are not common.
ACKNOWLEDGMENTS
I am greatly indebted to Drs. Norman F. Sohl and William A.
Cobban of the United States Geological Survey, and to Dr. Richard
S. Boardman of the United States National Museum, for their excel-
lent criticism of the manuscript and many suggestions during the
course of the study. Conversations with Dr. H. B. Stenzel of the
Shell Development Company were very helpful. Collections were
kindly donated to the National Museum by Dr. Bob F. Perkins of the
Shell Development Company and loaned by Dr. Donald E. Hattin
of the University of Indiana. Specimens that I collected during the
period 1958 to 1960 are on loan through the courtesy of the
University of Michigan Museum of Paleontology. The drawings
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 3
were made by Larry Isham, the photographs by Jack Scott, both of
the United States National Museum.
BIOSTRATIGRAPHY
Members of the Lopha lugubris group have equivalent stratigraphic
distribution in Turonian sediments of Colorado, New Mexico, and
Texas (fig. 1). The restricted ranges, broad geographic distribution,
and abundance of individual species and subspecies render them use-
ful as stratigraphic tools in regional correlation. In some areas they
are the best available indices.
Stratigraphic distribution in Texas.—Lopha bellaplicata novamexi-
cana n. subsp. has not yet been found in Texas. Lopha bellaplicata
bellaplicata (Shumard) is the oldest known representative of the
group on the Gulf Coast, marking a discontinuous faunal zone (zone
9 of Adkins and Lozo, 1951, p. 155) at the top of the Eagle Ford
Shale (late Middle and early Late Turonian; Cobban and Reeside,
1952, chart 10b). It has been reported from the upper Arcadia
Park Limestone and Shale Member, the upper South Bosque Marl
Member (questionably), and the upper few feet of the “Condensed
Zone” of Adkins and Lozo (1951, p. 155). Generally the species
occurs only in the upper 25 feet of the Eagle Ford, but locally it has
been reported ranging through as much as 70 feet of section. It
apparently does not range into the Austin Chalk, although reworked
fragments of shells have been found in a thin conglomeratic calcarenite
bed (“reworked Eagle Ford” zone) which locally lies between the
Austin and Eagle Ford, and which has been assigned by many workers
to the former.
Lopha bellaplicata bellaplicata is known to occur only in upper
Middle Turonian sediments in Texas, above the zone of Collignoni-
ceras woollgari (Mantell) (early Middle Turonian) and locally below
a widespread disconformity which, in the Western Interior, forms the
Middle—Upper Turonian boundary. Faunal associates in the U. S.
National Museum and U. S. Geological Survey collections from Texas
include an undescribed species of Inoceramus closely related to I.
dimidius White (and ancestral to it), Cardium pauperculum Meek,
and Cyprimeria? sp. or Tapes sp. cf. T. cyprimeriformis Stanton, all
characteristic of the middle Carlile Shale (Blue Hill and Codell Mem-
bers) in the southern Western Interior. Lopha blacki (White)
morphologically intergrades with L. bellaplicata bellaplicata and
comes from approximately equivalent upper Eagle Ford strata. It is
here considered a synonym of L. bellaplicata bellaplicata.
4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
The zone of Lopha lugubris lies predominantly above that of L.
bellaplicata bellaplicata, but their ranges overlap slightly (fig. 1).
At two known localities in Texas, the species are found together in
NEW MEXICO
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Fic. 1.—Stratigraphic range of oysters in the Lopha lugubris group from
Colorado, New Mexico, and Texas, and proposed correlations. Colorado
stratigraphy taken along the east flank of the Front Range (Cafion City, Pueblo,
Huerfano Park areas). New Mexico section interpolated from Cerrillos and
Carthage sections of Rankin (1944) and from stratigraphic data on collections
made between Cerrillos, N. Mex., and Trinidad, Colo. Texas section generalized
for central and northeast Texas.
the upper 2 or 3 feet of the Eagle Ford Shale. They are distinct in
this zone of overlap, and do not intergrade. L. lugubris does not
range below this level, as does L. bellaplicata bellaplicata. It
ranges upward, however, above the range of L. bellaplicata bellapli-
cata, through the calcarenite bed between typical Eagle Ford Shale
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 5
and Austin Chalk (fig. 1). A disconformity of unknown magnitude
separates the Eagle Ford and the calcarenite at many places. Speci-
mens of L. lugubris from this calcarenite are complete and do not
exhibit signs of wear. They appear to have lived during deposition
of the calcarenite rather than having been reworked from typical upper
Eagle Ford Shale, as some workers have suggested. A similar situation
exists in the Juana Lopez Member (Carlile Shale) of the Western
Interior. The precise age of the “reworked Eagle Ford” calcarenite
has not yet been established, but it appears to be lithologically and
faunally the southern equivalent of the Juana Lopez.
Stratigraphic distribution in the Western Interior—tThe strati-
graphic distribution of the Lopha lugubris group in the Western In-
terior is the same as that observed in the Texas Cretaceous sequence
(fig. 1), as are the general progression of ammonites and lithologies.
The occurrence of Jugubris-like oysters in Colorado, particularly in
Huerfano Park, is of great importance, since it is only here that all
members of the group have been found together geographically and
their stratigraphic relationships accurately established. In this area,
Lopha bellaplicata novamexicana occurs sporadically in septarian lime-
stone concretions of the upper Blue Hill Shale Member (late Middle
Turonian, lower part of the range of Collignoniceras hyatti: fig. 1).
L. bellaplicata bellaplicata and the variety A are common throughout
the Codell Sandstone Member (“‘Pugnellus Sandstone” of Stanton,
1893 [1894]: late Middle Turonian, upper part of the range of C.
hyatti). L. lugubris questionably occurs in the uppermost Codell
Sandstone (based on two poorly preserved specimens), and is common
throughout the Juana Lopez Member (Juana Lopez Sandstone of
Rankin, 1944; a calcarenite or limestone in Colorado) of the
Carlile Shale. The upper and lower contacts of the Juana Lopez are
disconformable throughout much of its geographic range in Colorado
and northern New Mexico.
In northeastern and north-central New Mexico, and parts of the
San Juan Basin, the Coloradoan sequence and distribution of the
ostreid elements is similar to that in southern Colorado (fig. 1). The
Juana Lopez Member is thicker in New Mexico, however, and locally
consists of calcareous sandstone, or of interbedded calcarenites, shales,
and sandy units. Lopha lugubris occurs throughout this member.
Those from the base are possibly distinguishable from those occurring
at the top of the sequence on the basis of relatively longer, coarser and
less numerous radiating plicae on the older forms. Not enough
specimens are available, however, to prove this statistically.
6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Elsewhere in New Mexico, where the Coloradoan sediments are
more uniform (Mancos Shale of most authors), the distribution of
members of the L. lugubris group is not as well established. Lopha
bellaplicata novamexicana occurs in the middle Mancos, in the zone
of Collignoniceras hyatti (late Middle Turonian). The range and
position of L. bellaplicata bellaplicata is not precisely known, except
that it occurs in the middle Mancos below the Juana Lopez calcarenites.
L. lugubris occurs widely in the middle and basal upper Mancos, in
calcarenites equivalent to the Juana Lopez Member. Here it is
associated with Prionocyclus wyomingensis wyomingensis Meek, P.
macombi Meek, and Scaphites warreni Meek and Hayden, a Juana
Lopez assemblage. It has also been reported from slightly younger
beds (zone of P. wyomingensis elegans Haas: middle Late Turonian).
Stratigraphic conclusions —Comparison of the Texas, northeastern
New Mexico, and south-central to southeastern Colorado Turonian
sediments reveals a marked similarity in the sequence of ostreids,
ammonites, sediment types (in part), and in the position of the
Middle-Upper Turonian boundary, in many places marked by a
disconformity. In these areas dark clay shale, locally sandy, silty,
and containing lensing siltstones, silty limestones, and sandstones
(upper Eagle Ford Shale ; Codell Sandstone in many places) underlies
this boundary. This unit contains L. bellaplicata bellaplicata and
species of Collignoniceras (C. hyatti, C. sp.) in all areas and is locally
underlain by sediments carrying L. bellaplicata novamexicana. Brown
to rusty, sandy calcarenites and calcareous sandstones, locally con-
taining fish tooth, bone, and phosphate pebble conglomerates overlie
the boundary, especially where it is marked by a disconformity
(Juana Lopez Member; “reworked Eagle Ford” zone), at many
localities. This unit contains L. lugubris and species of Prionocyclus
(P. wyomingensis wyomingensis, P. macombi, P. sp.) in the great
majority of localities where it is found. In both Colorado (question-
able occurrence) and Texas, L. lugubris is found rarely in the upper-
most part of the lower unit (upper Eagle Ford equivalents), partially
overlapping the range of L. bellaplicata bellaplicata.
I propose that the two sequences are correlative in the manner
shown on figure 1, and that they may be correlated on the basis of
lophid oysters as well as ammonites. Based on lithologic and faunal
relationships, I suggest that the thin calcarenite locally present above
the Middle-Upper Turonian boundary and disconformity in Texas
should not be assigned to the Austin but rather to the Eagle Ford,
forming the highest zone of that formation (zone of Lopha lugubris).
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 7
The Austin has been considered totally Coniacian in the past, although
locally, the lowermost Austin chalks contain a Late Turonian fauna.
The calcarenite unit is, without doubt, Late Turonian in age and
faunally allied with pre-Austin sediments.
HISTORY
Attempts to treat the Lopha lugubris group in the past have
encountered the many pitfalls inherent in taxonomic study of the
Ostreidae. It has been treated as a single variable species (Stanton,
1893 [1894], pp. 58, 59) and as a series of related species, some of
which appear valid, others merely environmental variants of described
forms. The problems which have produced such inconsistency are
those that have generally affected the taxonomy of ostreids in the
past: Inability to distinguish environmental control on shell form
from genetic shift; failure to define adequately the limits of specific
variability through the study of small and geographically restricted
samples rather than analysis of numerous, widely distributed “popula-
tions”; application of typologic paleontology ; limited knowledge of
modern representatives of the family; insufficient stratigraphic data;
and others. It is not surprising that the group has a complex nomen-
clatural history in previously published studies.
Conrad’s original description (1857, p. 156, pl. 10, figs. 5a, b)
was based on a few small, densely plicate specimens with large
attachment areas. These were obtained from calcarenites typical of
the lower Juana Lopez member (upper Carlile Shale: zone of
Prionocyclus macombi Meek and P. wyomingensis wyomingensis)
in New Mexico and all belong to Lopha lugubris s. 1. Shumard
(1860, p. 608) later recognized a larger, more coarsely plicate, and
somewhat older form, Ostrea bellaplicata, in the upper Eagle Ford
Shale of Texas. White’s Ostrea blacki (1880, p. 293, pl. 4, figs. 1, 2)
appears to be erected on worn, smoother, ecologic variants of L.
bellaplicata bellaplicata, The two forms occur in approximately time-
equivalent strata.
These names were used by a number of authors without much
change until Stanton (1893 [1894], pp. 58, 59) placed all members
of the group into synonymy with L. lugubris Conrad, regarding them
as ecologic variants of a single species. Stanton’s concept has been
generally perpetuated in this country, although the other names are
used occasionally in fieldwork, on collection labels, and in unpublished
faunal lists. In Mexico, however, Bose (1913, pp. 47, 48) recognized
L. lugubris, L. bellaplicata, and L. blacki as distinct species, but
8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
overlooked the different stratigraphic ranges of the first two forms.
Only mention has been made of the group since that time, and it
has not been widely used in biostratigraphic work. The appearance
of L. lugubris Conrad on most faunal lists compiled in this century
has only limited stratigraphic value in that it is probably used in the
concept of Stanton (1893) and indicates an age no more refined than
Middle and Late Turonian.
STUDY OF FOSSIL OSTREIDAE
The Ostreidae, and in particular Ostrea, Crassostrea, and related
genera, are among the most variable of shelled animals. The animal
readily adapts to a number of environmental situations without signifi-
cant change in morphology of the soft parts. Gross shell form, on
the other hand, is greatly affected by the surrounding environment
in many species. Long, narrow, straight shells are produced in
strong currents; quiet water favors more rounded, broader shells;
crowding produces elongate, irregular, laterally compressed forms;
the depth and size of the mature shell is related in some groups to the
amount of exposure in intertidal areas; high-energy shallow-water
environments produce heavier-shelled, more prominently ribbed forms
than do deep, quiet-water niches ; some ostreids form imbricate frills
to keep above soft mud and shifting sand bottoms, and so on. Many
morphologic features of the shell, therefore, are highly variable within
a single species, and must be analyzed with care. This is particularly
true in regard to shell outline, convexity, and strength of surface
ornamentation. Other structures, less affected by environmental
variation (shell structure, prodissoconch, denticles, position and shape
of muscle scar, cardinal area), form a more reliable basis for classifi-
cation.
Finally, modern types of Ostreidae (Ostrea, Crassostrea, etc.) are
generalized and successful animals, and have been exceptionally con-
servative in their evolution. They have undergone little basic change
in shell form since they became established as an important group
during the Mesozoic. Variants of living species are in many cases
indistinguishable from certain Cretaceous forms when only a few
shells are compared. Closely related species exhibit considerable
morphologic overlap, and the differences between them are commonly
subtle.
In studying the Lopha lugubris group, resolution of the problems
inherent in biologic interpretation of the Ostreidae required analysis
of large suites of specimens, including growth series, from many
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 9
localities and sediment types, representing a broad range of environ-
ments. Only in this way could normal variation limits, ecologic
control on shell form, and genetic shift be recognized. During the
course of this study, I was fortunate to have at my disposal the large
and well-documented collections of the U. S. National Museum, and
Denver and Washington collections of the U. S. Geological Survey.
These were supplemented by my own collections made over a period
of 5 years in the Western Interior, and by small lots lent or donated
for this study by various individuals. Several hundred measurable
specimens, including ontogenetic series, form the basis for species
descriptions and observations on stratigraphic distribution, variation,
ecology, and evolution.
Time equivalency of the various fossil beds from one area to another
was established on the basis of ammonites, species of /noceramus,
and widespread disconformities. The ammonite and inoceramid
species used are widespread, well-established faunal indices occurring
in a variety of sediment types (representing various environments)
and apparently subject to minimal facies control.
Simple biometric analysis of all available morphologic features,
using graphs, charts, and simple ratios, indicated structures which
might be useful in lophid taxonomy, and proved to be sufficient for
the recognition of specific differences, ontogenetic development, and
evolutionary trends within the Lopha lugubris group. Features that
were employed in these aspects of the study are: Maximum adult
size ; basic ornament pattern ; normal valve outline ; the distribution of
convexity on both valves; juvenile ornamentation; extent of valve
covered with plicae ; number, size, and bifurcation rates of the plicae
at given intervals; plication density in a given area or distance; gross
characteristics of the concentric ornamentation; differences between
the ornamentation of the auricles and main body of the shell; relative
development of the auricles and auricular sulci; angle of inclination
of the beaks and umbones, and independently of the valve; curvature
and position of the beaks and umbones; angle of the posterodorsal
slope; relative size and development of various parts of the cardinal
area; density and extent of the denticles on the dorsolateral valve
margins; relative size and position of the muscle scar; and in some
cases, the relative size, position, and inclination of the attachment
scar. To this list might be added comparison of various ratios, such
as length to height, length of the auricle to length of the shell, and
others.
Although ontogenetic studies have not been attempted to any extent
IO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
with fossil oysters, distinct and commonly abrupt changes in shell
morphology with growth are common, especially in the more ornate
groups, and can probably be tied to developmental phases of the
animal. In this study the terminology of Hyatt (1894, pp. 349-647 )—
nepionic (babyhood), neanic (youth), ephebic (adult), and gerontic
(senile )—is used to characterize growth periods between major mor-
phologic changes in the shell. In oysters, and more specifically in the
Lopha lugubris group, the nepionic stage is represented by the prodis-
soconch, the neanic (spat) stage by part or all of the umbo. The
nepionic—neanic transition is marked by development of adult hinge
characters, change in shell shape (usually from rounded to dorso-
ventrally elongate) , and development of coarser concentric ornamenta-
tion. The ephebic stage is characterized by adult ornamentation
(the plicae in Lopha), change in shell shape including development
of auricles, folds, etc, well-defined denticles and muscle insertion
areas, and further differentiation of the cardinal elements. The
neanic-ephebic boundary is marked in some lophids by the abrupt
appearance of plicae, development of auricular salients in the
marginal outline, and differentiation of the resilifer and lateral cardinal
plates on the hinge line. The gerontic stage is characterized by
flattening and flaring of the ventral and lateral shell margins, deterio-
ration of the ornament pattern, decrease in prominence of the radial
ornament, crowding and increase in prominence of the concentric
ornament, and decrease in prominence of structures related to sexual
maturity and reproductive function.
Graphs and drawings depicting ontogenetic trends in members of
the Lopha lugubris group are shown in figures 2-4, 6, 9, 11-18.
Geographic variation and environmental control on shell morphology
were determined by comparing a number of “populations” from time
equivalent but lithologically distinct sediments in different areas (fig.
14). Only L. bellaplicata bellaplicata exhibits significant variation
in both respects. Comparison of related forms from a number of
different stratigraphic levels, but from similar sediments (roughly
representing similar environments) is the most satisfactory method
of demonstrating evolutionary change in the lineage. Unfortunately,
this method is not wholly applicable to the L. lugubris group, since
there is little overlap of exact sediment type between faunal zones.
Evolution of this group, therefore, is necessarily determined by com-
paring total variation plots of forms from different stratigraphic
levels, irrespective of lithology (figs. 2-9). Such a system of separating
evolutionary change from geographic or environmental variation is
fo) —— L. BELLAPLICATA
Ge a
BELLAPLICATA
——
3400 3600 3800 4000 4200 4400
000 3200
all specimens
sing plication
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=
= L. BELLAPLICATA
ae
BELLAPLICATA
=
8
=
L. BELLAPLICATA NOVAMEXICANA
TERMINAL NUMBER OF PLICAE AT MARGIN
a
3800 4000 4200 4400
0 100 200 400 600 800 1000-1200 1400 1600 1600 2000 2200 2400 2600 2800 3000 3200 3400 3600
AREA; INSCRIBING RECTANGLE OF LEFT VALVE OUTLINE (SQ.MM.)
nm
>
rm
e i L. BELLAPLICATA BELLAPLICATA
L. BELLAPLICATA NOVAMEXICANA B
TERMINAL NUMBER OF PLICAE AT MARGIN
0 : 7
100 200 “ 460 600 800 1000 1200. 1400 1600 jg00. 2000. 2200. 2400 2600 2800 3000 3200
AREA; INSCRIBING RECTANGLE OF LEFT VALVE OUTLINE (SQ.MM.)
Lopha lugubris group. Increase in the density of the plicae, number per unit area, on left valves of progressively younger species. A, Scattergram for all specimens
shown b ~~ NEY Mexico, Texas, B, Scattergram of Colorado sample only. Arrows in lower left-hand corner of each graph indicate direction of increasing plication
y hypothetical regression lines visually fitted to plots of terminal species in group.
Fig, 2—Evolution of the
measured, from Colorad
density as
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NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN II
admittedly somewhat idealized. Obviously, it is not possible to
evaluate properly all the environmental factors acting on these
shells in different areas. The chemical environments of two very
similar sandstones may have been entirely different and may have
had a profound effect upon the type of shell produced in each area.
Analysis of chemical aspects of the paleoenvironment is difficult or
impossible in most coarse clastic sediments, and is well beyond the
scope of this study. It should be understood that in dealing with
environment here, I am dealing in generalities and am cognizant of
the limitations this places on the accuracy of my interpretations.
Gross morphologic similarities in form, ornament pattern, develop-
ment of the auricles, the cardinal area, and the muscle scar, in addition
to detailed morphologic overlap in marginal variants of consecutive
species clearly point out the close relationships of members in the
Lopha lugubris group and suggest that they represent a continuous
evolutionary sequence, without major break.
EVOLUTION
Several of the morphologic characters which are most important in
the differentiation of species and subspecies of the Lopha lugubris
group demonstrate significant evolutionary trends (figs. 2-9), most
of them chronoclinal. These reflect, in part, gradual adaption of the
lineage to a slowly changing regional environment characterized by
regression and shallowing of the interior seas, increased wave and
current action, and increased turbidity. The scope of these changes
from one level to another is well beyond the normal ecologic variation
caused by similar shallow water conditions in any member of the
group during its existence.
In graphing evolutionary trends in the Lopha lugubris group,
structures were compared wherever possible at equivalent ontogenetic
stages on the three principal species and subspecies. Comparison of
the terminal number of plicae at the margin of adult valves represents
such a plot and can be analyzed irrespective of the differences in
size range shown by L. lugubris when compared to subspecies of
L. bellaplicata.
In addition to these plots, it seemed desirable to employ another
type of comparison in which structures of adult valves from the three
forms of Lopha were contrasted at equivalent sizes (i.e., at 20 mm.
height) (figs. 6a, 7c). The purpose of this type of plot is twofold:
(1) It provides a basis for morphologic comparison of the species
and subspecies at equivalent sizes, and a test of their genetic
I2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Doh one gato pele hg
L. LUGUBRIS
| CENCE Sto
L. BELLAPLICATA BELLAPLICATA
cup emece ss
L. BELLAPLICATA NOVAMEXICANA
L. LUGUBRIS
L. BELLAPLICATA BELLAPLICATA
B L. BELLAPLICATA NOVAMEXICANA
L. BELLAPLICATA
AB LICAT.
Tr REEEAPLICATA NOVAME XICANA
BELLAPLICATA
Fic. 3.—For explanation, see opposite page.
C L. LUGUBRIS
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 13
distinction. (2) At the same time it demonstrates evolutionary
trends within the group in absolute measurements. These trends are
not as well shown by this type of plot as they might be by comparing
structures at the margins of adult shells, where morphologic differences
are emphasized, but they are validly illustrated and significant be-
cause even this method essentially compares structures at an approxi-
mately equivalent stage of development.
Plots of structures comparing them at a constant height were made
within the ephebic part of the shell for each species and subspecies ;
thus, only adult structures were compared. Ephebic development
starts at about 10 to 15 mm. height on all forms, the difference in
adult size between L. lugubris and L. bellaplicata (both subspecies)
representing mainly differences in rate and amount of ephebic growth.
Since L. bellaplicata bellaplicata and L. bellaplicata novamexicana
have nearly equivalent size ranges, comparison of any structure at a
given height on both is essentially a comparison made at equivalent
ontogenetic stages. Because adult shells of L. lugubris attain a much
smaller size, they theoretically should not be ontogenetically compa-
rable with subspecies of L. bellaplicata at a given height. Such a com-
parison is valid however because the ephebic morphology of this
species is strikingly constant. The plicae do not normally bifurcate
(fig. 6b and c) and their number is relatively constant anywhere on the
adult portion of the shell. In addition, beyond 20 mm. height, the
width of the plicae and sulcae remains relatively constant. Since
ephebic structures are so uniform in L. lugubris, and values obtained
Fic. 3—Evolutionary trends demonstrated by members of the Lopha lugubris
group. A, Comparison of cross sections through normal left valves. Beak is to
the left. Note general decrease in overall convexity, ventral migration of the
high point of the valve (illustrated by vertical lines through cross sections)
through time. B, Comparison of cross sections through right valves, beak to the
right. Note increase in relative convexity and shift in high point of valve
(illustrated by vertical lines through each cross section). C, Comparison of
midline traces of typical left valves showing decrease in curvature of beaks, and
in overall curvature of shell through time. Beaks dorsal in each case. Speci-
mens: A, Top row, left to right, U.S.N.M. 132157, U.M.M.P. 43472, U.S.N.M.
132154; middle row, left to right, U.S.N.M. 132307, 132243, 8024b; bottom row,
left to right, U.S.N.M. 132276, 132288, 132272. B, Top row, left to right,
U.S.N.M. 132164, 132198, 132168; middle row, left to right, U.S.N.M. 132306,
132305, 132244; bottom row, left to right, U.S.N.M. 132265, 132286, 132287.
C, L. lugubris, left to right, U.S.N.M. 132157, 132159, 132156; L. bellaplicata
bellaplicata, left to right, U.S.N.M. 132225, 132224, 132222; L. bellaplicata
novamexicana, left to right, U.S.N.M. 132275, 132267, 132263.
I4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
in measuring them do not vary significantly from one point to an-
other, they are comparable at any given height with those of L.
bellaplicata (either subspecies) regardless of whether or not they
represent an equivalent stage of ephebic development.
The absolute height of the smooth stage increases in progressively
younger species of the L. lugubris group (fig. 8), and its evolution is
characterized by transgression of its ventral margin from the neanic
to the ephebic part of the shell. The smooth stage terminates in the
early to middle neanic stage of L. bellaplicata novamexicana, and in
the middle to late ephebic stage of L. lugubris. Measurements of the
height of the smooth stage used in plotting evolution are therefore
not ontogenetically comparable for the three forms.
Correspondingly, the number of primary plicae arising at the edge
of the smooth stage have also been measured at different ontogenetic
stages. These are more readily comparable than the height of the
smooth stage, however, because on many specimens of L. bellaplicata
(both subspecies) and a few L. lugubris the number of primary plicae
can be directly contrasted at the neanic—ephebic boundary. Although
the plicae arise early in the ontogeny of the subspecies of L. bellapli-
cata, they do not undergo extensive bifurcation until the early ephebic
stage. The number of plicae at the neanic-ephebic boundary
therefore generally reflects the original number of primary plicae at
the edge of the smooth stage. In L. lugubris the plicae normally
arise at a later developmental stage, but on rare specimens with a
small attachment scar, also arise near the neanic-ephebic boundary.
In these specimens, the number of primary plicae is equal to the
number found in specimens where the plicae arise at a later develop-
mental stage. This indicates that the number of plicae is not onto-
genetically controlled in L. lugubris, and relatively constant in number
regardless of where they arise on the shell. Therefore, there is
some validity in comparing the initial number of primary plicae on
L. lugubris with subspecies of L. bellaplicata, despite the variation
in ontogenetic stage at their first appearance.
Important evolutionary trends noted in progressively younger
Turonian representatives of the Lopha lugubris lineage are:
1. Decrease in the maximum size attained by the species (fig. 2).
2. Slight decrease in the relative convexity of the left (lower,
attached) valve, and ventral migration of the high point of the valve
(figs. 3a, 4a, b).
3. Gradual increase in the relative convexity of the right (upper,
free) valve, particularly in the umbonal region (fig. 3b).
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 15
LEFT VALVE
25 L.BELLAPLICATA
iw eee ee
L. BELLAPLICATA
L.LUGUBRIS NOVAMEXICANA
Ip 20 25 30 35.40 45
HEIGHT (MM)
30) LEFT VALVE
25
= L. BELLAPLICATA NOVAMEXICANA—————_>
520
x
a |
9
=
10
o— ~~ _L. BELLAPLICATA
0
fas 4O) 15 »20 -25 30 35 40 45 "50 55 60° 65°" 7%
HEIGHT (MM)
Fic. 4.—Evolution in the Lopha lugubris group. A, Scattergram showing
relationship between valve height and the distance between the beak and high
point of the left valve, measured parallel to height. Note ventral shift of the
high point in progressively younger forms. Arrow in lower left-hand corner
denotes direction of ventral migration of high point as illustrated by hypothetical
regression lines fitted visually to plots of end members of group. B, Scattergram
showing relationship between height and width of left valves. Note slight
decrease in relative convexity of left valve in progressively younger forms.
Arrow in lower left-hand corner denotes direction of decreasing convexity as
illustrated by hypothetical regression lines fitted visually to plots of end members
of lineage.
16 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
L.BELLAPLICATA L.BELLAPLICATA
NOVAMEXICANA BELLAPLICATA L.LUGUBRIS
Geese.
LUGUBRIS
BELLAPLICATA
NOVAMEXICANA
Fic. 5.—Evolution in the Lopha lugubris group. A, B, C, Drawings and cross
sections of characteristic cardinal areas for species and subspecies within the
group. Note gradual deepening, and increase in curvature of the resilifer in
progressively younger forms. Also note increase in convexity of the lateral
cardinal areas, from slightly arched lateral cardinal plates in the subspecies
novamexicana, to distinct lateral cardinal folds in L. Iugubris. D, Outline
drawings of species and subspecies within the group, with the auricular sulci
shaded. Note narrowing of the sulci in progressively younger forms, and varia-
tion in shape of the valves, of the posterior auricle, and in development of the
anterior auricle. Specimens: A, U.S.N.M. 132263; B, U.S.N.M. 132243;
C, U.S.N.M. 132167; D. Top row, left to right, U.S.N.M. 13274, 132154,
U.M.M.P. 43472, 43464, U.S.N.M. 132157; middle row, left to right, U.S.N.M.
132229, 132225, 132308; bottom row, left to right, U.S.N.M. 132263, 132267,
132281, 132279.
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 17
4. Variation in the development of the auricles; a general trend
toward reduction in size of the auricles, and elimination of the
anterior auricle (fig. 5d). The size of the auricles increases from the
subspecies novamexicana to subspecies bellaplicata, and decreases
considerably in L. lugubris.
5. Reduction in the size (width, depth) of the auricular sulci,
relative to shell size (figs. 5d, 6a).
6. Increase in the number of radiating plicae, including an increase
in the number of primary plicae at the edge of the smooth stage,
increase in number at any given distance below the beak, increase
in total number developed at the margin of adult shells, and increase
in the plication density (number per unit area) (figs. 2, 7).
7. Decrease in the average width of the radiating plicae, measured
at a uniform distance below the beak in all species (fig. 7c).
8. Variation in the amount of bifurcation of primary plicae, with
an overall trend toward decrease in bifurcation rate (figs. 6b, c).
The bifurcation rate increases slightly from subspecies novame-xicana
to subspecies bellaplicata, then sharply decreases with the evolution
of L. lugubris.
9. Increase in the absolute height and relative extent of the
smooth stage on the early shell, particularly in left valves. This is the
distance between the beak and the first abrupt appearance of plicae
(fig. 8).
10. Some posterior migration of the beaks and umbos along the
dorsal margin, and increase in the amount of curvature of these
structures (figs. 3c, 5d, 9b).
11. Changes in the nature of the cardinal area: general, though
not chronoclinal, increase in the size of the resilifer relative to the
lateral cardinal areas ; increase in the convexity and prominence of the
lateral cardinal folds; development and accentuation of the marginal
cardinal troughs between the lateral folds and the valve margin
(figs. 5a-c).
12. Increase in the density of the denticles on the inner dorso-
lateral margins (fig. 9a).
Many of these trends are interpreted as adaptations to widespread
environmental changes through Middle and Late Turonian time,
established in the lineage through natural selection. They are adapta-
tions shown by many living and fossil, shallow-water, epifaunal
pelecypods. In the Lopha lugubris lineage they gradually evolved
with the steady change from quiet-water, mud-bottom conditions
(Blue Hill and lower to middle Mancos Shales), through near-shore,
18 SMITHSONIAN MISCELLANEOUS COLLECTIONS
127 U.BeLLAPLIcATA
NOVAMEXICANA—»,
WIDTH OF POSTERIOR AURICULAR
SULCUS 20MM. BELOW BEAK =
L. BELLAPLICATA
2 BELLAPICATA
5
28 * L. BELLAPLICATA
BELLAPLICATA
non nN
>- On
n
NN
TOTAL NUMBER OF PLICAE AT MARGIN
o
8 (OV l2) 14 MG 1B 620) 22) 124
INITIAL NUMBER OF PLICAE
nN
to
oO
C)
* L.LUGUBRIS
ny
10 CA 1... BELLAPLICATA
NOVAMEXICANA
$ RIGHT VALVE G
6
BAO 2 ie PIS IB 20)
(INITIAL NUMBER OF PLICAE
TOTAL NUMBER OF PLICAE AT MARGIN
3
24
VoL. 148
Fic. 6.—Evolution in the Lopha
lugubris group. A, Variation plot
showing relationship between the
width of the posterior auricular
sulcus 20 mm. below the beak and
the length of the left valve, the
most variable linear measurement.
Note variation within each form
and good separation of variation
plots, lack of correlation between
width and valve length, and de-
crease in the relative width of the
sulcus at this point in progres-
sively younger species and sub-
species (the latter defined by differ-
ences in the vertical range of the
individual variation plots). B, C,
Comparison of the bifurcation rates
of the radiating plicae on various
members of the group, showing an
increase in bifurcation of the plicae
from L. bellaplicata novamexicana
to the younger L. bellaplicata bella-
plicata and then an abrupt decrease
in bifurcation rate with the evolu-
tion of L. lugubris, in which the
majority of specimens lack bifurcat-
ing plicae. Arrows on right central
portion of B and C denote direction
of increasing bifurcation rate as
illustrated by hypothetical regres-
sion lines visually fitted to plots of
terminal members of group.
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—-KAUFFMAN 19
L. LUGUBRIS
A
L. LUGUBRIS
L. LUGUBRIS
B
O
8
6
rh a
BELLAPLICATA w 2
BELLAPLICATA z= ne SE a
ia = . ie BELLAPLICATA ee ee rcs
= : s BELLAPLICATA
S BELLAPLICATA 5
B & C
re .
« © °'g
w 6 “6
ao
=4 mA
= = 2
ie)
14
“ L. BELLAPLICATA
1
XICANA
chins L: BELLAPLICATA
NOVAMEXICANA
fo)
L. BELLAPLICATA
NOVAMEXICANA
On FH @®
4 6 8 10 [2 I4 16 18 2022 24
NUMBER OF PRIMARY PLICAE AT
FIRST APPEARANCE
}
WIDTH OF MEDIAN PLICA
20 MM.BELOW THE BEAK
8 10 12 14 I6 18 2022 24 26
TOTAL NUMBER OF PLICAE
AT MARGIN
Fic. 7.—Evolution in the Lopha lugubris group. A, Increase in total number of
radiating plicae developed at the margin of adult shells in progressively
younger species of the lineage. B, Increase in the total number of primary
plicae first appearing at the margin of the smooth stage on progressively younger
species. C, Decrease in the width of the median plica measured 20 mm. below
the beak on progressively younger species of the group. All measurements made
on left valves.
L. LUGUBRIS
>
~
L. BELLAPLICATA
BELLAPLICATA
Gentes 2 wtheeom
L. BELLAPLICATA NOVAMEXICANA
NUMBER OF SPECIMENS
nm ko
6 8 10 12 14 16 ite} 20 22 Cte cOmeeS
HEIGHT OF SMOOTH STAGE (MM.), RIGHT VALVE
L. LUGUBRIS
L. BELLAPLICATA BELLAPLICATA
NUMBER OF SPECIMENS
L. BELLAPLICATA NOVAMEXICANA
6 8 10 12 14 16 ISO een eet commas
HEIGHT OF SMOOTH STAGE (MM.), LEFT VALVE
Fic. 8.—Evolution in the Lopha lugubris group. Increase in the actual height of
the smooth umbonal area, dorsal to the abrupt appearance of radiating plicae,
in successively younger species and subspecies. A, Right valve. B, Left
(attached) valve, on which the trend is best observed.
20
4
L. LUGUBRIS
2
é (@)
Fd
Ww }2
2
hr
a 10
”
uw
2 8 L. BELLAPLICATA BELLAPLICATA
w
o
= 6
=
i A
4
2
%
0 ees L. BELLAPLICATA NOVAMEXICANA
(@) 4 6 8 10 12 14 16 18 2022 24 2 28
NUMBER OF DENTICLES IN 5MM LENGTH
40
L. BELLAPLICATA
NOVAM EXICANA——>*
ol
\o)
BEAK TO POSTERIOR EDGE (MM)
So a on
LENGTH,
oi
N
ao
6) =) 10 15) 20") 25 SOs" 135’ 40! 45 S50 S50" 1607-65. “70
LENGTH OF LEFT VALVE (MM)
Fic. 9.—Evolution in the Lopha lugubris group. A, Increase in the density of
the denticles along the inner lateral and dorsolateral margins in successively
younger species. B, Ventral shifting of the beaks along the dorsal margin in
successively younger species and subspecies, and decrease in the length of the
posterior auricle. Arrow in lower left-hand corner denotes direction of central
shifting of beak along dorsal margin as shown by hypothetical regression lines
visually fitted to plots of terminal species in lineage.
aI
22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
moderate- to shallow-water environments with active currents (upper
Eagle Ford Shale, Codell Sandstone, parts of the middle Mancos), to
shallow-water, inner-sublittoral, high-energy conditions, including
wave action, a great deal of reworking, and periods of nondeposition
(Juana Lopez Member, “Reworked Eagle Ford zone’).
Most of the trends thought to be selected for environmental changes
concern themselves with improving the hydrodynamic stability,
strength, and anchorage of the shell. Hydrodynamic stability of the
shell in the face of increased current and wave activity was probably
improved by the overall decrease in shell convexity, ventral migration
of the high point, reduction of projecting surfaces such as the auricles,
increase in relative symmetry of the shell, and evening of the overall
shell surface by a great reduction in the prominence of the auricular
sulci, interplical sulci, and plicae. Reduction in shell size may also
have affected stability of the shell, though it is more likely tied to the
restricted amount of available feeding time in active shallow-water
environments as compared to that available in deeper, nonagitated
waters.
The development of smaller and more numerous plicae by shallow-
water ostreids in this lineage appears to be a twofold adaptation to a
near-shore environment. Most obviously this results in strengthening
of the shell, necessary for life in the presence of waves, strong
currents, and continued buffeting, while at the same time eliminating
coarse projections from the shell surface, producing a more even, less
resistant surface over which water can flow. Even more important
may be the role of plications as an adaptation to feeding in a turbid,
high-energy environment. Development of extensively plicate and
crenulate commissures in marine bivalves allows the animal to reduce
considerably the gape of the valves during feeding over that required
by forms with smooth margins, without greatly altering the total
amount of open area between the valves for the influx of water. The
advantages of reducing the gape while maintaining normal water
intake in a turbid environment are apparent, since there is a
corresponding reduction in the size and possibly the amount of foreign
particles able to filter between the valves, and consequently a greater
degree of protection against clogging of the feeding mechanisms and
agitation of the mantle. This helps to offset the abundance of mobile
detritus found in near-shore, high-energy environments, and allows
the oyster to feed for longer periods of time, and tolerate greater
turbidity, than nonplicate species subject to the same conditions.
Progressively younger members of the lineage display a gradual
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—-KAUFFMAN 23
increase in the relative size of the attachment area, the general size
and inclination of the area being unusually consistent within species
and subspecies. Increase in the size of the attachment area, and
decrease in the angle between the area and the commissure both
appear to be adaptations to high-energy, near-shore conditions, pro-
viding a firmer anchor and lower, hydrodynamically more stable shell
in the face of strong current and wave action. There is evidence in
the Lopha lugubris group that these may be genetically controlled
features of the shell as well as adaptive variations of individual mem-
bers of the lineage.
Evidence favoring genetic control of inclination and size of the
attachment area is found in the end members of the lineage. All
observed specimens of L. bellaplicata novamexicana have a very
small attachment area. The size of the area relative to the size of the
adult shell possibly indicates early detachment of the shell from the
substrate and a free-living adult stage. Were this purely an adaptive
feature, one would expect it only in quiet-water environments, since
a free-living shell of the novame.xicana type in normal living position
(convex left valve downward) would be highly unstable in the face of
strong currents or wave action, and easily overturned and buried.
Although sediments containing most L. bellaplicata novamexicana
indicate quiet or slightly agitated water conditions, a few specimens
occur in coarse-grained, coarse-bedded sandstones of high-energy
environments. These maintain the small attachment area. Further,
no adaptive counterpart of the subspecies having a large attachment
scar is developed in the near-shore facies. Scar size thus appears to
be independent of environment in this case.
Similarly, L. lugubris has an exceptionally large, gently inclined
attachment area regardless of associated sediment type and inferred
environment. These features indicate attachment throughout life,
and are adapted to high-energy conditions. Sediments containing
most specimens of L. lugubris reflect such an environment. The
species is most common in cross-bedded, ripple-marked calcarenites
and calcareous sandstones. A number of examples from thinly
laminated shales and fine sandstones and siltstones, however, maintain
the large, gently inclined scar, even though it was probably not neces-
sary for firm anchorage in the more quiet water environments.
The change in inferred living habit from partially free to wholly
attached, and the consistency in the character of the attachment area
on these two forms, regardless of associated environment, suggest
genetic control on the size and inclination of the area.
24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
The middle member of the lineage, L. bellaplicata bellaplicata,
exhibits more variation in scar size (pl. 3), with individuals that
probably lived free during part of their adult life, and others that could
well have been attached throughout life. These two forms coexist in
the great variety of environments from which the species is known, but
there is a notable increase in the relative percentage of individuals
with large attachment areas in shallow-water sediments deposited
under high-energy wave and current conditions (Codell Sandstone).
Scar size thus appears to be largely adaptive and environmentally
controlled in this subspecies.
Small shell size is considered by some ecologists as an adaptation
to turbid, near-shore environmental conditions. This may be the
case in the L. lugubris lineage where there is a distinct trend toward
reduction in the average adult dimensions with the onset of shallow-
water conditions during the Late Turonian. Shallow-water epifaunal
elements are able to spend less time feeding than their counterparts
in deeper, quieter waters. Long periods during which little feeding
takes place are imposed on them by extended times of high turbulence
and water agitation. This restriction on food intake has been related
to the below average size of many shallow-water epifaunal pelecypod
species which develop to normal proportions in quiet, offshore waters.
This, of course, is purely an ecologic control on shell form. In the
many cases, however, where the smaller of two closely related species
or subspecies of epifaunal pelecypods lives closest to the inner sub-
littoral zones of constant water agitation and turbidity, small size
seems to be a genetic adaptation to the environment. The smaller
species, requiring less food, are better able to survive in environments
presenting shorter and more irregular feeding opportunities.
The changes of other structures through time are well defined and
easily recognized, but based on my present knowledge of the zoologi-
cal characteristics of the group and of the Turonian environment, it is
difficult to explain them in terms of adaptive features.
SHELL MORPHOLOGY
Standard terminology has been used wherever possible in describing
species and subspecies of the Lopha lugubris group (see Newell
1937, 1942, Shrock and Twenhofel, 1953, for definitions of standard
terms). A few new or rarely used terms are employed here for fea-
tures not generally considered in ostreid description. It is desirable to
briefly define these. In most cases this is simply accomplished by
means of an illustration (fig. 10a, b, c, d), especially in regard to
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—-KAUFFMAN 25
spacial divisions of the valve (fig. 10c; see explanation). Discussions
are presented below for new terms employed, as a key to abbreviated
ratios (tables 1-5) or where it seems possible that misunderstandings
may arise in interpretation of a term in the descriptions as it is
applied to the Ostreidae. The letters arranged alphabetically below
refer to fig. 12, and tables 1-5.
A: AATS—The ratio of the approximate area of the left (lower) valve to the
approximate area of the attachment scar, as determined by their
inscribing rectangles, oriented with their sides paralleling height
and length.
AA—Anterior auricle, or ear (fig. 10a); rarely developed and generally poorly
defined flattening and projection of the dorsoanterior margin,
generally separated from the main body of the shell by a small
auricular furrow or sulcus.
ANS—Anterior slope of the valve (includes lower part of the anterior auricle,
where developed) ; the portion of the shell between the dorsal and
anteroventral slopes, and the crest (fig. 10c).
A: P—tThe ratio of the area of a rectangle inscribing the valve to the number
of plications present at the valve margin.
AS—Auricular sulcus (figs. 10a-c) ; an external furrow or depression which
separates the anterior and posterior auricles from the main body
of the shell. In this group it is commonly expressed as a rela-
tively deep, slightly enlarged interplical sulcus.
AVS—Anteroventral slope of the shell, between the median plication, crest,
and anterior slope (fig. 10c).
CCP—Central cardinal plate. On the right valve, a flat surface developed in
the central cardinal area, in place of a shallow resilifer.
CR—Crest of the valve; the highest area of the valve, either slightly convex or
nearly flat, situated dorsocentrally (fig. 10c).
D—Denticles; small raised nodes, rounded to elongate, on the inner dorsolateral
margins of the valves (fig. 10d).
DS—Dorsal slope of the valves (includes the attachment scar where present;
fig. 10c).
HA—Hinge axis (cardinal axis), the axis of rotation of the valves (fig. 10d).
The ligament lies dorsal, the main part of the resilium ventral.
The only parts of the two shells always in contact. When the
hinge line is straight, it may parallel this axis.
H: L—Ratio of valve height to valve length.
HP—High point of the valve (fig. 10c), marking the point of greatest convexity.
This is usually within the crest on the median plication, and is a
good reference point for delineating the various flanks of the
valves.
H:DPAS—The ratio of the valve height to the greatest diameter of the
posterior adductor muscle scar.
H: HATS—tThe ratio of the valve height to the height of the attachment scar,
as measured on the left valve.
H: HD—The ratio of the valve height to the height of that part of the valve
bearing denticles along the inner lateral margins.
Fic. 10.—Morphology of oysters in the Lopha lugubris group, using specimens
of L. bellaplicata bellaplicata for illustration (A, C, U.S.N.M. 132222; B,
U.S.N.M. 132239; D, U.S.N.M. 8024d). A, External shell morphology of left
valve. B, External shell morphology of right valve. C, Spatial divisions of valve
referred to in text. D, Interior morphology of right valve. Symbols explained
in detail under “Shell Morphology.” AA, Anterior auricle. ADM, Anterodorsal
margin. AM, Anterior margin. ANS, Anterior slope. AS, Auricular sulcus.
ATS, Attachment scar. AVM, Anteroventral margin. AVS, Anteroventral
slope. B, Beak. C, Commissure. CR, Crest of valve. D, Denticles. DM,
Dorsal margin. DS, Dorsal slope. H, Height of valve. HA, Hinge axis.
HP, High point of valve. i, Angle of inclination. ICL, Imbricating concentric
lamellae. IPS, Interplical sulcus. L, Length of valve. LCP, Lateral cardinal
plate. MCT, Marginal cardinal trough. MF, Midcardinal fold. ML, Micro-
lamellae. MP, Median plica) MSD, Maximum diameter of posterior adductor
muscle scar. PA, Posterior auricle. paa, Posterior auricular angle. PAS,
Posterior adductor muscle scar. PDM, Posterodorsal margin. PLS, Postero-
ventral lip of the muscle scar. PM, Posterior margin. PP, Primary plica.
PS, Posterior slope. PVM, Posteroventral margin. PVS, Posteroventral slope.
R, Resilifer. SC, Subcardinal cavity. SP, Secondary plica. SS, Smooth stage
of umbo. U, Umbo. VM, Ventral margin. All figures <1.
26
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 27
H: HSS—tThe ratio of the valve height to the height of the smooth stage on
the early portion of the valve.
i—The angle of inclination of the valve (fig. 10c); the angle between the
plane of the hinge line (horizontal) and a line connecting the
beak (or center of the attachment scar) with the most distant
edge of the shell. This line generally roughly bisects the shell.
ICL—Imbricating concentric lamellae; the major concentric features of the
ornamentation (fig. 10b).
IPS—Interplical sulcus; the trough between any two plicae. The auricular sulci
are enlarged interplical sulci separating the auricles from the
main body of the shell (figs. 10a, b).
LCP—Lateral cardinal plates (fig. 10d, 5a-c); triangular flat areas for liga-
ment attachment on either side of the resilifer and midcardinal
fold (right valve). These are highly variable in size, and com-
monly bordered laterally by a shallow groove (marginal cardinal
trough).
L:LHL—Ratio of the length of the valve to the length of the hinge line.
L: LPA—Ratio of the length of the valve to the length of the posterior auricle.
MCT—Marginal cardinal trough. A shallow, narrow groove or trough on the
cardinal area between the lateral cardinal plate and upturned
lateral margin of the valve (fig. 10d).
MF—Midcardinal fold. The raised convex portion of the central cardinal area
on the right (upper) valve, below the resilifer (where present).
It occupies from one-fourth to the whole of the area.
ML—Microlamellae; very fine overlapping sheets of lamellar calcite. The
major ornament on the smooth stage of the shell and between
imbricating concentric lamellae over the rest of the shell (fig.
10b). They appear as simple growth lines in many cases.
MP—Median plica (figs. 10a, c); the major primary plication that runs down
the approximate center of the valve, passing through its high
point. It is usually the most prominent plica on the shell, and is
a useful reference line for defining the various flanks.
MSD—Maximum scar diameter (fig. 10d) ; the longest diameter of the posterior
adductor muscle scar, the least variable parameter of the scar
to measure; useful in ontogenetic study.
PA—Posterior auricle (figs. 10a-c), or wing of the shell (in the sense of
Newell, 1942, p. 22 as applied to the Mytilacea). This is a
prominent, flattened, projecting salient of the posterior and
dorsoposterior flanks of the shell, in some cases separated from
the main body of the shell by an auricular sulcus.
paa—Posterior auricular angle (fig. 10c) ; the angle between the dorsoposterior
margin of the posterior auricle and the plane of the hinge line
(horizontal reference line).
PD—Plication density. The number of plications per unit approximate shell
area (H XL).
PLS—Posteroventral lip of the adductor muscle scar (fig. 10d). A raised ridge
that bounds the scar posteriorly and ventrally in many species.
PP—Primary plica; one of the initial plications of the shell, arising at the edge
of the smooth stage and extending to the shell margin. It may or
may not give rise to other plicae by bifurcation (fig. 10a, b).
28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
PS—Posterior slope of the shell, including the posterior auricle (fig. 10c).
PV S—Posteroventral slope of the valves, bounded by the median plica, crest,
and posterior slope of the valve (fig. 10c).
SC—Subcardinal cavities; shallow re-entrants of the valve floor beneath struc-
tures of the cardinal area, predominantly below the midcardinal
fold or lateral cardinal plates.
SP—Secondary plica; one that arises through bifurcation from a primary plica-
tion (figs. 10a, b).
SS—Smooth stage; that portion of the beak, umbo (in many cases the whole
umbo), and adjacent parts of the valve that lack radiating plica-
tions (fig. 10b). This probably represents part or all of the
shell of the spat.
T—Thickness; valve thickness is employed in this study as the actual thickness
of the shell material. This is naturally variable in a single valve.
Valve thickness should not be confused with shell or valve width.
W-—Shell width; here defined as the broadest diameter of coattached valves when
viewed along the plane of the commissure. It is the length of a
diameter joining the high points of each valve and perpendicular
to the plane of symmetry. The width of a single valve is measured
similarly—between the high point of the valve and the com-
missure plane (or if the beak is overhanging, the plane passing
along its most projecting edge).
SYSTEMATIC PALEONTOLOGY
Genus LOPHA Bolten, J. F.: Emended Kauffman, 1964
1798. Botten, J. F. (=Roeding, P. F.), Museum Boltenianum sive catalogus
cimeliorum e tribus regnis naturae, pt. 2, pp. 168, 169.
1898. Dati, W. H., Contributions to the Tertiary Fauna of Florida. Trans.
Wagner Free Inst. Sci. Philadelphia, vol. 3, pt. 4, p. 672.
1936. Maury, C. J., Brazil Servico Geol. e Mineralog., Mon. 11, p. 157.
1937. ArKELL, W. J., A monograph of British Corallian Lamellibranchia.
Paleont. Soc., p. 180.
1940. Cox, L. R., The Jurassic Lamellibranch fauna of Kuchh (Cutch). Mem.
Geol. Surv. India, ser. 9, vol. 3, p. 95.
Type species——Ostrea crista-galli Linné, by subsequent designation,
Dall, 1898, p. 672.
Diagnosis ——Shell normally small to moderate size, subequilateral
to moderately inequilateral, slightly to moderately inequivalve, left
valve slightly larger and more convex than right. Outline ovate,
subround, or subquadrate; posterior auricle commonly developed.
Beak opisthogyre to suberect. External ornament subequally devel-
oped on both valves, consisting of strong radiating plicae originating
at the umbone and extending to the commissure, increasing by bifurca-
tion and intercalation. Commissure trace undulating, more rarely zig-
zag. Shell structure predominantly lamellate (subnacreous layer),
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 29
adjacent layers of gently inclined lamellae commonly with opposed
dips.
Cardinal area of both valves consisting of central triangular resilifer
and triangular, subequally developed, lateral cardinal plates. Resilifer
of right valve commonly bounded ventrally by a low lip or partial
midcardinal fold. Subcardinal cavities commonly absent. Dorso-
lateral inner valve margins subequally denticulate; denticles small,
simple, ovoid to elliptical, their long axis perpendicular to commissure.
Posterior adductor muscle attachment area posterocentral; outline
comma-shaped ; well defined.
Remarks.—Many recent workers have included Lopha (= Alec-
iryonia) in synonymy with Ostrea, or considered it a subgenus or
section of Ositrea. Modern representatives of Lopha lack a promyal
chamber and are monoecious as are species of Ostrea. Ranson (1942,
1948) has demonstrated that the prodissoconch features of Ostrea
and Lopha are similar as well. Paleontologists have continued to
use the name however, since Lopha is quite distinct from Ostrea
in shell sculpture, and the two do not intergrade. Ostrea rarely
develops plications, and in cases where they are present, they do not
approach those of Lopha in size or development. In addition, species
of Ostrea are more equivalve, generally lack curved beaks and umbos,
and have a flat commissure.
Perhaps the most important distinction between Lopha and Osirea
is in the shape of the muscle scar—comma-shaped in Lopha, con-
sistently laterally elongate, ovate to kidney-shaped, and larger in
Ostrea. This reflects basic differences in the anatomy of the muscle
itself. In combination, these distinctions are sufficient to consider
Lopha and Ostrea separate genera. Their similarities probably reflect
a common ancestry somewhere in the Mesozoic.
The name Alectryonia has commonly been applied to oysters with
the characteristics of Lopha, and the two are objective synonyms,
having the same type species. The popularity attained by Alec-
tryonia in recent years stems from Stenzel’s acceptance of the name in
place of Lopha (1947, p. 169, 177) under the rules of the Inter-
national Commission of Zoological Nomenclature that existed at the
time of his work. Lopha originally appeared in Bolten’s Catalogue
without description or definition other than “Lopha Der Hahnen-
kamm’’ (Lopha the cock’s comb: Stenzel, 1947, p. 177). A list of sev-
eral valid species followed, but with no indication as to which was the
type. Osirea crista-galli Linné, now considered the type species of
Lopha, headed the list. Subsequently, Alectryonia Fischer de Wald-
30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
heim was validly proposed in 1807 before Lopha was validated with
formal description. The new rules of the Commission, however,
published in 1961, do not demand formal description of a new genus
as long as it is accompanied by listing of a valid species. Thus Lopha
can be considered validly proposed as of 1798, and Alectryonia,
proposed later with the same type species, becomes a junior objective
synonym.
The restricted usage of Lopha here does not incorporate many
groups that have previously been assigned to the genus because of
their plicate shell, but which probably belong to distinct groups.
Among these are the plicate Pycnodonte, which have vesicular shells,
Arctostrea, a distinct lineage since the Jurassic, Agerostrea, a modifi-
cation of the Arctostrea branch, and the narrow elongate “tree
oysters” with their clasping shelly processes.
In published descriptions of Lopha or Alectryonia, certain mor-
phologic features are given as diagnostic of the group which I do not
consider significant at this taxonomic level. Curvature of the adult
hinge line is too easily distorted by variation in direction of adult
growth to be useful, especially for oysters growing in crowded con-
ditions. The divaricate pattern of radiating ornamentation attributed
to Alectryonia and Lopha is not characteristic of the genus but rather
of Arctostrea and some Rastellum. The use of this as a diagnostic
generic character reflects the time when these groups were all placed
under Lopha. Clasping shelly processes are rarely developed around
the attachment area of Lopha and are not diagnostic. They are
more typical of the so-called tree oysters, which probably constitute
a distinct group.
Characters of the shell which appear to be useful in distinguishing
Lopha from similar forms, and in separating the genera of plicate
oysters, are: General shell form; basic ornament pattern; relative
development of component parts of the cardinal area; presence,
morphology, and distribution of the denticles ; presence or absence of
subcardinal cavities ; depth of the valves (especially the left valve) ;
position, size, and shape of the posterior adductor muscle scar ; shell
structure ; and in some cases juvenile ornamentation and nature of the
commissure.
LOPHA LUGUBRIS Conrad
Plate 1, figures 1-18; plate 2, figures 1-17; plate 8, figure 12
Ostrea lugubris Conrap, U. S. Mex. Boundary Rep., vol. 1, p. 156, pl. 10,
figs. 5a, b, 1857—Coguanp, Mon. Genre Ostrea Terr. Cret., p. 66, pl. 36,
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 31
figs. 22, 23, 1869-—MrEEK, Macomb’s Expl. Exped. from Santa Fe to Junc-
tion Grand and Green Rivers, p. 123, pl. 1, figs. la-d, 1876—WuureE, 4th
Ann. Rep. U. S. Geol. Surv., p. 297, pl. 41, fig. 3, 1884.—Cractn, 4th Ann.
Rep. Geol. Surv. Texas, p. 204 (in part), 1893—Stanton, U. S. Geol.
Surv. Bull. 106, pp. 58, 59 (in part), pl. 4, figs. 1-5, non figs. 6-10, 1893
[1894]—Locan, The Univ. Geol. Surv. Kansas, vol. 4, pt. 1, p. 455 (in
part), pl. 91, figs. 1-5, nom figs. 6-10, 1898—HerricK and JoHNson, Bull.
Denison Univ. Sci. Lab., vol. 40, p. 202 (in part), 1900—Jounson, School
of Mines Quart., vol. 24, No. 2, pp. 186, 187, 1903a; Columbia Univ. Contr.
Geol. Dept., vol. 10, No. 90, pp. 114, 115 (in part), 1903b—SHImer and
Biopcett, Amer. Journ. Sci. Arts, 4th ser., vol. 25, p. 61 (in part), 1908.
Ostrea (Alectryoma) lugubris Conrad, Boss, Bol. Inst. Geol. Mexico, No. 30,
Algunas faunas del Cret. de Coahuila, pp. 47, 48, pl. 8, figs. 4-6, 1913.—
SHIMER and SHROcK, Index foss. N. Amer., p. 395, pl. 154, figs. 4, 5, 1955.
Alectryonia lugubris (Conrad) Apkins, Handbk. Texas Cret. Foss., p. 104
(in part), 1928.
DESCRIPTION
Material—Approximately 350 well-preserved specimens (measured)
and an additional 200 to 300 poorly preserved valves from various
localities in Texas, New Mexico, and Colorado, including most
illustrated types of the species. Ontogenetic series and large variation
suites are available from several New Mexico and Colorado localities.
General form.—Summary of measurements presented in table 1.
Shell small, inequivalve, left (lower) valve slightly larger, much more
convex than right valve. Valves slightly to moderately inequilateral,
normally prosocline ; beaks, umbos typically opisthogyre (exogyroid )
(pl. 1, fig. 5). Left valves commonly round, subround, or broadly
subovate, rarely subelliptical ; right valves subovate to elliptical, slightly
curved (pl. 1, figs. 1-6; pl. 2, figs. 1-3, 5-12 typical of species).
Height normally greater than length. Anterior and ventral margins
slightly to moderately and unevenly rounded, posteroventral corner
narrowly rounded, posterior margin slightly concave to nearly straight
on valves with posterior auricle, otherwise moderately curved. Dorsal
margins short, rounded, moderately inclined anteriorly, gently sloping
posteriorly over auricle, recessed posteriorly adjacent to beak, umbo.
Convexity.—Left valve moderately to highly convex, rarely flattened ;
high point subcentral, on ventral edge of attachment scar. Anterior,
posterior, ventral, ventrolateral flanks moderately to steeply sloping ;
dorsal and dorsolateral flanks, including attachment scar, gently
sloping. Right valve flat to moderately convex, normally slightly
arched, with umbo more inflated (pl. 2, figs. 2, 6) ; rarely concave.
Some right valves with upturned margins and submarginal trough.
32 SMITHSONIAN MISCELLANEOUS COLLECTIONS
VoL. 148
Tas_e 1.—Summary of measurements on specimens of Lopha lugubris (Conrad)
Character Valve
; fL
etehte (i) eno. 3 oe ere soci eeyerteets R
1p,
Deength (la) ee eters oiler aitteartelor R
: 1B,
NEGO (GINO \tacemica ames be Pubimadur a
Percent valves with H>L.......... oR
Percent valves with L>H.......... LR
Percent valves with H=L.......... iE 182
Area, inscribing rectangle of valve
CHIDGLDE. oB- psitainten ts dare one ares, IL
Length, beak to posterior margin
CEEBIPD aie arc cer ace eo cicencie sietans IL.
ieee. Ji MR Ib: baa oAsEoAAueonoDA so 1G
Angle ‘of inclination: (1) ...-.... <2. 2. :
Height of attachment scar (HATS). L
Length of attachment scar (LATS). L
Area, inscribing rectangle of attach-
ment scar (HATSIXLATS)). 22.5 IL,
Ratio, area of scar (inscribing rec-
tangle) : area of valve (inscrib-
ANG TECLANLIE) |) ayer ister ciorsiieieioe IL,
Percentage of valves with plicate
exterior surface (not including
those with only the margin plicate
OF Crenulate ss ..6eetacpauesyajelxgdin oto ante In
Height, smooth young stage (HSS),
on dorsal part of plicate valves... ;
HSS on left valves with HSS >
HAIRS) he SR ea ane ie
Ratios Hes ee a ee :
Number of primary plicae at first L
appearance. casecern ce esccescete ir
Number of plicae at 10 mm. H (on L
shells where HSS<10 mm.)...... ie
Number of plicae at 20 mm. H....... iz
Total number of plicae (marginal
COUNE)) ate aie crevavs Taner nvevoretoicrereroueneterevaters
Number plicae in 20 mm. L at
20 mm. H (median plica central).. L
R
No. of
specimens
175
161
173
161
Range
7.6-41.2
7.4-23.9
7.5-23.3
4.6-23.0
1.5-9.6
1.0-6.2
118.8-564.0 mm.
2.5-11.0
0.31-0.55
43°-97°
40°-93°
4.4-20.0
4.0-17.5
mm.
mm.
mm.
mim.
mm.
mm.
mm.
mm.
mm.
mm.
Average
17.3 mm.
15.2 mm.
14.9 mm.
12.8 mm.
3.7 mm.
2.7 mm.
90.7%
7.9%
1.4%
272.5 mm.
6.5 mm.
0.43 :1 mm.
73.4°
Wflesy”
12.3 mm.
9.5 mm.
17.6-285.4mm.? _121.9mm2
0.13 :1-0.78:
9.4-21.1 mm.
7.1-21.1 mm.
9.0-20.2 mm.
0.60 :1-1:1
0.62 :1-1:1
10-24
13-24
10-18
13-16
15-24
14-24
10-24
13-25
5.75-11.0
5.25-8.5
1
0.46: 1
81.7%
23.0%
15.0 mm.
14.2 mm.
13.7 mm.
0.80:1
0.92:1
18.1
16.9
14.7
14.7
19.6
18.8
18.8
17.0
7.32
6.8
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 33
Table 1—Summary of measurements on specimens of Lopha lugubris
(Conrad )—continued
Character Valve
Width of median plica at 20 mm. H.. 2
Percentage of plicate valves with
bifercating plicae « «.ch:acy «yo nis. 0.350 0 2
R
Percentage increase in plicae by
bifurcation (measured only on
valves with bifurcating plicae).... .
Percentage of specimens with opis-
thogyre beaks and umbones........ I
Percentage of specimens with or-
thogyre beaks and umbones........ i
Percentage of specimens with proso-
gyre beaks and umbones........... 4
Length of hinge line (LHL)........ =
Tingy SE Ses Ne eae 2
Extent of denticles on inner margins
(in terms of valve height; HD).... =
2 TYSTSISAT ES ND 1S eae A a L
R
Number of denticles in 5 mm. length
along dorsolateral margins, just
below cardinal careéaiersis si 53... blesc i
Maximum diameter of muscle scar
‘CLIO glee ane er a .
No. of
specimens Range Average
50 1.2-35 mm. 2.1 mm.
24 1.1-3.1 mm. 2.1 mm.
130 23.8%
32 18.8%
13 4.5-22.2% 9.22%
Z 6.7% 6.7%
157 78.9%
161 72.79%
157 3.3%
161 3.7%
157 17.8%
161 23.6%
33 2.3-8.5 mm. 5.1 mm.
26 2.8-8.1 mm. 4.4 mm.
34 0.15:1-0.55:1 0.33:1
26 0.17 :1-0.43 :1 0.28 :1
32 2.2-9.6 mm. 4.7 mm.
25 1.2-10.2 mm. 4.6 mm.
32 0.12:1-0.41:1 0.26:1
25 0.08 :1-0.51:1 0.26 :1
18 9-17 13.2
18 11-29 14.3
32 3.0-7.8. mm. 5.1 mm.
18 3.3-8.6 mm. 5.3 mm.
Auricles—Anterior auricle rarely developed, most common on
right valve. Auricle small, rounded, flattened salient of dorsoanterior
margin (pl. 2, fig. 5), in some cases separated from shell by shallow,
broad anterior auricular sulcus. Posterior auricle present on 59 per-
cent of measured specimens; small to medium size, subtriangular,
elongate, flattened, margin rounded, position dorsoposterior (pl. 1,
fig. 4). Auricle rarely separated from main body of shell by shallow,
broad auricular sulcus. Auricular sulci corresponding to enlarged
interplical sulci on plicate valves.
Beaks, umbones.—Typically opisthogyre, rarely erect, more com-
34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
monly prosogyre, predominantly exogyroid on left valves, attaining
three-quarters to one and one-half volutions (pl. 1, fig. 5, text fig. 3c)
on both prosogyre and opisthogyre shells; strongly curved where not
exogyroid, Beaks, umbos moderately curved posteriorly on most
right valves. Beak pointed (right valve) to narrowly rounded (left
valve), situated centrodorsally or just posterior to midline. Prodis-
soconch rarely preserved, smooth, flat, separated from umbo by single
prominent growth line or concentric constriction. Beak, umbo flat
to concave on left valve, deformed on attachment scar; slightly to
moderately inflated on right valve, in some cases separated from rest
of valve by prominent constriction and/or abrupt change in ornament
(pli 2, figs: 2, 5,6):
Attachment area.—Situated on dorsoposterior flank, large on most
left valves (pl. 1, figs. 1-14), equal to one-half area of shell, flat to
concave, gently inclined to plane of commissure (average angle 24°),
outline rounded to subovate, similar to ultimate shape of valve.
Ornament of attachment area reflects surface to which attached, nor-
mally Ostrea and Inoceramus shells; area marked with concentric
lines and folds. No clasping processes developed. Attachment area
commonly obscures beak, umbo.
Ornamentation, left valve—Beak smooth; early part of umbo
smooth, central and ventral portions covered with fine growth lines,
small concentric undulations. Free surfaces of most valves covered
with coarse, simple (primary), radiating plicae (pl. 1, figs. 1, 2, 4-6),
originating abruptly at or near margin of attachment area and extend-
ing to commissure, rarely bifurcating ; rare valves smooth, with plicae
reflected as marginal crenulations, or with plicae greatly reduced in
prominence (pl. 1, figs. 3, 11-14). All gradations known between
smooth and fully plicate forms. Primary plicae straight to slightly
curved, slightly broader than high, crests rounded, flanks steep, more
prominent centrally than laterally, becoming higher, more angular,
broader, more prominent with age. Secondary plicae smaller, lower
than primaries, more rapidly expanding in size (pl. 1, fig. 4).
Interplical sulci deep, steep-walled, narrower than plicae, angular to
narrowly rounded at base. Commissure strongly undulating, rarely
zigzag, at intersection with plicae.
Concentric ornament between edge of attachment area and plicate
portion of valve with faint growth lines, microlamellae, more rarely
with crowded, coarse, flat, major overlapping lamellae. Plicate portion
of valve characterized by moderately spaced to crowded overlapping
lamellae separated by very fine growth lines. Lamellae irregularly
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 35
spaced, normally flat, terminally in contact with succeeding ones;
rarely raised. Plicae rugose at intersection with lamellae.
Ornamentation, right valve-—Ornament of right valve distinct
from that of left valve. Beak and early umbonal area smooth ; central,
ventral portions of umbo marked with faint growth lines, less com-
monly with small, low undulations and microlamellae, rarely with scat-
tered coarse lamellae or undulations on ventral umbo. Majority of
specimens lack radiating sculpture over rest of valve, but many of these
have marginal crenulations near commissure (pl. 2, figs. 1, 8). Plicae
variously developed on minority of specimens (pl. 2, figs. 2-7), never
covering more than half of valve, commonly confined to marginal 5
mm. Plicae originate abruptly, on strongly plicate valves at edge of
inflated umbonal area (pl. 2, fig. 5); plicae prominent, rounded,
with steep flanks, becoming coarser with age, rarely bifurcating ;
secondary plicae smaller, more rapidly expanding than primaries.
Plicae rugose at intersection with concentric lamellae; plicae of right
valve more prominent, sharper, than those of left. Interplical sulci
deep, narrow, sharp-based, steep-walled.
Concentric ornament variable, depending on extent of plicae. Low,
evenly convex valves lacking plicae covered with faint concentric
growth lines, microlamellae, low, broad undulations (pl. 2, fig. 11)
except at margin where coarse, crowded lamellae occur. Valves with
inflated, smooth umbo and flat flanks (pl. 2, fig. 2) exhibit coarse,
crowded, major lamellae, raised growth lines, small prominent undula-
tions on flanks; ornament more prominent near commissure. On
plicate valves, prominent lamellae and/or concentric constrictions
occur at inner margin of point of origin for plicae (pl. 2, figs. 5, 6).
Growth lines and lamellae occur throughout plicate portion of valve.
Cardinal area—Composed of subcentral resilifer and/or mid-
cardinal fold (right valve), bounded laterally by flat to moderately
arched lateral cardinal plates or folds for ligament attachment. Resili-
fer of left valve shallow to moderately concave, elongate-triangular
with twisted apex, higher than long, slightly flared ventrally, equal to
or larger than lateral cardinal plates or folds (pl. 1, fig. 16). Lateral
plates, folds subequal, variable in relative size, flat to arched, obscure
to prominent, triangular with curved dorsal apices, in some valves
separated from lateral margins by narrow lateral cardinal grooves
(pl. 2, fig. 17), otherwise merging with margin. Lateral cardinal areas
of right valve similar, less commonly arched.
Central part of cardinal area variable in right valves, ranging from
flat midcardinal plate to shallow concave resilifer with raised ventral
36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
lip or partial midcardinal fold (pl. 2, fig. 17). Rarely, entire midcar-
dinal fold developed (pl. 2, fig. 14), slightly to moderately convex.
Cardinal area of both valves marked by moderately strong, irregularly
spaced, crowded, raised horizontal lines transected by finer, more
crowded, more evenly spaced, raised vertical lines, forming reticulate
pattern. Hinge line short, straight to slightly curved (concave
ventrally), situated ventral to hinge axis.
Denticles——Denticles present on inner dorsolateral margins of all
valves, rarely extending below upper one-third of margin; small,
simple, elongate perpendicular to shell margin, subround to ovate,
crowded, distributed along commissure and in shallow trough just
inside it ; color whitish, lighter than surrounding shell.
Inner valve surface—Commissure undulating, more rarely zigzag.
Plicae reflected internally as rounded, low folds and sulci, nearly
equal in extent to external trace of plicae, more prominent toward
commissure. Fine, irregularly spaced, sinuous, pallial or vascular
grooves transgress most of inner shell surface (pl. 1, fig. 17).
Muscle scar—Monomyarian, posterior adductor muscle insertion
area (scar) subcentral, slightly posterior to midline, comma-shaped
to subcrescentic, moderately curved, slightly to moderately concave,
prominent. Surface of area marked with faint concentric lines and
microlamellae, crowded near ventral and posterior margins, their
trace conforming to growth lines. Posterior and ventral part of
area bordered by low, raised, lip; dorsal and dorsoanterior margins
overlapped by inner shell layers.
Shell structure-—Valves of medium thickness, variation in thickness
moderate. Shell thickest at cardinal area, moderately thick over
attachment area, thinning laterally, posteriorly. Thickness of average
left valve: at cardinal area 0.9 mm.; middle of attachment area 0.6
mm.; high point 0.5 mm.; 2 mm. from ventral margin, 0.5 mm.
Periostracum, prismatic layer, hypostracum not observed on sectioned
valves. Subnacreous layer forms greatest part of shell, consisting of
flat to gently curved calcite lamellae, parallel to one another on free
flanks of valve, and curved, slightly inclined plates in distinct sets or
layers over attachment scar. Inclination of plates in one layer com-
monly opposed to those of adjacent layers (pl. 8, fig. 12). Cardinal
area composed of slightly curved, subparallel, thin lamellae of calcite.
ONTOGENY
Lopha lugubris is the species least suited for ontogenetic study in
this group owing to the size of the attachment scar, which obscures
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 37
the nepionic and neanic development of many left valves, the lack of
immature shells in the collections, and the limited size range of the
species. Ontogenetic trends can be studied in the following structures,
which are graphed or illustrated in figures 2-4, 6b, c, 9, 11-13.
Concentric ornament.—Nepionic shell smooth, transition to neanic
marked by single growth line or small constriction. Neanic stage with
fine growth lines, becoming coarser, more crowded, mixed with micro-
lamellae ventrally. Neanic—ephebic boundary poorly defined. Ephe-
bic stage with coarse growth lines, microlamellae and scattered macro-
lamellae, faint undulations, on left valve. Right valve with faint
growth lines during early ephebic stage (ventral umbo), abrupt con-
striction of shell at midephebic stage, marking cessation of major
growth in body size, prominent lamellae, growth lines in late ephebtc.
Gerontic stage characterized by crowded, coarse major lamellae, small
undulations near margin, marking great reduction in rate of shell
growth, sharp change in concentric ornament marks ephebic—gerontic
boundary.
Radiating ornament.—Plicae appear abruptly in muddle to late
ephebic (most left, some right valves), rarely earlier, marking point
where shell begins to grow free of substrate ; plicae becoming higher,
broader, sharper, and rarely bifurcating through late ephebic, gerontic
stages.
Marginal outline —(See fig. 11.) Nepionic: Prodissoconch sub-
round. Neanic: Ventral growth exceeds lateral, outline vertically
ovate, slight expansion of posterior flank. Ephebic: Ventral and
posterior growth exceed that anteriorly and are nearly equal. Auricles
form in early ephebic stage, expand with age. Relationship between
expansion rate of auricle and overall lateral ephebic growth constant
(fig. 12a). Gerontic: Outline remains essentially the same, slight
flaring of ventral, ventrolateral margins.
Curvature of midline axis—WNepionic: Slight, poorly known.
Neanic: Moderate to great (fig. 3c), gradually decreasing in late
neanic stage and through ephebic and gerontic stages, becoming slight.
Convexity.—On right valve (fig. 3b), gradual increase in degree of
outward curvature from nepionic through early neanic, greatest in
late neanic, early ephebic, gradually to abruptly decreasing through
late ephebic. Gerontic stage marked by abrupt flattening, upturning
of margin.
Internal structures.—Rate of expansion of muscle scar, hinge line,
constant, and less than rate of shell growth during neanic and early
ephebic stages, tapered off gradually during late ephebic, and gerontic
38 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
stages (figs. 13b, c). Elements of cardinal area poorly differentiated
in neanic stage, becoming well defined at later stages. Extent of
denticles relative to height of shell, and density of denticles, greatest
during neanic, early ephebic stages, gradually decreasing in later
growth stages (fig. 13a).
Attachment scar—Rate of size increase relative to total size of
shell constant throughout neanic, ephebic stages, demonstrating con-
tinued growth of attachment area throughout life.
A
B
Fic. 11—Ontogeny of Lopha Iugubris (Conrad). Growth line traces at
approximately 1.25 mm. intervals on representative left (A) and right (B)
valves of the species, showing developmental history of the marginal outline.
Drawings <2. A, U.S.N.M. 132156; B, U.S.N.M. 132164.
REMARKS
Lopha lugubris (Conrad) is the most distinct member of the group
and easily differentiated from related older species. In the Western
Interior, it is the terminal member of the lineage known. On the
Gulf Coast, however, Lopha panda (Morton) (Campanian, Lower
Maestrichtian) possibly represents a stratigraphic extension of the
lineage. Forms definitely connecting the two are presently unknown
in this country.
Lopha lugubris may be distinguished from L. bellaplicata bella-
plicata (Shumard) and L. bellaplicata novame.xicana n. subsp. by its
smaller size, greater relative height, much-reduced posterior auricle,
general absence of an anterior auricle, subovate to subelliptical mar-
ginal outline, shorter, more inclined dorsolateral margins, subcentral
and strongly curved to exogyroid beak and umbo, much larger and
more gently inclined attachment scar, less convex left valves and
VALVE LENGTH (MM)
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 39
relatively more convex right valves, relatively larger muscle scar, a
less inflated midcardinal fold (where present), and in having the
resilifer relatively larger than either lateral cardinal plate or fold.
It may be further distinguished from older species by the external
ornamentation of the valves. In L. lugubris, the majority of right
valves lack plicae, and smooth left valves are common. Plicate
valves may be distinguished from those of older species in the follow-
30 30
fo ed
[o) u
to
oO
VALVE LENGTH (MM)
a
VALVE LENGTH (MM)
a
5 5
RIGHT VALVE
ant hioets Cs ig ais. 20. 2s °46 lo SIs 20
LENGTH: BEAK TO VALVE HEIGHT (MM) VALVE HEIGHT (MM)
POSTERIOR EDGE
(MM)
Fic. 12.—Ontogeny in Lopha lugubris (Conrad). A, Relationship between
length of the left valve and the distance between the beak and posterior edge,
measured parallel to the length. B, C, Relationship between height and length
of the left and right valves, respectively. Approximate boundaries between
ontogenetic stages marked by dashed lines. N= Neanic; E= Ephebic;
G = Gerontic.
ing manner: The plicae appear at a later stage of development, rarely
bifurcate, and then only in the ephebic stage, and are smaller, nar-
rower, and more numerous than those of other species. The auricular
plicae are similar to those of the main body of the shell. L. lugubris is
further distinct in generally lacking coarse concentric sculpture, and
in having the plicae well defined on part of the valve interior.
No species of oysters known to me are closely comparable to L.
lugubris, although marginal variants of some North American and
foreign species resemble it. Notable among these are “Ostrea” sem-
plana Sowerby, L. bellaplicata bellaplicata, and L. panda Morton.
No consistent ecologic control on any morphologic feature was
25
DENTICLE HEIGHT (MM)
LENGTH:HINGE LINE (MM)
1,)
o
15). 20
SHELL HEIGHT (MM)
| DENTICLE HEIGHT (MM)
10 15 20 25
O
LENGTH OF VALVE(MM) 10 15 20
®
LENGTH: HINGE LINE (MM)
12 14 16 18 200s Via2 24
VALVE HEIGHT (MM)
MAXIMUM DIAMETER OF SCAR
MAXIMUM DIAMETER OF SCAR
12 14 16 is 20
VALVE HEIGHT (MM)
22 24
Fic. 13.—Ontogeny in Lopha lugubris (Conrad). A, Relationship between
valve height and the amount of dorsal and lateral margin covered with denticles,
measured parallel to valve height. B, Relationship between the length of the
hinge line and the length of the valve. C, Relationship between the maximum
diameter of the muscle scar and the height of the valve. All lines fitted visually.
Approximate boundaries between ontogenetic stages marked by dashed lines.
E = Ephebic; G= Gerontic; R = Right valve; L = Left valve.
40
25
LENGTH OF VALVE (MM)
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 4I
noted in comparing suites of specimens from calcarenite, calcareous
sandstone, dark shale, and conglomeratic calcarenite facies. The
species is amazingly consistent in form for an ostreid. Similarly,
there appears to be no recognizable geographic variation between
Texas and northern Colorado. There is, however, some suggestion
of stratigraphic variation which, when studied with large suites of
specimens, may prove to be of subspecific importance. In Colorado
and New Mexico, the species ranges through the Juana Lopez
Member and its equivalents. In New Mexico, where the Juana Lopez
includes a relatively thick series of calcarenites, shales, and calcarous
sandstones, specimens of L. lugubris (particularly left valves) from
the base of the section appear to be covered to a greater extent with
radiating plicae than those from the top, which typically have the
plicae limited to the valve margins. The younger specimens also have
denser plication. Similar trends were noted at scattered localities in
southern Colorado. The proper interpretation of these apparent trends
must await larger collections, with better stratigraphic data, than are
now available.
Specimens of Lopha lugubris commonly occur in great numbers in
basal Upper Turonian calcarenites of the Juana Lopez Member and
its equivalents. The valves are typically unbroken, separated, and
oriented with the convex surface upward. They do not occur in beds
or “colonies,” and very few show any evidence of deformation due to
crowding. In many cases, they are the only well-preserved, complete
shells in the sediment.
Of particular interest is the commonly developed reverse curvature
of the valves, and the development of exogyroid beaks in either direc-
tion. In most species of oysters that develop tightly coiled or exogy-
roid beaks and umbones, the direction of coiling is relatively constant
and appears to be genetically controlled. Exceptions to the rule are
deformed specimens growing in crowded living conditions. There are
examples of reverse curvature in many of these species, but it is rare
in almost all of them. The unusual coiling behavior of L. lugubris
therefore provoked an investigation to see whether it was due to a
breakdown in normal genetic control over coiling direction, or whether
the species was capable of attachment by either valve.
Well-developed reverse beak curvature is found in 17.8 percent
of all left valves and 23.6 percent of all right valves of L. lugubris.
In most of these, the coiling is exogyroid. In all cases of reverse cur-
vature the muscle scar retains its position just posterior to the midline
and there is no alteration in the structure of the cardinal areas on
42 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
either valve. I conclude from this that the direction of curvature is
variable and not rigidly controlled genetically in this species (although
posterior curvature dominates). Consistency in the position of the
muscle scar and cardinal characters on both valves, irrespective of
coiling direction, indicates attachment is always by the left valve, as in
other ostreids.
Stratigraphic and geographic occurrence.—Lopha lugubris ranges
through the Juana Lopez Member and its equivalents (zones of
Prionocyclus wyomingensis wyomingensis: early Late Turonian, and
P. wyomingensis elegans: middle Late Turonian) in central, south-
central, and eastern Colorado, western Kansas, and northern New
Mexico. The primary types were reported to have come from beds
containing P. macombi (P. wyomingensis wyomingensis zone). It
has been found at an equivalent level in the Mancos Shale of western
Colorado and New Mexico. In Huerfano Park, Colo., fragments
questionably referable to this species were collected in the upper part
of the “Pugnellus Sandstone” (Codell Sandstone Member, Carlile
Shale; upper part of zone of Collignoniceras hyatti) associated with
L. bellaplicata bellaplicata. The ranges of these species overlap
slightly in Texas also, where L. Jugubris is found in the upper 3 feet
of the Eagle Ford Shale (late Middle Turonian, upper part of L. bella-
plicata bellaplicata zone) and in the overlying conglomeratic calcaren-
ite bed between typical Eagle Ford Shale and Austin Chalk. Hattin’s
report of this species from the Blue Hill Shale Member in Kansas
(lower part of zone of Collignoniceras hyatti; 1962, p. 84) is based on
a typical specimen of L. lugubris collected by J. B. Reeside, Jr.
Pieces of matrix adhering to the specimen are rusty-brown calcarenite
characteristic of the Juana Lopez Member in Colorado and at scattered
Kansas localities, and the specimen probably came from a higher level
than Reeside assumed. I have also examined specimens from the
Fairport Chalk Member which Hattin assigned to this species (1962,
p. 54). These belong to a distinct lineage and appear most closely
related to the younger “Ostrea” tecticosta Gabb.
Specimens of Lopha lugubris used in this study were obtained from
localities 1 through 39 and 48, described in detail at the end of this
report.
Illustrated and measured specimens.—Lectotype, selected by
Stanton (1894), U.S.N.M. 9822, the original of Conrad’s plate 10,
figure 5b (1857) ; Stanton’s hypotypes, reillustrated (1893, pl. 4),
U.S.N.M. 22859a (Stanton’s fig. 5) 22859b (Stanton’s fig. 3),
22860a (Stanton’s fig. 2) ; Meek’s hypotype (1876, pl. 1, fig. la),
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 43
U.S.N.M. 20255 ; new hypotypes, U.S.N.M. 8354, 22008a, b, 22210a,
b, 22211, 132154-132168 inclusive, 132174, 132198, 132258,
132285; U.M.M.P. 43463-43465 inclusive, 43470-43472, inclusive,
43476, 43484, 43486, 43487. Measured specimens, unfigured,
U.S.N.M. 22210c, 132169-132173 inclusive, 132175-132197 inclusive,
132199-132210 inclusive: U.M.M.P. 43460-43462 inclusive, 43467-
43469 inclusive, 43473-43475 inclusive, 43477, 43488, 43489, 43491.
Specimens from the upper Codell Sandstone questionably referred
to this species, U.S.N.M. 132211,,132212.
LOPHA BELLAPLICATA BELLAPLICATA (Shumard)
Plate 3, figures 1-18; plate 4, figures 1-8; plate 5, figures 1-15;
plate 6, figures 7-24; plate 8, figures 10, 11
Ostrea bellaplicata SHuMARD, Trans. St. Louis Acad. Sci., vol. 1, p. 608, 1860.—
Waite, 4th Ann. Rep. U. S. Geol. Surv., p. 292, pl. 47, figs. 1, 2, 3, 1884.—
Cracin, 4th Ann. Rep. Geol. Surv. Texas, p. 199, 1893—Bé6sr, Algunas
faunas del Cret. Sup. Coahuila, p. 48, 1913—Wunton, Univ. Texas Bull.
2544, p. 62, pl. 8, fig. 5, 1925.
Ostrea (Alectryonia) bellaplicata Wutite, 11th Ann. Rep. U. S. Geol. Geogr.
Surv. Terr. Idaho and Wyoming, pp. 276, 277, pl. 4, figs. 3a, b; pl. 8,
figs. 2a, b, 1879.
Ostrea (Alectryonia) blackii Wuire, Proc. U. S. Nat. Mus., vol. 2, p. 293, pl. 4,
figs. 1, 2, 1880; 12th Ann. Rep. U. S. Geol. Geogr. Surv. Terr. Wyoming
and Idaho, pt. 1, pp. 11, 12, pl. 14, figs. la, b; pl. 17, fig. 5a, 1883.
Ostrea blackti Wuite, 4th Ann. Rep. U. S. Geol. Surv., p. 292, pl. 45, fig. 1;
pl. 46, fig. 2, 1884.
Ostrea lugubris Conrad, Stanton, U. S. Geol. Surv. Bull. 106, pp. 58, 59, pl. 4,
figs. 6-10, non figs. 1-5, 1893 [1894]—Locan, The Univ. Geol. Surv.
Kansas, vol. 4, pt. 1, pp. 445, 446, pl. 91, figs. 6-10, 1898—Hm, 21st Ann.
Rep. U. S. Geol. Surv., pl. 40, fig. 9, 1901—Herrick and JonNnson, Bull.
Denison Univ. Sci. Lab., vol. 40, p. 202 (in part), 1900.—Jounson, School
of Mines Quart., vol. 24, No. 2, pp. 186, 187 (in part), 1903a; Columbia
Univ. Contr. Geol. Dept., vol. 10, No. 90, Geol. of the Cerrillos Hills, New
Mexico, p. 114 (in part), 1903b—SHImMER and Biopcert, Amer. Journ.
Sci. Arts, 4th ser., vol. 25, p. 61 (in part), 1908—Hopxins, Powers,
Rosinson, U. S. Geol. Surv. Bull. 736, pl. 3, figs. 1, 2, 1923——Apx1ns
and Lozo, Stratigraphy of the Woodbine and Eagle Ford, Waco Area,
Texas, pl-'5, fig. 1;.1951.
Alectryoma lugubris, Apkins, Handbk. Texas Cret. Foss., p. 104 (in part),
pl. 16, fig. 5; pl. 24, figs. 8, 9, 1928. Listed on pls. 16, 24, as A. lugubris
(bellaplicata).
DESCRIPTION
Material Approximately 400 well-preserved specimens (measured )
from localities in Texas, New Mexico, and Colorado, including large
44 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
variation and ontogenetic series, fossil “populations,” and most North
American types of the species. Numerous additional fragments.
General form.—Summary of measurements presented in table 2.
Shell attaining moderate size, average size decreasing from south
(Texas) to north (Colorado) (fig. 14a, c); inequivalve, left valve
slightly larger, much more convex than right; slightly to moderately
inequilateral, prosocline to acline. Outline commonly round to ovate,
subquadrate, rarely triangular (pls. 3-6; pl. 3, figs. 1, 3, 5, 9-15
typical) ; height slightly greater than length on majority of specimens.
Anterior, ventral margins straight to slightly curved; ventrolateral
margins moderately curved ; posterior margin with moderately convex
curvature in absence of auricle, moderately concave beneath auricle
when developed. Dorsolateral margins normally straight to slightly
curved, gently inclined (pl. 3, fig. 3), posterodorsal margin longest,
equaling two-thirds to slightly over one-half total length of shell.
TABLE 2.—Summary of measurements for Lopha bellaplicata bellaplicata (Shumard)
No. of
Character Valve specimens Range Average
; Ly 171 12.2-69.0 mm. 38.7 mm.
Height SEW) pt eiicts beter toe chine anc R 12 POE poe ao th
a if 173 6.3-66.1 mm. 37.5 mm.
Lenothy GC) ssaiertoeebicintec eras naire R 2 40689 deal. ne
: L 162 3.0-28.5 mm. 13.4 mm.
Width GW) "ast sonst < ce tr orere erae R 109 ee a aa
Percent valves with H > Eo. /:.....2 LR 186/265 70%
Percent’ valves with Hi... cae: LR = 13/265 5%
Percent valves with H<L.......... ER” *66/265 25%
: pa 105 171 153-4416mm.?—-:1670.5 mm.”
A o le of valve...
rea, inscribing rectangle of valve - 5] 235-3637 mm? 17821 mm?
L h . :
pao all BO eu es gah ae ee ae 52404eamn. yi22d mee
Melee cased Seine Sty Aeacang serra R 109 iisea yee sect gees
Ratio BP swap Coat hee 15 150 0.33 : 1-0.76:1 0.58 :1
Angle between dorsal and dorso-
posterior margins 2). kines scl iL 56 5-47° 2347
Angle tof inclination (1)n.-.-e-e-e: LR 249 62-95° 79°
Percent of specimens with observable
attachment scare aceite Is ASTSYAL8} 80%
Height of attachment scar (HATS).. L 123 1.0-42.6 mm. 7.8 mm.
Length of attachment scar (LATS)... L 137 1.1-36.0 mm. 10.1 mm.
Area, inscribing rectangle of attach-
ment «scar. (HATS < PATS Des 1G 124 2-1367.5mm.? 111.9mm.’
Height of smooth portion of shell
dorsad to plicate ornamentation....
IL, 50 1.5-17.4 mm. 5.9 mm.
R 36 0-36.8 mm. 24.7 mm.
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN
45
Table 2— Summary of measurements for Lopha bellaplicata bellaplicata
(Shumard)—continued
Character Valve
Number of primary plicae at first L
BONearancer te scarce cea ee R
Total number of plicae (plicate
valves only )— L
AT LObmm=sheishtssee seen cn aa R
: 1;
Pte20 mame ete ht. jesse, specie 4
R
INGESO mine heights... ces. e eee 4
At 40 mm. height............... =
At 50 mm. height............0.. fs
Total number of plicae at margin.... :
Number of plicae in 20 mm. length (L
at, 20) mim. Height... escs accesses sce [R
Percentage increase in plicae by
bifurcation? So. cnn. oe: JS ee
Width of posterior auricular sulcus,
20 min. below beak... ...0000).0.5 IL,
Width of median plica 20 mm. below
[Dyer co CRS et ee ee IL,
Inclination of beak, umbo: L
RELcent OpisthOPyre: Jac0. ceca es I
Percent, orthopyre: .!504 asad een =
IPEVCEDE PrOSOSy TEs <a crerare< ctoveiejorerens zs
Length of hinge line (LHL)........ _
Ratio WOEILA ws, Jerlavole vi ule. =
Height of denticulate portion of
lege he sa batcee Cl WD) Peery yin ere care i
Number of denticles in 5 mm. distance L
1 ria ara ates. Acct AD Poeepal Ra
along margin } R
: IL,
Reel CIC NETO) UES ee! 3 gdh eh elt ies
atio. In
Maximum diameter of muscle scar (L
TDS PARES SOR. Eke ees
(MDS) F
REND Serle vce ta ce =
No. of
specimens
50
36
78
115/173
68/112
44/173
Range
6-17
4-22
8-19
6-16
10-21
7-22
12-27
8-22
13-22
8-23
14-23
11-22
9-27
1-26
3-8.5
4-7
12-263%
0-400%
2.4-9.4 mm.
2.0-7.3 mm.
4.2-29.0 mm.
5.1-28.5 mm.
0.21 :1-0.75:1
0.16 :1-0.60:1
5.1-30.0 mm.
1.8-33.0 mm.
5-13
6-20
0.15: 1-0.69:1
0.09 : 1-0.79 :1
5.2-20.3 mm.
7.2-20.1 mm.
0.23 :1-0.42:1
0.24 :1-0.41:1
Average
10.6
13.4
46 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Rarely, dorsolateral margins moderately rounded or steeply inclined
(pl. 5, figs. 7, 10). Left valve typically moderately to highly convex,
rarely flattened (pl. 5, figs. 1, 2 typical). High point dorsocentral,
commonly on crest of median plica. Slope of anterior, ventral flanks
moderate, dorsal slope steep, posterior slope gentle, flattened on
auricle. Right valves slightly concave, flat, or gently arched, in rare
cases gently and irregularly undulating. High point of right valve on
umbone.
Auricles—Anterior auricle a flattened dorsoanterior expansion of
margin and first few plicae ; auricle small, rounded, semicircular, com-
monly absent, in most cases separated from body of shell by an
enlarged interplical sulcus, the anterior auricular sulcus (pl. 3, fig. 15).
Posterior auricle variable, normally well developed, ranging from
indistinct, small, flattened area on dorsoposterior flank (pl. 3, fig. 13)
to prominent, flattened, projecting dorsoposterior salient (pl. 4, fig. 2),
straight dorsally, narrowly rounded posteriorly, slightly curved to con-
cave ventrally, delineated by concave midposterior notch in valve
outline. All gradations noted between the two forms. Auricle sepa-
rated from body of shell by faint and shallow, to deep and prominent
auricular sulcus, an enlarged interplical sulcus (pl. 3, figs. 11, 15),
connecting umbo and midposterior notch.
Beaks, umbos.—Opisthogyre, rarely exogyroid (one volution).
Beak of left valve flat, small, bluntly pointed to moderately rounded,
commonly obscured by attachment scar. On right valve, posterior
curvature of beak, umbo, greater than on left, rarely orthogyre or
exogyroid, moderately convex, smooth or with faint growth lines
(pl. 5, fig. 7). Left and right umbones typically moderately to highly
inflated, rarely flat, right valve with greatest umbonal convexity.
Umbonal axes moderately curved, opisthocline medially, acline ven-
trally on umbo. Beaks situated anterior to midline, about one-third
the length from the anterior margin, slightly elevated above dorsal
margin but not projecting.
Attachment scar—Predominantly small, commonly minute or
apparently missing, rarely large (pl. 3, fig. 17), position middorsal
on early part of umbone; highly variable in shape, normally round to
subovate, slightly concave, steeply inclined to plane of commissure.
Attachment commonly to small, smooth oyster shells, other Lopha,
elongate objects (sticks, etc., but without clasping processes) gastro-
pods, and large pelecypods. Shell thin in area of scar, apparently
reinforced with secondary calcite layers in some specimens. Shape,
size of scar unrelated to that of adult valve, or to plication density.
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 47
Ornamentation, left valve-—Beak smooth or with fine growth lines ;
first 3-8 mm. of umbo with fine growth lines, flat microlamellae, faint
concentric undulations, rarely faint radiating undulations (pl. 3, fig.
3). Majority of shell marked with coarse radiating plicae transected
by prominent concentric lamellae (pl. 3, fig. 15). Plicae arise abruptly
on early part of umbo, extend to commissure, increasing in number
irregularly through bifurcation, especially on early plicate portion of
valve, posterior auricle, and on ventral and lateral margins of large
shells. Plicae high, rounded, steep-flanked, broader than angular
interplical sulci between them, becoming coarser but lower, more
rounded with age, faint or absent near margins of largest valves.
Secondary plicae smaller, lower, narrower than primaries but more
rapidly expanding, commonly equal to primary plicae in size at valve
margin. Posterior auricular plicae smaller, narrower, more divergent,
more extensively bifurcating, more curved than those of main body
of shell (pl. 3, fig. 11). Plicae most prominent centrally and ventrally
on valve; spinose, subnodose, fluted on rare left valves where inter-
sected by coarse, raised concentric lamellae (pl. 3, fig. 6; pl. 4,
fig. 4). Rare adult shells smooth, or with plicae faintly developed
throughout (L. blacki types), expressed mainly as marginal crenula-
tions.
Development of plicae preceded by formation of a few coarse,
crowded lamellae on umbone. Concentric sculpture on plicate portion
of valve consisting of prominent, moderately to widely spaced, con-
centric lamellae separated by numerous, very fine, crowded, irregu-
larly spaced, growth lines and microlamellae (pl. 3, fig. 15). Major
lamellae terminally in contact with succeeding ones, or raised above
valve surface, forming flutes over plicae.
Ornamentation, right valve—Right valve distinct from left in
detail of ornament. Beak smooth or with faint growth lines. Umbo
almost totally devoid of plicae; smooth stage higher than that of left
valve (pl. 5, fig. 7). Umbo smooth or with very fine, crowded, growth
lines and microlamellae; commonly with narrow zone of crowded,
coarse lamellae ventrally, near point of origin of plicae. Plicate
portion of valve marked by numerous, raised, closely spaced, major
concentric lamellae (pl. 5, fig. 8), becoming crowded near margin of
adult valves, much coarser than on left valve.
Plicae originate abruptly on ventral portion of umbo or below it;
plicae very prominent, high, steep-sided, with sharp to narrowly
rounded crests, fluted and spinose at intersection with major concentric
lamellae. Interplical sulci narrower than plicae, deep, angular at
48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
base, more prominent than those of left valve. Radial elements most
prominent at valve margin, becoming coarser with age.
Cardinal area.—Composed of central resilifer bounded laterally by
flat to slightly arched, striated, triangular lateral cardinal plates.
Resilifer of left valve shallow (most common) to moderately concave,
triangular to subtriangular with bent dorsal apex, slightly flared base ;
moderately narrow (common) to broad (rare). Lateral cardinal
plates subequal to moderately unequal (on shells with prominent
posterior auricle), posterior plate largest; each plate larger than
resilifer in most valves. Narrow marginal cardinal troughs commonly
developed between lateral cardinal plates and margin of valve, most
common on left valves. Cardinal area of right valve similar to left
except for resilifer, which is commonly shallow (concave), flat, or
rarely raised into a low midcardinal fold. Majority of right valves
with shallow resilifer bounded ventrally by a raised lip (partial mid-
cardinal fold).
Cardinal area marked with moderately strong, crowded, irregularly
spaced, horizontal striae, raised lines, and narrow ridges of various
sizes. Horizontal elements transected by faint, crowded, vertical lines.
Ornament most strongly developed in adult shells, on lateral cardinal
plates. Cardinal area color-banded on some specimens, with narrow,
dark horizontal lines on lighter background. Hinge line short to
moderately long (in presence of well-developed posterior auricle),
straight to slightly curved (common), concave toward center of valve
except below resilifer, where slightly convex (pl. 5, fig. 13).
Denticles—Present on inner dorsolateral margins of both valves;
small, simple, subround to elongate perpendicular to margin, in some
valves their trace visible on lateral margin of shell, crossing lamellae.
Interspaces equal to or slightly wider than denticles. Denticles
situated on commissure and in narrow trough just inside it, generally
restricted to dorsolateral margins, rarely extending well down margin,
generally faint on young shells, best developed on adults, becoming
indistinct on large old valves.
Commissure, interior surface——Commissure situated at margin of
left valve, just inside margin of right valve; normally undulating,
rarely zigzag or flattened (old specimens). Plicae faintly expressed on
interior of left valves near margins, more prominent on interiors of
right valve, extending to center as rounded folds, sulci. Scattered,
sinuous, pallial grooves faintly developed on a few valves.
Muscle scar—Monomyarian, insertion area of moderate size, well
defined, subcrescentic to comma-shaped if not worn (pl. 5, fig. 13),
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 49
slightly concave, bordered ventrally, posteroventrally by low raised
lip, overlapped dorsally and anteriorly by inner shell layers; position
subcentral, in posteroventral quadrant of valve on corner nearest
center. Surface of area coarsely striated with flat, crowded micro-
lamellae, scattered raised ridges, their trace conforming to the growth
lines ; rare muscle scars exhibit faint radiating lines.
Shell structure—Thickness moderately variable in single valve;
greatest in cardinal area and vicinity of beak and umbone, thinning
ventrally and laterally. Crest of left valve commonly thinner than
shell immediately around it. Shell thickness of average left valve:
cardinal area, 4.1 mm.; crest, 2.9 mm.; 10 mm. above ventral margin,
1.8 mm. Right valve: Cardinal area, 6 mm., center of valve 2.3
mm. ; 10 mm. above ventral margin, 1.4 mm. Only subnacreous layer
preserved, forming bulk of shell, consisting of subhorizontal to gently
curved and inclined plates of calcite arranged en echelon in distinct
to roughly defined layers. Inclination of plates in each layer opposed
to that in every other, or every third layer adjacent to it (pl. 8, fig. 11).
Individual calcite plates thin, moderately short, of irregular thickness,
with irregular terminations. Layered arrangement of plates, and
opposed inclination of units well defined over most of shell, less
distinct in cardinal-umbonal area, where orientation of plates more
uniform, not commonly with opposed inclination.
ONTOGENY
Numerous well-preserved specimens of Lopha bellaplicata bella-
plicata in the collections used for this study retain the morphologic
detail of the early ontogenetic stages. The small size, or apparent
absence, of the attachment scar on many left valves is of additional
help in ontogenetic study since it allows observation of even the
earliest stages of the attached valve, an opportunity not afforded by
many species of oysters. Graphs and figures depicting the ontogenetic
development of L. bellaplicata bellaplicata are presented in figures
2-4, 6b, c, 9b, 14-17. Ontogenetic changes were observed in the
following structures.
Concentric sculpture —Nepionic shell smooth or with faint growth
lines; nepionic—neanic boundary marked by a prominent growth
line. Fine growth lines characterize early neanic development ; middle
and late neanic marked with more crowded growth lines, micro-
lamellae, small folds and undulations, becoming progressively coarser.
Abrupt appearance of plicae during neanic preceded by a few, closely
spaced, moderately coarse lamellae or growth lines. Ephebic stage
50 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
characterized by scattered coarse lamellae on left valve, some raised
above shell surface, and by numerous, closely spaced, very prominent
raised lamellae on right valve. Growth lines, microlamellae crowded
between major lamellae. Neanic—ephebic boundary marked on many
LEFT VALVE
LEFT VALVE =e ainele 2
COLORADO
(VAR.A)
Vi etet®
Pf eB ZTEXAs
VALVE HEIGHT (MM)
NUMBER OF SPECIMENS
\<couoraco (S.S.)
SS
LEFT VALVE
R
ees (SS.) — . a O00 . . =
TERMINAL NUMBER OF PLICAE AT MARGIN
1500 2000 2500 3000 ~°
AREA, INSCRIBING RECTANGLE OF VALVE OUTLINE (SQ.MM)
C
Fic. 14.—Geographic variation in Lopha bellaplicata bellaplicata; comparison of
Texas and Colorado specimens of the typical form of the subspecies, and
Colorado representatives of L. bellaplicata bellaplicata variety A. A, Variation
in height to length relationship and size range. B, Variation in width of the
median plica 20 mm. below the beak. C, Variation in size range, and in number
of plicae relative to area of an inscribing rectangle of valve.
shells by first common occurrence of major lamellae. Lamellae be-
come gradually coarser, more elevated, more crowded through
ephebic development, probably recording a decrease in growth rate
and increase in the length of resting periods with increasing age.
Gerontic stage characterized by numerous, coarse, crowded lamellae
and coarse growth lines near margin of old shells.
Radiating sculpture——Neanic stage marks first abrupt appearance
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 51
of plicae, anywhere from earliest to late neanic in left valves, at or
near beginning of ephebic development in right valves. Plicae be-
come gradually coarser with age to late ephebic stage on left valves
(about 40 mm. height) ; beyond this they become fainter, broad, low
folds, many of which disappear with continued deterioration of
ornamentation during gerontic development. Plicae of right valve
become coarser with age through at least early gerontic stage. Plicae
bifurcate throughout development ; bifurcation greatest in late neanic
or early ephebic stage, again at late ephebic development, the former
possibly marking a period of accelerated growth.
A B
Fic. 15.—Ontogeny of Lopha bellaplicata bellaplicata (Shumard). Growth line
traces at approximately 2.5 mm. intervals on representative left (A) and right
(B) valves of the species. Traces show developmental history of the valve
outline and the auricles. Drawings <1. A, U.S.N.M. 132225; B, U.S.N.M.
132239,
Convexity— Outward curvature of valves (convexity) slight in
nepionic shell, on the left valve (fig. 3a) becoming moderate to great
during neanic and early ephebic development, decreasing through
late ephebic stage. Relatively abrupt flattening, flaring of flanks
characterizes gerontic development. On right valves (fig. 3b),
moderate outward curvature characterizes neanic, earliest ephebic
stages; gradual to abrupt flattening occurs during most of ephebic
stage, Upturning of valve margin and flaring are common gerontic
characters.
Valve outline and auricles—(Based on fig. 15.) Nepionic shell
subround. Neanic shell ovate, with ventral growth exceeding lateral
growth. Auricles appear as faint salients of dorsolateral margins in
AREA; INSCRIBING RECTANGLE OF
Fic. 16.—A,
cessation of
Ny
o
RIGHT VALVE
LONGEST DIAMETER OF
MUSCLE SCAR (MM.)
a
ny
o
a
3
LONGEST DIAMETER OF
MUSCLE SCAR (MM.)
35 40 45 50 55
VALVE HEIGHT (MM.)
5920) 25 s0
4500
4090
(SQ.MM.)
a
fo)
oO
oO
AREA; INSCRIBING RECTANGLE OF
VALVE OUTLINE
8 10 12 14 I6 18 20 22 24 26 28
NUMBER OF RIBS
4500
4000
= L. bellaplicata
= bellaplicata
§ 3000
LTT)
z
a
5 2000
°o
WwW
>
“Z 1000
>
34 6 8 10 12 14 16 18 20 22 24 26 28 30 32
CONVEXITY OF LEFT VALVE (MM),
Ontogeny of the muscle scar in Lopha bellaplicata bellaplicata
(Shumard), showing relationship between maximum diameter of the posterior
adductor muscle scar and the height of the valve. Note the decline and virtual
scar growth with increased size and age. Approximate boundaries
between ontogenetic stages marked by dashed lines. E = Ephebic ; T = Ephebic—
Gerontic transition; G—=Gerontic. B, Comparison of the plication density of
Lopha bellaplicata bellaplicata with that of L. blacki (White), showing total
overlap of the two forms. C, Comparison of the relative convexity of L. bella-
plicata bellaplicata and L. blacki, showing nearly total overlap between the two
52
No. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 53
late neanic or early ephebic stage, corresponding to development of
plicae. During ephebic and gerontic development ventral and pos-
terior growth exceeded that anteriorly and the auricles continued to
expand at a constant, but greater, rate than normal lateral expansion.
Curvature of growth axis (midline) —(See fig. 3c.) Axis slightly
curved in nepionic shell, more moderately curved during neanic
and early ephebic development, slightly curved, becoming nearly
straight through ephebic and gerontic stages. Inclination of neanic
shell possibly opisthocline. Ephebic, gerontic shells prosocline.
Muscle scar —Scar growth constant through neanic, ephebic stages,
at a rate less than overall growth of shell ; growth rate tapers off dur-
ing latest ephebic stage (40 to 45 mm.), corresponding to decrease in
rate of shell growth, and ceases altogether in gerontic stage (fig. 16a),
after animal reaches maximum size. Muscle scar migrates ventrally
through neanic, ephebic stages, with increase in shell size.
Cardinal area.—Elements of cardinal area distinct in early ephebic
stage, becoming thicker, broader, better defined at a diminishing rate
through life of animal. Length of hinge line gradually increasing
through middle ephebic stage at a rate slightly less than overall lateral
expansion of valve; during late ephebic and gerontic stages growth of
hinge line continues, but at a rate greater than that of lateral expan-
sion of valve (fig. 17c).
Denticles——Present in all observed stages, forming throughout life
and gradually extending farther down commissure with age. Rate of
transgression of denticles down margin (denticle height vs. valve height
at various growth stages) uniform and less than rate of ventral shell
expansion during neanic through mid-ephebic stages (20-43 mm.
height), accelerating and eventually exceeding rate of ventral shell
growth in late ephebic and gerontic stages (fig. 19b). Density of
denticles decreased at a variable rate throughout growth of shell to
gerontic stage (fig. 17a), where it remained stable.
REMARKS
Lopha bellaplicata bellaplicata is the best-known species in the
L. lugubris group. It is represented by a greater number of individuals,
from more localities, and from a broader geographic range than any
other member of the group. This is primarily due to its extensive
occurrence in the upper Eagle Ford Shale of Texas, and the numerous
collections available from that area.
L. bellaplicata bellaplicata may be distinguished from the mor-
phologically similar subspecies novamexicana by its more rounded or
54 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
= =
5 os
z z
a LEFT VALVE “20 RIGHT VALVE
g z
BIS al
:
10 mA
Bs aie
= 20 25 3 35 40 45 50 55 60 655 20 25 30 35 40 45 50
2 VALVE HEIGHT (MM) z VALVE HEIGHT (MM)
_35 3
FS LEFT VALVE RIGHT VALVE
o
HEIGHT OF DENTICULATE MARGIN
HEIGHT OF DENTICULATE MARGIN (MM)
ee ed
fe)
O30 25 30 35 40 45 50 55 60 6 20 25 30 35 40 45 50 55 60 65
VALVE HEIGHT(MM) VALVE HEIGHT(MM)
LEFT VALVE RIGHT VALVE
T
e
e
‘
= t
t 1
t 1
t e
{ '
‘ ‘
t ’
t 1
1 !
1 1
{ 1
i 1
' ’
I I
t i]
is 20 25 30 35 40 45 50 55 60 IS 20 25 30 35 40 45
VALVE. LENGTH (MM) VALVE LENGTH(MM)
Fic. 17—Ontogenetic development of Lopha bellaplicata bellaplicata (Shumard).
A, Relationship between number of denticles in 5 mm. length (measured along
margin) and valve height, showing decrease in density with age, and with
increase in size. B, Relationship between the height of the valve and the extent
of the denticulate portion of the margin, measured in terms of height, showing
increase in extent of denticles with age and size. C, Relationship between length
of hinge line and valve length, showing increase in size of hinge line relative to
lateral expansion with age and size. All lines fitted visually. Approximate
boundaries between ontogenetic stages marked by dashed lines. E = Ephebic;
T = Ephebic-Gerontic transition ; G= Gerontic.
G
55
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 55
subquadrate outline, less oblique shell, gently sloping posterodorsal
margin, more projecting dorsoanterior margin and auricle, larger and
better-defined posterior auricle, which is dorsoposterior rather than
centroposterior in position, and by its less convex left valve, especially
in the umbonal area. In the subspecies bellaplicata, the plicae
originate at a later developmental stage, especially on the right valve,
and are smaller, narrower, more numerous, more extensively bifur-
cating, and differentially developed on the auricles and main body of
the valve. The posterior auricular sulcus is narrow and composed of
a single, accentuated interplical sulcus.
The differences between L. bellaplicata bellaplicata and L. lugubris
have previously been discussed under “Remarks” for the latter species.
L. bellaplicata bellaplicata is easily distinguished from its variety A
by being broader, rounder, less erect, auriculate, and in having better
defined, much more numerous plicae.
Among foreign species of Lopha, L. bellaplicata bellaplicata is
most closely comparable to Lopha syphax (Coquand), a Lower
Cenomanian species which is larger, more coarsely and irregularly
ribbed, and has a more pronounced anterior auricle. It further
differs from the North American species in being proportionately
higher, having a larger posterior auricle, and a more twisted umbone.
This form may well be ancestral to the North American group of
L. lugubris.
White (1880, p. 293; 1883, p. 12) gave the name Ostrea
(Alectryonia) blacki (a Lopha) to a variant of L. bellaplicata bella-
plicata which he considered distinct on the basis of its greater size,
flatter valve, coarser and less numerous plicae, proportionately broader
ventral dimension of the valves, and longer, more oblique dorsal
margin. He evidently did not recognize the apparent age equivalency
of the two forms. Cragin (1893, p. 199) and later writers have
established that the two species both came from the upper Eagle Ford
Shale of Texas. The present study validates this observation.
White’s syntype lot of L. blacki consists of 26 specimens, most of
them large, displaying late ephebic or gerontic ornament, and obviously
worn. Among these latter specimens are the ones White illustrated
(1880, pl. 4, figs. 1, 2; 1883, pl. 14, figs. la, b, pl. 17, fig. 5a; 1884,
pl. 45, fig. 1, pl. 46, fig. 2). His collection also includes, however,
specimens identical to Lopha bellaplicata bellaplicata, and a complete
morphologic gradation exists between the two forms in this and other
collections from the upper Eagle Ford Shale.
Differences between the species cited by White break down under
50 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
simple biometric comparison. The syntype lot of L. blacki contains
predominantly large individuals, but all fall within the size limits of
L. bellaplicata bellaplicata populations (fig. 16b). The plicae are
not less numerous than those of L. bellaplicata bellaplicata (fig. 16c).
They appear broader owing to the great amount of wear on certain
valves. The valves are neither flatter (fig. 16b), nor broader ventrally
than typical examples of L. bellaplicata bellaplicata, and there is total
overlap in the inclination of the dorsal margin. Slight differences
existing between these forms are probably the product of environ-
mental control. Examples of L. blacki are from a relatively coarse
argillaceous sandstone, while forms typical of L. bellaplicata bella-
plicata occur in finer clastic and mud facies.
Lopha bellaplicata bellaplicata occurs in a number of different
sediments over a broad area and provides a good basis for the study
of environmental control on shell form. This opportunity is not
presented by other members of the group, which occur in more uni-
form lithologies. Large collections of L. bellaplicata bellaplicata were
obtained from buff calcarenitic chalk, gray carbonaceous and calcare-
ous shale with numerous shell fragments, shaly calcarenite, sandy
shale, and in argillaceous to calcareous quartz sandstone (Colorado).
A single specimen from New Mexico was found in dark clay shale.
In collections from Texas, oysters from the calcarenitic marl units
are thinner shelled, less convex, less inclined, and have less prominent
posterior auricles than those from calcarenitic, sandy, or clay shale,
and from thin calcarenites. Specimens from the latter lithology have
the largest, thickest shells. These differences are probably related to
differences in the energy conditions of the environment. Current and
wave action was probably much stronger in the shallow-water environ-
ment where the calcarenites were formed than it was in the quieter,
presumably deeper marl-forming areas. Thickening of the shell
appears to be an adaption to this more active environment, its chief
function being to strengthen the valves.
Specimens from New Mexico, found as gypsum replacements in
dark clay shale, are typical of the species. The Colorado sample,
however, shows significant environmental, and possibly geographic
variation. Specimens from the Codell Sandstone Member (“Pugnellus
Sandstone’’) of south-central Colorado attain a much smaller size than
those from Texas and show a somewhat greater variation in marginal
outline. The majority of specimens from Colorado, though smaller,
are typical of the species and closely comparable morphologically to
the Texas forms (compare pl. 3, figs. 1-15, with pl. 6, figs. 7-15).
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 57
Marginal variants of the Colorado sample, however, show structural
features that are not within the range of variation observed for the
Texas specimens. The most notable variant, here termed variety A,
is a narrow, high form with relatively few plicae and no auricles
(pl. 6, figs. 1-6, 19), possibly but not definitely a product of crowded
growth conditions. This form is treated separately on subsequent
pages.
A second unusual variant of Colorado L. bellaplicata bellaplicata
assemblages is exceptionally long, with abnormally produced anterior
and posterior auricles and, in some cases, very broad, rounded, plicae
(pl. 6, figs. 11, 15). This form is also represented by a single
specimen in the upper Blue Hill Shale, where it is probably a marginal
variant of L. bellaplicata novame.xicana, gradational into the younger
L. bellaplicata bellaplicata.
Finally, rare specimens of L. bellaplicata bellaplicata from Colorado
are nearly smooth, and lack well-developed plicae (pl. 6, figs. 17, 18,
21, 24), a condition not attained by Texas representatives of the
species. This is most commonly expressed on right valves.
Analysis of these differences between Texas and Colorado repre-
sentatives of L. bellaplicata bellaplicata is difficult, since it is not
possible here to separate geographic variance from environmental
variance. The shallow-water, high-energy environment indicated by
the Codell Sandstone lithology and sedimentary structures is not
duplicated in Texas, so there is no basis for comparison of environ-
mental influences. I would not consider any of the unique variation
in morphology shown by the Colorado sample as being particularly
adaptive to the shallower, more turbid, active Codell environment.
Modern oysters do not show such structural adaptations in similar
niches. This is the only argument that can be presented in favor of the
differences being geographic, and thus genetically controlled. Even if
this were the case, I would not consider the differences between the
Texas and Colorado samples to be of subspecific magnitude, especially
since they are shown by a very small percentage of the specimens
examined.
Stratigraphic and geographic occurrence.—In Texas, L. bellaplicata
bellaplicata occurs in the upper 50 to 70 feet of the Eagle Ford Shale,
being most common in the upper 15 to 25 feet, and forming prominent
beds in the upper 2 to 5 feet at various localities. The species has
been found in New Mexico at only one locality, in the dark shale of
the Benton Subgroup (Mancos), on the Zuni Indian Reservation.
In Colorado, the species is restricted to the “Pugnellus Sandstone’’
58 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
(Codell Sandstone Member) of the Carlile Shale, where it is found in
limestone and calcareous sandstone lenses throughout the unit.
In Colorado, the species has been found at localities 40-43, 55, and
58-61; in New Mexico, at locality 45; in Texas, at localities 15, 44,
46-54, 56, and 57, described in detail at the end of this report.
Illustrated and measured specimens.—The holotype is presumed to
have been lost in the fire at the St. Louis Academy of Science. Neo-
type, here selected, a mature left valve (pl. 3, fig. 11), U.S.N.M.
132222. White’s hypotypes, paired valves (1879; 1884), illustrated
on plate 3, figure 13, U.S.N.M. 12383; White’s “paratype” of O.
(A.) blacki (1884, pl. 46, fig. 2), U.S.N.M. 8024b. Stanton’s
hypotypes (1893 [1894], pl. 4), U.S.N.M. 11822a (Stanton’s fig. 8),
U.S.N.M. 22860b, c, d (Stanton’s figs. 9, 6, 4, respectively), 22861
(Stanton’s fig. 7). New hypotypes, U.S.N.M. 8024a, c. d;
U.S.N.M. 11882b;U.S.N.M. 22009a, b;U.S.N.M. 22011b;U.S.N.M.
132213-132221, inclusive, U.S.N.M. 132223-132244, inclusive;
U.S.N.M., 1132250; 0132251) 132283, 132284,~ 432305-132508),
U.M.M.P. (University of Michigan Museum of Paleontology) 38038,
38039, 38041, 43466, 43478, 43482, 43483. Measured specimens,
unfigured: U.S.N.M. 8024e, U.S.N.M. 11882c, U.S.N.M. 22009;
U.S.N.M 22011lc; U.S.N.M. 22860e, U.S.N.M. 132245-132249,
inclusive; U.S.N.M. 132291-132300, inclusive, 132304.
LOPHA BELLAPLICATA BELLAPLICATA var. A
Plate 6, figures 1-6, 19
DESCRIPTION
Material—36 left and right valves, moderately well preserved,
from the Codell Sandstone Member. (“Pugnellus Sandstone’’), Car-
lile Shale, at a number of localities in Huerfano Park, Colorado. The
collection includes mostly small individuals, forming a partial growth
series.
General form.—Summary of measurements presented in tables
3, 4. Shell small, inequivalve, left (lower, attached) valve much
more convex, slightly larger, less curved dorsally than right; most
valves slightly inequilateral, prosocline to erect. Highly variable in
outline: typically elongate-ovate along midline axis (pl. 6, figs. 1,
2, 5) less commonly broadly subovate due to lateral flaring of pos-
terior or posteroventral margins (pl. 6, figs. 6, 19), or irregularly
elongate due to crowded growing conditions. Height greater than
length. Anterior margin steeply inclined, straight to slightly and
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 59
irregularly curved, without anterior auricle. Ventral margin moder-
ately to narrowly rounded, regular to irregular. Posterior margin with
irregular outline, slightly concave (outward) dorsally, moderately to
TABLE 3.— Summary of measurements on left valves of Lopha bellaplicata
bellaplicata var. A
Character ee Range Average
iEfete ite GE) as aecceetac ister tor ieteretec 21 15.4-38.4 mm. 23.4 mm.
WWeriatir oy? eccentrics eres 22 10.1-29 mm. 17.0 mm.
Rattorlerpede Pst ee ata s Sears wale ce oe 17 0.56 :1-1.20:1 0.73 :1
Winidthw@Wh) tease tos arbi acct 43 23 3.0-12.9 mm. 7.7 mm.
Area, inscribing rectangle of valve
NY NRO ag Ue ee ne 20 179.6-1128.1mm.? 432.9 mm.?
Length; beak to posterior margin
CIO BOE etedin's setets Nas tdniste Sa aes was 22 3.9-14.4 mm. 9.4 mm.
IRation@ic Bil stiameeries cyto eoticleror nic 21 0.39 :1-0.71:1 0.53 :1
Angle of inclination (i)............ 20 67-101° 82.3°
Height of attachment scar (HATS):
Maximum vertical diameter...... 20 2.6-21.9 mm. 9.8 mm.
In plane of commissure........... 20 1.4-21.9 mm. 8.4 mm.
Length of attachment scar (LATS). 20 2.3-17.2 mm. 9.5 mm.
Area, inscribing rectangle of attach-
qent,.scar (HATS < LATS) ...... 20 6-354.8 mm.* 110.6 mm?
Height, smooth young stage (HSS),
dorsalipartior walvesee nese es eo 22 2.3-23.4 mm. 9.98 mm.
Height, plicate portion of valve..... 20 4.9-26.5 mm. 13.6 mm.
Ratio VHISS) dec sccaelt aadmocaes 20 0.108 :1-0.777 :1 0.432 :1
Number of plicae at first appearance. 22 4-12 8
Number of plicae at 10 mm. height.. 14 4-12 8.5
Number of plicae at 20 mm. height... 16 5-12 9.6
Total number of plicaest 2s 2.25.66.: 22 4-14 9.3
Number of plicae in 10 mm. distance
(length) 10 mm. below beak...... 13 3-6.75 48
Width of median plica at 10 mm.
Reighba res eee Sete g ees 21 0.8-2.6 mm. 1.7 mm.
Percentage of plicate valves with
bihurcating, plicde iy. -/-1..asicrersciacteoes 23 78.3%
Percentage increase in number of
plicae ‘by bifurcation............. 18 9.1-41.7% 17.9%
Curvature of beaks and umbones:... 21
Opisthosyre) 2Secceder LI. nkoeo: 81%
(ONG hstven eee hy oe oe a 9.5%
EALOSOSYEG Naan eV ego, ae ae 3/ 2c 9.5%
slightly convex ventrally (pl. 6, figs. 2, 6, 19). Dorsal margin short,
straight to moderately curved, generally equal to width of attachment
scar. On rare specimens, ventroposterior margin flared outward,
considerably flattened, forming small, rounded, semicircular, pos-
60 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
terior auricle separated from main body of shell by a broad, shallow,
indistinct auricular sulcus, generally a broadened interplical sulcus or
2 sulci with the intermediate plication greatly reduced.
Right valve flat to slightly arched; convexity greatest in umbonal
region; flanks flat, rarely concave near margin when ventral edge
upturned. Left valve moderately to highly convex, convexity greatest
at upper edge of attachment scar where prominent; otherwise crest
and high point situated medially on lower third of valves. Anterior
slope typically steep, ventral slope shallow, posterior slope steep
dorsally, moderate to gentle or irregular ventrally, depending on devel-
opment of posterior auricle.
TABLE 4.—Representative measurements of right valves associated with Lopha
bellaplicata bellaplicata var. A and possibly belonging to this form.
U.M.M.P. U.M.M.P.
Character 43406 43413
Fleets (GED) 0 she coset ree aerate eine 19.1 mm. 16.7 mm.
Meno thi aCe yy ake s revere verarete ve tekarvereus eichertions Setees 9.6 mm. 15.8 mm.
Wadi” CW") cea ce create nee ccm aaeistere’s 3.5 mm. 4.8 mm.
Feightcardinal areata: ir cscenccceeces eos 2.2 mm.
Wengthninge oine, \ te cet cise eice outers « 3.9 mm.
Width, «midceardinall) told’. .eha0.0na cha ceee es 1.9 mm.
Hetehet, denticulate mato... «ss carci ete 7.1 mm.
Number of denticles in 5 mm. distance........ 11
Maximum diameter of muscle scar........... 6.9 mm.
Minimum diameter of muscle scar............ 3.6 mm.
Distance (height), dorsal edge of muscle scar
LO DEAL ha. as chee Hee eke nee ee 8.1 mm.
Anple-of anclination (i) ...6-neencrasee eee 82° 61°
Number of major lamellae in 5 mm. height
(snidvalive)y ie eee ee oe ae 3
Beaks and wmbos.—Beak, umbo unknown on left valve, obscured
by attachment scar, apparently slightly recurved, orthogyre to slightly
opisthogyre. Beak of right valve known from numerous, nearly smooth,
associated upper valves; pointed to narrowly rounded, smooth, nor-
mally opisthogyre, moderately recurved. Umbone gently arched, in
some valves separated from main body of shell by a constriction or
large lamella.
Attachment scar.—Area of attachment terminal, small to medium
size, round to subovate, flat to slightly concave, steeply inclined or
vertical relative to plane of commissure, rarely moderately inclined.
Sear surface smooth or with faint concentric markings of shell to
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 61
which oyster attached; attachment to other Ostrea and Inoceramus
shells. In some specimens scar area appears secondarily thickened
by additional layers of lamellar calcite.
Ornamentation, left valve—vVariable: Beak and early umbo
smooth, or with fine concentric ornamentation. Lower umbo and
portion of valve between attachment scar and plicate flanks marked
by numerous fine, crowded, overlapping lamellae, fine growth lines,
and scattered concentric undulations or moderate size lamellae. All
lamellae terminally in contact with succeeding ones.
Plicae commonly arise abruptly at or slightly below ventral edge of
attachment scar (pl. 6, fig. 2). Plicae large, coarse, rounded, broader
than interspaces between them, their width greater than their height,
subequally developed to irregular (compare pl. 6, fig. 1, with fig. 2),
bifurcating irregularly over entire valve; rate of bifurcation greatest
dorsally. Secondary plicae rapidly expanding, rarely attaining size
of primaries near commissure. Plicae become broader, lower, more
rounded, indistinct near ventral and ventrolateral margins of a few
valves, rarely disappearing altogether (pl. 6, figs. 2, 4). Interplical
sulci narrow, sharp to narrowly rounded at base.
Concentric ornamentation on plicate portion of valve consisting of
numerous crowded, subequally to irregularly spaced, fine to medium
size, overlapping lamellae, most terminally in contact with succeeding
lamellae, and scattered coarse, raised lamellae; latter particularly
common near margin. Plicae finely fluted at intersection with major
lamellae. Radial and concentric ornamentation of posterior auricle,
where developed, more irregular than that of main body of shell;
plicae smaller, more curved and sinuous, more extensively bifur-
cating. Concentric elements coarser on auricle.
Ornamentation, right valve-—Beak smooth; umbone with scattered
fine growth lines and faint concentric undulations. Remainder of
valve covered with numerous fine growth lines, scattered flat lamellae
of several sizes, and low concentric undulations, irregularly spaced
and unequally developed, becoming coarser toward valve margins.
Some valves with several coarse lamellae crowded near margins.
Majority of specimens lack radiating ornamentation. A few right
valves have traces of plicae near and on margins. Rare valves
exhibit well-developed plicae similar to those of left valve; plicae
arise abruptly near ventral and ventrolateral margins and extend to
the edge. Variants of these associated right valves illustrated on
plate 6, figures 3, 4.
62 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
REMARKS
The collections contain no valves with the interior preserved, and
the thin, fragile nature of the shell makes it difficult to excavate one
successfully. Presumably, the internal structures are the same as
those on L. bellaplicata bellaplicata forma typica. Right valves
were not found coattached with left valves. Their description is based
on numerous smooth valves occurring in the same sediment and con-
forming in shape and size to typical left valves.
It seems advisable to describe separately this marginal variant of
L. bellaplicata bellaplicata for two reasons. First, a continuous mor-
phologic series cannot be established between the typical form of the
species and variety A. The specimens illustrated on plate 6, figures 6
and 19, are the only ones that approach the typical form, and these
show significant differences. Graphs and charts comparing structures
of the two forms invariably show a bimodal distribution with little
overlap (figs. 14a-c). There is a possibility, therefore, that the
differences between the two forms are not totally environmental, but
genetic, and that they were related and coexisting subspecies or
species.
This possibility is further evident considering the apparent environ-
ment of deposition of the Codell Sandstone Member. The Codell
contains a diverse normal marine, shallow-water invertebrate
fauna. The deposit has all the characteristics of a shallow-water,
inner sublittoral sand sheet formed under moderate- to high-energy
conditions of current and wave action. Variety A and the typical
form of the species occur together, represented by numerous well-
preserved shells, in the same lenses of fossils. They appear to have
lived together and were probably subject to the same environmental
influences. L. bellaplicata bellaplicata var. A occurs characteristically
in clusters, where the elongate form of the shell appears to be, in part,
a product of crowding. But free-growing examples are also known,
and these are equally elongate. The form, convexity, and ornamenta-
tion are more regular on the free-growing specimens. The differ-
ences between the two forms therefore do not appear to be ecologic,
or wholly a product of growth habit, indicating that L. bellaplicata
bellaplicata var. A may be genetically distinct from the typical form
of the species. The small number of specimens available for study,
their limited size range, and lack of knowledge concerning the shell
interior do not permit verification of these differences, or formal
description of a new species or subspecies. Based on modern obser-
vations, it seems more likely that a single variable ostreid species
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 63
would occupy such a well-defined ecologic niche than that two closely
related species or subspecies would be living together and competing
for the same niche.
Recognition of the variety is of additional importance since it may
be the source from which contemporary and younger species of
Lopha, having generally similar features, originated. Such ostreids,
mostly undescribed, occur at various localities and stratigraphic
levels in the Western Interior and will be the object of future study.
They are not found in older sediments.
The morphologic distinctions between L. bellaplicata bellaplicata
and variety A have been previously discussed under “Remarks” for
the former subspecies.
Stratigraphic and geographic occurrence-——The variety occurs
throughout the Middle Turonian “Pugnellus Sandstone” (Codell
Sandstone member) of the Carlile Shale at localities 41, 58, 59, 60, and
61 in Huerfano Park, Colo. Rare marginal variants of the Texas and
Colorado collections of L. bellaplicata bellaplicata approach this
form, but none attain it.
Illustrated specimens.—Left valves: U.S.N.M. 22011a, d; 132249;
U.M.M.P. 38051, 38052; associated right valves, illustrated;
U.S.N.M. 132259, U.M.M.P. 43413; hypotypes. Measured speci-
mens, not illustrated: U.S.N.M. 132301-132303 ; U.M.M.P. 43406.
LOPHA BELLAPLICATA NOVAMEXICANA new subspecies
Plate 7, figures 1-19; plate 8, figures 1-9
DESCRIPTION
Material—About 100 well-preserved specimens (measured), pre-
dominantly left valves, from 4 localities in New Mexico and 8 localities
in Colorado, including ontogenetic series and 2 large suites of speci-
mens from single localities.
General form.—Summary of measurements presented in table 5.
Shell attaining moderate size ; inequivalve, left (lower, attached) valve
slightly larger, much more convex than right valve ; slightly to moder-
ately inequilateral, prosocline. Valves close-fitting, outline moder-
ately variable ; typically subovate, commonly subquadrate or elongate-
ovate parallel to axis of inclination, rarely rounded (pl. 7, figs. 1-5,
10-12, 14-19; pl. 8, figs. 7-9 typical of subspecies). Height greater
than length in most specimens. Anterior margin slightly curved dor-
sally and ventrally, moderately rounded medially. Ventral margin
moderately and evenly rounded ; ventroposterior corner more narrowly
64 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
TABLE 5.—Summary of measurements for Lopha bellaplicata novamexicana
No. of
Character Valve specimens Range Average
; IL 67 14.2-90 mm. 39.5 mm.
la lstgayer (CS Boyden soins SAS aoa cana dee R 3 18.3-53.6 mm. pS aay
Ib, 67 13.4-61 mm. 35.9 mm.
Lengths (12) 2. .s.c5'2 so gslaeees cheterorincs R 3 20.7-51.5 mm. eee.
‘ 1, 67 5.0-28.9 mm. 15.7 mm.
Width GW) UA. CRE. R 6 Sef A phate Sree
Percent valves with H>L.......... TER 959/75 78.6%
Percent valves with H<L.......... LER 16/75 21.4%
Percent valves with H=L.......... LR 0 0
Area, i ibi tang! i
A ee L) Re ee Ce ern Gs 201-4050.4 mm2 1550 mm.2
Sp akebiil Cal A R 8 379-2760 mm? 1125 mm.2
Length, k i i
ED SATIS acrearaeeas © asco? 54°41 Ovsam.1) Wl 22 Sean:
CM soc Ae eA REDE, MEERA. P R 8 eT ns oat,
; ; E 50 0.40 :1-0.83 :1 0.63 :1
Ratio MBER Loh. Metal ase: <d Ir Re aoe Ker
Anele otinclination(1) le seeceseciee ce LR 64 59°-89° 76.5°
Percent of specimens with observa-
blejattachnient seaf..g.j60 cecdectae ss IE 84 20.2%
Height of attachment scar (HATS). L 13 1.0-12.1 mm. 4.7 mm.
Length of attachment scar (LATS).. L 17 2.1-22.3 mm. 7.3 mm.
Area, inscribing rectangle of attach-
ment scar (HATS X LATS)..... Ib 24 2.1-265.0 mm2 39.3 mm?
Ratio, area, inscribing rectangle of
scar : area, inscribing rectangle of
ValVercte taeda pees lone ae 1 24 0.002: 1-0.24:1 0.04:1
Height of smooth portion of valves
: 1U, 26 1.0-7.3 mm. 2.7 mm.
dorsad to pl HSS) tea ciaecee.
One LOE ieae. CEES) a 11 4.0-11.1 mm. 6.3 mm.
F is 26 0.03 : 1-0.18:1 0.08 :1
RATION CEES Sete rwes ec tine dniasieene mere q
ae 5 110.15 :1-0.35:1 0.25 :1
Number of plicae (total) :
Primary plicae at first appearance.. 2 if ae He
: ; ie 50 7-19 11.5
; ft.
Number of plicae at 10 mm. height R rf 8-15 120
Number of plicae at 20 mm. height. . z ie aus ne
Number of plicae at 30 mm. height. . = e aa a
Number of plicae at 40 mm. height. . i 4 = oo
Number of plicae at 50 mm. height. . z ae sir
Total number of plicae at margin.... L 52 9-21 14.4
R 11 10-17 13.9
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 65
Table 5—Summary of measurements for Lopha bellaplicata
novamexicana—continued
No. of
Character Valve apecumens Range Average
Number of plicae in 20 mm. length
Mt s20 nin” heieht ..56 oss ee os e's L 64 3-8 4.75
(R 15 4-6 4.43
Width of median plica 20 mm. below
Dea artery ectsctec nero crates cere oe IU: 63 2.2-8.3 mm. 49 mm.
Percent increase in plicae by bifurca- ce 44 7-200% 849%
e = oO (4)
PLOW gor ieveeraiere anaveiaie ease ie etasaareus areca leis eke )R 11 6-77% 37%
Width of posterior auricular sulcus
20 tam. below, Dealke..2.< /e.05 4 <.c:0a'0,0.6 Iv 43 3.9-12.4 mm. 6.6 mm.
Inclination of beak, umbo (67 left
valves, 8 right valves) :
Percent opisthogyre .) 2. ...5.25... : a wee
J/0
IE 14 20.9%
Percent Ofhogyre sc << oo sineas sc oe R 5 62.5%
Percent’ prosOgyre i402: 23.0. 8..2: 3 a rs
Length of hinge line (LHL)........ A : ie a
7 ae ies
N ” : iF 1 8
umber of denticles in 5 mm. length. R 1 9
Maxi diameter of 1
AS ae = i muscle scar L i 1d0h aes:
es OR So MN ME Saige R 1 ise
J ECE DISSES (et ee era L 1 0.37 :1
Ratio, area of scar : area of valve... L 1 0.08 : 1
rounded. Posterior margin straight to gently curved except in valves
with prominent posterior auricle, where concave notch developed in
outline at intersection with posterior auricular sulcus. Dorsolateral
margins straight to slightly curved; dorsolateral corners narrowly
rounded over auricles. Anterodorsal margin steeply to moderately
inclined ; inclination least in presence of auricle. Posterodorsal mar-
gin longest, moderately inclined with or without auricle.
Left valve moderately to highly convex (pl. 8, figs. 1-3) ; high point
dorsocentral, just anterior to midline, on median plica. Anterior and
dorsal flanks steeply sloping; ventral, posteroventral, posterodorsal
flanks moderately sloping ; posterior flank slopes steeply into auricular
sulcus, becomes flat beyond this. Right valve flat to slightly concave
dorsally and centrally, slightly convex ventrally, ventrolaterally, rarely
66 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
with margins upturned, forming shallow submarginal trough. High
point central to posterocentral.
Auricles.—Anterior auricle not commonly developed (20 percent
of left valves, 5 percent of right valves), dorsoanterior in position,
small, flat, subtriangular, terminally rounded, bearing 1 or 2 flattened
primary plicae. Anterior auricular sulcus prominent, deeper, broader
than adjacent interplical sulci (pl. 7, figs. 10, 11). Posterior auricle
small to large, typically of moderate size, flat to slightly convex ; out-
line subtriangular, with posterior apex situated centrally on posterior
margin (pl. 7, figs. 3, 4, 10, 11). Auricular sulcus very prominent,
composed of single broad interplical sulcus, or 2 adjacent interplical
sulci with intermediate plica greatly reduced or absent (pl. 7, figs. 10,
11). Auricle smaller, less distinct on right valves than on left valves ;
rarely absent.
Beaks and umbos.—Normally slightly opisthogyre, rarely prosogyre,
orthogyre, or with strong posterior curvature; slightly projecting,
incurved, commonly extending inward beyond plane of commissure
on left valve. Beaks small, narrowly to broadly rounded, flat to
slightly convex, smooth, situated one-third to slightly less than one-
half the length from the anterior margin, commonly obscured on
attachment scar. Umbo of left valve highly arched, prominent,
plicate. Umbone of right valve flat, smooth to partially plicate.
Curvature of umbonal axis gentle, dorsally orthocline to slightly
opisthocline, ventrally prosocline.
Attachment scar.—Small, indistinct, commonly not visible or absent ;
round to subovate, flat to slightly concave, steeply inclined to plane of
commissure ; terminal and central in position, or on posterior slope
of early umbo. Attachment to smooth, slightly convex surfaces, pre-
dominantly other oysters, smooth clams. Shell moderately thick over
attachment area.
Ornamentation, left valve-—Beak smooth, earliest umbo bearing
growth lines, fine concentric lamellae. Plicae originate abruptly on
early umbo, at edge of attachment scar (where present), or rarely
on middle umbo. Primary plicae typically large, narrow in early
stages, broader than high on adult part of shell, becoming broader,
more rounded, lower with age, extending to margin on largest valves.
Crests of plicae moderately to narrowly rounded, flanks moderately
inclined. Plicae bifurcate over entire valve; bifurcation rate high on
umbonal and subumbonal areas, low and irregular over rest of valve.
Secondary plicae smaller, narrower, more rapidly expanding than
primaries, some attaining size equal to primaries near margin. Rare
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 67
valves with sharp, narrow plicae over entire valve (pl. 7, fig. 11).
Plicae of posterior auricle smaller, more curved, more irregular, and
more extensively bifurcating than those of main body of shell.
Concentric sculpture over plicate portion of valve consisting of
fine, crowded, irregularly spaced growth lines and flat microlamellae
dorsally, becoming gradually coarser ventrally. Coarse, raised, major
lamellae appear at midvalve (pl. 7, figs. 10, 18), and are scattered
singly, or in groups of 2 or 3, over ventral half of valve, intercalated
with growth lines and microlamellae. Major lamellae coarsest, most
crowded near commissure. Plicae fluted at intersections with major
raised lamellae.
Ornamentation, right valve.—Right valve distinct from left in detail
of ornamentation. Beak smooth; umbo with fine growth lines, micro-
lamellae, faint undulations, becoming coarser ventrally. Plicae arise
abruptly at edge of umbo, preceded by a few coarse, crowded major
lamellae and/or concentric ridges. 75 to 80 percent of valve pli-
cate. Plicae coarse, higher than wide initially, becoming broader with
age but remaining prominent; crests narrowly rounded to angular,
flanks steep; plicae sparsely bifurcating throughout, generally near
margins, much less than on left valve. Interplical sulci narrow, with
angular to narrowly rounded bases. Concentric ornament of plicate
flanks consisting of numerous, prominent, raised lamellae, moderately
and unevenly spaced centrally, crowded ventrally, commonly marking
major constrictions or change in slope of shell surface, more promi-
nent on right than on left valve. Major lamellae intercalated with nu-
merous crowded, growth lines and microlamellae. Plicae spinose, fluted
at intersection with major lamellae. Typical right valves illustrated on
plate 7, figures 8, 9.
Cardinal area.—Known from single right and single left valves; on
left valve consisting of subcentral, broad, shallow, triangular resilifer,
and equally large, flat, subequal (posterior largest), subtriangular,
lateral cardinal plates. Surface of cardinal area marked with closely
spaced, moderately strong horizontal lines of various sizes and by
fine, crowded, subequally spaced, raised vertical lines. Cardinal area
of right valve similar, but with ventral half of resilifer convexly
folded, forming a low lip.
Denticles—Denticles present on inner dorsolateral margins of
both valves; small, simple, rounded to ovate, crowded, moderately
convex, situated on commissure, rarely reflected on thick lateral edges
of auricles.
Commissure.—Commissure at edge of right valve, just within edge
68 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
of left valve; flat dorsolaterally, undulating at intersection with major
plicae elsewhere. Internal expression of plicae variable, typically
developed as low, rounded folds and sulci confined to valve margins,
less commonly extending to center of shell, becoming more subtle
inward. Thick-shelled specimens commonly with lamellate lateral
edges of shell flattened in plane of commissure (pl. 7, fig. 5).
Muscle scar —Monomyarian ; posterior adductor scar large, situated
centroposteriorly, or in upper part of posteroventral quadrant of valve
(pl. 7, fig. 5) ; comma-shaped, arcuate, slightly concave, well defined,
overlapped dorsally, anteriorly by inner shell layers, bordered ventrally
by a low, raised lip. Surface striated, covered with fine, crowded,
microlamellae and raised lines, irregularly spaced, conforming to
trace of growth lines.
Shell structure—Periostracum, prismatic layer, and hypostracum
not observed. Subnacreous layer forms bulk of shell, consisting of
several layers of slightly curved, inclined calcite plates arranged en
echelon within each layer. Inclination of plates in each layer may be
opposed to that of adjacent layers. Individual plates and layers
flatter, more conformable around cardinal area and at ventral edge.
Nacreous layer thin, composed of flat calcite lamellae. Shell thick;
thickness of a typical left valve (height 38 mm., length 34 mm.)
through the hinge area, 4.5 mm. ; thickness at crest, 3.4 mm. ; thickness
5 mm. above ventral margin, 2.3 mm.
ONTOGENY
A few significant ontogenetic trends regarding the external features
of the shell are worthy of note. Internal structures of the valves are
virtually unknown in this respect.
Concentric sculpture——Nepionic stage smooth. Neanic stage with
fine growth lines, microlamellae initially, becoming coarser toward
late neanic. Early to middle neanic in left valve marked by a few,
coarse, crowded growth lines, lamellae, and ridges just before abrupt
development of plicae. Ephebic stage marked by development of
scattered (left valve) to moderately spaced (right valve) major con-
centric lamellae in addition to fine ornament, possibly marking growth
rests, and becoming somewhat more crowded in late ephebic as
growth slowed. Gerontic stage marked by crowded, coarse lamellae
and growth lines near margin.
Radiating sculpture.—Plicae abruptly appear in early, rarely middle
neanic stage on left valves, at the beginning of ephebic development
on right valves, becoming coarser, more prominent, broader, more
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 69
rounded with age through the middle ephebic stage ; becoming lower,
more subtle during late ephebic and gerontic stages, especially on
left valves. Bifurcation rate highest during neanic, low and irregular
at later stages.
Convexity— Outward curvature of shell growth moderate to great
through neanic and early ephebic development, gradually decreasing
in later growth (fig. 3a), becoming moderate to slight. No flattening
and flaring noted in late growth stages.
Marginal outline ; auricles—( Based on fig. 18.) Nepionic shell sub-
round, Neanic shell ovate, longer than high; lateral growth exceeded
B
A
Fic. 18.—Ontogeny of Lopha bellaplicata novamexicana new subspecies. Growth
line traces at approximately 2.5 mm. intervals on representative left (A) and
right (B) valves of the subspecies, showing developmental history of the
marginal outline and the auricles. Drawings X1. A, U.S.N.M. 132267,
B, U.S.N.M. 132265.
ventral growth during neanic and early ephebic stages. Ephebic stage
marked by ventral growth exceeding lateral expansion and the latter
becoming irregular. Auricles appear in early ephebic as more rapidly
expanding salients of lateral margins, continue to grow at a more
accelerated rate throughout life. Gerontic growth similar to that of
ephebic stage.
Curvature of growth axis (midline)—Curvature slight during
nepionic, neanic, early ephebic stages, decreasing uniformly through
ephebic and gerontic stages, becoming nearly straight (fig. 3c).
REMARKS
The distinction between L. bellapliata novamexicana and its most
closely comparable relative, L. bellaplicata bellaplicata has been
discussed in detail under the “Remarks” section of the latter sub-
7O SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
species. Basically, L. bellaplicata novamesxicana is distinguished by
its more oblique marginal outline, greater convexity of the umbonal
region, larger, broader, less numerous plicae, reduced and more
centrally situated auricles, much larger posterior auricular sulcus, and
more inclined posterodorsal margin. The plicae arise at an earlier
developmental stage than in L. bellaplicata bellaplicata. No other
Cretaceous species of Lopha are closely comparable. Young shells of
these two subspecies are nearly identical (compare pl. 3, figs. 1-9,
with pl. 7, figs. 1-3), but average adult shells are readily distinguished.
Marginal variants of the subspecies show overlap of many structures.
Shells of this subspecies are typically found complete, with both
valves intact and well preserved. Although they are common at
some localities, they have not been observed living gregariously in
beds or “oyster reefs,’ and show no evidence of crowding. The
small size of the attachment scar (in some cases too small to be
observed, or preserved, on the beak) possibly indicates early detach-
ment from the substrate and predominantly a free life.
Lopha bellaplicata novamexicana is known from three lithofacies:
Fine- to medium-grained, well-sorted, cross-bedded marly sandstone ;
similar sandstone with an argillaceous cement and abundant carbo-
naceous debris; and sandy, argillaceous, limestone concretions or
lenses (septarian) in a sandy shale matrix. The first two types are
from New Mexico, and the concretions mark its occurrence in
Colorado. The only observable morphologic differences between
forms from the two States which may be environmentally controlled
are (1) the sharper plicae on many Colorado examples (pl. 7, fig. 11),
and (2) the tendency for some Colorado specimens to have a ventral
“hump,” or sharp break in slope about one-third the height from the
ventral margin. On the steep slope below this break, the plicae on
certain specimens show greater bifurcation than is normal for the sub-
species. No such structure was noted on New Mexico specimens.
These differences are difficult to evaluate in light of the sparse knowl-
edge concerning the paleoenvironment to which this form was sub-
jected. Similar irregularities in growth form are produced in some
oysters exposed to abrupt changes in rate of sedimentation, in others
periodically exposed in intertidal zones. This structure is genetically
produced in certain species of Inoceramus, irrespective of environ-
ment. It isa gerontic feature of other pelecypods.
Stratigraphic and geographic distribution—Lopha bellaplicata nova-
mexicana is the oldest known member of the L. lugubris group. It
is commonly found in the middle Mancos Shale of New Mexico, in the
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN Fis
zone of Collignoniceras hyatti (Stanton) (late Middle Turonian),
well below the occurrence of L. lugubris. Its position relative to
L. bellaplicata bellaplicata in New Mexico is uncertain, however, since
the latter is rare in this area, and the two have not yet been found
associated.
The stratigraphic relationship between L. bellaplicata bellaplicata
and the subspecies novamexicana can be established in Huerfano
Park, Colo. Here, typical examples of L. bellaplicata bellaplicata
are found throughout the Codell Sandstone Member (‘‘Pugnellus
Sandstone”) (pl. 6, figs. 7-9, 12). Below this unit, in the upper part
of the Blue Hill Shale Member, septarian limestone concretions con-
tain scattered but characteristic examples of the subspecies nova-
mexicana (pl. 7, fig. 11). The two forms do not have overlapping
ranges in this area, although rare individuals transitional between
them occur as marginal variants of each form. This occurrence sug-
gests, therefore, that L. bellaplicata novame-xicana is characteristic of
the lower part of the Collignoniceras hyatti zone (Blue Hill Shale
Member equivalents) and L. bellaplicata bellaplicata marks the upper
part of the C. hyatti zone (Codell Sandstone Member: “Pugnellus
Sandstone” of older authors). If future collections prove this to be
true over a broad area in the Western Interior, these ostreids will have
particular importance as stratigraphic markers, since the faunas of
these two units overlap in almost every other respect. The subspecies
novame.xicana occurs at localities 62 through 73, described in detail at
the end of this report.
Illustrated and measured specimens.—Holotype, a typical left valve
with the interior excavated, U.S.N.M. 132267 (pl. 7, fig. 10).
Figured paratypes, left and right valves, U.S.N.M. 22012; U.S.N.M.
132260-132266 inclusive; U.S.N.M. 132268-132282 inclusive;
U.S.N.M. 132286-132288 inclusive. Measured, unfigured paratypes,
U.S.N.M. 132252-132257 inclusive, 132290. University of Michigan
Museum of Paleontology (U.M.M.P.) 43480, 43481. Sectioned
specimen, discussed, U.S.N.M. 132289.
COLLECTING LOCALITIES
Collecting localities and stratigraphic information are cited as they
appear in the Mesozoic catalogs of the U. S. Geological Survey and
U. S. National Museum. In many cases, data available for older
collections are brief and generalized. Many such collections have
been omitted from this study for this reason. Others have been
incorporated because it is obvious from the locality data and from
72 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
associated matrix at what stratigraphic level they were obtained.
Localities cited for the latter collections contain, in parentheses,
stratigraphic data which is not listed in our catalogs and which
represents my own interpretation, based on experience in the areas in
question. For localities that I have not actually visited, this infor-
mation is followed, in parentheses, by a question mark. I have
collected from all other areas in the past 6 years, and feel certain of
the stratigraphic assignments.
Lopha lugubris (Conrad)
1. U.S.G.S. 513—“Colorado Formation” (Juana Lopez equivalent ?), hills
6 miles each of Mexican settlements on road from Jemez to Copper
City, N. Mex. 100 feet above massive gray sandstone standing on edge.
Collected by J. W. Powell, 1887.
2. U.S.G.S. 747—“Colorado Formation” (Juana Lopez Member of the
Carlile Shale), Rattlesnake Buttes, 18 miles east of Walsenburg Post
Office, Colo. Collected by T. W. Stanton, 1890.
3. U.S.G.S. 827—“Colorado Formation” (Juana Lopez Member, Carlile
Shale), near Malachite, Huerfano County, Colo. Collected by T. W.
Stanton, 1891.
4. U.S.G.S. 833—100 to 600 feet above base of Colorado Shale (Juana Lopez
equivalent ?), near Mancos, Colo. Collected by T. W. Stanton, 1891.
5. U.S.G.S. 1306—Benton (Subgroup: Juana Lopez Member, Carlile Shale),
12 miles northwest of Pueblo, Colo., lat. 38°25’, long. 104°47’. Collected
by G. K. Gilbert, 1893.
6. U.S.G.S. 1380—Upper Benton (Subgroup: Juana Lopez equivalent ?),
mesa 5 miles west of Drip Springs, lat. 37°38’, long. 104°30/, Colo.
Collected by G. K. Gilbert, 1894.
7. U.S.G.S. 2005—Colorado (Group: Juana Lopez equivalent ?), about
150 feet above top of Dakota Sandstone, railroad cut north of Thompson
Park, Colo. Collected by A. C. Spencer, 1897.
8. U.S.G.S. 2009—Colorado (Group), Mancos Shale (Juana Lopez equivalent
?), near F—down corral on middle Mancos (River ?), La Plata Quad.
Colo. Collected by W. T. Lee.
9. U.S.G.S. 2015—Colorado (Group: Juana Lopez equivalent ?), west fork
of Mancos (River ?), 10,700 feet elevation, Colo. Collected by W.
Cross.
10. U.S.G.S. 2019—Colorado (Group: Juana Lopez equivalent in Mancos
Shale), second fossil layer exposed northwest of Mancos, Colo. Col-
lected by Mr. Cane, 1895.
11. U.S.G.S. 3673—(Colorado Group, Juana Lopez equivalent), “Ostrea”
lugubris zone, Rio Puerco, about 5 miles above San Ygnacio, Albuquer-
que Quad., N. Mex. Collected by T. W. Stanton, 1906.
12. U.S.G.S. 4358—Benton (Subgroup), fine brown sandstone ledges 400 feet
above Dakota Sandstone (Juana Lopez equivalent), Willow Creek at
the old wagon road south of Blue Mountain, sec. 12, T. 3 N., R. 102 W.,
coal fields of northwest Colorado and adjacent territory. Collected by
H. S. Gale, 1907.
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 73
13.
14.
15.
16.
17.
18.
19:
20.
21.
22.
23.
24.
25.
U.S.G.S. 4456—Benton (Subgroup: Juana Lopez equivalent ?), horizon
No. 2 (J. H. Gardner: unpublished), about 60 feet below main massive
sandstone of Coloradoan age, 5 miles below Arnold’s store, 10 miles
northeast of Gallup, N. Mex. Collected by J. H. Gardner, 1907.
U.S.G.S. 6516—Upper part of the Benton (Subgroup: Juana Lopez
equivalent), 150 to 200 feet above the Greenhorn Limestone, branch of
Vermejo Creek, about 12 miles northwest of Vermejo Park Post Office,
N. Mex. Collected by T. W. Stanton, 1910.
U.S.G.S. 7539—Eagle Ford Shale, layer No. 1, quarry of the Texas
Portland Cement Co., 2.5 miles due east of Eagle Ford, Dallas County,
and 3 miles west of Trinity River at Dallas, Tex. Collected by L. W.
Stephenson, 1911.
U.S.G.S. 7579—Basal bed of the Austin Chalk, on Walnut Creek, about
1 mile east of Watters’ Station, Travis County, Tex. Collected by
L. W. Stephenson, 1911.
U.S.G.S. 7993—Colorado (Group: Juana Lopez equivalent), in 50 feet of
yellow calcareous shaly sandstone, zone of Prionocyclus wyomingensis
and Scaphites warreni, about 3.5 miles south of Casa Salazar, Mt.
Taylor Quad., N. Mex. Collected by W. T. Lee and T. W. Stanton,
1912.
U.S.G.S. 9250—Mancos Shale, 300 to 400 feet above the base, near Delta,
Colo. Collected by G. H. Stone, 1915.
U.S.G.S. 10368—Colorado (Group: Juana Lopez equivalent ?), 14 miles
S. 20° W. from Shiprock Mt. (Wilson Peak), sec. 5 or 8, T. 9 N.,
R. 4 W., Navajo Meridian, near the base of Beautiful Mt., San Juan
Basin, N. Mex. Collected by W. E. Bryant, Dobbin, and J. B. Reeside,
Jr., 1920.
U.S.G.S. 10506—Mancos Shale, 300 feet above Dakota Sandstone,
Scaphites zone (Juana Lopez equivalent), 1.5 miles west of Durango,
NW1/4 SE1/4 sec. 18, T. 35 N., R. 9 W., Ignacio Quad., Colo. Col-
lected by J. B. Reeside, Jr., 1920.
U.S.G.S. 12883—Reworked Eagle Ford Shale zone in the base of the
Austin Chalk, exposures in bank of creek east of railroad, south of
Colorado River, south of Austin, Travis County, Tex. Collected by
L. W. Stephenson, 1924.
U.S.G.S. 13663—(Juana Lopez equivalent), 2 miles north of Whitewater,
Grand Junction region, Colo. Collected by J. B. Reeside, Jr., 1926.
U.S.G.S. 14691—“Blue Hills Shale” (Carlile Shale, questionably from
pockets of Juana Lopez Limestone at top of so-called Blue Hill Shale of
older authors), Lopha lugubris zone, near Beloit, Kans. Collected by
by J. B. Reeside, Jr., 1929.
U.S.G.S. 15923—Mancos Shale, 348 feet below Gallup Sandstone (Juana
Lopez equivalent ?), triangulation point, Gallup, approximately center
of sec. 12, T. 14 N., R. 2 W., southern San Juan Basin, N. Mex.
Collected by C. B. Hunt and party, 1931.
U.S.G.S. 18876—“Codell ? Sandstone” (Juana Lopez Member at top of
Codell), thin beds 30 feet below highly fossiliferous zone (of Mancos
Shale), on Biltabito Road, 15 miles west of junction with highway to
Gallup, 15 miles west of Shiprock bridge, San Juan County, N. Mex.
Collected by N. W. Bass, 1943.
74
26.
Li.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
U.S.G.S. 20562—Upper Cretaceous (Juana Lopez equivalent ?), approxi-
mately 2 miles west-southwest of Hagan, sec. 6, T. 12 N., R.6 E., Tejon
Grant, N. Mex. Collected by C. E. Stearns, 1946.
U.S.G.S. 24443—Frontier Sandstone (Juana Lopez equivalent ?), 1.75
miles northwest of Newcastle, SE1/4 sec. 23, T. 5 S., R. 91 W., Glen-
wood Springs Quad., Colo. Collected by N. W. Bass, 1952.
U.S.G.S. 25592—Mancos Shale (Juana Lopez equivalent), 525 feet above
base, section No. 2, southeast Gypsum Valley—Disappointment Valley
area, aerial photo D.R.N. 2-10, San Miguel County, Colo. Collected by
O. T. Marsh, 1955.
U.S.N.M. Cat. No. 8354—Colorado (Group: Juana Lopez equivalent),
Colorado. Type specimen with no other locality data.
U.S.N.M. Cat. No. 9822—Upper Cretaceous (Juana Lopez equivalent),
zone of Prionocyclus macombi ?, rocks east of Red River (Canadian),
Santa Fe road, N. Mex. T. A. Conrad.
U.S.N.M. Cat. No. 20255—Middle Cretaceous, Colorado (Group: Juana
Lopez equivalent), Vada del Chama, N. Mex.
Juana Lopez Member (top), Carlile Shale, Colorado Group, low cliff along
the northwest side of Oak Creek, NE1/4 SW1/4 sec. 5, T. 27 S.,
R. 68 W., Huerfano Park, Huerfano County, Colo. Collected by
E. G. Kauffman, 1958.
Juana Lopez Member, Carlile Shale, Colorado Group, in a stream gully
1.3 to 1.5 miles north-northwest of Red Wing, on the Jones’ Cattle
Company Ranch, SW1/4 SE1/4 sec. 26, T. 26 S., R. 71 W. Huerfano
Park, Huerfano County, Colo. Collected by E. G. Kauffman, 1959.
Juana Lopez Member, Carlile Shale, Colorado Group, 4 mile east of
Maes’ School, north of an unimproved dirt road, along the Fort Hays
limestone hogback, SE1/4 sec. 11, T. 26 S., R. 69 W., Huerfano Park,
Huerfano County, Colo. Collected by E. G. Kauffman, 1958.
Juana Lopez Member, Carlile Shale, Colorado Group, along the Fort Hays
Limestone hogback south of unimproved dirt road, 0.8 mile southeast of
Maes’ School, NW1/4 NE1/4 sec. 14, T. 26 S., R. 69 W., Huerfano
Park, Huerfano County, Colo. Collected by E. G. Kauffman, 1958.
Juana Lopez Member, Carlile Shale, Colorado Group, on the southeast side
of Oak Creek, 0.2 mile southwest of Badito, NW1/4 NE1/4 sec. 8,
T. 27 S., R. 68 W., Huerfano County, Colo. Collected by E. G. Kauff-
man, 1958.
Juana Lopez Member, Carlile Shale, Colorado Group, in a subsidiary
stream valley of Pantleon Creek, north of an unimproved road crossing
sec. 28, on the Jones’ Cattle Company Ranch, S1/2 NW1/4 sec. 28,
T. 26 S., R. 71 W., Huerfano Park, Huerfano County, Colo. Collected
by E. G. Kauffman, 1959.
Juana Lopez Member, Carlile Shale, Colorado Group, 2-3 miles north of
Thatcher, Colo., in Juana Lopez—Fort Hays limestone hogback, on
east side of dirt road leading north from general store and Thatcher
School, 50 to 100 yards east of road. Collected by E. G. Kauffman,
1961.
Juana Lopez Member, Carlile Shale, Colorado Group, 2-3 miles north of
Thatcher, Colo., on west side of dirt road leading north from Thatcher
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 75
School, in two fault or slump blocks, 0.5 and 0.7 mile west of road.
Collected by E. G. Kauffman, 1961.
Lopha bellaplicata bellaplicata (Shumard)
iS:
40.
41.
42.
47.
48.
49.
50.
U.S.G.S. 7539 (same as listed for Lopha lugubris)—Eagle Ford Shale,
layer No. 1, quarry of Texas Portland Cement Company, 2.5 miles due
east of Eagle Ford, Dallas County, and 3 miles west of Trinity River at
Dallas, Tex. Collected by L. W. Stephenson, 1911.
U.S.G.S. 741—Colorado Group (Codell Sandstone Member, Carlile Shale),
near Charles Smith’s Ranch, on Muddy Creek, 10 miles above Gardner
Post Office, Huerfano Park, Huerfano County, Colo. Collected by
T. W. Stanton, 1890.
U.S.G.S. 743—Colorado Group (Codell Sandstone Member, Carlile
Shale), 1 mile east of Quillian’s Ranch on Williams Creek, Huerfano
Park, Huerfano County, Colo. Collected by T. W. Stanton, 1890.
U.S.G.S. 1310—Benton (Subgroup: Codell Sandstone Member, Carlile
Shale), near 3-R Ranch, lat. 38°2’, long. 104°57’, Colo. Collected by
G. K. Gilbert, 1893.
. U.S.G.S. 1318—Benton (Subgroup: Codell Sandstone Member, Carlile
Shale), near Turkey Creek, lat. 38°30’, long. 104°49’, Colo. Collected by
G. K. Gilbert, 1893.
U.S.G.S. 439b—(Eagie Ford Shale), 2 miles east and 3 miles south of
Denison, Tex. Collected by R. T. Hill, 1886.
. U.S.G.S. 8081—Benton ? (Subgroup: Mancos Shale), on surface of steep
slope at B-34, sec. 18, T. 10 N., R. 17 W., Zuni Indian Reservation,
N. Mex. Collected by D. E. Winchester, 1912.
. U.S.G.S. 10046—Eagle Ford Shale, 7 miles west of Palestine at the salt
works, on ridge $ mile northeast of plant, Texas. Collected by O. B.
Hopkins, 1915.
U.S.G.S. 11096—Eagle Ford Sandstone, in pebble bed 15 to 25 feet below
Ector Chalk, in big gully 1 mile southeast of Bells, Tex. Collected by
O. B. Hopkins, 1918.
U.S.G.S. 11732—Upper 3 feet of the Eagle Ford Shale, in quarry of the
Texas Portland Cement Company plant west of Dallas, Tex. Collected
by T. W. Stanton, 1923.
U.S.G.S. 12942—Eagle Ford Formation, Palestine salt dome, east of salt
works, at an old cabin, Anderson County, Tex. Collected by L. W.
Stephenson, 1924.
U.S.G.S. 14553—Sand of upper Eagle Ford age, Whitesboro road, 1.75
miles west of Sherman, Grayson County, Tex. Collected by L. W.
Stephenson, T. W. Stanton, and J. B. Reeside, Jr., 1929.
. U.S.G.S. 19017—Upper part of the Eagle Ford Shale, North-South Road,
1.7 miles W. by S. of Ellsworth, 5.4 miles southwest of Denison,
Grayson County, Tex. Collected by R. T. Hazzard, 1941 (?).
U.S.G.S. 22608—Eagle Ford Shale, 3 miles southeast of Mountain Creek
Power Plant, Dallas County, Tex. Collected by Mrs. Renfro.
. U.S.N.M. Cat. No. 8024—Eagle Ford Shale, Collin County, Tex.
U.S.N.M. Cat. No. 11882—Eagle Ford Shale, near Sherman, Tex.
76
So:
56.
oa
58.
a2.
60.
61.
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
U.S.N.M. Cat. No. 22861—Colorado Group (Codell Sandstone Member),
at Carlile Springs, 18 miles west of Pueblo, Colo.
U.S.N.M. Cat. No. 12383—Eagle Ford Shale, Denison, Tex.
B. F. Perkins collection No. 55-206—Upper Eagle Ford Shale, Turonian,
Jefferson Blvd., roadcut, Dallas County, Tex. Collected by B. F.
Perkins, 1955. U.S.N.M. accession 241760.
Codell Sandstone Member (“Pugnellus Sandstone” of Stanton, 1894),
Carlile Shale, Colorado Group, 50 to 100 yards southwest of Lower
Pass Creek School, along Colorado State Highway 305, SE1/4 sec. 7,
T. 27 S., R. 70 W., Huerfano Park, Huerfano County, Colo. Collected
by E. G. Kauffman, 1959, 1961.
Codell Sandstone Member (“Pugnellus Sandstone” of Stanton, 1894),
Carlile Shale, Colorado Group, in a stream gully 1.3 to 1.5 miles north-
northwest of Red Wing, on the Jones’ Cattle Company Ranch,
SW1/4 SE1/4 sec. 26, T. 26 S., R. 71 W., Huerfano Park, Huerfano
County, Colo. Collected by E. G. Kauffman, 1959.
Codell Sandstone Member (“Pugnellus Sandstone” of Stanton, 1894),
Carlile Shale, Colorado Group, in a subsidiary stream valley of Pantleon
Creek, north of an unimproved dirt road crossing sec. 28 on the Jones’
Cattle Company Ranch, S1/2 NW1/4 sec. 28, T. 26 S., R. 71 W.,,
Huerfano Park, Huerfano County, Colo. Collected by E. G. Kauffman,
1959.
Codell Sandstone Member (“Pugnellus Sandstone” of Stanton, 1894),
Carlile Shale, Colorado Group, in a wooded area 0.4 mile east of
Turkey Creek, NE1/4 NW1/4 sec. 22, T. 25 S., R. 69 W., Huerfano
Park, Huerfano County, Colo. Collected by E. G. Kauffman, 1959.
Lopha bellaplicata novame-xicana new subspecies
62.
63.
64.
65.
66.
67.
U.S.G.S. 738—Colorado Group (septarian limestone concretion zone,
upper Blue Hill Shale Member, Carlile Shale), near Badito, Huerfano
County, Colo. Colected by T. W. Stanton, 1890.
U.S.G.S. 3295—Colorado Group (Mancos Shale ?), Carthage, N. Mex.
Collected by W. T. Lee, 1905.
U.S.G.S. 3297—Colorado Group (Mancos Shale ?), $ mile south of 3295,
Carthage, N. Mex. Collected by W. T. Lee, 1905.
U.S.G.S. 5303—Colorado Group, Benton (Subgroup: Mancos Shale),
710 feet above the Dakota Sandstone, SW1/4 NE1/4 sec. 9, T. 5 S.,
R. 2 E., New Mexico, P. M., 0.5 mile N. 30° from Manilla Mine,
Carthage, N. Mex. Collected by J. H. Gardner, 1908.
U.S.G.S. D2042—Massive sandstone in the Mancos Shale, zone of
Collignoniceras hyatti, just north of U. S. Highway 380, 7.75 miles east
of San Antonio, Socorro County, N. Mex. Collected by W. A. Cobban.
Blue Hill Shale Member, Carlile Shale, Colorado Group, in septarian lime-
stone concretions 10 to 15 feet below the top of the member, and in
lenticular limestone beds at the Blue Hill-Codell Sandstone contact,
lower part of the zone of Collignoniceras hyatti, 100 yards southwest of
Lower Pass Creek School, just west of Colorado State Highway 305,
SE1/4 sec. 7, T. 27 S., R. 70 W., Huerfano Park, Huerfano County,
Colo. Collected by E. G. Kauffman, 1959, 1961.
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN a7
68. Upper Blue Hill Shale Member, Carlile Shale, Colorado Group, in a 2-
inch limestone overlying cone-in-cone beds, septarian limestone concre-
tion zone, zone of Collignoniceras hyatti, stream gully 1.3 to 1.5 miles
north-northwest of Red Wing, on the Jones’ Cattle Company Ranch,
SW1/4 SE1/4 sec. 26, T. 26 S., R. 71 W., Huerfano Park, Huerfano
County, Colo. Collected by E. G. Kauffman, 1959.
69. Blue Hill Shale Member, Carlile Shale, Colorado Group, zone of septarian
limestone concretions in upper 10 feet of member, 1 mile east of
Williams Creek, 4 mile south of unimproved dirt road, W1/2 NE1/4.
sec. 12, T. 25 S., R. 70 W., Huerfano Park, Huerfano County, Colo.
Collected by E. G. Kauffman, 1959, 1961.
70. Blue Hill Shale Member, Carlile Shale, Colorado Group, zone of septarian
limestone concretions in upper 20 feet of member, along the Fort Hays
Limestone hogback south of an unimproved dirt road, 0.8 mile southeast
of Maes’ School, NW1/4 NE1/4 sec. 14, T. 26 S, R. 69 W.,,
Huerfano Park, Huerfano County, Colo. Collected by E. G. Kauffman,
1958.
71. Blue Hill Shale Member, Carlile Shale, Colorado Group, zone of septarian
limestone concretions in upper 25 feet of member, below Codell Sand-
stone—Juana Lopez limestone hogback 0.5 mile north of Colorado State
Highway 69, near center of sec. 31, T. 26 S., R. 68 W., 1.4 miles east of
Farisita, Huerfano Park, Huerfano County, Colo. Collected by E. G.
Kauffman, 1959.
72. Blue Hill Shale Member, Carlile Shale, Colorado Group, septarian lime-
stone concretion zone in upper 15 feet of member, just below Juana
Lopez-Fort Hays Limestone hogback, 2-3 miles north of Thatcher, Colo.,
50 to 100 yards east of an improved dirt road leading north from gen-
eral store and Thatcher School. Collected by E. G. Kauffman, 1961.
73. Blue Hill Shale Member, Carlile Shale, Colorado Group, septarian lime-
stone concretions in upper part of member, 1 mile north of the
Arkansas River, on slopes surrounding a dry tributary, SE1/4 NE1/4
sec. 25, T. 20 S., R. 66 W., Pueblo County, Colo. Collected by E. G.
Kauffman and F. Collier, 1962.
Lopha bellaplicata bellaplicata var. A.
Collected in the Codell Sandstone Member, Carlile Shale, Colorado Group, at
localities 41, 58, 59, 60, and 61, previously cited under Lopha bellaplicata.
LITERATURE CITED
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NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 79
Hr Rel.
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1903a. The geology of the Cerrillos Hills, New Mexico. School of Mines
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Linng£, CARL.
1758. Systema naturae, etc., 10th ed., vol. 1, p. 704. Stockholm.
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figs. la-d.
NEwELL, N. D.
1937. Late Paleozoic pelecypods: Pectinacea. Univ. Kansas, State Geol.
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Rankin, C. H.
1944. Stratigraphy of the Colorado Group, Upper Cretaceous, in northern
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RANSON, GILBERT.
1942. Note sur la classification des Ostreides: Bull. Geol. Soc. France,
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80 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Scumoipt, F. C.
1818. Versuch tiber die beste Einrichtung zur Aufstellung, etc., p. 69.
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1953. Principles of invertebrate paleontology, 2d ed., pp. 363-402. New
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1860. Descriptions of new Cretaceous fossils from Texas. Trans. St. Louis
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1893 (1894). The Colorado Formation and its invertebrate fauna. U. S.
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1947. Nomenclatural synopsis of supraspecific groups of the family
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1954. The genera of oysters and the Australian species. Australian Journ.
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1936. Sur la classification des huitres. Acad. Sci. U.R.S.S., Comptes
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NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 81
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1925. The geology of Denton County. Univ. Texas Bull. 2544, p. 62, pl. 8,
fies 5e
EXPLANATION OF PLATES
U.S.N.M. = United States National Museum
U.M.M.P. = University of Michigan Museum of Paleontology
U.S.G.S. = United States Geological Survey
PLaTE 1
Lopha lugubris (Conrad)
Fig. 1. Lateral view (XI) of a left valve with reverse curvature; a hypotype
from a calcarenite bed between typical Austin Chalk and Eagle Ford Shale
(locality 16, U.S.G.S. loc. 7579) ; U.S.N.M. 132154.
Fig. 2. Lateral view of a typical left valve (<I); Stanton’s hypotype from
Mancos, Colo. (locality 4, U.S.G.S. 833), the original of his plate 4,
figure 3 (1893) ; U.S.N.M. 22859b.
Fig. 3. Lateral view (2) of a left valve with abnormally small attachment
area; a hypotype (locality 38) ; U.S.N.M. 132155.
Fig. 4. Lateral view (1) of a typical left valve, the lectotype; the original
of Conrad’s (1857) plate 10, figure 5b, (locality 30, east of Red River,
Santa Fe Road, N. Mex.) ; U.S.N.M. 9822.
Fig. 5. Lateral view (2) of a typical left valve; a hypotype from the
upper Eagle Ford Shale of Texas (locality 15, U.S.G.S. 7539) ; U.S.N.M.
132156.
Fig. 6. Lateral view (2) of a left valve with well-developed reverse curva-
ture of the exogyroid beaks and umbo; a hypotype from Huerfano Park,
Colo. (locality 34) in the Juana Lopez Member (Carlile Shale) ;
U.M.M.P. 43472.
Fig. 7. Lateral view (<2) of a typical left valve; a hypotype from the zone
of Prionocyclus wyomingensis wyomingensis, near Casa Salazar, N. Mex.
(locality 17, U.S.G.S. 7993) ; U.S.N.M. 132157.
Fig. 8. Lateral view (2) of an unusually erect left valve; a hypotype from
the upper 3 feet of the Eagle Ford Shale, Texas (locality 48, U.S.G.S.
11732) ; U.S.N.M. 132158.
Fig. 9. Lateral view (2) of a left valve with a large, flat attachment scar
and somewhat restricted plicae; a hypotype from the Juana Lopez Member,
Huerfano Park, Colo. (locality 34) ; U.M.M.P. 43464.
Fig. 10. Lateral view of a left valve (X2); a hypotype from the Juana
Lopez Member, Huerfano Park, Colo. (locality 34); U.M.M.P. 43472.
Fig. 11. Lateral view (<2) of a distorted left valve with plicae limited to the
margins; a hypotype from Mancos, Colo. (locality 4, U.S.G.S. 833) ;
U.S.N.M. 22210a.
Fig. 12. Lateral view (2) of a nearly smooth left valve with only faint
marginal plicae; a hypotype from the Juana Lopez Member, Huerfano
Park, Colo. (locality 34) ; U.M.M.P. 43465.
Fig. 13. Lateral view (2) of an erect left valve with a large scar and
relatively few, restricted, marginal plicae; a hypotype from the Juana
Lopez Member, Huerfano Park, Colo. (locality 36); U.M.M.P. 43476.
82
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 83
Fig. 14. Lateral view (2) of a left valve with radiating ornament restricted
to marginal crenulations; a hypotype from the upper Eagle Ford Shale of
Texas (locality 15, U.S.G.S. 7539) ; U.S.N.M. 132159.
Fig. 15. Interior view (2) of a large left valve showing internal reflection
of ornamentation, marks of the attachment area, and the normal position
of the muscle scar; a hypotype, the original of Stanton’s plate 4, figure 5
(1893) (locality 4, U.S.G.S. 833) ; U.S.N.M. 22859a.
Fig. 16. Interior view (2) of a left valve showing nature of cardinal area,
denticles, muscle scar, and internal reflection of the ornamentation; a
hypotype from Colorado (locality 29) ; U.S.N.M. 8354.
Fig. 17. Interior view (2) of a left valve showing fine interior lines on
inner surface, denticles, cardinal area, and muscle scar; a hypotype from
the zone of Prionocyclus wyomingensis wyomingensis (Juana Lopez
equivalent), near Casa Salazar, N. Mex. (locality 17; U.S.G.S. 7993) ;
U.S.N.M. 132160.
Fig. 18. Interior view (2) of a left valve; hypotype illustrated by Meek
on plate 1, figure la (1876), from Vada del Chama, N. Mex. (locality
SL's Wes: Ni. 20255.
PLATE 2
Lopha lugubris (Conrad)
Fig. 1. Lateral view (X2) of an unusually elongate right valve showing
strong lamellae developed at beginning of plicate stage of valve, and
weak plicae; a hypotype from the upper Eagle Ford Shale of Texas
(locality 15, U.S.G.S. 7539) ; U.S.N.M. 132161.
Fig. 2. Lateral view (2) of a typical plicate right valve, showing abrupt
formation of plicae at margin of smooth stage; hypotype illustrated by
Stanton (1893, pl. 4, fig. 2), from Huerfano Park, Colo. (locality 3,
U.S.G.S. 827) ; U.S.N.M. 22860a.
Fig. 3. Lateral view of a right valve (2); a hypotype from Rattlesnake
Buttes, Colo. (locality 2, U.S.G.S. 747) ; U.S.N.M. 22008a.
Fig. 4. Lateral view (2) of an unusually elongate, curved, plicate right
valve; a hypotype from the zone of Prionocyclus wyomingensis wyoming-
ensis (Juana Lopez equivalent) near Casa Salazar, N. Mex. (locality 17,
U.S.G.S. 7993) ; U.S.N.M. 132162.
Fig. 5. Lateral view (2) of a coarsely plicate right valve showing sharp
demarcation between smooth stage and plicate portion of valve; a hypo-
type from near Mancos, Colo., in the Juana Lopez equivalent (locality 10,
U.S.G.S. 2019) ; U.S.N.M. 132163.
Fig. 6. Lateral view (2) of a plicate right valve characteristic of the
species, showing abrupt origin of plicae, and reflection of attachment sur-
face on smooth stage of valve; a hypotype from the upper Eagle Ford
Shale of Texas (locality 15, U.S.G.S. 7539); U.S.N.M. 132164.
Fig. 7. Lateral view (2) of a right valve showing reflection of attachment
surface on smooth stage, and restriction of plicae to marginal area. This
form is intermediate between plicate and nonplicate types. A hypotype
from near Mancos, Colo. (locality 4, U.S.G.S. 833) ; U.S.N.M. 22210b.
84 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Fig. 8. Lateral view (2) of a right valve with radiating ornament limited
to crenulations in marginal lamellae; a hypotype from Huerfano Park,
Colo. (locality 34) ; U.M.M.P. 43470.
Fig. 9. Lateral view (X2) of an elongate, nonplicate right valve; a hypotype
from Huerfano Park, Colo. (locality 32) ; U.M.M.P. 43487.
Fig. 10. Lateral view (2) of a smooth right valve showing reflection of
attachment surface (probably an Inoceramus shell) on exterior of upper
valve; a hypotype from near Mancos, Colo. (locality 4, U.S.G.S. 833) ;
U.S.N.M. 22211.
Fig. 11. Lateral view (2) of a smooth right valve showing nature of
growth lines and fine lamellae; a hypotype from Huerfano Park, Colo.
(locality 58) in the Juana Lopez Member; U.M.M.P. 43484.
Fig. 12. Lateral view (X2) of a small right valve with well-developed
marginal lamellae, and faint crenulations on the anterior and ventral
borders; a hypotype from Huerfano Park, Colo. (locality 33) in the
Juana Lopez Member ; U.M.M.P. 43471.
Fig. 13. Interior view (2) of a thick right valve showing unusually deep
but typically shaped posterior adductor muscle scar, traces of fine
radiating incised lines on inner surface of valve; a hypotype from Rattle-
snake Buttes, Colo. (locality 2, U.S.G.S. 747) in the Juana Lopez Mem-
ber; U.S.N.M. 22008b.
Fig. 14. Interior view (2) of a small right valve with unusually large
cardinal area, typical muscle scar, and well-developed denticles (repre-
sented by notches) ; a hypotype from Rattlesnake Buttes, Colo. (locality 2,
U.S.G.S. 747), in the Juana Lopez Member; U.S.N.M. 22008b.
Fig. 15. Lateral view (2) of a typical right valve, nonplicate, and with
reverse curvature; a hypotype from Huerfano Park, Colo. (locality 34),
in the Juana Lopez Member ; U.M.M.P. 43486.
Fig. 16. Interior view (2) of a typical right valve showing nature of
cardinal area, well-developed denticles, a typical muscle scar, and fine,
sinuous, incised lines on the inner valve surface; a hypotype from the
Mancos Shale, San Miguel County, Colo. (locality 28, U.S.G.S. 22592) ;
U.S.N.M. 132258.
Fig. 17. Interior view (2) of a right valve with unusually large resilifer
and muscle scar, well-developed denticles; a hypotype from near White-
water, Colo., from the Juana Lopez Member equivalent in the Mancos
Shale (locality 22, U.S.G.S. 13663) ; U.S.N.M. 132165.
PiaTeE 3
(All figures <1)
Lopha bellaplicata bellaplicata (Shumard)
Figs. 1, 3, 9, 11, 15, 18. Lateral views of typical left valves of the species,
placed in a growth series; note characteristic outline, nature and extent
of auricles and auricular sulci, small attachment scars, nature of plicae and
height of smooth stage; all specimens hypotypes from the upper Eagle
Ford Shale, 2.5 miles east of Eagle Ford, Dallas County, Tex. (locality
15, U:S.G.S. 7539)... Catalogs, Nos. 1 (CU:S/N-M, 132213) 3. (WS. Nee
132215), 9 (U.S.N.M. 132220), 11 (U.S.N.M. 132222, the neotype),
15 (U.S.N.M. 132225), and 18 (U.S.N.M. 132228).
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 85
Fig. 2. Lateral view of a left valve, abnormally short owing to reduced
posterior auricle; a hypotype from the upper Eagle Ford Shale, 2.5 miles
east of Eagle Ford, Dallas County, Tex. (locality 15, U.S.G.S. 7539) ;
U.S.N.M. 132214.
Fig. 4. Lateral view of a left valve with reduced posterior auricle, unusually
large attachment scar and prominent umbo; a hypotype from the upper
Eagle Ford Shale of Texas (locality 15, U.S.G.S. 7539, cited above) ;
U.S.N.M. 132216.
Fig. 5. Lateral view of a worn left valve with unusually large smooth stage;
a hypotype from the Eagle Ford Shale at Sherman, Tex. (locality 54),
the original of Stanton’s plate 4, figure 8 (1893); U.S.N.M. 11882a.
Fig. 6. Lateral view of a left valve with unusually large attachment scar;
posterior auricle broken; a hypotype from the upper Eagle Ford Shale,
Dallas County, Tex. (locality 15, U.S.G.S. 7539, cited above) ; U.S.N.M.
132217.
Fig. 7. Lateral view of an abnormal left valve; note unusual height, reduction
of auricles, broad plicae, a hypotype from the upper Eagle Ford Shale,
Dallas County, Tex. (locality 57) ; U.S.N.M. 132218.
Fig. 8. Lateral view of an unusual left valve with broad plicae, fluted at
their intersection with coarse concentric lamellae, and abnormally large
smooth umbonal area. This form is possibly transitional to Lopha panda
(Morton). A hypotype from the upper Eagle Ford Shale, Dallas County,
Tex. (locality 15, U.S.G.S. 7539, cited above) ; U.S.N.M. 132219.
Fig. 10. Lateral view of a typical left valve with abnormally projecting beak
and early umbo; a hypotype from the upper Eagle Ford sands, 1.75 miles
west of Sherman, Tex. (locality 50, U.S.G.S. 14553) ; U.S.N.M. 132221.
Fig. 12. Lateral view of a left valve, unusual in having a nearly centrally
situated beak and broad plicae; a hypotype from the upper Eagle Ford
Shale, Dallas County, Tex. (locality 15, U.S.G.S. 7539, cited above) ;
U.S.N.M. 132223.
Fig. 13. Lateral view of White’s hypotype (1879, pl. 4, figs. 3a, b) from the
Eagle Ford Shale at Denison, Tex. (locality 56) ; U.S.N.M. 12383.
Fig. 14. Lateral view of a typical adult left valve; a hypotype from upper
Eagle Ford sands, 1.75 miles west of Sherman, Tex. (locality 50, U.S.G.S.
14553) ; U.S.N.M. 132224.
Fig. 16. Lateral view of an unusually elongate, high left valve, more inclined
than normal, and with a large attachment scar; a hypotype from Dallas
County, Tex. (locality 57) ; U.S.N.M. 132226.
Fig. 17. Lateral view of a typical left valve with an unusually large attach-
ment scar, a hypotype from the upper Eagle Ford Shale, 2.5 miles east of
Eagle Ford, Dallas County, Tex. (locality 15, U.S.G.S. 7539, cited
above) ; U.S.N.M. 132227.
PLATE 4
(All figures <1)
Lopha bellaplicata bellaplicata (Shumard)
Fig. 1. Lateral view of a left valve from White’s syntype lot of Lopha blacki.
Note that other than the projecting beak and umbo, deformed by the
86 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
attachment scar, and the rounded nature of the plicae (worn), the nature
of the valve is identical with those of L. bellaplicata bellaplicata illustrated
on plates 3 and 4; hypotype (of L. bellaplicata bellaplicata) from the
upper Eagle Ford Shale, Collin County, Tex. (locality 53); U.S.N.M.
8024a.
Fig. 2. Lateral view of a large left valve with unusually well developed
posterior auricle and faint, worn plicae; hypotype from upper Eagle Ford
sands, 1.75 miles west of Sherman, Tex. (locality 50, U.S.G.S. 14553) ;
U.S.N.M. 132229.
Fig. 3. Lateral view of a typical left valve. Note change in prominence of
plicae at midshell, giving rise to faint plicae similar to those on L. blacki
(White). A hypotype from the upper Eagle Ford Shale, 2.5 miles east of
Eagle Ford, Dallas County, Tex. (locality 15, U.S.G.S. 7539) ; U.S.N.M.
132230.
Fig. 4. Lateral view of an unusually flat left valve with abnormal prosocline
inclination, a hypotype from the upper Eagle Ford Shale, Dallas County,
Tex. (locality 57) ; U.S.N.M. 132231.
Fig. 5. Lateral view of an adult left valve showing extensive bifurcation of
plicae, and unusually reduced posterior auricle; a hypotype from the upper
Eagle Ford Shale, 2.5 miles east of Eagle Ford, Dallas County, Tex.
(locality 15, U.S.G.S. 7539) ; U.S.N.M. 132232.
Fig. 6. Lateral view of the smoothest specimen from White’s syntype lot of
L. blacki, considered here a smooth variant of L. bellaplicata bellaplicata
(Shumard). The original of White’s plate 46, figure 2 (1884). Hypotype
from the upper Eagle Ford Shale, Collin County, Tex. (locality 53) ;
U.S.N.M. 8024b.
Fig. 7. Lateral view of a large left valve showing large attachment scar but
otherwise typical of the species; hypotype from the upper Eagle Ford
Shale, Dallas County, Tex. (locality 15, U.S.G.S. 7539, cited above) ;
WS NEIMG 1 32233:
Fig. 8. Interior view of a left valve showing nature and position of muscle
scar, flattened lateral lamellae forming part of commissure, and unusually
massive cardinal area with characteristic structures; a hypotype from
the upper Eagle Ford Shale, Dallas County, Tex. (locality 57) ; U.S.N.M.
132234.
Puiate 5
(All figures 1)
Lopha bellaplicata bellaplicata (Shumard)
Figs. 1-4. Anterior (side) views of representative left valves, illustrating the
range of variation in convexity. No. 1 is typical of the species. 1-3,
Neotype and hypotypes from the upper Eagle Ford Shale, Dallas County,
Tex; Cocality 15, U.S.G.S.7539))= U-S:N.M. 1132222 (fics De USN
132228 (fig. 2); U.S.N.M. 132235 (fig. 3). 4, Hypotype from the upper
Eagle Ford Shale, Dallas County, Tex. (locality 57) ; U.S.N.M. 132231.
Figs. 5-8. Lateral views of typical right valves, arranged in growth series.
Note development of auricles (fig. 7 is atypical in this respect, having
rounded auricles), anterior position of beaks, posterior curvature of beaks,
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 87
nearly straight dorsal margin, height of smooth stage (greater than on
average left valves), the abrupt appearance, prominence, and bifurcation
of the plicae, and the well-developed concentric lamellae. Hypotypes
from the upper Eagle Ford Shale, 1.5 miles east of Eagle Ford, Dallas
County, Tex. (locality 15, U.S.G.S. 7539); U.S.N.M. 132236 (fig. 5);
U.S.N.M. 132237 (fig. 6); U.S.N.M. 132238 (fig. 7); U.S.N.M. 132239
(fig. 8).
Fig. 9. Lateral view of a right valve from the syntype lot of “Ostrea” blacki
White. Note the only difference between this specimen and typical right
valves of L. bellaplicata bellaplicata is the height of the smooth stage.
A hypotype of L. bellaplicata bellaplicata from the upper Eagle Ford
Shale in Collin County, Tex. (locality 53) ; U.S.N.M. 8024c.
Figs. 10, 13. Lateral and interior views of an abnormal right valve lacking
auricles and prominent plicae. Note nature of cardinal area and muscle
scar, both characteristic for the species. A hypotype from the upper
Eagle Ford Shale of Texas (locality 57, previously cited); U.S.N.M.
132240.
Fig. 11. Lateral view of a nearly smooth right valve of a mature shell, a
marginal variant occurring with specimens illustrated in figures 5-8.
Compare with figure 12, a syntype of L. blacki (White). Hypotype from
the upper Eagle Ford Shale of Texas (locality 15, U.S.G.S. 7539,
previously cited) ; U.S.N.M. 132241.
Figs. 12, 15. Lateral and interior views of a smooth right valve with faint
plicae and well-developed interior features. Hypotype of Lopha bella-
plicata bellaplicata from the upper Eagle Ford Shale of Collin County,
Tex. (locality 53) ; U.S.N.M. 11882b.
Fig. 14. Lateral view of an unusually elongate right valve with characteristic
ornamentation, somewhat worn; hypotype from the upper Eagle Ford
Shale of Dallas County, Tex. (locality 15, U.S.G.S. 7539, previously
cited) ; U.S.N.M. 132242.
PLATE 6
Lopha bellaplicata bellaplicata (Shumard), variety A
Fig. 1. Lateral view (1) of a typical left valve, showing shape, plicae,
narrow beak and umbo, and small attachment scar. A hypotype from the
Codell Sandstone Member, Carlile Shale, Huerfano Park, Colo. (locality
41, U.S.G.S. 743) ; U.S.N.M. 22011a.
Fig. 2. Lateral view (2) of a left valve with an unusually large attachment
scar; a hypotype from the Codell Sandstone Member, Huerfano Park,
Colo. (locality 59; U.M.M.P. 38052.
Fig. 3. Lateral view (1) of a small plicate upper valve associated with
L. bellaplicata bellaplicata var. A; a hypotype from the Codell Sandstone
Member of Huerfano Park, Colo. (locality 58); U.S.N.M. 132259.
Fig. 4. Lateral view (1) of a smooth, elongate right valve associated with
specimens of L. bellaplicata bellaplicata var. A; a hypotype from the
Codell Sandstone Member, Huerfano Park, Colo. (locality 61);
U.M.M.P. 43413.
88 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Fig. 5. Lateral view (2) of a left valve with unusually broad plicae; a
hypotype from the Codell Sandstone Member, Huerfano Park, Colo.
(locality 59) ; U.M.M.P. 38051.
Fig. 6. Lateral view of a left valve (1) with a prominent attachment scar ;
hypotype from the Codell Sandstone Member, Huerfano Park, Colo.
(locality 41, U.S.G.S. 743) ; U.S.N.M. 22011d.
Fig. 19. Lateral view (X1) of a small left valve showing ventral flaring of
the lateral margins; a hypotype from the Codell Sandstone Member,
Huerfano Park, Colo. (locality 61) ; U.S.N.M. 132249.
Lopha bellaplicata bellaplicata (Shumard) : forma typica
Fig. 7. Lateral view (1) of a small left valve typical of the species, a
hypotype from the Codell Sandstone Member, Huerfano Park, Colo.
(locality 40, U.S.G.S. 741) ; U.S.N.M. 22009a.
Fig. 8. Lateral view (<1) of a left valve with moderately large attachment
scar: a hypotype figured by Stanton (1893, pl. 4, fig. 4) from the Codell
Sandstone Member, Huerfano Park, Colo. (locality 41, U.S.G.S. 743) ;
U.S.N.M. 22860d.
Fig. 9. Lateral view (1) of a left valve, characteristic of the species; hypo-
type from the Codell Sandstone Member, Huerfano Park, Colo. (locality
61) ; U.M.M.P. 38038.
Fig. 10. Lateral view of an unusual left valve (1) with abnormally elongate
posterior auricle, broad, faint plicae; a hypotype from the Codell Sand-
stone Member, Carlile Shale, Huerfano Park, Colo. (locality 61);
U.M.M.P. 43482.
Fig. 11. Lateral view (1) of a mature left valve, slightly longer than
average, similar to Texas specimen illustrated on plate 3, figure 12;
hypotype from the Codell Sandstone Member, Huerfano Park, Colo.
(locality 40, U.S.G.S. 741) ; U.S.N.M. 22009b.
Fig. 12. Lateral view (1) of a typical left valve, a hypotype from the
Codell Sandstone Member, Huerfano Park, Colo. (locality 59);
U.M.M.P. 38039.
Fig. 13. Lateral view (1) of a nearly symmetrical left valve with a large
attachment scar and unusually inflated umbone, a hypotype from the
Codell Sandstone Member, Huerfano Park, Colo. (locality 41, U.S.G.S.
743) ; U.S.N.M. 22011b.
Fig. 14. Lateral view (<1) of a mature left valve with unusually deep
attachment scar, abnormally situated dorsoposteriorly; a hypotype from
the Codell Sandstone Member, Huerfano Park, Colo. (locality 59) ;
U.M.M.P. 38041.
Fig. 15. Lateral view (1) of a large left valve with extended auricles,
abnormally broad plicae, and subcentral beak; a Colorado variant of the
species not yet found elsewhere; a hypotype from the Codell Sandstone
Member, Carlile Springs, Colo, (locality 55); the original of Stanton’s
plate 4, figure 7 (1893) ; U.S.N.M. 22861.
Fig. 16. Interior view of a left valve (1) showing normal cardinal area,
denticles, internal reflection of ornamentation, and posterior adductor
muscle scar, the hypotype figured by Stanton (1893, pl. 4, fig. 9), from the
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN 89
Codell Sandstone Member, Huerfano Park, Colo (locality 41, U.S.G.S.
743) ; U.S.N.M. 22860b.
Fig. 17. Lateral view of a typical right valve from Colorado (2) showing
limited extent of plicae, concentric ornamentation, shape; a hypotype
from the Codell Sandstone Member, Huerfano Park, Colo. (locality 61) ;
U.M.M.P. 43466.
Fig. 18. Lateral view (2) of a totally nonplicate right valve, otherwise
typical of the species; a hypotype from the Codell Sandstone Member,
Huerfano Park, Colo. (locality 59) ; U.M.M.P. 43483.
Fig. 20. Lateral view (1) of a large, unusually high right valve, showing
typical development of the concentric lamellae; a hypotype from the
upper Eagle Ford Shale, Dallas County, Tex. (locality 15, U.S.G.S.
7539) ; U.S.N.M. 132250.
Fig. 21. Lateral view (1) of a nearly smooth right valve showing a few,
sinuous, irregular plicae near margin; a hypotype from the Codell Sand-
stone Member, Huerfano Park, Colo. (locality 59); U.M.M.P. 43478.
Figs. 22, 23. Dorsal and posterior views (X11) of a small left valve with
plicae less extensive than average, and an unusually large attachment
scar; the hypotype illustrated by Stanton (1893, pl. 4, fig. 6), from the
Codell Sandstone Member, Huerfano Park, Colo. (locality 41, U.S.G.S.
743) ; U.S.N.M. 22860c.
Fig. 24. Lateral view of a large, old right valve showing degeneration of
radial ornamentation near margin, and increase in number and prominence
of the concentric lamellae with age; a hypotype from the upper Eagle
Ford Shale, Dallas County, Tex. (locality 15, U.S.G.S. 7539) ; U.S.N.M.
IKY7A 8
PLATE 7
(All figures <1)
Lopha bellaplicata novamexicana Kauffman, new subspecies
Figs. 1, 2. Lateral views of immature left valves, typical of the subspecies.
Note general similarity to immature left valves of L. bellaplicata
bellaplicata (pl. 3) but the smaller auricles and more inclined postero-
dorsal margin in the subspecies novamexicana at this and later growth
stages. Paratypes from the zone of Collignoniceras hyatti (Stanton),
Mancos Shale, Socorro County, N. Mex. (locality 66, U.S.G.S. D2042) ;
U.S.N.M. 132260 (fig. 1), and 132261 (fig. 2).
Fig. 3. Lateral view of a young adult left valve, typical of the subspecies
except for narrow auricular sulci. Note broad plicae. A paratype from
the Colorado Group (Mancos?), Carthage, N. Mex. (locality 64, U.S.G.S.
3297) ; U.S.N.M. 132262.
Figs. 4, 5. Lateral and interior views of a typical adult valve showing broad,
widely spaced plicae, few in number, inclined posterodorsal margin,
broad posterior auricular sulcus, and the nature of the cardinal area and
muscle scar. A paratype from the Mancos Shale, Socorro County, N. Mex.
(locality 66, U.S.G.S. D2042) ; U.S.N.M. 132263.
go SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Fig. 6. Lateral view of a small, incomplete, right valve showing broad plicae
and short smooth stage. A paratype from the Mancos Shale, Socorro
County, N. Mex. (locality 66, U.S.G.S. D2042) ; U.S.N.M. 132264.
Fig. 7. Lateral view of a small, unusually curved right valve with recurved
beak and umbo, short smooth stage limited to umbo, and typical plicae.
A paratype from the Colorado Group (Mancos Shale?), Carthage,
N. Mex. (locality 64, U.S.G.S. 3297) ; U.S.N.M. 132262.
Fig. 8. Lateral view of an adult right valve similar in shape to those of
L. bellaplicata bellaplicata, but with a much shorter smooth umbonal area.
Note coarse lamellae, characteristic plicae. A paratype from the Colorado
Group (Mancos) at Carthage, N. Mex. (locality 63, U.S.G.S. 3295) ;
U.S.N.M. 132265.
Fig. 9. Lateral view of a right valve with reverse inclination (opisthocline)
and enlarged anterior auricle. Note broad plicae, short smooth stage
limited to umbo. A paratype from the Mancos Shale, zone of
Collignoniceras hyatti, Socorro County, N. Mex. (locality 66, U.S.G.S.
D2042) ; U.S.N.M. 132266.
Fig. 10. Lateral view of a left valve, characteristic of the subspecies. Note
broad plicae, few in number, broad posterior auricular sulcus, inclination
of posterodorsal margin. The holotype, from a massive sandstone in the
Mancos Shale, zone of Collignoniceras hyatti, Socorro County, N. Mex.
(locality 66, U.S.G.S. D2042) ; U.S.N.M. 132267.
Fig. 11. Lateral view of a left valve with narrow plicae, otherwise typical
of the subspecies; a paratype from the septarian limestone concretion
zone, upper Blue Hill Shale Member, Huerfano Park, Colo. (locality 62,
U.S.G.S. 738) ; U.S.N.M. 22012.
Fig. 12. Lateral view of a left valve with narrow ribs, or plicae, occurring
along with normal individuals of the subspecies in the Mancos Shale near
Carthage, N. Mex. (locality 63, U.S.G.S. 3295). Compare this with
figure 11, from the Blue Hill Shale Member, Huerfano Park, Colo. A
paratype, U.S.N.M. 132268.
Fig. 13. Lateral view of an unusually broad variant of the subspecies from
the Blue Hill Shale Member, Huerfano Park, Colo. (locality 69), closely
comparable to marginal variants of L. bellaplicata bellaplicata from the
Codell Sandstone in the same area (see pl. 6, fig. 15). A paratype;
U.S.N.M. 132269.
Fig. 14. Lateral view of a high left valve with reduced posterior auricle;
paratype from the Mancos Shale at Carthage, N. Mex. (locality 65,
U:S.G:S. 5303) ; U:SN.M.-132270:
Fig. 15. Lateral view of an exfoliated left valve, showing characteristic
outline and radial ornamentation; a paratype from the Mancos Shale at
Carthage, N. Mex. (locality 64, U.S.G.S. 3297); U.S.N.M. 132271.
Fig. 16. Lateral view of a robust left valve, characteristic of the subspecies; a
paratype from the Mancos Shale, zone of Collignoniceras hyatti, Socorro
County, N. Mex. (locality 66, U.S.G.S. D2042); U.S.N.M. 132272.
Fig. 17. Lateral view of a left valve with posterior auricle larger than normal
and density of plicae approaching that of L. bellaplicata bellaplicata; a
paratype from the Mancos Shale, Carthage, N. Mex. (locality 65,
U.S.G.S. 5303) ; U.S.N.M. 132273.
NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP—KAUFFMAN gI
Fig. 18. Lateral view of a large left valve, characteristic of the subspecies;
a paratype from the Mancos Shale at Carthage, N. Mex. (locality 64,
U.S.G.S. 3297) ; U.S.N.M. 132274.
Fig. 19. Lateral view of an unusually high left valve, otherwise characteristic
of the subspecies; a paratype from the Mancos Shale at Carthage, N.
Mex. (locality 65, U.S.G.S. 5303) ; U.S.N.M. 132275.
PLATE 8
Lopha bellaplicata novamexicana Kauffman, new subspecies
Fig. 1-3. Anterior views of left valves illustrating the range in convexity, the
great convexity of the umbonal region, and the dorsal position of the high
point of the valve. All specimens from the Mancos Shale of New Mexico,
zone of Collignoniceras hyatti. 1, U.S.N.M. 132282, from locality 66.
2, U.S.N.M. 132271, from locality 64. 3, U.S.N.M. 132276, from locality
66. All figures <1.
Fig. 4. Lateral view (<1) of a left valve, characteristic of the subspecies
except for fainter plicae; paratype from locality 66, U.S.G.S. D2042,
Mancos Shale, zone of Collignoniceras hyatti, Socorro County, N. Mex.
U.S.N.M. 132277.
Fig. 5. Lateral view (1) of a left valve with large vertical attachment
scar and unusually fine plicae; paratype from the Mancos Shale, zone of
Collignoniceras hyatti, Socorro County, N. Mex. (locality 66, U.S.G.S.
D2042) ; U.S.N.M. 132278.
Fig. 6. Lateral view (<1) of a large left valve transitional with L. bella-
plicata bellaplicata in development of plicae and auricular sulci, but retain-
ing characteristic shell form of the subspecies; a paratype from the
Mancos Shale, zone of C. hyatti, Socorro County, N. Mex. (locality 66,
U.S.G.S. D2042) ; U.S.N.M. 132279.
Fig. 7. Lateral view of a large left valve (1) characteristic of the sub-
species; a paratype from the zone of C. hyatti, Mancos Shale, Socorro
County, N. Mex. (locality 66, U.S.G.S. D2042) ; U.S.N.M. 132280.
Fig. 8. Lateral view (1) of a typical left valve with worn plicae; a paratype
from the zone of C. hyatti, Mancos Shale, Socorro County, N. Mex.
(locality 66, U.S.G.S. D2042) ; U.S.N.M. 132281.
Fig. 9. Lateral view (1) of a typical large, adult left valve; a paratype
from the zone of C. hyatti, Mancos Shale, Socorro County, N. Mex.
(locality 66, U.S.G.S. D2042) ; U.S.N.M. 132282.
Lopha bellaplicata bellaplicata (Shumard)
Fig. 10. Thin section (4) through the umbo and cardinal area of a large
left valve; section parallel to the hinge line. Note major layers in sub-
nacreous layer, and fine crystalline calcite sheets within them. Fine layers
inclined to plane of major layers over umbo, parallel to this plane
laterally; a hypotype from the upper Eagle Ford Shale, Dallas County,
Tex. (locality 15, U.S.G.S. 7539) ; U.S.N.M. 132283.
Fig. 11. Thin section (<4) taken along the median plica, showing the struc-
ture of the subnacreous shell layer, the “hingement” of the valves, position
g2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
of the ligament, and the position of the cardinal axis on the cardinal plate.
Note that subnacreous layer is composed of distinct major calcite layers
(lamellae) parallel to the surface of the shell; each layer is composed of
fine fibrous-appearing calcite crystals or plates inclined to the plane of the
major layers, and in many cases, with opposed inclination within or
between major layers. A hypotype from sands of upper Eagle Ford age,
Grayson County, Tex. (locality 50, U.S.G.S. 14553); U.S.N.M. 132284.
Lopha lugubris (Conrad)
Fig. 12. Thin section (8) through part of the left valve, showing major
calcite lamellae in subnacreous layer and minor inclined fibrous calcite
crystals or plates within them, as described for figure 11. A hypotype
from New Mexico (locality 1, U.S.G.S. 513) in the zone of Prionocyclus
wyomingensis. U.S.N.M. 132285.
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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 6, PLATE 1
LOPHA LUGUBRIS (CONRAD): LEFT VALVE
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 6, PLATE 2
LOPHA LUGUBRIS (CONRAD): RIGHT VALVE
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 6, PLATE 3
LOPHA BELLAPLICATA BELLAPLICATA (SHUMARD): LEFT VALVE. TEXAS
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
VOL. 148, NO. 6, PLATE 4
SMITHSONIAN MISCELLANEOUS COLLECTIONS
LEFT VALVE. TEXAS
LOPHA BELLAPLICATA BELLAPLICATA (SHUMARD):
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
AITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 6, PLATE 5
13
LOPHA BELLAPLICATA BELLAPLICATA (SHUMARD): LEFT AND RIGHT VALVES. TEXAS
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 6, PLATE6
LOPHA BELLAPLICATA BELLAPLICATA (SHUMARD): VAR. A AND FORMA TYPICA:
LEFT AND RIGHT VALVES. TEXAS AND COLORADO
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
{ITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148, NO. 6, PLATE 7
LOPHA BELLAPLICATA NOVAMEXICANA KAUFFMAN, N. SUBSP.-:
LEFT AND RIGHT VALVES. COLORADO AND NEW MEXICO
(SEE EXPLANATION OF PLATES AT END OF WZ)
SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOL. 148, NO. 6, PLATE
LOPHA BELLAPLICATA NOVAMEXICANA KAUFFMAN, N. SUBSP.:
L. BELLAPLICATA BELLAPLICATA (SHUMARD): L. LUGUBRIS (CONRAD)
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
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VOLUME 148, NUMBER 7
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§
AN ACCOUNT OF THE ASTROPHYSICAL
OBSERVATORY OF THE SMITHSONIAN
INSTITUTION, 1904-1953
By
Cc. G. ABBOT
Research Associate, Smithsonian Institution
(PusticaTion 4656)
CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
FEBRUARY 24, 1966
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SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 148, NUMBER 7
Roebling Fund
PN ACCOUNT OF THE ASTROPHYSICAL
OBSERVATORY OF THE SMITHSONIAN
INSTITUTION, 1904-1953
By
C. G. ABBOT
Research Associate, Smithsonian Institution
(PusiicatTion 4656)
CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
FEBRUARY 24, 1966
PORT CITY PRESS, INC.
BALTIMORE, MD., U. S. A. ot
ANVACCOUNT. OF. THE ASTROPHYSICAL
OBSERVATORY OF THE SMITHSONIAN
INSTITUTION, 1904-1953
By Cuartes G. Assot, D.Sc.
Research Associate, Smithsonian Institution
THE SMITHSONIAN’S ASTROPHYSICAL OBSERVATORY was founded by
Secretary Samuel P. Langley in 1890. Until 1900 the Observatory’s
original research activities included developing and improving appa-
ratus, and mapping the then little-known infrared spectrum of the
sun. The bolometer, which Langley had invented about 1878, was
given photographic registration, tamed to be as quiet and reliable as
a mercury thermometer, and used to record small depressions where
absorption lines occurred in the solar spectrum. The Observatory’s
highly exact determinations of the dispersion of rock-salt and fluorite
prisms fixed the wavelengths of these absorption lines. Volume 1 of
the Annals, describing all of this work, was published in 1900. Expe-
ditions to North Carolina and to Sumatra observed the total solar
eclipses of 1900 and 1901, and a small eclipse volume was published
in 1903.
The Observatory then took up measurement of the intensity of the
sun’s radiation, the variability of it, and the transmission of radiation
by the earth’s atmosphere in the visible and infrared spectrum. The
average intensity of solar radiation received by the earth, called the
“solar constant,” was then unknown between the limits 1.76 and
4.0 calories per square centimeter per minute. Solar constant research
and the dependence of weather on solar variation principally occupied
the Observatory from 1904 through 1953.
ADMINISTRATION OF THE OBSERVATORY, 1904-1953
FINANCIAL SUPPORT
A breakdown of the Observatory’s financial support from 1904
through 1953 shows that the average yearly support for this period
was $37,000.
SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 148, NO. 7
2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Congressional appropriations 5... <i 2... «.<m« $1,148,000
Giits by: John, A. Roebling 2 2ess0 eee ee 617,000
Grants by National Geographic Society........ 65,000
From Smithsonian, fands: 2 Miles tinak ws ial tae 10,000
Other Gitte 2 TAL tb SE REE 10,000
Totaly cess iets encom rake eons One erm ee $1,850,000
The finances were managed by the Smithsonian Disbursing Office.
STAFF
The number of persons employed for all purposes varied from 2
to 14.
BUILDINGS
With headquarters in Washington, instruments were designed and
constructed there, and early observations were made there. However,
most of the observing later was done on several high mountains in
distant arid lands. In all, 16 structures were built in these far-off
lonely places to house observers and instruments. A valuable sug-
gestion by E. B. Moore led us to construct underground laboratories
in sloping ground for the spectrobolometric apparatus. Thus we
obtained constant temperature. We fed the sun-rays into these
tunnels horizontally with coelostats.
ACTIVITIES OF THE OBSERVATORY, 1904-1953
INSTRUMENTS
Five kinds of pyrheliometers for measuring the intensity of sun-
rays were designed. These included the silver-disk, the water-flow, the
water-stir, the improved Angstrom, and the automatic-balloon pyrheli-
ometers. For measuring sky-radiation the pyranometer was designed.
Other instruments designed included the vacuum bolometer, special
extrapolator for spectral atmospheric transmission measures, appa-
ratus for observing stars by day for guiding airplanes, a compact
spectrobolometer for expeditions, eclipse apparatus, high intensity
lamps for Fowle’s infrared investigation, numerous supports for
mirrors, and many other observing devices. All of these instruments
were constructed by Andrew Kramer, instrument maker for the
Observatory, 1891-1950, and after 1950 by Darnel Talbert.
NO. 7 ASTROPHYSICAL OBSERVATORY, 1904-1953—ABBOT 3
PUBLICATIONS
Quarto volumes 2-6 of the Annals, prepared by C. G. Abbot, F. E.
Fowle, and L. B. Aldrich, and volume 7, prepared by L. B. Aldrich
and W. H. Hoover, were published 1908-1953. About 150 papers,
mostly published in Smithsonian Miscellaneous Collections, were
written by members of the staff.
THEORETICAL FINDINGS
Langley showed about 1880 that, to determine the solar constant,
the spectral transmission of the atmosphere must be measured. This
was always done by us with a clock-operated recording spectro-
bolometer in Langley’s Method (now often called the “long method’’).
Langley did not publish a complete theory of this method, and he
used it erroneously in publishing his Mount Whitney Expedition of
1881. This error gave his preferred solar constant value 3.07 instead
of 2.0 calories. The full theoretical demonstration, and examples of
the correct application of Langley’s method are published in Annals,
volume 2.
Although Langley’s method is fundamental, it requires several
hours of observing while the sun’s air mass or atmospheric path
changes from (say) 3.5 to 1.5 times that for vertical sun. During this
considerable time the transparency of the atmosphere always changes.
If it grows clearer for small air masses the resulting solar constant
is too large, and vice versa. Hence only large groups of solar constant
measures by Langley’s method can be trusted ; these give mean values
nearly correctly.
A brief method for measuring spectral transparency was required,
so that several values of the solar constant could be obtained daily,
with little atmospheric variation affecting any one of them. Then
the day’s mean value would be good. .
From 1920 to 1924 the A.P.O. developed the “short method.” This
is empirical, depending on the fact that the brightness of the sky near
the sun is greater as the sky becomes more hazy. It is found pos-
sible to draw curves suited at all times to yield transmission coefficients
suited to each station occupied for all of the 40 wavelengths used in
Langley’s method. A “short method” measurement requires only
one reading of the pyranometer of sky-brightness near the sun. So
in the 10 minutes employed for making a spectrobolometric graph of
1] will use the abbreviations “A.P.O.” for Astrophysical Observatory, and
“Pub.” for publication.
4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
the solar spectrum, with a reading of the pyranometer on a limited
sky area surrounding the sun, a reading of the pyrheliometer on the
sun itself, and a theodolite measurement of the sun’s zenith distance,
the observations are complete.
We made three or sometimes five determinations of the solar con-
stant a day by the short method, and used their mean value for the
day’s result. From 1924 to 1952 over 9,000 mean daily values of the
solar constant were obtained. Many of them were observed from
three independent stations on the same day. It is shown by table 1,
page 13 of Smithsonian Publication 4545,? that by comparing 1992
pairs of solar constant observations of the same day, made individu-
ally at stations separated by thousands of miles, some in the Northern,
others in the Southern Hemisphere, and at all times of the year, the
probable error of a single day’s observation of the solar constant at
one station is 4 of 1 percent. All of the approximately 9,000 daily
determinations, published in volumes 6 and 7 of Annals, were scru-
tinized at Washington, and unanimously approved for publication by
a committee comprising L. B. Aldrich, W. H. Hoover, and Mrs.
A. M. Bond.
TOWER TELESCOPE
Langley hoped that these 9,000 daily determinations would prove
that a strong correlation could be found between daily solar constant
values and simultaneous observations of the distribution of the
intensity of solar radiation along the east-west diameter of the sun’s
disk. Some preliminary observations of that distribution were made
in Washington in 1908. Later a tower telescope to form an 8-inch
image of the sun was erected on our observatory on Mount Wilson,
about 1913. From 1913 to 1920, on all observing days, the telescope
also was adjusted between observations to form a solar image on the
slit of the spectrobolometer. The telescope clock was then stopped,
and the solar image was allowed to drift centrally over the slit. Thus
was recorded M-shaped distribution curves in five wavelengths on
each day that a solar constant value was obtained. See figure 52,
Pub. 4545.?
Owing to inexactness of solar constant values due to the fluctuation
of atmospheric transmission during the several hours required for
solar constant measures by Langley’s method (used exclusively on
2 Solar variation and weather, by C. G. Abbot. Smithsonian Miscellaneous
Collections, vol. 146, No. 3. 1963.
NO. 7 ASTROPHYSICAL OBSERVATORY, I904-1953—-ABBOT 5
Mount Wilson, 1905-1920) it was not then possible to be assured of
the correlation between solar constant and diametral distribution. But
when the family of harmonic variations in the solar constant values
became known about 1940, the solar constant value was back-casted
from 1920 to 1913, and such correlation seemed indicated. See fig-
ures 50 and 51, Pub. 4545.2, Solar contrast observations were dis-
continued in 1920, and solar constant determinations have never been
made anywhere in the world since 1955. So this correlation cannot
now be fully proved.
PRINCIPAL RESEARCHES
Leading Operations of the Smithsonian Astrophysical Observatory,
1895 to 1955* (Smithsonian Pub. 4222) gives brief summaries of
82 researches, with bibliographic references to the original publica-
tions of them. I select here for notice a few of the most important
researches which occupied the years 1904 to 1953.
1. Inventions of pyrheliometers, vacuum bolometer, pyranometer,
honeycomb pyranometer, two-mirror coelostat, highly sensi-
tive radiometer, and solar heat collector.
2. Absolute measurement in heat units to 1 percent of the solar
constant, with probable error of a day’s measurement at one
station 3 of 1 percent relative to other day’s measures.
3. Fixing the limits of sun’s radiating temperature as between
5800° and 7000° C. Abs. Four methods used.
4. Measurement of atmospheric spectral transmission in 40 wave-
lengths at 10 stations located between sea level and 14,500
feet elevation.
5. Determining the distribution and intensity of radiation in the
solar spectrum at 10 stations, and outside the earth’s atmos-
phere.
6. Short method for the solar constant, and also automatic balloon
determination.
7. Discovery of solar variation between limits of 2.0 percent in
amplitude.
8. Discovery of a 27-day period in “solar constant” variation.
9. Discovery of a numerous harmonic family of exact periods in
solar variation with a master period of exactly 273 months.
3 Leading operations of the Smithsonian Astrophysical Observatory, 1895 to
1955, by C. G. Abbot. Smithsonian Miscellaneous Collections, vol. 131, No. 1.
1955.
6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
10. Discovery of these identical harmonic periods in terrestrial
temperature, and in precipitation, and a method of long-
range forecasts based thereon.
11. Discovery of opposing trends in terrestrial temperature, at-
tending for 16 days after rising and falling trends in solar
radiation.
12. Fowle’s work on terrestrial radiation and its absorption.
13. Aldrich’s measure of the earth’s albedo.
14. Aldrich’s work with the honeycomb pyranometer.
15. Aldrich and Hoover’s work, in volume 7 of Annals, on the
solar constant, and on solar and sky radiation at military
camp sites.
16. Work of the Division of Radiation and Organisms, a subsidi-
ary branch of the A.P.O., founded by Secretary Abbot in
1929.
CRITICISM OF CERTAIN METEOROLOGICAL FINDINGS
While many of the pieces of work are everywhere praised and
accepted,* professional meteorologists have disparaged the alleged
results indicated by numbers 2, 7, 8, 9, 10, and 11, listed above. I had
hoped to overcome their doubts by my publication 4545.2 However,
recent private advices from responsible officers of the U.S. Weather
Bureau, the American Meteorological Society, and the High Level
Atmospheric Observatory at Boulder, Colorado, convince me that
their doubts still remain. As I feel quite certain of the soundness of
these A.P.O. results, I feel a duty to dispel these official objections.
In the remainder of this paper new evidence will be presented.
A DEFENSE OF CERTAIN METEOROLOGICAL FINDINGS
SOLAR RADIATION AND ITS VARIABILITY
Numbers 2 and 7—The accuracy of A.P.O. measures of the solar
constant, and the limits of its variation.
Referring to table 1, page 13 of Pub. 4545,? the probable error of
one day’s solar constant measure at one station (usually the mean of
three independent observations) is 4 of 1 percent. It is certified by
1992 pairs of solar constant measures on identical days made at four
observing stations at all times of the year. One station is in the
Southern, three in the Northern Hemisphere, and they are separated
by thousands of miles. Table 1, just cited, is composed of four sec-
4 See expert opinions given in volume V of Annals, A.P.O., pp. 32-35.
NO. 7 ASTROPHYSICAL OBSERVATORY, 1904-1953—ABBOT 7
tions whose individual mean values differ only through the small range
from 76.0 to 77.9 parts in 10,000 of the solar constant.
As for the extreme limits of solar variation, I sent Dr. Roberts
of High Level Observatory a rough plot of all Montezuma solar
constant daily mean values, 1923 to 1952. He retains a copy of it.
From numerous of these values, some as low as 1.910, some as high
as 1.970, I believe it fair to set solar variation limits as above 2 per-
cent. Dr. Franz Baur of the University of Frankfurt, A.M., Germany,
has published 2.2 percent as his conclusion.°®
On one occasion the solar constant appears to have gone as low as
1.870 calories in 1922 and 1923, for a considerable time. This unique
depression may be associated with a long-range period in solar varia-
tion that would require scores or centuries of years of observation to
verify.
PERIODIC SOLAR VARIATION
Number 8—The 27-day period in solar variation.
It has long been known that the sun’s surface shows rotation vary-
ing in velocity from the sun’s equator to its poles. At the equator the
sun rotates in about 25 days, and in about 35 days at 80° latitude.
A weighted value of the sun’s rotation period, considering areas and
latitude, may be taken at 27 days. In Pub. 2499,° I showed strong
correlation in solar constant measures ranging continuously from
+25 to —30 percent, with a period of 27 days. See figure 15, Pub.
4545.2 This wide range was observed in Mount Wilson values in 1915,
but not in other years, 1912-1920.
Having discovered the master period, 22 years, 9 months (273
months) in solar variation about 1940, it seemed to me probable that
the highly accurate solar constant measures made at Montezuma would
show a 27-day period strongly in the year 1937 (1915+22 years),
perhaps repeated several times. I have computed from records in
volume 6 of the Observatory’s Annals for four recurrences of the
27-day period in daily solar constant values observed at Montezuma
from early April to late September of 1937. Table 1 and accompany-
ing Figure 1 show the detailed and mean results. A 27-day periodic
5 Met. Rundschau, 17 January, Jahrb. 1, Heft 1964, pp. 19-25.
: rte : 273 273
6 Solar rotation and solar variation. Periods 27 days and 2250 and 3500
months shown by correlation in 1915 and 1916, by C. G. Abbot. Smithsonian
Miscellaneous Collections, vol. 66, No. 6. 1918.
VoL. 148
SMITHSONIAN MISCELLANEOUS COLLECTIONS
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NO. 7 ASTROPHYSICAL OBSERVATORY, I904-1953—ABBOT 9
variation, with an amplitude of about 4 percent of the solar constant,
appears as the mean result of four well-observed repetitions.
This new evidence and that of 1915 (Pub. 4545, fig. 15) seems to
me to show decisively the 27-day rotation period in solar variation.
I have referred to the apparent 27-day effect on Washington pre-
cipitation at pages 45 and 46, and table 8 of Pub. 4545.? Using 27.0074
days as the exact period, I found good success in predicting the
CALORIES
Fic. 1—The 27.006-day period in solar variation.
175 days more apt to have rain in Washington than the other 190 or
191 days of the years 1942-1954. (See table 8, Pub. 4545.*) The
formula failed only in 1952 and 1953 (possibly because of bomb
explosions and fallout). Continuing to use the same formula in pre-
diction for the year 1963, the whole group of preferred days proved
displaced, recurring one day too early. But if the period is slightly
changed to 27.0056 days it would have made no difference in fore-
casts prior to 1954, but in 1963 the preferred days (one day earlier)
would have had 1.30 times the average precipitation falling in all
others.
Io SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
OPPOSING SOLAR TRENDS
Number 11—I mportant opposed trends in solar variation.”
The A.P.O. at Washington devoted much effort after 1942 to
studying such upward and downward trends in solar variation as are
shown in figure 46, Pub. 4545,? not here reproduced. It was
found that the temperature in Washington and several other United
States and European cities responded to these solar trends by long-
lasting marches, opposed like right and left hands. So many papers
have been published on this observation that it seems superfluous
to bring more evidence here. Figures 46, 47, and 49, and pages 52 to
57 of the text of Pub. 4545? show that large opposed temperature
changes occurred simultaneously in Europe as well as in the United
States in response to over 300 cases of such opposite solar trends. (See
fig. 45, Pub. 45457.) Pub. 3771 ® presents a long investigation of the
subject. It ends with a summary containing 18 sections. Not only
solar constant measures, but solar faculae, calcium flocculi, and iono-
spheric phenomena act as triggers to set off these opposed long-
continued large temperature variations.
In Pub. 4462 ° of 1961 it is suggested that much better solar con-
stant measures could be made from earth satellites than from moun-
tains, because the atmosphere would be eliminated. If that were done,
forecasts of detailed world temperature, depending on trends of solar
variation, could be obtained covering 16 to 20 days in advance con-
tinuously. (The above cited fig. 49 of Pub. 4545 ? is given originally
in Pub. 4462.°)
TERRESTRIAL WEATHER
Number 10—Harmonic periods and long-range forecasts.
We now come to the important claim of a harmonic family in
weather changes identical in periods with such a family in solar varia-
tion, but showing far more percentage change in weather than in
solar variation. Even more obnoxious to meteorologists has been the
claim that useful weather predictions can be made from knowledge
7I insert Number 11 before Number 10, because Number 10 is potentially our
most important discovery, requiring extensive comment and deserving the most
emphatic place of all our discoveries.
8 Weather predetermined by solar variation, by C. G. Abbot. Smithsonian
Miscellaneous Collections, vol. 104, No. 5. 1944.
9 16-day weather forecasts from satellite observations, by C. G. Abbot. Smith-
sonian Miscellaneous Collections, vol. 143, No. 2. 1961.
NO. 7 ASTROPHYSICAL OBSERVATORY, I904-1953——-ABBOT II
of it, 10 or even 50 years in advance, or backwards. Recently, how-
ever, some meteorologists seem to be more favorably impressed.
Some confusion has been caused by over-riding periods.
It must be clear to all that if there actually is such a large harmonic
family in weather periods, ranging in lengths from 4 months to the
master period of 273 months, then a tabulation at individual stations
of weather periods, e.g., of EASES Fe months must be overlaid by
4
shorter periods, such as a et cetera. So the primary tabulation
for a 684-month period must necessarily look very rough. It may not
even suggest a “hidden” period of 684 months unless those overlying
shorter harmonics can first be removed.
I now refer the reader to the accompanying figures 2, 3, and 4, pre-
pared from Jon Wexler’s electronic tabulations of monthly “World
Weather Records,” 1870 to 1940. He obtained monthly normals of
precipitation at Rome, Italy, Kief, U.S.S.R., Capetown, South Africa,
and other stations, separately for years when Wolf sunspot numbers
= 20. From these he obtained the departures in percentage of normal
for all months, 1870-1949. These are divided into four groups which
we call Category 1, Divisions 1 and 2; Category 2, Divisions 1 and 2.
“Division” refers to first and second half of the interval 1870-1949.
“Category” refers to Wolf numbers = 20 sunspot numbers.
Figure 2, for the 684-month period in Category 2, combines Divi-
sions 1 and 2 at Rome, Italy. It shows five starting dates: June 1902,
February 1908, October 1913, June 1919, and March 1925. A lack
of recorded observations in later years before 1949 prevented using
a sixth column. The mean of these 5 columns is plotted in the bottom
full curve. No one seeing this curve could suppose it would easily
be resolved, and would disclose a smooth sine curve of 684 months.
But when the over-riding periods BOS DUS, AON 213. Bi Saas are
8 12928" Ae 20.44
successively computed and removed, as shown in figure 2, there re-
sults the beautiful smooth sine curve shown at the top of figure 3,
a
representing only 28 or 684 months. Its amplitude is over 30 percent
of normal precipitation.
I am sure it will not be necessary to so particularly describe figures 3
and 4 relating to Kiev, U.S.S.R. and Cape Town, South Africa, which
each include one group of Jon Wexler’s electronic tabulations, being
273
for the periods 273 and oF months, respectively. They display over-
12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
‘ 273273 243 ‘ 273273273278
riders, 5693440’ for Kiev, and 18’ 27' 4563" for Cape Town.
These two stations, cleared, show smooth sine curves, respectively, of
amplitudes 25 and 16 percent of normal precipitation. I call attention
ater i861 Pet
HB tae :
sist jada od
ear 733
fooe - : He
|
i
ae AST Ne { ry aon ; Soe HE a H enue 7 $ |
Htigs arittee Hag 1H “Hy aie] Bat tesla NeHtiys
é ere Pang a dea irene
FEU GbE at aah
eH WH el '
Fic. 2.—Rome, Italy. 684 Month Period Cleared.
vata é tree tii
hee
1. a
a =
Pearse a ees “eesseasa 6
iu - 5
to the far geographical separation of the three cities concerned in
figures 2, 3, and 4. Similar results, not so fully exposed in the pub-
lishing of them as figures 2, 3, and 4, are shown for several U.S cities
in figures 18, 19, 20, 23, 24, and 25 of Pub. 4545 ? and for other sta-
tions not here cited. Altogether the figures just cited would display,
NO. 7 ASTROPHYSICAL OBSERVATORY, I904-1953—-ABBOT 13
necessarily as super-riders, the existence of nearly all of the 27 periods,
harmonics of 273 months, which we use in forecasting weather.
Similar clearing gives similar sine-curve results for long periods at all
54 stations so far forecasted.
Referring now to figure 21 of Pub. 4545,? it shows the actual plus
rirTiiiy
sanear.
gtenvecassces
.
db sBeee
* e955 oes
Fic. 3.—Kiev, U.S.S.R., Precipitation. 344 Month Period Cleared.
and minus quantities which resulted from tabulations I made for
St. Louis, working on them alone without electronic assistance. These
23 columns of figures, being added, gave a 20-year back-cast from
the mean date 1897 of the precipitation at St. Louis, 1875-1879. It is
nearly identical with the actual precipitation observed. As stated in
Pub. 4211,?° all that work was done on 5-month consecutive means
1060-year weather forecasts, by C. G. Abbot. Smithsonian Miscellaneous
Collections, vol. 128, No. 3. 1955.
14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
of the monthly records of St. Louis, 1854-1940. Such 5-month con-
secutive smoothing is also used in Jon Wexler’s electronic tabulations
for foreign stations, mentioned above. But that does not prejudice
at all our discovery that very successful long-range forecasts can be
made. See also figure 22 of Pub. 4545?
a | |
mca PN
Soe te
P Li
88 | Bee
AR APR
legwl tl igen | ee
[CP Se | |
sae
soe
Se a
pet tag
aban oo
tb elatad
cl
Lips
a
oe
LE
a
gq
fF
el
ie
rf
"4
a
4
4
|
=
|
I
rT
aso
‘a
is]
oar
id
Fic. 4—Cape Town, South Africa Precipitation. 304 Months Cleared.
Landsberg, Mitchell, and Crutcher, in their paper on climatological
data for Woodstock, Md., describe that station “as a member of the
Weather Bureau’s Climatological Benchmark Network.” I feel very
grateful to Dr. Landsberg that he has sent me two sheets of the
monthly records of precipitation at Woodstock covering 1870 to
1963. Mr. Jon Wexler has prepared these records for my use to
make an analysis with forecast through 1969. I have made such a
forecast 1950 through 1969 for Woodstock, which shows correlation
NO! 7 ASTROPHYSICAL OBSERVATORY, I904-1953—-ABBOT 15
with observation from 1950 to 1963 of about +42 percent. Unfor-
tunately displacements of obviously similar features made this cor-
relation coefficient fully 10 percent lower than those for most U.S.
stations. Rectifying these obvious displacements, I found a correla-
tion coefficient of +72 percent for Woodstock.
Figures 2, 3, and 4 of the present paper, and figures 18, 19, 20,
21, 22, 23, 24, and 25 of Pub. 4545,? and many examples I have en-
countered in forecasts of precipitation for 54 cities show how over
30 regular periods, harmonics of 273 months, are “hidden” if one
regards meteorological time as if it were a river running serenely
forever in a smooth uniformly inclined channel. All researchers do
so who neglect tume of the year, sunspot activity, and march of popu-
lation, all affecting atmospheric transparency, and neglect the super-
position of short-period harmonics confusing longer ones.
CLASSIFIED REFERENCES FROM SMITHSONIAN PUBLICATIONS
A. Accuracy of the solar constant as measured.
(1) Annals, A.P.O., vol. 6, p. 163. Published 1942.
(2) Smith. Misc. Coll., vol. 134, No. 1, Pub. 4265, p. 2. Published 1956.
(3) Smith. Misc. Coll., vol. 146, No. 3, Pub. 4545, table 1, pp. 10-15. Pub-
lished 1963.
B. “Hidden” periodicities.
In solar constant measures:
(1) Smith. Misc. Coll., vol. 117, No. 10, Pub. 4088. Published in 1952.
(2) Smith. Misc. Coll., vol. 128, No. 4, Pub. 4213, pp. 4 and 6, table 1, fig. 1,
and pp. 9 and 10, fig. 2. Published 1955.
In weather:
(2) Smith. Misc. Coll., vol. 117, No. 16, pp. 11-18, 5 tables, 8 figs., Pub. 4095.
Published 1952.
(3) Smith. Misc. Coll., vol. 121, No. 5, pp. 2-5, table 1, fig. 1, Pub. 4103. Pub-
lished 1953.
(4) Smith. Misc. Coll., vol. 128, No. 3, pp. 1,2, Pub. 4211. Published 1955.
(5) Present paper, Number 10 “Harmonic periods and long-range forecasts.”
C. Weather forecasts do not require solar observations.
Their independence from all solar measures except Wolf numbers. = 20.
(1) Smith. Misc. Coll., vol. 121, No. 5, line 22, p. 2; line 15, p. 11, Pub. 4103.
Published 1953.
D. High positive correlation with events.
(1) Smith. Misc. Coll. vol. 128, No. 3, pp. 4-5, Pub. 4211. Published 1955.
(2) Smith. Misc. Coll., vol. 139, No. 9, p. 1, Pub. 4390. Published 1960.
(3) Smith. Misc. Coll., vol. 146, No. 3, pp. 60, 63, 64, Pub. 4545. Published
1963.
(4) Smith. Misc. Coll., vol. 143, No. 5, p. 5, fig. 4, Pub. 4471. Published 1961.
I have (unpublished) the correlation coefficient between back-cast and obser-
16 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
vation for St. Louis monthly precipitation, 24 months, 1878 and 1879. It is
based on all records 1854 to 1939, centering at 1897. It is + 87.5+ 6.5 percent.
E. Average deviations of forecasts from events are no greater at wide depar-
tures from normal, or after long lapse of time.
(1) Smith. Misc. Coll., vol. 143, No. 5, pp. 1, 6, table 1. Pub. 4471. Published
1961.
(2) Smith. Misc. Coll., vol. 128, No. 3, Pub. 4211. Published 1955.
SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 148, NUMBER 8
Roebling Fund
FORECASTING FROM HARMONIC
PERIODS IN PRECIPITATION
By
Cc. G. ABBOT
Research Associate, Smithsonian Institution
GERM "INCRE
FOIA)
m <pcE AW0,0
e-INCeS
\\
CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
MARCH 23, 1966
vias
ks Tas Tih
NIM
hea
Ry
SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 148, NUMBER 8
Roebling Fund
FORECASTING FROM HARMONIC
PERIODS. IN. PRECIPITATION
By
Cc. G. ABBOT
Research Associate, Smithsonian Institution
(PupBLicaTIon 4659)
ABR
Gift-\
Publishes
Copy |
CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
MARCH 23, 1966
PORT CITY PRESS, INC.
BALTIMORE, MD., U. S. A.
FORECASTING FROM HARMONIC PERIODS
IN PRECIPITATION
By C. G. Asgor
Research Associate, Smithsonian Institution
THIS PAPER presents evidence showing that the identical family of
harmonic periods found in solar variation is also present strongly in
terrestrial precipitation, and may be used for long-range forecasting.
I wish to direct attention of those interested in water supply to fig-
ures 7 and 8, and to the Conclusion of this article. Figures 7 and 8
show in A the march of yearly precipitation at two stations for 36
years. The curves A in figures 7 and 8 are made from recorded
observations after it happened. The curves B, which are for practical
purposes nearly identical with curves A, could be predicted and were
actually predicted from records of observations made long ago before
the events happened.
1. PERIODS IN SOLAR VARIATION
Volumes 5, 6, and 7 of the Annals, Smithsonian Astrophysical
Observatory, tabulate over 9,000 days’ measures of the solar constant
of radiation. At page 13 and figure 1, Smithsonian Publication 4545,
it is computed that the daily accidental error of a measure of the solar
constant from one solar station is 0.007 calorie. Considering the num-
ber of stations responding, and the loss of days by clouds or other
causes, the accidental probable error of mean monthly values is esti-
mated at 0.05 percent of the solar constant.
Mr. Jon. Wexler has electronically smoothed the monthly solar
constant values, 1921 through 1952, by the formula c'=1/10 (a+2b+
4c+2d+e) which gives the central month, c, # as much weight as
the total weight of the other four. His results are given by table 1 and
figure 1.
In the year 1922 an exceptional depression of about 8 percent in
figure 1 is seen. This may possibly indicate the existence of a solar
period of long duration. The results from 1923 to 1955 display many
cases of long trends with amplitudes of solar variation up to 3 per-
cent. Figure 8a of Publication 4545 shows that the monthly values of
the solar constant repeated themselves, approximately, in great detail
with an interval of 273 months.
SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 148, NO. 8
Date
1921
1922
1923
1924
1925
1926
J
UZOMP HH 2 > SHY ZOUPHH SD BHO ZONED BIO ZOWPINE DEA ZOUPSM E> BIO ZOU PAD Ba
Solar
constant
+39
+31
SMITHSONIAN MISCELLANEOUS COLLECTIONS
Date constant
1927 J
F
1928
1929
1930
1931
1932
OZOMTHHE > BY ZOUD UZ > BIO ZOU DED 2 HHO ZOUPU E> BO ZOUPU PRI ZOWPA ESS
TABLE 1.—Smooth Solar Constant
Solar
Solar
Date constant
1933
1934
1935
1936
1937
1938
PAO DHHS > SHO ZONPU 2S > BY ZOWPHHE > SIO ZONSAAZ > BAI ZOOPAN ES > SAO ZOUPS Ey ET
+18
sede
1939
1940
1941
1942
1943
1944
OZOMD UZ > By ZONPHU 2 > SD ZOU DU Z > SHY ZOU RUZ SHAD ZOUPH E> BAIA ZOUPINE > BI
Solar
Date constant
+3
1945
1946
1947
1948
1949
1950
OZOM DHHS > SHY ZON PS > Sr ZOUPUNS > BIO AON SUE > SIO ZOU PME SE IO ZOUSATE pS Sa
Solar
Date constant
+1
4
vot. 148
1951
1952
OUP HZ > BHO ZOURUUZ> Zhi
Solar
Date constant
(221
22
23 24 25
Fic. 1—Smoothed solar constant.
Scale: 2 = 75 solar constant.
26
4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
I have now analyzed Wexler’s smoothed values to see if 27 exact
submultiples of 273 months, which I have long believed in, are verified.
The number of repetitions decreases from 77, for 44 months, to 5
7 Ear Faas :
273 4 273, a2 to =, Sub-periods removed
a Tie
Monthly solar constants, smoothed, 1923 to 1952. Formula: C=. (4+2B4+4C+2D+E).
Section 2. Section 3.
Ordinates scale: sta Solar constant = 2.
Fic. 2.—Solar periodic variation.
for 275 684 months. With only 3 repetitions for 91 months, I
omitted ae All periods longer that 153 months had one or more
over-riders, exactly their submultiples in length, whose amplitudes I
no. 8 HARMONIC PERIODS IN PRECIPITATION—ABBOT 5
computed and subtracted, in a method illustrated below in figure 3
for 542 months. My results, all closely approximating to sine curves,
are shown in figure 2.
Me an oF BRepttitions ofFeriod 273 re, cleo oie Bie we ond Be 273 Not neato ae
-|0 7
Fic. 3.—A solar constant period cleared of submultiples.
Amplitude: 0.20 percent.
The harmonics of 273 months are shown in figure 2 to range in
amplitude from 0.10 to 1.05 of 1 percent of the solar constant. All
are far greater than the accidental error of monthly solar constant
6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
measures as given above. And as each harmonic period is the mean of
many determinations, their amplitudes have probable errors far too
small to be due to chance.
2. PERIODIC TERRESTRIAL PRECIPITATION
Convinced 20 years ago of existing solar periodic variation, I
noticed in the long monthly records of Peoria, Ill., an indication of a
period of about 23 years in precipitation. I then tried during several
years to find other periods there. They appeared to exist, but to suffer
variable displacements associated with changes in atmospheric trans-
parency. Persevering, ways avoiding these difficulties were found,
leading at length to a method of long-range forecasting which I used
with surprising success on the records of St. Louis. See Smithsonian
Publication 4545, figures 21, 22, and 25, and explanatory text.
Prof. Wexler, of State University of Arizona, interested his son,
Jonathan Wexler, in my forecasting. Jon. Wexler, a student in
electronic programming, saw how the computing might be greatly
aided. Since 1955, he has prepared for my forecasts the long rec-
ords of precipitation of 55 stations in all parts of the world. I have
described in the publication “Solar Energy,” volume 1, No. 1, 1956,
and volume 2, No. 1, 1957, the tedious process used for my forecasts.
Smithsonian Publication 4390 gives forecasts, 1950 to 1967, for
32 stations in the United States. But while over 5,000 copies of
it were sold, besides 1,500 copies freely distributed by the Institu-
tion, professional meteorologists are still skeptical, notwithstanding
evidences of useful value given in pages 1 to 6 of Smithsonian Publi-
cation 4471. Hence it seems good to present now, in detail, evidence
that the identical family of harmonic periods found in solar variation
is also present strongly in terrestrial precipitation, and may be used
for long-range forecasting.
Figure 4 plots the forms and amplitudes of 26 periods in the precipi-
tation of Rochester, N.Y., 1884-1955, as computed by Jon. Wexler in
273
3 months is omitted from figure 4
222 separate tabulations. Period
me : Tey abe
because repetitions are too few for good evidence. Period agi
found in evidence at Rochester only as represented by the shorter
over-riding periods ae and is a: “3 is strong itself in St. Louis
precipitation. See Publication 4545, page 32, and at other stations.
no. 8 HARMONIC PERIODS IN PRECIPITATION—ABBOT 7
I give in figure 4 only the periods in Category 2. These, about
60 percent of the whole record, relate to intervals when Wolf sunspot
numbers exceed 20. The other 40 percent (in Category 1) were also
computed and used in the forecast below. But as their forms and
amplitudes are similar to those of Category 2, I omit printing them
SER tene el eka a!
STN ori cla te
ae
=
Vid a valle |
Eee Ee (ei een ee ey
Jigs e aa
eases eens se Mes
[is ladles a a Lael ed
e
IN
cS | =
aS
it
je
S
=
Fic. 4.—Rochester harmonic periods, 1884-1956.
Ordinates percent normal precipitation.
here. I give in table 2 details of interest regarding the periods plotted
in figure 4.
In Section 3 of figure 4 (184 to 684 months) all periods had over-
riding subperiods, such as 4, 4, 4. These were removed and not shown.
Figure 3 illustrates by numbers and forms the method of clearing
8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
long periods from over-riders, applicable both in radiation and in
precipitation.
3. LONG-RANGE PREDICTION OF PRECIPITATION
It is urged by experts in meteorology that exact measurements of
precipitation are so difficult, its local distribution so extraordinarily
TABLE 2.—Harmonic Periods in Rochester, N.Y., Precipitation
Exact Fractions of 273 Months, Category 2 Only
Amplitude Number of
Period percent of normal repetitions
Number Fraction in months precipitation per period
1 Ye 4 3 127
2, V4 5448 8 111
3 V5 6% 9 91
4 Vag 7 9 90
5 Vg 742 8 as
6 Vg 871 13 66
7 Yoo 9140 21 60
8 Vg 934 17 58
9 yz 10% 10 56
10 We 10% 15 53
11 V4 1136 18 48
12 Yoo 12%2 10 47
13 Vy; 13 14 41
14 Yo 131349 19 41
15 Vg 15% 15 36
16 Vs 184% 8 29
17 Ya 19% 12 26
18 Vg 2234 11 23
19 Vy 24%1 7 22
20 Yo 27%0 10 20
21 % 3014 9 19
22 % 344 9 14
23 Vy, 39 7 14
24 ¥ 45% 9 11
25 V% 5436 10 8
26 Y% 68% — 5
27 , 91 — 3
irregular, its jumps between zero and super-normal amplitude so
erratic that 50 years of observation are hardly enough to give satis-
factory monthly normals. Hence they prefer to do research with
temperature and pressure, hoping through atmospheric circulation to
find a path to advance in the forecasting of precipitation. My former
chief, the late Dr. S. P. Langley, encouraged me to hope that knowl-
edge of solar radiation and of its atmospheric transmission might
no. 8 HARMONIC PERIODS IN PRECIPITATION—ABBOT 9
open a direct path to foreknowledge of precipitation, that highly
important variable in agriculture and water supply.
This hope has now been realized by a combination of five discoveries
of the twentieth century. For more than 10 years now it has been
possible, with these five helps, to make useful forecasts longer than
one generation in advance. The discoveries referred to are as follows:
1. Nearly a century of patiently continued weather records are
now available. They embrace many stations in all continents, and are
published in World Weather Records.
2. Both the sun’s radiation and the long-continued weather records
contain as many as 27 harmonic periods, exact submultiples of 273
months, of equal lengths in solar radiation and in weather.
3. While solar variation varies in amplitude, its phases appear
constant. Weather phases, on the other hand, vary considerably as
conditions alter in the atmosphere. These phase shifts, which may be
as great as several months, differ with length of period, locality, time
of the year, sunspot frequency, and growth of population. These diffi-
culties require a large number of divisions to be made of the long
weather records. Indeed, 222 tables for each station are required,
as I have explained in previous publications.
4. The invention and development of the electronic computer
makes it possible to handle the multiplication of phase differences, and
any desirable smoothing of arrays of numbers in a few moments,
instead of years, as when I computed alone for St. Louis forecasts,
1854 through 1957.
5. The introduction of the smoothing formula 34 (a+2b+4ce+
2d+e) is highly valuable. In it the value c has 2 as great weight as
the four neighboring values combined. With an irregular variable,
like precipitation, smoothing is necessary. But to avoid displacing
phases by smoothing, it must avoid giving preponderant weight to
values outside the central value.
Before demonstrating more, it may not be superfluous to point out
that with nearly 100 years of records available, they may fairly be
used, not only for prediction but to test the validity of predictions
when made. For if all records of N years be employed in a prediction,
the monthly records of a single year cannot affect the prediction for
that year by more than an That quantity diminishes proportionally
with the increase of N and reaches the negligible value of 1 percent
when N=100.
VOL. 148
SMITHSONIAN MISCELLANEOUS COLLECTIONS
Io
Bs Ses peAtasqOQ ‘—sed9104F
‘uoreydioaid “x “Ny ‘ JajsayDOY—s “OTT
no. 8 HARMONIC PERIODS IN PRECIPITATION—-ABBOT II
Figures 5 and 6 give 6-year samples, graphically, of forecasts at
Rochester, N.Y., and Nashville, Tenn., within the interval 1921
through 1956. That entire interval has been forecasted. Its forecast
has been compared to observed departures from normal, and smoothed
by the formula 75 (a+2b+4c+2d+e). I give here only 6-year por-
tions of the comparison for I wish to keep this paper as brief as
possible. I fear that Smithsonian Publication 4545, on which I placed
high hopes, is too long, so that no one but myself ever reads it. The
forecasts given in figures 5 and 6 employ all the “World Weather”
records. These comprise for Rochester, 1884 through 1956, 72 years,
and for Nashville, 1870 through 1956, 86 years.
Readers may notice that due to the new smoothing formula, this
comparison mostly avoids the distressing shifts of prominent features
which sometimes amounted to 3 or 4 months in Publication 4390.
Both stations are included in the tables given in Publication 4390,
and Nashville is illustrated there in figure 29,
I have preferred to use Nashville forecast, 1950-1956, because it
was given 1950-1957 in Publication 4390, plate 3. Now employing
the new smoothing formula the new illustration is better. Besides, it
shows in 1950 to 1952 shifts and differences in amplitude of features
that may have resulted from hydrogen bombing by the U.S.A. and
the U.S.S.R. about 1950. I have found similar indications in nearly
all of 23 foreign stations I have forecasted.
Now I proceed to considerations which seem to me to clinch the
case for the validity and usefulness of long-range forecasts of pre-
cipitation. Figures 7 and 8 give for both Rochester and Nashville:
(A) percentage-yearly departures from the mean, 1921 through
1956, and 1921 through 1956, respectively, of the total rainfall
observed. (B) Departures from the smoothed means (of 72 and 86
years respectively) of forecasts, 1921 through 1956. These are com-
puted from all monthly records of 72 and 86 years respectively.
(C) Values of (A) smoothed by 75(a+2b+4c+2d+e), and (D)
values of (B) smoothed similarly.
First consider Rochester, figure 7, only. It will be seen from (A)
and (B) that the mean of all yearly departures, 1921 through 1956,
of (B), involving my forecast, is smaller than that of (A) observed.
These results are 9.3 and 11.5 percent. But it is also quite obvious
that if one confines attention to large departures, (B) has a much
larger advantage over (A). These results support long-range predic-
tions somewhat.
But what really clinches the case for the validity of my forecasting,
and all it comprises, is the second pair of curves (C) and (D). For
VOL. 148
SMITHSONIAN MISCELLANEOUS COLLECTIONS
12
yor sss peArasqQ ‘—}sed010,7
‘uoReHderd “uuay, ‘oTIAyseN—9 “OI
Mester
Sat
ve eS od
no. 8 HARMONIC PERIODS IN PRECIPITATION—-ABBOT 13
both curves show four major episodes. They are 1922 to 1928; 1928
to 1940; 1940 to 1949; and 1949 to 1954. Curve (C) is rigidly con-
ditioned by observation. But curve (D), on the other hand, depends
on forecasting, based on all the monthly observations, 1884 through
1956.
It shows in D, however, the same four great trends in precipitation
Tasle 3.—Harmonic Pertods in Solar Constant Exact Fractions of
273 Months, Category 2 Only
Amplitude Number of
Period percent of solar repetitions
Number Fraction in months constant per period
1 es 4% 0.10 127
2 Yes 5%s 0.08 106
3 Vs 6%45 0.22 91
4 lk ‘i 0.25 90
5 log 7IA2 0.11 73
6 Yes 8341 0.05 66
7 Yao 940 0.11 60
8 log 934 0.15 58
9 7 10% 0.20 56
10 Ye 10% 0.18 53
11 VY, 113 0.32 48
12 Yo 12%2 0.25 47
13 Peal 13 0.27 41
14 Yo 131349 0.10 41
15 Vg 15% 0.20 36
16 Vs 181% 0.17 29
17 V4 19% 0.10 26
18 Vo 2234 0.10 23
19 VY 24%1 0.11 22
20 Yo 27%40 0.15 20
21 % 3014 0.13 19
22 a7 341% 0.24 14
23 yy 39 0.75 14
24 ¥ 45% 0.20 11
25 y 5436 0.35 8
26 aA 68144 0.65
27 % 91
as those actually observed to be real in (C). If the forecasts making
up curve (D) were not sound, there is not one chance in a thousand
that the two curves would be so similar. Moreover, the curve (D)
has a smaller average departure from curve (B) than curve (C) has
from curve (A), and curve (D) is far smoother than curve (C).
Now we turn to Nashville in figure 8, with its four curves of the
same letters as Rochester. Obviously the same remarks hold almost
in toto.
VOL. 148
SMITHSONIAN MISCELLANEOUS COLLECTIONS
14
‘uoreydrseid Ayread “ZX “Ny ‘19ysayIOY—"Z “DIT
(a+p2+2b+qe+n) 0% ‘3urqjoourg
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HARMONIC PERIODS IN PRECIPITATION—ABBOT 15
no. 8
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co aa idee Se ts ag le eh east ek.
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16 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
CONCLUSION
I feel that I may now justly claim to have made with my associates
three discoveries of merit:
1. The sun’s radiation varies far beyond accidental errors of
observation, in numerous harmonic periods exactly related to 273
months.
2. Harmonic periods of these identical lengths exist, and with
much greater percentage amplitude, in long records of the precipita-
tion at scores of stations in all parts of the world.
3. Useful forecasts for many future years may be made when
amplitudes and forms of these harmonic periods are determined from
official records of precipitation for many past years.
It is shown that such forecasts are as close to observation at inter-
vals when wide departures from the normal occur, as when the
precipitation is nearly normal. (See Smithsonian Publication 4471,
page 6, 1961.)
It would be interesting if some expert in mathematics should dis-
cover why terrestrial precipitation reacts so strongly to small per-
centage changes in the solar constant. I suggest a possible explana-
tion in Smithsonian Publication 4135, page 3.
Mathematics may even be necessary in order to trace effects of cer-
tain human actions which may make records of the past inaccurate for
future forecasts. Such may be super-powerful nuclear bombs, com-
bustion of long train-loads of oil to propel spacecraft, and means
used to effect changes in weather to improve it, as now proposed. All
these may change atmospheric circulation and make past records use-
less for forecasting in the future.
LITERATURE CITED
Solar variation, a leading weather element, by C. G. Abbot. Smithsonian
Miscellaneous Collections, vol. 122, No. 4. 1953. (Smithsonian Publica-
tion 4135.)
A long-range forecast of United States precipitation, by C. G. Abbot. Smith-
sonian Miscellaneous Collections, vol. 139, No. 9. 1960. (Smithsonian
Publication 4390.)
A long-range temperature forecast, by C. G. Abbot. Smithsonian Miscellaneous
Collections, vol. 143, No. 5. 1961. (Smithsonian Publication 4471.)
Solar variation and weather, by C. G. Abbot. Smithsonian Miscellaneous Col-
lections, vol. 146, No. 3, 1963. (Smithsonian Publication 4545.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 148, NUMBER 9
Charles B. and Mary Waux Walcott
Research Fund |
ia alter | 4- JUN ~ 9
Copy _| /
NEW LOWER CAMBRIAN TR
FAUNULE FROM THE TACONIC
SEQUENCE OF NEW YORK
(WitH 12 PvratEs)
By
FRANCO RASETTI
Johns Hopkins University, Baltimore, Md.
Honorary Research Associate, Smithsonian Institution
‘TZ
THsOe, |
eEaEOR ON
SHUINGYON® we
(PusLicaTION 4662)
CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
MAY 23, 1966
SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 148, NUMBER 9
Charles D. and Mary Waux Walcott
Research Fund
NEW LOWER CAMBRIAN TRILOBITE
FAUNULE FROM THE TACONIC
oe OURNCE OF NEW YORK
(Wir 12 Prates)
By
FRANCO RASETTI
Johns Hopkins University, Baltimore, Md.
Honorary Research Associate, Smithsonian Institution
e Me a
“Ls,
sell
(PusticaTion 4662)
CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
MAY 23, 1966
PORT CITY PRESS, INC.
BALTIMORE, MD., U. S. A.
CONTENTS
Page
dasteodtetionm and, ACKHOWIECSMENES «0... <0.01c sis cise eieis-c sve cccies cues de vw ewadiers 1
@cctirrence and! ereservation of the’ Possils. 5.5... <0. -cceecinciec cece ciieces 2
Nee anduceharacten Of tne Patnttles 6.6.5. 5.<-+10.0.0:0,0 dare «oid 9,0 8 #eyals 0.6 o/deainvnlal tc 4
Systematic Descriptions:
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Paar ragl ES REN NUD Ty OVATE op 8 eSicie s.r ere\c once o</s;t/are.cio si eter ays.e 6 eo) 0167s ores artes 7
ative OE Se MIDAS S28 es ces cle dee eos Kaede Lelee cede eeees ciimete 39
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arti mE MOCECEIMIMICH, saceriacs Sete phe esd wid obs ae Se «aide aee Sie = ae earners 46
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Charles DB. and Matpy Waux Walcott Research Fund
NEW LOWER CAMBRIAN TRILOBITE FAUNULE
FROM THE TACONIC SEQUENCE OF
NEW YORK
By
FRANCO RASETTI
Johns Hopkins University, Baltimore, Md.
Honorary Research Associate, Smithsonian Institution
(WitTH 12 Prates)
INTRODUCTION AND ACKNOWLEDGMENTS
THE Lower CAmMprRIAN formations of the Taconic sequence in New
York are among the most thoroughly investigated deposits of this age
in eastern North America. After the classic faunal studies of Ford
and Walcott in the second half of the last century, no essentially
new faunules were discovered. Lochman (1956) described several
new species and gave a general review of the known Lower Cambrian
fossils of the sequence, occurring in what was formerly known as the
Schodack Formation, now subdivided (Zen, 1964) into several units.
All the species may be considered members of a single assemblage,
named from the characteristic olenellid trilobite Elliptocephala asa-
phoides.
The discovery of an essentially new Lower Cambrian trilobite
faunule was therefore unexpected. In 1956 Mr. Thomas W. Tal-
madge noticed the presence of fossiliferous limestone outcrops on a
hill south of North Chatham, Columbia County. In 1963 Dr. John
M. Bird collected small samples from two of these outcrops and
submitted them to the U.S. Geological Survey for identification of
the fossils. Dr. A. R. Palmer prepared and examined the specimens
and recognized in one of the collections the presence of trilobites
unlike any of those previously known from the Lower Cambrian of
the Taconic sequence or any other region. He suggested to the
writer a study of the new faunule. Collections much larger than the
original ones were made by Dr. Bird and the writer, until most of the
accessible, fossiliferous portions of the limestone outcrop had been
recovered and examined. Hundreds of trilobite specimens, represent-
SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 148, NO. 9
2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
ing about 30 species, largely new and belonging to new genera,
form the object of the present study.
The writer is indebted to the American Philosophical Society for
grant No. 3454-P which defrayed field and laboratory expenses. He
thankfully acknowledges the enthusiastic cooperation of Dr. John M.
Bird in quarrying the limestone and searching for other fossiliferous
localities. Thanks are also due to Dr. A. R. Palmer for suggesting
this study and for valuable discussions on Cambrian faunas; to Mr.
Thomas W. Talmadge for information on the results of his strati-
graphic studies in the East Chatham quadrangle and for accompany-
ing the writer on a field excursion; to Dr. George Theokritoff for
information on an undescribed Lower Cambrian faunule from Wash-
ington County, New York; to Dr. E-an Zen for discussions on the
Taconic sequence; and to Mr. A. W. A. Rushton of the British
Geological Survey for communicating specimens and photographs of
an undescribed faunule from England which shows interesting affini-
ties with the one described herein.
OCCURRENCE AND PRESERVATION OF THE FOSSILS
The Cambrian strata in the northwestern quarter of the East Chat-
ham 74-minute quadrangle are notable for the development of regu-
larly bedded limestone units, an unusual feature in the Cambrian
of the Taconic sequence in Columbia and Rensselaer Counties, New
York, where fossiliferous limestone generally occurs only in con-
glomerates. Among the localities where such limestone beds form
outcrops is a hill (Griswold farm) about 1 mile southeast of North
Chatham, Columbia County. The summit of the hill is a plateau
where limestone beds interstratified with black shale form scattered
outcrops. The beds strike north-south and dip steeply (50°-60°)
east. All the fossils described herein (with the exception of one
species from Quebec, Canada) were recovered from a limestone bed
traceable through intermittent outcrops over a distance of several
hundred feet. Even though fossils of the same faunule were observed
at several places along this bed, only one block of limestone, about
1 foot thick, 5 feet long, excavated to a depth of 3 feet, supplied
all the described fossils, the remainder of the limestone usually being
too fine-grained to yield fossils. About 400 pounds of rock were
removed and examined. The limestone is dark-gray, finely granular
to aphanitic, in some portions the bedding being clearly marked by
layers of more abundant insoluble material or fossil fragments, else-
NO. Q NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 3
where indistinct. Most of the fossils were concentrated in small
pockets.
The fossiliferous outcrop is located 27 mm from the west edge
and 164 mm from the north edge of the East Chatham 74-minute
USGS quadrangle, scale 1 : 24,000 (USGS collections 3810, 4216;
writer’s collection cs-4). The faunule from this bed is referred to
hereafter as the Acimetopus bilobatus faunule from one of the most
common and characteristic trilobites.
The most common fossils are small inarticulate brachiopods, espe-
cially an acrotretid and less abundant linguloid forms. Trilobites are
also copious in some portions of the rock, but most of the specimens
are too fragmentary for identification. Evidently the tests were trans-
ported by currents for considerable time and distance before being
covered by the sediment. All the trilobites are dismembered, except
one cephalon with two thoracic segments attached. Nevertheless,
many of the compact eodiscid cephala and pygidia did not suffer
excessive damage. In exposing the fossils, the matrix invariably sepa-
rates at the boundary of the outer surface of the test, hence orna-
mentation is well preserved. Some of the specimens suffered slight
flattening or fracturing in the slumping or compaction of the sedi-
ment. Distortion due to tectonic deformation of the rock is present
to a slight degree in some of the material.
The size of the trilobites presents an unusual situation. The Eodis-
cids are, on the average, large for the family. Examples of Litometo-
pus longispinus indicate that the species attained a length of 50 mm,
almost gigantic for an Eodiscid. Most of the examples are much
smaller, but very small, immature specimens seem to be lacking,
cephala or pygidia below 3 or 4 mm in length being rare. All the
Olenellids on the contrary are of small size, fairly complete cephala
not exceeding 4-5 mm in length. It seems difficult to attribute this
fact to the delicate nature of the olenellid tests and their consequent
fragmentation, since no fragments indicating individuals of medium
or large sizes were observed. In the well-known conglomeratic lime-
stones at Schodack Landing and Troy, even though the trilobite
tests are excessively fragmentary and no large cephala have been
recovered, the presence of adult examples of Elliptocephala asa-
phoides is proved by the frequent occurrence of fragments of their
large pleurae. Nor can the lack of very small Eodiscids and large
Olenellids be attributed entirely to sorting by current action, since
very small brachiopods and relatively large Eodiscids are rather
common,
4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
AGE AND CHARACTER OF THE FAUNULE
The present information is insufficient to determine the precise
relative age of the new faunule with respect to other known Lower
Cambrian faunules of North America, and in particular of the Taconic
sequence. The scanty stratigraphic evidence that might supply such
information is summarized below.
Other fossiliferous strata form outcrops east of the bed yielding
the Acimetopus faunule, and a greater variety of Cambrian fossils
was obtained from limestone blocks in the surrounding stone walls,
partly derived from beds not presently exposed. The next bed to the
east, 45 feet higher stratigraphically than the Acimetopus stratum
(under the unconfirmed assumptions that the intervening beds form
an orderly stratigraphic succession and that the strata are not in-
verted), yielded a Pagetides faunule, also collected at several other lo-
calities in the northeastern quarter of the East Chatham quadrangle.
Pagetides elegans and another species of the genus are by far the most
common identifiable fossils in this faunule ; Olenellid fragments, Bon-
nia and Prozacanthoides have been observed. The third fossiliferous
limestone bed, which under the above assumptions would be about 450
feet higher stratigraphically than the Acimetopus bed, yielded Pagetia
and Peronopsis, almost certainly indicative of the Middle Cambrian.
Trilobites of the typical Elliptocephala asaphoides assemblage, such as
Elliptocephala itself, Calodiscus lobatus, or Serrodiscus speciosus, have
never been seen at the locality, either in outcrops or loose blocks;
they are known in the East Chatham quadrangle only from the
exposures of the Ashley Hill Conglomerate (Dale, 1904; Zen, 1964)
whose type locality lies in the northeastern quarter of the quadrangle.
The structure of the area is exceedingly complicated, as may be
observed, for example, in a deep cut on the road from North Chat-
ham to Malden Bridge, which exposes a considerable thickness of
limestone beds interstratified with black shale. The strata appear
closely folded, causing some intervals to be repeated in reverse order,
even though the dip seems to remain fairly constant. It would be
difficult to discern such structures from scattered outcrops as observed
at the Acimetopus locality, where one might readily be misled to
infer an orderly succession. Limestone beds in the road cut yielded
a Pagetides faunule, hence they may be equivalent to a portion of
the section on the Griswold farm. For these reasons, the succession
of faunules outlined above, i.e., in ascending order the Acimetopus,
Pagetides, and Pagetia-Peronopsis faunules, is only suggested as
tentative. Talmadge (private communication) from purely strati-
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 5
graphic and structural evidence had previously reached the conclusion
that by and large the strata on the Griswold farm become progres-
sively younger toward the east, which would confirm the suggested
order. He also considers all these strata higher than the Ashley Hill
Conglomerate, Since the latter holds the Elliptocephala fauna not
only in boulders, but also in a regularly bedded limestone interval
at the base of the conglomerate, one might conclude that the latter
fauna is older than the Acimetopus and Pagetides faunules.
The Elliptocephala asaphoides assemblage extends through a con-
siderable thickness of strata in Washington County (Lochman, 1956;
Theokritoff, 1964). It is possible that the difference between the
Acimetopus bilobatus faunule and that assemblage is one of environ-
ment rather than age. A faunule reported by Theokritoff (1964)
from Washington County, believed to be somewhat younger than the
typical Elliptocephala asaphoides assemblage, shows no particular
resemblance to the one described herein.
The Acimetopus bilobatus faunule is notable for the number and
variety of trilobites of the family Eodiscidae, of which 9 new genera,
20 new named species, and an unnamed one are described herein,
all based on cephala. A few unassigned pygidia, in part possibly
representing additional species, are also described. None of the
Eodiscidae can be referred to previously known species, even though
several are referable to the well-known genera Calodiscus and Ser-
rodiscus.
The Olenellidae are represented by numerous fragments of small
individuals, referable to three species, none of which is the common
Elliptocephala asaphoides known from numerous localities in the
Taconic sequence of Washington, Rensselaer, and Columbia Coun-
ties. Immature Olenellid cephala cannot be specifically identified by
comparison with adult individuals, and even the generic reference
may remain doubtful, since several of the genera were based on the
features of the entire exoskeleton. Two of the species are tentatively
referred to Paedeumias and one to Olenellus; none shows close
resemblance to named species.
The opisthoparian trilobites are represented by four undetermined
species of Bonnia, a pygidium referred to Kootenia, and a peculiar
pygidium belonging to an undescribed genus of uncertain affinities.
Conspicuously absent from the Acimetopus bilobatus faunule are
Eodiscids with eyes and facial sutures, which constitute the family
Pagetiidae, even though species of Pagetides are the most common
trilobites in the nearest fossiliferous outcrop. Also totally absent are
6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
the ptychoparioid trilobites, so common in the late Lower Cambrian
deposits of the Appalachian and Cordilleran provinces. No fragments
referable to the Agnostids were observed.
Even though the Acimetopus bilobatus faunule has few, if any,
species in common with the Elliptocephala asaphoides assemblage,
the latter is still the Lower Cambrian fauna of North America which
it resembles most closely. Possibly all the species, and many of the
genera, are different, but the same families are represented, approxi-
mately in the same relative abundance: the Eodiscidae and Olenel-
lidae are common, Bonnia and Kootenia are rare in both cases.
The Acimetopus bilobatus faunule shows far less affinity with the
late Lower Cambrian fauna of the Pacific province (cratonic facies
of Lochman and Wilson, 1958), which is characterized by the abun-
dance of Ptychoparioids and Bonnia, frequently includes Kootemia,
Protypus, and Prozacanthoides, and also Pagetia and Pagetides. The
resemblance is not very close either with the typical late Lower
Cambrian fauna of the Acado-Baltic province (eugeosynclinal facies
of Lochman and Wilson), chiefly characterized by the Protolenidae,
where the Eodiscids are represented both by oculate (Hebediscus),
and blind genera (Calodiscus, Cobboldites, Serrodiscus). In North
America faunules of this type are known from Massachusetts and
eastern Newfoundland (Hutchinson, 1962). The evidence favors the
reference of the new faunule, like the Elliptocephala asaphoides
assemblage, to an “intermediate realm’ (Lochman and Wilson,
1958) between the cratonic and eugeosynclinal sedimentary prov-
inces.
Through the courtesy of Mr. A. W. A. Rushton, the writer was
able to examine specimens and photographs of a remarkable new
faunule discovered in the Purley Shales of Warwickshire, England.
The faunule includes several new species of Eodiscidae, of which two
belong to new genera, one is a Serrodiscus remarkably similar to
Serrodiscus subclavatus described herein, and another is definitely
referable to Acidiscus, closely resembling Acidiscus hexacanthus in
possessing two pairs of marginal cephalic spines. The Eodiscidae
in the Purley Shales are associated with Ellipsostrenua and Condy-
lopyge. Even though all the previously described species of this
agnostid genus occur in the Middle Cambrian, the remainder of the
faunule is suggestive of a late Lower Cambrian age. A fairly close
time equivalence of the two faunules may be indicated by the
presence of closely related Eodiscidae.
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 7
SYSTEMATIC DESCRIPTIONS
GENERAL STATEMENT
All the fossils described herein were deposited in the U.S. National
Museum collections, excepting one specimen from Quebec which is
in the collections of the Geological Survey of Canada.
All the illustrations show the outer surface of the test.
The abbreviations (tr.) for transverse, (sag.) for sagittal, and
(exsag.) for exsagittal qualify such terms as “wide,” “short,” etc.,
whenever the direction of the measurement might otherwise be mis-
interpreted. ,
Family EODISCIDAE Raymond, 1913
The Eodiscidae are the most numerous and interesting of the tri-
lobites described herein, as they show a greater variety of forms
than the genera previously known. Hence the characters observed
in the different parts of the exoskeleton are briefly discussed.
All the species described herein are represented by separate cephala
and pygidia; hence the number of thoracic segments is unknown.
Owing to the large number of species occurring in the same bed,
matching of cephala and pygidia presented a problem. In several
cases assignments with varying degree of probability could be made.
Criteria for associating cephala and pygidia that were used are
general shape, size, surface ornamentation, and frequency of occur-
rence. It is unlikely that the collection contains a pygidium for every
cephalon or vice versa. To avoid the risk of nomenclatural confusion,
no taxa were based on pygidia; those pygidia that could not be
assigned to cephala are described and illustrated but not named.
Features of the various parts of the exoskeleton are discussed
below.
Glabella.—The glabella shows considerable variety of form. It may
be tapered as in Bolboparia, where it is short in proportion to the
length of the cephalon; more or less parallel-sided as in most of the
species ; or even somewhat expanded toward the front as in Serrodis-
cus subclavatus and Bathydiscus dolichometopus. Lateral furrows
are usually short and shallow or absent. However, in Acimetopus,
Analox, and some species of Calodiscus, the glabella is divided by
a deep transverse furrow into an anterior and a posterior lobe. A
tendency in this direction had been observed, for example, in Calo-
discus lobatus and its form agnostoides (Lochman, 1956), in C.
helena, C. meeki, and even in Serrodiscus speciosus (Rasetti, 1952).
8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
In these cases there may even be two shallow furrows across the
glabella. The sharp and deep transglabellar furrow of Acimetopus
bilobatus and Calodiscus reticulatus, and the somewhat shallower one
of Analox bipunctata, seem to represent more advanced stages of
this type of glabellar lobation. A sharp transverse furrow was pre-
viously known in Opsidiscus bilobatus (Westergard, 1946) and Tan-
nudiscus tannuolaicus (Pokrovskaya, 1959). It is not clear whether
the transglabellar furrow in these Eodiscids, and the possibly homol-
ogous furrow in the Agnostids, result from modification of one of
the pairs of glabellar furrows, or are independent of them, represent-
ing a secondary segmentation. The doubt is suggested by the prob-
able secondary nature of the segmentation of the pygidial axis in the
Agnostids (Palmer, 1955).
In Acimetopus the glabellar lobation is the most specialized of
any described Eodiscid, the broad transglabellar furrow possessing a
pair of small, rounded lobes at the sides.
In Stigmadiscus, and to a lesser extent in Acidiscus, the two pairs
of lateral glabellar furrows assume the form of short, fairly deep pits,
a feature unusual in the family even though it occurs in other groups
of trilobites.
Another unusual character for the Eodiscids is the extension of
the posterior portion of the glabella into an upright spine, observed
in Acidiscus, Acimetopus, and Bolboparia. In Acidiscus there is, in
addition, an occipital spine, whereas in Acimetopus and Bolboparia
the occipital ring is short and simple.
Cephalic border.—A definite border furrow and border around the
cephalon are present in all genera excepting Analox where the lateral
border is missing, although an anterior border of triangular shape
and the posterior border are well developed. One of the striking
features of the border in several of the new genera is the develop-
ment of marginal spines at various positions.
One pair of short, lateral marginal spines is observed in Acimeto-
pus, Bolboparia, Litometopus, and Acidiscus birdi. Two pairs are
present in Acidiscus hexacanthus and Oodiscus subgranulatus. As
the spines vary in position, it is questionable whether they can be
homologized among the different species.
The posterior cephalic border shows variable features that can
not be readily homologized among the different genera. In many of
the species it bears a pair of spines, which may vary in position from
less than halfway from the axial furrow to the genal angle (in Oodis-
cus, Bathydiscus, and Stigmadiscus stenometopus) to the proximity
of the genal angle as in Serrodiscus subclavatus, Actmetopus biloba-
NO. Q NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 9
tus, Bolboparia superba, Acidiscus birdi, Litometopus longispinus,
and Stigmadiscus gibbosus. Presumably the spine should be con-
sidered homologous in all these genera, but there are no decisive
arguments in favor of this assumption. In Oodiscus and Bathydiscus
the base of the spine coincides with the position of a sharp genicula-
tion, the portion of the posterior border distal to this point being
sharply bent downward and somewhat forward. In Litometopus
longispinus and, to a lesser extent, in Serrodiscus subclavatus, the
posterior border presents an unusual feature consisting of a narrow
ridge separated from the main part of the border by a short, trans-
verse furrow. The distal end of this ridge produces a slight rearward
projection of the posterior margin. In one specimen of Serrodiscus
subclavatus preserving two thoracic segments attached to the cepha-
lon, the ridge on the cephalic margin is seen to correspond to the
fulcrum on the anterior margin of the first thoracic segment. A simi-
lar feature is present at the articulation between the first and second
thoracic segments. In Litometopus longispinus the tooth on the pos-
terior cephalic border is more conspicuous. In both species the
“genal” spine is located more distally than these features.
Pygidium.—The pygidia present less variety than the cephala. The
axis is always well defined except in one unassigned pygidium where
the axial furrow is barely indicated. In Acimetopus and Bolboparia
there is a large, upright spine on the second axial ring. In Serrodiscus
subclavatus there is a long spine on the posterior part of the unseg-
mented axis. In Acidiscus there are spines on several of the axial
rings. Border furrow and border are well differentiated in all pygidia.
A well-developed articulating facet is present in all genera; this is
the most obvious feature for distinguishing pygidia from cephala
in doubtful cases. Marginal spines, sometimes visible from above,
more often appearing as extensions of the doublure and hence ventral
in position, may be present. In most species the doublure is reflexed
as usual in trilobite pygidia. However, in Analox bipunctata and the
pygidium attributed to Bathydiscus dolichometopus, the pygidial
doublure forms an almost vertical face rather than being reflexed
inward to parallel the dorsal exoskeleton. In neither species this
feature is present in the cephalon, where the doublure appears to
be narrow and not sharply defined, the dorsal test being gradually
downrolled.
Ornamentation.—The outer surface of the test may be smooth,
punctate, finely granulate, coarsely granulate with granules of one
size (Acimetopus) or different sizes (Bolboparia). The larger of
these granules seem broken at the tip and may represent the bases
Io SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
of short spines. Calodiscus reticulatus has a strong reticulate orna-
mentation.
Classification.—The Eodiscidae of North America have so far
been referred to five genera (Rasetti, 1952): Calodiscus Howell,
1935 (type species, Agnostus lobatus Hall) ; Dawsonia Hartt in
Dawson, 1868 (type species, Microdiscus dawsoni Hartt in Dawson) ;
Eodiscus Hartt in Walcott, 1884 (type species, Eodiscus pulchellus
Hartt in Walcott=Microdiscus scanicus Linnarsson) ; Serrodiscus R.
and E. Richter (type species, Eodiscus (Serrodiscus) serratus R.
and E. Richter) ; and Weymouthia Raymond, 1913 (type species,
Agnostus? nobilis Ford). Of these five North American Eodiscid
genera, Dawsonia and Eodiscus occur exclusively in the Middle Cam-
brian Paradoxides beds; the other genera are Lower Cambrian.
Genera that have been proposed for Eodiscidae from Europe
and Asia are Cobboldites Kobayashi, 1943 (type species, Microdis-
cus comleyensis Cobbold) ; Metadiscus Kobayashi, 1943 (type spe-
cies, Microdiscus sculptus Hicks); Ladadiscus Pokrovskaya, 1959
(type species, Ladadiscus limbatus Pokrovskaya). To these genera
the writer would add Tannudiscus Pokrovskaya, 1959 (type spe-
cies, Tannudiscus tannuolaicus Pokrovskaya), originally assigned to
the family Opsidiscidae (Pokrovskaya, 1959), which seems of
questionable validity since Opsidiscus, which has vestigial eyes but
no facial sutures, could be referred either to the Pagetiidae or the
Eodiscidae, the presence of a transglabellar furrow having little sig-
nificance. Tannudiscus has no trace of eyes and should be placed in
the Eodiscidae even if a separate family Opsidiscidae were recog-
nized.
The nine new genera described herein approximately double the
size of the family and it was considered whether the additional
knowledge suggested some grouping of the genera that would indicate
evolutionary trends. On the basis of present knowledge there seems
to be no basis for a meaningful arrangement of the genera. The glabel-
lar lobation, which in general is one of the important taxonomic
features in trilobites, seems of little significance, as shown by the
gradual transition from generalized lobation to the specialized loba-
tion where all furrows have disappeared but for a deep, straight
transglabellar furrow (Calodiscus reticulatus). Other characters, such
as shape and relative length of the glabella, cephalic border furrow
and border, glabellar, occipital and marginal cephalic spines, orna-
mentation, etc., seem even less significant, as also are believed to
be the pygidial features. Even an arrangement of the genera based
on characters of little evolutionary and taxonomic significance would
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI II
be difficult to carry out because genera that are alike in one feature
are apt to be strikingly different in one or several others. For this
reason the genera are described herein in alphabetical order.
ACIDISCUS Rasetti, new genus
Description—Cephalon of moderate convexity, semielliptical.
Glabella not reaching the anterior border, subcylindrical, with two
short, somewhat pit-like pairs of lateral furrows, in the two known
species possessing a small upright spine on its posterior portion.
Occipital furrow wide; occipital ring well defined, bearing a spine.
Posterior border straight from the axial furrow to the base of the
genal spine. Lateral cephalic border with one or two pairs of mar-
ginal spines.
Pygidium with long, multisegmented axis. Geniculation situated
rather distally; facet well developed. Pleural regions unfurrowed;
border and border furrow well developed, of average width. Surface
smooth or with weak ornamentation. The narrow doublure may
be extended into short spines.
Type species——Acidiscus birdi Rasetti, new species.
Occurrence——Late Lower Cambrian of New York. Also in the
Purley Shales of Warwickshire, England (Rushton, private com-
munication).
Discussion.—This genus is obviously a close relative of Serrodis-
cus. The pygidium is much the same as in that genus. The cephalon,
however, has important distinctive features, the most significant being
the development of glabellar and occipital furrows. Another distinc-
tive character is the tendency to develop spines on the glabella,
occipital ring, at the genal angle, and on the cephalic border. The
glabellar furrows also indicate relationship to Stigmadiscus; in sev-
eral features Acidiscus may be considered transitional between the
latter genus and Serrodiscus.
ACIDISCUS BIRDI Rasetti, new species
Plate 1, figure 2; plate 6, figures 11-19
Available material—Numerous cephala and pygidia, of which a few
are fairly complete.
Description—Cephalon semielliptical. Glabella rising well above
the cheeks, very convex transversely, tapered in anteriormost por-
tion, narrowly rounded in front, occupying with occipital ring more
than two-thirds of cephalic length. Two pairs of distinct, short,
I2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
somewhat pit-like lateral furrows; the posterior pair longer, directed
backward almost to meet occipital furrow, hence defining small,
elongate-triangular basal lobes. The glabella reaches maximum ele-
vation near the posterior end, at the level of the posterior pair of
lateral furrows, where it possesses a small upright spine. Occipital
furrow deepened into a pair of small pits laterally, wide medially;
occipital ring of moderate length (sag.), extended into a spine incom-
plete in all specimens. Cheeks convex, not separated medially by a
preglabellar depression, sloping steeply to border furrow in posterior
portion. Border lying in a plane, slightly convex, widest medially,
narrowing toward the genal angles, possessing a pair of small lateral
spines anterior to the level of the front end of the glabella. A series
of five or six pairs of low tubercles, as usual in species of Serrodiscus,
is visible on the lateral border. The posterior border furrow is
directed outward and slightly forward from the axial furrow, thus
forming an angle with the posterior cephalic margin and giving the
posterior border an elongate-triangular shape. Posterior cephalic mar-
gin straight from axial furrow to base of short, outward-directed
genal spine.
Pygidium similar to cephalon in general shape, somewhat more
distinctly subtriangular. Axis narrow and long, barely failing to
reach the posterior border furrow, fully segmented for the entire
length, composed of 12 rings including the terminal one. There is a
short, upright spine on each of the first seven axial rings. Pleural
regions convex, totally unfurrowed. Border furrow deep, border rela-
tively narrow, of almost even width. Articulating facet well devel-
oped. Border extended downward and inward into narrow doublure
forming a series of blunt spines not visible except by removing the
matrix under the border; terrace lines on doublure following the
serrated outline.
Surface of test mostly smooth, except for granules visible in some
specimens on the last few axial rings and sometimes on the posterior-
most portion of the pleural regions. Length of largest (incomplete)
cephalon 18 mm, width 20 mm. Length of largest pygidium 12 mm,
width 16 mm.
The species is named for Dr. John M. Bird who collected the
holotype.
Occurrence.—Collection cs-4, North Chatham.
Types.—Holotype: U.S.N.M. 145987. Paratypes: U.S.N.M.
145988.
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 13
ACIDISCUS HEXACANTHUS Rasetti, new species
Plate 7, figures 1-6
Available material_—_T wo cephala and one pygidium.
Description.—It is sufficient to point out the differences from the
type species. Shape and convexity of cephalon and pygidium the
same as in A. birdt, Glabella and occipital ring, including the spines,
almost identical. Cephalic border bearing, in addition to an anterior
pair of spines as in A. birdi, a second pair halfway between the first
pair and the genal angle. Posterior cephalic border and genal spine
as in preceding species. Lateral border lacking tubercles.
Pygidium (referred to the species on account of the ornamentation)
with entirely segmented axis, also showing 12 rings including the
terminal section. Axial spines developed on the first six instead of
seven rings. The character of the pygidial doublure has not been
ascertained.
Surface of cheeks and pleural regions of pygidium covered with
small, sparse, but sharply elevated granules. The ornamentation is
less marked in the holotype cephalon than in the paratype cephalon
and pygidium. Similar individual variations in the identical type of
ornamentation were observed in Oodtscus subgranulatus.
Occurrence.—Collection cs-4, North Chatham.
Types.—Holotype: U.S.N.M. 145989. Paratypes: U.S.N.M.
145990.
ACIMETOPUS Rasetti, new genus
Description—Cephalon and pygidium strongly convex. Glabella
divided by a deep, wide transglabellar depression into anterior and
posterior lobes. Anterior lobe bulbous, not reaching the anterior
border. Transglabellar depression subdivided laterally into two pairs
of furrows, isolating a pair of small lobes ; these furrows are confluent
medially into one broad furrow. Posterior glabellar lobe strongly
elevated and extended into a long, uptilted spine. Occipital ring short
(sag.), well defined by occipital furrow, not spinose, partly concealed
in dorsal view by the rearward extension of the glabella. Cheeks
strongly convex, confluent anteriorly without any trace of a pre-
glabellar depression, in their posterior portion overhanging the bor-
der furrow. Border well developed, defined by a deep border furrow,
approximately lying in a plane, wide anteriorly, tapering toward the
genal angle, extended into a pair of small lateral spines. Near the
genal angle the lateral border furrow is confluent with the deep
posterior border furrow; the border at this point is greatly reduced.
14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
The posterior cephalic margin is straight, lacking geniculation, and
extends into a short, outward-directed genal spine.
Pygidium with strongly elevated axis, furrowed for entire length
and showing in type species nine segments; axis almost reaching the
border, possessing a strong upright spine on the second ring. Pleural
regions strongly convex and steeply downsloping ; border furrow deep,
border of even width, lacking spines. Surface strongly granulate.
Type species—Acimetopus bilobatus Rasetti, new species.
Occurrence.—Late Lower Cambrian of New York.
Discussion—The genus is characterized by the glabella deeply
divided into anterior and posterior lobes, a feature present in some
forms of Calodiscus, and also well developed in Analox. However,
Acimetopus is unique in the development of the extra pair of small
lateral lobes in the transglabellar depression.
ACIMETOPUS BILOBATUS Rasetti, new species
Plate 2, figure 3; plate 4, figures 1-14
Available material—Numerous, well-preserved cephala and py-
gidia. The assignment of the two shields to one species is unquestion-
able because of the unique ornamentation among the members of
the faunule.
Description.—Features indicated in the generic description are not
mentioned. The anterior glabellar lobe is exceedingly convex, falling
vertically to the preglabellar field, moderately rounded anteriorly
and slightly wider than the posterior lobe; the latter is more nearly
straight-sided. The glabellar spine varies somewhat in size and atti-
tude among the specimens; on the average it is directed upward at
an angle about 30° and is sharply pointed. The border spines are
situated somewhat in advance of the midpoint of the anterior glabellar
lobe and are short and rapidly tapered.
The pygidial axis is deeply furrowed for the entire length, the
furrows being deeper laterally. The second segment has a strong,
long upright spine whose base somewhat encroaches on the adjacent
ring furrows; it was not possible in any case to extract the entire
spine from the matrix. The pleural regions are so convex that they
somewhat overhang the border furrow, which is deep and wide.
Border convex, relatively narrow.
Entire surface covered with large, elevated granules of one size.
Length of largest cephalon, exclusive of glabellar spine, 9.5 mm,
width 10 mm. Length of largest pygidium 7.5 mm, width 7 mm.
Occurrence.—Collection cs-4, North Chatham.
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 15
Types——Holotype: U.S.N.M. 145991. Paratypes: U.S.N.M.
145992.
ANALOX Rasetti, new genus
Description.—Cephalon of moderate overall convexity, well rounded,
somewhat narrowing toward the front. Glabella terminating in the
merged axial and border furrows, divided into posterior and anterior
lobes by a wide, moderately deep transglabellar furrow; no other
furrows present. Posterior glabellar lobe strongly elevated and
extended backward into a broad spine. Occipital ring short, barely
differentiated under the rearward extension of the glabella. Anterior
border swollen medially, defined by a pair of furrows directed out-
ward and forward from the anterior angles of the glabella, not reach-
ing the cephalic margin but ending abruptly in a pair of pits. Lateral
border absent; cephalic margin in this portion downrolled into the
doublure. Posterior border furrow and border well developed ; genic-
ulation distally located ; genal spine absent. Border furrow extended
for a short distance forward from the genal angle and then fading
out.
Pygidium about equally wide and long, rather strongly convex;
posterior outline regularly rounded. Axis relatively narrow, defined
by a narrow but deep axial furrow, not greatly raised above the
general convexity, in type species showing seven rings plus a terminal
section, lacking nodes or spines. Border present but exceedingly
narrow, defined by an equally narrow border furrow. Doublure form-
ing a vertical face, not extended into spines.
Type species —Analox bipunctata Rasetti, new species.
Occurrence.—Late Lower Cambrian of New York.
Discussion—tThe glabella with its transglabellar furrow is like
certain forms herein attributed to Calodiscus. The unique feature
of the genus is the lack of a lateral cephalic border. The pygidium
in dorsal view resembles the pygidia of Pagetides, but has the unusual
vertical doublure.
ANALOX BIPUNCTATA Rasetti, new species
Plate 2, figure 2; plate 6, figures 1-10
Available material—Numerous, well-preserved cephala and py-
gidia. This is one of the more common species of the Acimetopus
bilobatus faunule.
Description—Most of the features were indicated in the generic
diagnosis. Glabella defined by a broad, fairly deep axial furrow;
16 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
anterior glabellar lobe barely rising above the cheeks; posterior lobe
extended into a broad spine tilted at about 30° ; the spine appears to
be bluntly terminated, although this portion is not well preserved in
any of the cephala. The cephalic margin lies approximately in a
plane. The pygidial axis has rings well defined by straight ring fur-
rows becoming gradually shallower toward the rear, deeper
medially, and shallower near the axial furrows. The axis does not
reach the posterior border, although it appears almost to do so in
dorsal view on account of the strongly downsloping marginal por-
tions of the pleural regions. The excessively narrow lateral border
furrow and border maintain an almost even width throughout. The
anterior border furrow instead is relatively wide; the anterior py-
gidial margin has a straight transverse course from the axial furrow
to the geniculation, which is closer to the lateral margin than to the
axial furrow. The facet is well developed.
The surface of the test is finely punctate, this ornamentation both
in the cephalon and pygidium being more marked on the pleural
than the axial parts. Length of the larger cephala, exclusive of
glabellar spine, 4 mm, width 5 mm. Length of largest pygidium
3.5 mm, width 4 mm.
Occurrence.—Collection cs-4, North Chatham.
Types.—Holotype: U.S.N.M. 145093. Paratypes: U.S.N.M.
145094.
BATHYDISCUS Rasetti, new genus
Description—Cephalon with considerable relief. Glabella with
almost undifferentiated occipital ring prominent, slightly expanded
forward, reaching the anterior border, unfurrowed. Cheeks convex
and downsloping. Border convex, wide, well defined by a border
furrow inbent on either side of the anterior portion of the glabella
to merge with the axial furrow. In anterior view, the medial por-
tion of the border is seen to be slightly arched, instead of lying in a
plane as in most Eodiscids. Posterior cephalic border with sharp
geniculation and short, erect spine located close to axial furrow as
in Oodiscus. Surface of test smooth.
Pygidium tentatively assigned to the type species with long, well-
defined, unfurrowed axis not reaching the border furrow. Border
furrow narrow laterally, widened posteriorly ; border narrow, slightly
elevated. Doublure not reflexed to parallel the dorsal exoskeleton as
in most Eodiscids, but almost vertical, with a slight inward slope,
wide everywhere except in the posteriormost portion. This attitude
of the doublure gives the pygidium as a whole an unusual depth.
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 17
Type species——Bathydtscus dolichometopus Rasetti, new species.
Occurrence.—Late Lower Cambrian of New York.
Discussion.—The cephalon indicates close relationship to Oodis-
cus as evidenced by the same general shape, characters of glabella
and occipital ring, position of the geniculation and spine on the
posterior border. The chief difference is the extension of the glabella
encroaching upon the anterior border furrow and the peculiar inbend
of the latter at the sides. Another important feature is the arched
anterior border, which does not occur in Oodiscus. If the pygidium
is correctly assigned, its peculiar doublure represents one of the most
characteristic features of the genus.
BATHYDISCUS DOLICHOMETOPUS Rasetti, new species
Plate 1, figure 3; plate 9, figures 1-16
Available matertal.—Several cephala and about an equal number
of pygidia.
Description—Cephalon highly convex, semielliptical, well
rounded in front. Glabella strongly elevated, slightly pear-shaped,
well rounded in front, totally unfurrowed. Occipital furrow very
shallow at the sides, obsolete medially ; occipital ring very short, con-
tinuing the longitudinal profile of the glabella, extended farther back-
ward than the cheeks. Cheeks very convex, laterally sloping down
vertically to the border furrow. Border furrow well impressed, later-
ally paralleling the cephalic margin, anteriorly inbent at each side
to merge with the axial furrow that separates the front of the glabella
from the border. Border convex, wide, lacking tubercles. Cephalic
doublure very narrow, normally reflexed. Border in anterior view
arched medially, paralleled by the border furrow which rises on each
side to meet the axial furrow. The pygidium is referred to the species
chiefly on account of the position of the geniculation and the fit of
the up-arched anterior border of the cephalon and down-arched
posterior border of the pygidium, an arrangement that must have
ensured a close fit of the two shields in enrollment. Pygidium widest
at anterior end, semielliptical, with strong relief. Axis elevated, well
defined by the axial furrow, tapered, occupying about three-fourths
of the pygidial length, unfurrowed. Articulating half-ring short (sag.),
defined by a deep articulating furrow. Pleural regions convex and
downsloping. Anterior border with sharp geniculation at one-third the
distance from the axial furrow to the lateral margin; articulating facet
well developed. Border narrow and but slightly elevated laterally,
defined by a very shallow border furrow, but elevated at the level
18 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
of the posterior end of the axis. Beyond this elevation the border
appears concave upward in posterior view, while the border furrow
widens and the border becomes almost flat medially. Doublure wide,
sloping but slightly inward and forming an almost vertical face. The
edge of the doublure does not partake of the downward curve of the
posterior border, hence the doublure is much narrower in its poste-
riormost portion. Doublure with irregular terrace lines and smooth
margin. Upper surface of cephalon and pygidium perfectly smooth.
Length of largest pygidium 11 mm.
Occurrence.—Collections cs-4 and USGS 4216, North Chatham.
Types.—Holotype: U.S.N.M. 145995. Paratypes: U.S.N.M.
145996-7.
BOLBOPARIA Rasetti, new genus
Description.—Cephalon with strong relief. Glabella well tapered,
pointed in front, highest posteriorly where it extends into an upright
spine. Lateral furrows short, of generalized pattern. Occipital fur-
row distinct, occipital ring short (sag.) and simple. Cheeks as a
whole forming a subquadrate area in dorsal view, rising from a low
posterior part to their highest point near the anterolateral angles,
here bulging and overhanging the lateral border. The relatively long
(sag.) preglabellar field is a broad depression separating the bulging
cheeks. Anterior portion of border expanded ; border narrowest later-
ally under the bulge of the cheeks, widening again toward the
genal angle, extended into a pair of small, lateral spines and near the
genal angle carrying one or more pairs of tubercles. In front of the
genal angle the lateral border furrow merges with the posterior bor-
der furrow, at considerable distance from cephalic margin. Posterior
border furrow directed obliquely outward and forward from the
axial furrow, sharply turning outward after merging with the lateral
border furrow, and reaching the lateral cephalic margin well in
advance of the genal angle which bears a small spine.
Pygidium semielliptical, strongly convex transversely. Axis well
defined, long, with numerous rings, the second bearing a large spine.
Pleural regions unfurrowed; border narrow, extended into minute,
downward-directed spines. Surface of test densely granulate in the
three known species.
Type species—Bolboparia superba Rasetti, new species.
Occurrence.—Later Lower Cambrian of New York and Quebec.
Discussion.—This is probably the most distinctive of all the new
genera of Eodiscidae described herein. The short, downsloping
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 19
glabella and the bulging cheeks give it a very peculiar aspect. Among
previously known forms it might perhaps be compared with Calo-
discus walcotti Rasetti (1952), unfortunately known from a single,
somewhat incomplete cephalon. This form also has a pointed, but
much longer, glabella, whose posterior portion is extended into a
spine. The cheeks, however, have a normal shape.
BOLBOPARIA SUPERBA Rasetti, new species
Plate 3, figure 1; plate 5, figures 1-6
Available material—aA few cephala, small and more or less frag-
mentary excepting the holotype which is a large, almost perfect exam-
ple. Also a thoracic segment attributed to the species.
Description—Cephalon somewhat wider than long, widest at the
posterior third, slightly narrowed toward the genal angle, pointed
in front. Glabella occupying about two-thirds of the cephalic length,
defined by a very deep axial furrow, well tapered, pointed in front,
extended into a slender almost vertical spine just in front of the
occipital furrow. Lateral furrows short, merging with the axial
furrow ; two pairs relatively deep, one additional pair barely visible.
Occipital furrow straight, deeper at the sides, but not quite connect-
ing with the axial furrows ; occipital ring wider medially, with rounded
outline. Cheeks bounded by an irregular line, consisting of strongly
oblique posterior border furrow, followed by an almost longitudinal
section of the lateral border furrow; at this point the cheeks are
widest, then narrow again for a considerable, fairly straight portion;
then the outline curves sharply inward in correspondence with the
highest part of the bulge and becomes fairly straight, transverse in
the anterior portion. The border furrow is well marked all around
the cheeks and attains its maximum depth anterolaterally. The bor-
der extends into a pair of small, slender spines located somewhat
back of the level of the anterior end of the glabella. Two rounded
tubercles are located in the wider portion of the lateral border just
in front of the posterior border ; as mentioned in the generic diagno-
sis, a deep furrow separates here the lateral border, elevated into
the posterior tubercle, and the posterior border, carrying the short
genal spine.
Entire surface very densely covered with granules of various sizes ;
the largest appear broken at the tip and may represent the bases
of short spines. Length of largest (holotype) cephalon 9.0 mm,
width 11.0 mm.
A peculiar thoracic segment is attributed to the species because
20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
the ornamentation of the pleura is similar to that of the cephalon.
On each side of the axis there is an oblique furrow, directed outward
and forward, reaching the axial furrow at the anterior corner of the
ring. The pleura is flat and horizontal for most of its length, with a
furrow paralleling and close to the posterior margin. The anterior
margin has a very sharp geniculation, where it bends backward and
downward, forming a marked facet. At the fulcrum a very narrow
ridge is set off near the anterior margin by a shallow furrow, a feature
also observed in Serrodiscus subclavatus. The distal end forms a
short, sharp spine directed outward and backward.
Occurrence.—Collection cs-4, North Chatham.
Types.—Holotype: U.S.N.M. 145998. Paratypes: U.S.N.M.
145999,
BOLBOPARIA ELONGATA Rasetti, new species
Plate 3, figure 2; plate 5, figures 7-12
Available material—A few cephala, of which two reasonably
complete, and three tentatively assigned, incomplete pygidia.
Description—The cephalon is so similar to the type species
that it is sufficient to point out the differences. Cephalon somewhat
longer than wide. Glabella proportionately narrower and longer
than in B. superba, bearing the same kind of lateral furrow and
posterior spine. Anterior cephalic outline somewhat more sharply
pointed; cheeks bulging anteriorly but not as much as in the type
species ; outline at the anterolateral corners turning even more abruptly
than in that species. Posterior portion of border furrow even more
oblique than in B. superba, forming an angle of 45° with the axis
of the body. Widened posterior portion of lateral border bearing two
pairs of tubercles as in preceding species. Genal angle not well pre-
served. Length of largest cephalon 8 mm. Ornamentation as in pre-
ceding species.
Three incomplete examples of a pygidium undoubtedly belong to
Bolboparia as they match the unique ornamentation of the cephala.
However, the reference to B. elongata rather than B. superba, sug-
gested by the relatively narrow shape, is tentative. Axis moderately
wide, slightly tapered, defined by deep axial furrows, almost reaching
the posterior border, furrowed for entire length, showing approxi-
mately 12 rings; end portion not well preserved. A broad-based
spine on the second ring encroaches on the adjacent ring furrows.
Pleural regions attaining a vertical slope, almost concealing the bor-
der in dorsal view. Border furrow well impressed; border vertical,
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 21
extended into about 12 pairs of minute spines. Length of largest
pygidium 8 mm.
Occurrence.—Collection cs-4, North Chatham.
Types.—Holotype: U.S.N.M. 146001. Paratypes: U.S.N.M.
146002.
BOLBOPARIA CANADENSIS Rasetti, new species
Plate 5, figures 13, 14
Available material——aA single, well-preserved cephalon.
Description.—Cephalon relatively broad and short as in B. superba.
Glabella somewhat longer in proportion to the cranidium, long and
narrow, subconical, pointed in front. Three pairs of lateral furrows
impressed, the posteriormost pair deep, short, pit-like, the other two
similar but increasingly shallow. The glabellar spine is broken off,
but its base shows that it was large and equally located as in B.
superba. Occipital furrow straight, of even width throughout ; occip-
ital ring short and simple. Outline of the cheeks of the same general
type as in B. superba, but differing in several details. The posterior
portion, from the axial furrow to the widest point of the cheeks, is
almost straight, since there is hardly any change of direction between
the posterior border furrow and the posterior portion of the lateral
furrow. Where these furrows meet, there is the usual deep furrow
directed toward the cephalic margin; but in the present species this
furrow extends also inward and forward, forming a broad, shallow
depression across the cheek reaching the axial furrow at the level
of the middle pair of glabellar furrows. At the widest point, the
cheek outline forms a narrowly rounded angle, continues straight
forward and somewhat inward to the anterolateral corners where
the cheek attains its highest elevation, and then curves to a transverse
inward course as in B. superba. As a whole the cheeks acquire thereby
a peculiar subhexagonal outline. The border furrow and border are
much like the other species, except that there is only one, large
tubercle at the posterior end of the lateral border. The small lateral
border spines are in the same position as in B. superba. Ornamenta-
tion identical with the other two species of the genus. Length of
cephalon 4.5 mm, width 4.8 mm.
Occurrence.—The single known specimen was collected by Mr.
Claude Hubert when mapping an area near the south shore of the St.
Lawrence River in Quebec. The collection, designated as 63-F24, is
stated to be made from a calcarenite bed a half mile north of Elgin
Station, L’Islet County. The locality is about 60 miles northeast of
22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Levis. Unfortunately no other identifiable fossils were recovered from
this bed, although trilobite fragments presumably representing Ole-
nellids were observed. Lower Cambrian strata are known from this
general area, and were designated by the writer (Rasetti, 1964) the
Charny formation, to avoid the confusion associated with names pre-
viously in use. The easternmost occurrence of identified Lower Cam-
brian beds in place (the Botsfordia pretiosa shale) previously reported
was about 20 miles northeast of Levis; hence Mr. Hubert’s finding
extends the known presence of Lower Cambrian strata 40 miles north-
east. Lower Cambrian fossils at many other localities farther east are
only found in boulders in Lower Ordovician conglomerates.
It should be pointed out that the only Lower Cambrian Eodiscid
trilobites previously known from the Charny formation (Rasetti,
1945) belong to the family Pagetiidae. The same applies to the forms
described (Rasetti, 1948) from conglomerate boulders. However,
Raymond (1913) mentioned the presence of a blind Eodiscid,
Serrodiscus speciosus, in the boulders at Bic. The writer, who col-
lected thousands of Lower Cambrian trilobite specimens from that
and nearby localities, was unable to find this species or any other
blind Eodiscid. Search in the collections of the Geological Survey of
Canada and the U.S. National Museum failed to yield any such
material from the Bic locality. Hence the writer (1948) did not
include Serrodiscus speciosus in the list of species from the Lower
Cambrian of the Quebec conglomerates.
Recently two good specimens of Serrodiscus speciosus, one cepha-
lon and one pygidium, bearing labels of the Bic locality and pre-
served in the characteristic, light-gray limestone prevailing in those
conglomerates, were discovered in the collections of the New York
State Museum. The writer was able to examine these through the
courtesy of Dr. Donald W. Fisher. It is thus now ascertained that
there are at least two blind Eodiscids in the Lower Cambrian of
Quebec.
Type.—Holotype: Geological Survey of Canada No. 19887.
Genus CALODISCUS Howell, 1935
Type species.—A gnostus lobatus Hall.
CALODISCUS FISSIFRONS Rasetti, new species
Plate 9, figures 17-21
Available material—A few cephala, mostly fragmentary, and
two tentatively assigned pygidia.
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 23
Description.—Glabella divided by a broad transverse furrow into
anterior and posterior lobe; lobation more marked in larger individ-
uals. Anterior lobe rounded, slightly narrower than posterior lobe;
the latter rising steeply and extended upward and backward beyond
the occipital ring ; whether this extension is rounded or pointed at the
extremity could not be determined, as this portion is incompletely
preserved. One pair of short lateral furrows is visible on the posterior
lobe. Occipital ring short (sag.), mostly masked in dorsal view by
the glabellar extension, directed inward and backward at the sides.
Cheeks strongly convex, in their posterolateral part overhanging the
border furrow. Border expanded medially and causing a slight median
inbend of the border furrow which here forms a depression by merg-
ing with the axial furrow; border narrowing gradually toward the
genal angle. Posterior cephalic border poorly preserved. Surface of
test faintly reticulate; lateral border with four or five pairs of low
tubercles.
Pygidium tentatively referred to the species on account of similar
ornamentation with axis well defined by deep axial furrows, showing
about seven rings plus a terminal unsegmented section, almost
reaching border. The first three rings may have had a node. Anterior
border furrow deep and wide, with well-developed geniculation and
facet. Lateral and posterior border furrow and border narrow through-
out. Pleural regions unsegmented, very convex like the cheeks.
Width of largest cephalon 9.5 mm; length of holotype cephalon
4.6 mm, width 5.6 mm. Length of largest pygidium 5.0 mm, width
6.0 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion—This species differs considerably from C. lobatus
in the shape of the glabella, divided by a broad transverse furrow
and with the rear lobe extended backward above the occipital ring.
However, the presence of one or more, shallow transglabellar fur-
rows is a feature present in species obviously congeneric with C.
lobatus, and even in the form agnostoides of this species which
Lochman (1956) showed to intergrade with the typical form. Calo-
discus helena (Walcott) has a broad, very shallow transglabellar
furrow and a rearward extension of the glabella, although not as
pronounced as in the present species, and on the whole the cephala
of C. helena and C. fissifrons are very similar. The pygidium of C:
helena, however, differs considerably in the broad, paucisegmented
axis from any pygidium observed at the North Chatham locality.
Types.—Holotype: U.S.N.M. 146004. Paratypes: U.S.N.M.
146005.
24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
CALODISCUS RETICULATUS Rasetti, new species
Plate 1, fig. 1; plate 7, figures 12-18
Available material—A few cephala, mostly fragmentary.
Description.—Glabella divided by a deep, wide transverse fur-
row into two lobes. Anterior lobe subovate, very convex, anteriorly
sloping down almost vertically to the broad depression formed by
the coalescence of the axial and border furrows. Glabella constricted
at the transverse furrow. Posterior lobe widening backward from the
transverse furrow, rising steeply, extended well beyond the general
outline of the cephalon; seemingly rounded at the posterior end,
although this portion is not completely preserved in any of the speci-
mens. Occipital ring differentiated under the rearward glabellar exten-
sion, at least at the sides where it is directed rather backward than
inward. Cheeks very convex, at least posteriorly where they over-
hang the lateral border furrow. Border expanded medially as in
preceding species, slightly convex, narrowing toward the genal angle,
lacking tubercles. Posterior border set off by a wide, deep furrow,
rather wide in distal portion; genal angle narrowly rounded, lacking
spine.
Surface of test covered with raised lines forming a reticulate pat-
tern. The largest cephalon has a width of 10.5 mm and a length of
approximately 10 mm.
Occurrence.—Collections cs-4 and U.S.G.S. 4216, North Chatham.
Discussion.—This species is closely related to the preceding, dif-
fering in the deeper division of the glabella by a transverse furrow,
greater elevation of the two glabellar lobes, reticulate ornamentation,
and lack of tubercles on the border. Clearly the present species is
so strikingly different from Calodiscus lobatus that, were intermediate
forms unknown, reference to the genus would hardly be suggested.
However, when one considers the series Calodiscus lobatus, C. loba-
tus agnostoides, C. helena, C. fissifrons, and C. reticulatus, it appears
difficult to decide where to place a possible generic boundary.
Types.—Holotype: U.S.N.M. 146006. Paratypes: U.S.N.M.
146007 and 146008.
CALODISCUS OCCIPITALIS Rasetti, new species
Plate 9, figures 22, 23
Available material—One cephalon.
Description —Cephalon semielliptical, of low convexity. Glabella
elevated above the cheeks, higher posteriorly, with little longitudinal
convexity, parallel-sided in the posterior two-thirds, anteriorly taper-
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 25
ing to a fairly sharp point, occupying about two-thirds of the
cephalic length, unfurrowed. Occipital furrow deeper laterally,
impressed throughout ; occipital ring extended into a robust, horizon-
tal spine longer than all the rest of the cephalon. Cheeks lowest
medially, slightly convex, their outline forming a sharp angle at the
posterolateral corner. Border furrow well impressed; border convex,
fairly wide, of about even width but for a slight narrowing toward
the genal angle, bearing a few, indistinct tubercles. Posterior border
furrow deep and wide; posterior border with geniculation about half-
way between axial furrow and genal angle, the latter lacking a spine.
Surface of test smooth. Length of cephalon (exclusive of occipital
spine) 3.4 mm, width 3.8 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion—This form seems referable to Calodiscus even
though it differs in several features from all previously described
species. Its chief distinguishing characteristics are the relatively
short glabella, well-impressed occipital furrow, excessively long occip-
ital spine, narrowness of the border furrow, and even width of the
border.
Types.—Holotype: U.S.N.M. 146003.
LEPTOCHILODISCUS Rasetti, new genus
Description —Cephalon of moderate convexity. Glabella defined
by deep axial furrow but not rising much above the cheeks, narrow
and long, tapered, pointed in front, not reaching the anterior border,
unfurrowed. Occipital furrow deep; occipital ring extended into
spine. Cheeks everywhere convex, not separated in front by a pre-
glabellar depression. Border very narrow, wire-like, well defined by
narrow border furrow, narrowest in frontal portion, somewhat wid-
ened laterally. Posterior border furrow deep; posterior border widen-
ing distally, with geniculation near genal angle. Surface of test in
type species punctate.
Type species—Leptochilodiscus punctulatus Rasetti, new species.
Occurrence —Late Lower Cambrian of New York.
Discussion.—This simple eodiscid cephalon does not seem refer-
able to described genera. Compared with Calodiscus, it shows impor-
tant differences that are sufficient to doubt a close relationship. In
Calodiscus the anterior border is much wider, usually widest medially,
and the cheeks are separated in front of the glabella by a more or
less extended preglabellar depression. The glabella of Leptochilodts-
cus is unusually long and pointed. The deep occipital furrow and
spinose occipital ring also are not suggestive of Calodiscus.
26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
LEPTOCHILODISCUS PUNCTULATIS Rasetti, new species
Plate 1, figure 5; plate 11, figures 1-7
Available material—Four cephala in fair state of preservation.
Description—Cephalon of about equal length and width, well
rounded anteriorly. Glabella rising steeply above the occipital fur-
row, then sloping down toward a low anterior end without much
longitudinal convexity, tapered at low, almost uniform rate but for a
barely perceptible constriction at one-third the distance from the an-
terior end, reaching not far from the anterior border furrow. Occipital
furrow deep and wide; occipital ring at lower level than glabella,
extended into a slender, moderately long spine. Axial furrow deep
except in its anteriormost portion. Cheeks rising above the axial
furrow, convex transversely, in posterior portion sloping down steeply
to border furrow. Border defined by narrow but fairly deep border
furrow, convex, wire-like, very narrow in frontal portion. A unique,
though inconspicuous, feature of the border is a slight widening
that occurs at the point where the margin forms an angle of 45°
with the sagittal line; here a small pit, distinguishable in all speci-
mens, occurs on the upper surface. The portion of the border pos-
terior to the pit remains wider than the frontal border. Another
characteristic feature of the border is its sinuous outline in frontal
view ; the border curves slightly downward medially, upward at the
sides of the median downbend, then again downward to assume a
smooth course laterally. The slight crushing of the test in some
specimens has made these features visible in dorsal view also. Pos-
terior cephalic border with straight margin from axial furrow almost
to genal angle, at this point reaching maximum elevation and sharply
turned downward and forward to join the lateral border, possibly
extended into a genal spine. Posterior border furrow deep and wide.
Surface of cheeks definitely pitted in all specimens; similar but shal-
lower ornamentation on glabella. Length and width of largest cepha-
lon 4.4 mm.
Occurrence.—Collections cs-4 and U.S.G.S. 4216, North Chat-
ham.
Types.—Holotype: U.S.N.M. 146009. Paratypes: U.S.N.M.
146010 and 146011.
LITOMETOPUS Rasetti, new genus
Description—Cephalon relatively wide, almost semicircular, with
considerable relief. Glabella long and narrow, slightly tapered,
reaching the anterior border furrow which therefore merges medially
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 27
with the axial furrow. Glabellar and occipital furrows entirely obso-
lete. Cheeks convex; border wide, convex, downrolled into the dou-
blure. Posterior cephalic border with a blunt tooth, extended at the
genal angle into strong spine.
Pygidium similar in shape to cephalon, more tapered posteriorly.
Axis reaching posterior border, unfurrowed, well defined by axial
furrow. Border furrow well impressed ; border flat, fairly wide; dou-
blure sloping inward at about 45° to vertical, with serrated margin.
Size large for an Eodiscid.
Type species—Litometopus longispinus Rasetti, new species.
Occurrence.—Late Lower Cambrian of New York.
Discussion.—This form is a close relative of Serrodiscus, sharing
with that genus the shape of the glabella, the general structure of the
pygidium, and a slightly serrated doublure. Chief differences are
the width and convexity of the cephalic border, the entire lack of
preglabellar field, the unusual tooth at the posterior cephalic border,
and the strong genal spine. The last two features also distinguish
the genus from Cobboldites comleyensis, which has an equally long
glabella and a similar pygidium. The very large size of Litometopus
contrasts with the small size of the known examples of Cobboldites.
LITOMETOPUS LONGISPINUS Rasetti, new species
Plate 3, figure 3; plate 8, figures 1-9
Available material—A few cephala and a larger number of pygidia.
Description.—Cephalon 1.3 times wider than long, with uniformly
rounded anterior and lateral outline. Glabella widest at the undif-
ferentiated occipital ring, with slightly concave lateral outline,
rounded in front, well defined by the axial furrow, convex in both
directions. Cheeks very convex, sloping down steeply to the deep
border furrow. Border wide anteriorly, narrowing toward the genal
angle, convex, downrolled into doublure, showing a pair of small
lateral spines somewhat anterior to the cephalic midlength. Border
furrow becoming very shallow at the genal angle; genal spine strong,
curving inward, not greatly tapered, when complete probably equal-
ing the cephalon in length. Posterior border furrow well impressed ;
posterior border straight from axial furrow to near base of genal
spine, where it forms an obtuse tooth set off by a narrow, short
furrow. Surface of test sparsely punctate, more distinctly in larger
individuals. The largest (holotype) complete cephalon has a length
of 8.3 mm and a width of 10.7 mm. However, a large cephalon in
the collection, crushed by the slumping of the sediment in such
28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
manner that the anterior portion was bent under the posterior part,
but nevertheless recognizable, has a width of 30 mm excluding the
genal spines.
Pygidium 1.4 times wider than long. Axis well defined by the
axial furrow, just touching the border furrow, not showing segmen-
tation except for the articulating half-ring. Pleural regions convex.
Anterior border with sharp geniculation at two-fifths the distance
from axial furrow to lateral angle; facet well developed. Lateral bor-
der flat, defined by sharp change in slope, widening from anterior
angle to midlength, then narrowing again, narrowest medially. Dou-
blure somewhat wider than border, marked with terrace lines that fol-
low the blunt serrations of the margin. Surface pitted like the cepha-
lon. Length of largest pygidium 16 mm, width 22 mm.
From the proportions of the various parts and the size of the
largest cephalon, the presence of individuals about 50 mm long may
be inferred. This may be the largest size for an Eodiscid ever
reported.
Occurrence.—Collection cs-4, North Chatham.
Types.—Holotype: U.S.N.M. 146012. Paratypes: U.S.N.M.
146013.
OODISCUS Rasetti, new genus
Description.—Cephalon tending to a subquadrate shape. Gla-
bella with undifferentiated occipital ring ovate, occupying more than
one-third of the cephalic width, strongly elevated, totally unfurrowed.
Preglabellar field short (sag.). Cheeks convex and downsloping. Bor-
der furrow and border well defined all around the cephalon; lateral
border may show one or two pairs of short spines; in one species
the frontal border bears a pair of tubercles. Posterior border with
sharp geniculation and short spine at one-third the distance from axial
furrow to rounded genal angle.
Pygidium with tapered, unfurrowed axis not reaching posterior
border. Border furrow and border as in cephalon; border lacking
marginal spines.
Type species —Oodiscus subgranulatus Rasetti, new species.
Occurrence.—Late Lower Cambrian of New York.
Discussion.—The type species and others included in the genus
have a rather simple structure which, nevertheless, distinguishes them
clearly from previously known Eodiscidae such as Serrodiscus and
Calodiscus. The glabella is wider relative to the entire cephalon than
in these genera, and has an oval shape; the undifferentiated occipital
ring extends farther back than usual relative to the cheeks. The
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 29
geniculation of the posterior cephalic border, marked by a short
spine, is much closer to the axial furrow than in previously known
Eodiscidae. The pygidium, compared with Serrodiscus, has a shorter
axis and lacks marginal spines.
OODISCUS SUBGRANULATUS Rasetti, new species
Plate 1, figure 4; plate 10, figures 1-10
Available material_—Several cephala and pygidia more or less
completely preserved.
Description—Cephalon somewhat widening forward from the
genal angle, widest slightly in front of the midlength, well rounded
anterolaterally, with almost straight portion of frontal outline. Gla-
bella ovate, somewhat pointed in front, not reaching anterior border
furrow, strongly elevated above the cheeks, sloping down from pos-
terior to anterior end. Occipital furrow barely indicated by a pair
of exceedingly shallow lateral depressions, very short (sag.), rounded.
Cheeks strongly downsloping posteriorly, gradually flatter toward
the anterior part; no preglabellar depression. Border somewhat con-
vex, well defined by border furrow, of even width around the anterior
half of the cephalon, narrowing toward the genal angle, bearing two
pairs of small, short marginal spines, one pair at the level of the
cephalic midlength, a second pair halfway between the first and the
genal angle. Lateral border furrow continued into posterior border
furrow ; the latter directed outward and forward from axial furrow,
curving outward distally, hence as a whole convex forward. Posterior
border horizontal in inner third, then sharply downturned to reach
the much lower level of the genal angle; a small, upright spine at the
geniculation, usually broken in extracting the specimen from the
matrix. Genal angle narrowly rounded.
Pygidium assigned to the species on the basis of similar shape
and identical ornamentation, less convex than cephalon, about paral-
lel-sided in anterior half, well rounded posteriorly. Axis widest at
the base, not greatly elevated, tapered, unfurrowed, occupying two-
thirds of pygidial length. Anterior border straight, transverse from
axial furrow to geniculation which is relatively close to axial furrow,
distally slanted backward and with marked facet, paralleled by well-
impressed anterior border furrow; remainder of border furrow and
border as in cephalon; border lacking spines. Doublure reflexed in
usual manner.
Cheeks and pleural regions of the pygidium covered with small,
sparse granules, of density variable in different individuals. The py-
30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
gidia usually show one or two small median nodes on the anterior
portion of the axis when the preservation is perfect. Length of largest
cephalon 8.0 mm, width 8.8 mm. Length of largest pygidium 8.0 mm,
width 8.0 mm.
Occurrence.—Collection cs-4, North Chatham.
Types.—Holotype: U.S.N.M. 146014. Paratypes: U.S.N.M.
146015.
OODISCUS BINODOSUS Rasetti, new species
Plate 10, figures 16-18
Available material—tThree cephala, of which only the holotype
well preserved. Pygidia may be present, but cannot be identified
among similar species of the genus.
Description.—The cephalon is so similar to the type species that
only the differences are listed. Glabella narrower and of more
uniform elevation throughout its length, slightly longer, almost reach-
ing the anterior border furrow. Border furrow and border some-
what wider; anterior border bearing a pair of low, closely spaced
tubercles that somewhat encroach upon the border furrow. Lateral
border spines seemingly absent. Posterior border furrow straighter
than in type species; geniculation with small, upright spine. Surface
of test smooth. Length of largest cephalon 6.5 mm.
Occurrence.—Collection cs-4, North Chatham.
Types.—Holotype: U.S.N.M. 146016. Paratypes: U.S.N.M.
146017.
OODISCUS LONGIFRONS Rasetti, new species
Plate 10, figures 20, 21
Available material—aA few cephala, none of which well preserved.
Description—Glabella of the same shape as in the type species,
but longer, just reaching the anterior border furrow. Border furrow
and border somewhat wider than in O. subgranulatus ; anterior border
furrow showing a slight median inbend where it merges with the axial
furrow; anterior border lacking nodes. Lateral border seemingly
lacking spines, but none of the specimens are well preserved enough
for this feature to be established with certainty. Geniculation of
posterior border as in the two preceding species. In the holotype a
pair of low, inconspicuous nodes is present on the downsloping
portion of the posterior border between the geniculation and the
genal angle, but this feature is indistinct in the paratypes.
Occurrence.—Collection cs-4, North Chatham.
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 31
Types——Holotype: U.S.N.M. 146018. Paratypes: U.S.N.M.
146019.
OODISCUS, species undetermined No. 1
Plate 11, figures 8-11
Available matertal—aA few pygidia, of which two well preserved.
Description—Axis very prominent, unfurrowed, slightly tapered,
rounded posteriorly, not reaching the posterior border furrow. Pleu-
ral regions convex and downsloping. Anterior border with genicu-
lation relatively close to axial furrow and well-developed facet. Bor-
der furrow wide, relatively shallow. Border flat, rather wide. Anterior
angles of pygidium sharp. Doublure sharply reflexed, apparently
with smooth margin. Length of largest specimen 8.2 mm, width 8.0
mm. Surface of test smooth.
Occurrence.—Collection cs-4, North Chatham.
Discussion—tThis pygidium seems definitely to belong to Oodiscus,
but it cannot be determined to which, if any, of the species based
on the cephala it should be referred. Compared with the pygidium
assigned to O. subgranulatus, it has a more prominent and longer
axis.
Disposition of material—Figured specimens: U.S.N.M. 146020.
OODISCUS, species undetermined No. 2
Plate 11, figures 12, 13
Available material_—A few pygidia.
Description—The pygidia in question do not appreciably differ
in shape from those referred to O. subgranulatus, but lack the
ornamentation of the cephala and pygidia of that species. Hence they
may belong to a similar species, possibly O. binodosus, that has a
smooth cephalon. The assignment cannot be decided on the basis
of the available evidence.
Occurrence.—Collection cs-4, North Chatham.
Disposition of material—Figured specimens: U.S.N.M. 146021.
Genus SERRODISCUS R. and E. Richter, 1941
Type species—Eodiscus (Serrodiscus) serratus R, and E. Richter.
SERRODISCUS SUBCLAVATUS Rasetti, new species
Plate 2, figure 1; plate 8, figures 10-19
Available material_—Numerous cephala and pygidia, including one
cephalon with two thoracic segments attached.
32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Description —Glabella with totally undifferentiated occipital ring
defined by an exceptionally deep axial furrow, strongly convex trans-
versely, unfurrowed, slightly narrowed from the occipital ring to the
level of the posterior third, then slightly expanded forward, sharply
narrowed and somewhat pointed in front, reaching the border fur-
row. Cheeks very convex, posteriorly overhanging the border furrow,
anteriorly separated by a narrow (tr.) preglabellar depression formed
by the merging of the axial and border furrows. Border strongly
convex, fairly wide, defined by a deep border furrow, contributing
to the great relief of the cephalon. Tubercles on the border moder-
ately elevated, generally seven or eight pairs present, about equally
spaced. Posterior border furrow deep; posterior border straight from
axial furrow to sharp geniculation which is located not far from genal
angle and is marked by a short spine. A characteristic feature of
the border is a very narrow, shallow furrow parallel and close to the
posterior margin that sets off a slight, obtuse expansion. The artic-
ulated specimen shows that this feature corresponds to a similar
one at the fulcrum of the anterior margin of the first thoracic seg-
ment. However, the geniculation of the posterior cephalic border
with its spine is situated farther outward. In front of the spine the
cephalic border curves downward and forward to join the lateral
border which as usual is at a lower level; no sharp angle is formed,
and the cephalic border is narrowest at this point.
First thoracic segment with anterior margin distally from the above-
mentioned fulcrum sharply bent backward to form a well-developed
facet. Axis not preserved. Second segment showing a very convex
axial lobe and deep axial furrow. Pleural articulation between first
and second segment with features similar to those present between
the cephalon and the first segment, but more distally located. Anterior
margin beyond the geniculation bent downward but not backward.
Posterior margin with geniculation situated still farther outward, dis-
tally strongly bent forward and downward. Third thoracic segment
not preserved.
Pygidium with strong relief. Axis prominent, defined by deep axial
furrow, convex in both directions, totally unfurrowed, not quite
reaching the border furrow. Articulating half-ring expanded medially
by a rearward median inbend of the articulating furrow. Axis bearing
a strong median spine at about four-fifths of its length; this spine
is broken off in all pygidia except one specimen where it could be
partly restored. Pleural regions strongly convex, near posterior end
forming a narrow, convex band between the end of the axis and the
border furrow. Border furrow deep; border narrower than in cepha-
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 33
lon, extended downward into a series of short spines somewhat
visible in dorsal view by producing a wavy outline; seven or eight
pairs of such spines are usually present. A. R. Palmer (private com-
munication) suggested to the writer that such spines may fit the
reverse side of the tubercles of the cephalic border when the animal
is enrolled. The structures in the present species may support this
interpretation since the tubercles and spines are in about equal num-
bers and similarly spaced.
Surface of cephalon and pygidium densely covered with fine gran-
ules. Length of largest cephalon 11 mm, width 11 mm. The entire
pygidia recovered are somewhat smaller.
Occurrence.—Collection cs-4, North Chatham.
Discussion.—Even though the close affinity to typical species of
Serrodiscus can hardly be doubted, this form presents numerous
differences from all those previously described. The most conspicu-
ous features are the great convexity of the cephalon, depth of the
axial furrows, unusual length and somewhat clavate shape of the
glabella, and unfurrowed pygidial axis bearing a spine. The most
similar form is an undescribed species from the Purley Shales of
England (Rushton, private communication).
Types——Holotype: U.S.N.M. 146022. Paratypes: U.S.N.M.
146023.
SERRODISCUS SPINULOSUS Rasetti, new species
Plate 7, figures 7-11
Available material —A few cephala and one pygidium.
Description.—Glabella with undifferentiated occipital ring widest
at posterior end, narrowed forward for a short distance, then parallel-
sided, strongly tapered in frontal portion and rather pointed medi-
ally, unfurrowed. Glabella of moderate convexity, anteriorly reaching
the border on account of a sharp median inbend of the border furrow
which thus merges for a short distance with the axial furrow. Occipi-
tal ring bearing a short spine. Cheeks slightly convex, downsloping.
Border widest medially on account of the above-mentioned feature
of the border furrow, narrowing toward the genal angle, bearing
several pairs of very low, somewhat indistinct tubercles. Posterior
border wide (exsag.), extended into short, sharply pointed genal
spine. No geniculation features on posterior cephalic margin between
axial furrow and genal spine. Cephalic border narrowest at postero-
lateral angles in front of genal spine.
Pygidium referred to the species with long, totally unfurrowed
axis almost reaching posterior border. Articulating half-ring expanded
34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
medially as in preceding species. Pleural lobes of moderate con-
vexity; border furrow well impressed. Border fairly wide, convex,
extended ventrally into a series of short spines, producing in dorsal
view a waviness of the margin. Seemingly there was a spine on the
posterior part of the axis.
Surface of test of cephalon and pygidium perfectly smooth. Length
of largest cephalon 5.6 mm, width 5.2 mm. Length of pygidium
4.7 mm, width 5.6 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion.—This form is fully typical of Serrodiscus in all respects
excepting one unusual feature, the inbend of the anterior border
furrow causing it to merge with the axial furrow. Other distinguish-
ing features are the occipital and genal spines, the shape of the
glabella, and the unfurrowed pygidial axis.
Types.——Holotype: U.S.N.M. 146026. Paratypes: U.S.N.M.
146027.
SERRODISCUS LATUS Rasetti, new species
Plate 10, figures 12-15
Available material—Three cephala, of which one excellently pre-
served.
Description—Glabella with totally undifferentiated occipital ring
slightly tapered, straight-sided, well defined by deep axial furrows,
somewhat pointed in front, almost reaching the border, unfurrowed.
Cheeks convex, rising somewhat above the axial furrows, steeply
sloping to border furrow at the sides. Border furrow deep all around
the cheeks, medially almost meeting the axial furrow. Border some-
what convex and on the average horizontal, widest medially and but
slightly tapering to the genal angle, bearing a few pairs of low
tubercles. Posterior border furrow and border about as wide as
lateral border ; posterior cephalic margin straight and transverse from
axial furrow to geniculation, then turning downward and forward to
the genal angle which bears a minute spine. Surface of test smooth.
Length of largest cephalon 5.0 mm, width 6.2 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion.—The cephalic features agree with Serrodiscus, but in
the absence of a pygidium it is questionable whether the species
should not rather be referred to Calodiscus, or possibly Cobboldites.
The cephalon differs markedly from C. speciosus and other described
species in the general outline, regularly curved in front rather than
pointed, deep axial furrows, and great convexity of the cheeks.
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 35
Types.—Holotype: U.S.N.M. 146024. Paratypes: U.S.N.M.
146025.
SERRODISCUS, species undetermined
Plate 10, figure 19
Available material—One incomplete cephalon.
Description—Glabella approximately parallel-sided, rounded in
front, not greatly elevated, occupying with the occipital ring two-
thirds of the cephalic length. One pair of glabellar furrows, very
broad and shallow, is impressed all across the glabella. Occipital
furrow visible as a pair of shallow, broad depressions at the sides.
Occipital ring somewhat elevated medially, rounded, lacking node or
spine. Cheeks moderately convex, preserved only in their anterior
part. Preglabellar field flat, fairly extended. Border furrow shallow;
border wide, flat, apparently lacking tubercles. Anterior outline of
cephalon unusually pointed medially. Surface of test smooth. Length
of cephalon 5.6 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion——tThis cephalon cannot be referred to any described
species, but is too incomplete to warrant a name. The proportions
of the various parts are somewhat like S. speciosus, but the glabella
is shorter and less tapered, the entire cephalon more nearly triangular,
the border wider, and the occipital ring is raised at the posterior
margin.
Disposition of material—Figured specimen: U.S.N.M. 146028.
STIGMADISCUS Rasetti, new genus
Description —Cephalon semielliptical, lacking lateral spines. Gla-
bella approximately parallel-sided, rather pointed in front, rising
above the downsloping cheeks, elevated in front of the occipital
furrow. Glabellar furrows impressed as two pairs of deep lateral pits
close to the axial furrow. Occipital furrow similarly deepened into a
pair of pits. Occipital ring well differentiated, bearing a node or
spine. Cephalic border narrow, defined by shallow border furrow.
Posterior border bearing a pair of short spines, located either about
halfway between the axial furrow and the genal angle, or close to
the genal angle. Surface of test smooth. Other parts of exoskeleton
unknown.
Type species—Stigmadiscus stenometopus Rasetti, new species.
Occurrence.—Late Lower Cambrian of New York.
36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Discussion—The genus is proposed for two species whose most
distinctive character is the pit-like structure of the glabellar furrows,
a feature so far never observed in the Eodiscidae. The type species
shows marked affinity with Acidiscus, where the glabellar furrows
are relatively short and deep and the occipital furrow has a similar
structure. The other described species, Stigmadiscus gibbosus, shows
some resemblance to an Agnostid cephalon in the proportions of the
various parts. Whether this similarity is purely accidental, or we
are dealing with an Eodiscid evolving into an Agnostid, cannot be
decided at present, especially in the absence of thorax and pygidium.
STIGMADISCUS STENOMETOPUS Rasetti, new species
Plate 3, figure 5; plate 12, figures 1-7
Available material—Several cephala, of which two fairly complete.
Description——Cephalon of low convexity. Glabella relatively nar-
tow, slightly tapered from the occipital ring to the anterior pair of
lateral furrows, very slightly expanded in front, somewhat pointed,
occupying about two-thirds of cephalic length. Axial furrow deep
posteriorly, shallower anteriorly. Longitudinal profile of glabella ris-
ing gradually from front to back, where it reaches its highest eleva-
tion in the form of a rounded ridge that drops abruptly to the level
of the occipital furrow. In some of the specimens there is an indica-
tion of a small, broken spine at this highest point, whereas other
individuals where the test at this place is well preserved do not show
a spine. Occipital ring moderately long (sag.), bearing a short spine.
Cheeks slightly convex, downsloping ; lateral border narrow, of even
width, defined by a border furrow that becomes progressively shal-
lower and broader forward. Posterior border furrow deeper than
lateral border furrow, almost straight, slightly convex forward, join-
ing the lateral border furrow near the genal angle which is fairly
sharp but seemingly not extended into a spine. Posterior cephalic
border wider and better defined than lateral border, extended into
a short, horizontal spine located somewhat closer to the axial furrow
than to the genal angle. The portion of the posterior border beyond
the spine is somewhat slanted forward. Surface of test smooth.
Length of holotype cephalon 9.0 mm, width 9.9 mm. The largest
glabella indicates a cephalon 12.5 mm in length.
Occurrence.—Collection cs-4, North Chatham.
Types.—Holotype: U.S.N.M. 146029. Paratypes: U.S.N.M.
146030.
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 37
STIGMADISCUS GIBBOSUS Rasetti, new species
Plate 3, figure 4; plate 12, figures 8-13
Available material—About half a dozen cephala, mostly in medi-
ocre state of preservation.
Description.—Cephalon equally wide and long, moderately convex,
semielliptical. Glabella narrowed forward in its posteriormost portion
from the wider occipital ring, almost parallel-sided in its medial
part, rapidly tapered and somewhat pointed in its anterior fourth.
Two posteriormost pairs of lateral furrows deep, short, pit-like; no
indication of other pairs. A broad transglabellar depression is located
somewhat in advance of the anterior pair of lateral furrows. The
glabella rises in bulbous shape behind this depression and drops
sharply to the occipital furrow. The occipital furrow is impressed
at the sides in form of a pair of small pits, shallower than the glabellar
furrows, not connecting with the axial furrow, and is extended medi-
ally into a shallower, still well-impressed portion. Occipital ring
short, bearing a small node. Cheeks rather flat in front of the
glabella, not forming a definite depression. Border furrow shallow
and poorly defined anteriorly, gradually becoming narrower and
deeper toward the genal angle. Border poorly defined, somewhat
convex, reduced in width toward the genal angle. Posterior border
furrow directed outward and forward, forming a considerable angle
with the posterior cephalic margin and hence producing an elongate,
triangular posterior border which extends into a short spine located
very close to the genal angle. The posterior cephalic margin slopes
down somewhat in connecting the posterior with the lateral border.
Surface of test smooth. Length and width of largest cephalon 6.8 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion.—This form seems closely related to the type species,
with which it shares the pit-like glabellar furrows and the elevation
of the posterior portion of the glabella. In other respects there are
conspicuous differences, which made the writer hesitate whether the
two should be referred to the same genus. In Stigmadiscus gibbosus
the glabella is larger in proportion to the whole cephalon, the occipi-
tal ring is shorter and lacks a spine, the glabellar boss is defined both
in front and back, instead of rising gradually in the frontal part as
in S. stenometopus. Perhaps the most significant difference of all is
in the position of the spine on the posterior cephalic border, in the
present species close to the genal angle so that it may be called a
“genal” spine. These various differences give to Stigmadiscus gib-
38 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
bosus a somewhat Agnostid-like aspect that is completely lacking in
the type species.
Types.—Holotype: U.S.N.M. 146031. Paratypes: U.S.N.M.
146032.
Undetermined pygidia
Several pygidia, undoubtedly belonging to the family Eodiscidae
and possibly to some of the named species, are described hereafter.
Possible assignments are suggested in some cases.
Undetermined pygidium No. 1
Plate 11, figures 17-21
Available material_—Three examples.
Description—Pygidium of strong convexity especially in the trans-
verse direction. Axis strongly prominent, moderately tapered, reach-
ing the posterior border furrow, showing eight rings plus a terminal
section defined by exceedingly shallow furrows; articulating half-ring
short (sag.), articulating furrow straight. Pleural regions convex,
laterally sloping down vertically to border furrow. Border very nar-
row, ventrally extended into 8 to 10 pairs of short, somewhat back-
ward-directed spines. Outline of border arched in posterior view.
Surface of test with very shallow puncta, not equally distinct in the
available specimens. Length of largest pygidium 4.4 mm, width 4.4
mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion.—The narrowness of the border and the shallowly punc-
tate surface suggest the possibility that this is the pygidium of
Leptochilodiscus punctulatus.t
Disposition of material—Figured specimens: U.S.N.M. 146033.
Undetermined pygidium No. 2
Plate 11, figures 14-16
Available material—Three more or less complete examples.
Description.—Pygidium with considerable relief. Axis prominent,
relatively wide, tapered to a rather sharp point, almost reaching the
posterior border furrow, composed of six rings plus a terminal sec-
1 Copious material, collected from another locality after this paper was written,
unquestionably supports this assignment.
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 39
tion. Ring furrows with peculiar structure, deepening to pair of pits
at the sides some distance from the axial furrow; the medial portion
of the ring furrow narrower and shallower, concave toward the front.
The axial rings bore spines of decreasing length, broken off in the
available specimens. Pleural regions unfurrowed, downsloping ; bor-
der furrow narrow but deep; border narrow, but expanded into four
pairs of wide, short, somewhat blunt spines about evenly spaced.
The spines are directed outward, not downward as in many species
of Serrodiscus. Surface of test smooth. Length of largest pygidium
5.7 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion.—It is questionable whether this peculiar pygidium
belongs to any of the cephala known from the locality.
Disposition of material—Figured specimens: U.S.N.M. 146034.
Undetermined pygidium No. 3
Plate 10, figure 11
Available material_—A single, well-preserved example.
Description —Pygidium of low convexity, almost semicircular.
Axis defined anteriorly by very shallow axial furrows, the remainder
undifferentiated from the pleural regions. Articulating half-ring and
furrow well defined. Anterior outline straight in dorsal view, with
geniculation about halfway between axial furrow and anterior angle,
with border bent downward but not appreciably backward. Border
furrow well impressed, border flat, of almost even width throughout.
Doublure vertical, narrow, with smooth margin. Surface of test
smooth. Length of pygidium 7.0 mm, width 10.3 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion—In the general shape this pygidium recalls Litometo-
pus longispinus, but differs markedly in the lesser convexity and
especially in the almost complete obsolescence of the axial furrows.
It should presumably be associated with a cephalon with poorly
differentiated glabella, but no such form is present in the collection.
Disposition of material—Figured specimen: U.S.N.M. 146035.
Family OLENELLIDAE Vogdes, 1893
Olenellids are relatively common in the faunule, but owing to the
thinness of their test, they are usually much more fragmentary than
the Eodiscids. Cephala of three different species have been identified.
40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
These are all represented by small, evidently immature specimens.
No fragments of either cephala or thoracic segments seem to indicate
the presence of animals much larger than the cephala illustrated.
Genus PAEDEUMIAS Walcott, 1910
Type species.—Paedeumias transitans Walcott.
PAEDEUMIAS, species undetermined No. 1
Plate 12, figures 23-25
Available material—Fairly numerous, complete cephala from 1.5
to 4 mm in length.
Description—Glabella well-defined, narrow, parallel-sided, with
frontal lobe not wider than the posterior lobes. Frontal lobe ovate,
defined by a furrow deep at the sides, shallow but distinct medially.
Next three lobes of about equal length, separated by deep, trans-
verse furrows at the sides, not extended medially. Occipital furrow
similar to the preceding glabellar furrows; occipital ring apparently
extended into a short spine, not well preserved in any of the cephala.
Palpebral lobes separated by a shallow depression from frontal gla-
bellar lobe, with curvature increasing backward, almost reaching the
posterior cephalic margin. There is a fairly wide, well-defined space
between the glabella and the palpebral lobe. Border wide, convex,
of about the same width frontally and laterally. Distance from ante-
rior end of glabella to anterior border furrow almost equal to length
of frontal glabellar lobe. A median ridge connecting the front end
of the glabella with the border furrow is visible at least in the larger
specimens. From the posterior end of the palpebral lobe a narrow
outward-directed ridge reaches the posterior cephalic margin at the
base of a moderately long intergenal spine. Beyond this spine, the
posterior margin turns slightly forward to the base of the genal spine,
which is less conspicuous than the intergenal spine.
The preceding description was based on cephala about 4 mm in
length. In a fairly well-preserved cephalon 1.5 mm in length illus-
trated herein, the intergenal spines are very close to the genal angle;
in addition, there is a pair of small procranidial spines. These changes
in the relative size and position of the spines, as far as can be ascer-
tained from the meager material available, seem to parallel those
observed by Palmer (1957) in the ontogeny of Olenellus gilbert.
Occurrence.—Collection cs-4, North Chatham.
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 4!I
Discussion—The reference to the genus is chiefly suggested by
the considerable length of the preglabellar field and the presence of
a preglabellar ridge ; however, these may be juvenile features. The
present form is almost identical with an immature cephalon attributed
to Paedeumias from a conglomerate boulder near Levis, Quebec,
figured by the writer (Rasetti, 1948, pl. 2, fig. 5). If this cephalon
is conspecific with the larger one from the same locality (Rasetti,
1948, pl. 2, fig. 6), the reference to Paedeumias seems well founded.
Comparison with immature cephala of Elliptocephala asaphoides
shows that the present species differs in several respects.
Disposition of material—Figured specimens: U.S.N.M. 146036.
PAEDEUMIAS?, species undetermined No. 2
Plate 12, figures 19, 20
Available material—aA few, incomplete cephala.
Description.—Glabella flat, hardly elevated above the cheeks,
defined by a shallow axial furrow only in the portion corresponding
to the posterior lobe; the two preceding lobes extend, undifferentiated
from the cheek, as far as the palpebral lobe. Glabella tapered, with
frontal lobe considerably narrower than the posterior lobe and the
occipital ring. Three pairs of glabellar furrows increasing in depth
rearward, fairly well impressed at the sides, fading out medially,
oblique and approximately parallel to each other. Occipital furrow
of identical character; occipital ring as long as the last glabellar
lobe, bearing a node. Palpebral lobes broad, scarcely elevated, pos-
teriorly reaching the level of the midlength of the occipital ring. A
narrow rim, set off by a narrow furrow, encircles the palpebral lobe.
All the cephala are broken at the outer edge of this rim, i.e., at the
upper boundary of the visual surface of the eye, where the facial
suture is located in opisthoparian trilobites; the remainder of the
pleural portions of the cephalon is completely missing. The area
comprised between the glabella and the palpebral lobe is very narrow,
and defined only posteriorly as previously indicated. Length of gla-
bella plus occipital ring 5-6 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion.—This form has features unusual among the Olenellids
of the late Lower Cambrian, especially the tapered glabella and the
well-defined narrow rim around the palpebral lobe. It cannot be
identified with any described species known to the writer.
Disposition of material—Figured specimens: U.S.N.M. 146037.
42 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Genus OLENELLUS Billings, 1861
Type species.—Olenus thompsoni Hall.
OLENELLUS, species undetermined
Plate 12, figures 21, 22
Available material—aA few, incomplete cephala.
Description.—Glabella well defined by a deep axial furrow, on
the average somewhat expanded forward. Frontal lobe large; second
lobe short and wide, set off by narrow, fairly deep lateral furrows
at the sides both from the frontal lobe and the third lobe; both pairs
of furrows become very shallow medially. The second lobe expands
laterally to touch the palpebral lobe, from which it is separated by an
oblique furrow, extension of the first pair of glabellar furrows. Third
and fourth glabellar lobes narrower, bounded by the axial furrow
laterally, far from reaching the palpebral lobe; third pair of lateral
furrows and occipital furrow similar to second pair of furrows. There
was a node, broken off in the available specimens, across the occipi-
tal furrow, rather than on the occipital ring as usual. Palpebral lobes
wide, long, set off by a very shallow furrow from the frontal glabellar
lobe, showing a poorly defined rim, set off by an exceedingly shallow
furrow, representing about one-third of the width of the palpebral
lobe. Other cephalic parts not preserved. Length of glabella plus
occipital ring 4-5 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion.—The features of this species, as far as can be observed
on the incomplete cephala, agree with Olenellus, but reference to
other genera of the family cannot be excluded. The shape of glabella
and palpebral lobe shows a marked resemblance to Holmia kjerulfi
(Linnarsson).
Disposition of material—Figured specimens: U.S.N.M. 146038.
Family DORYPYGIDAE Kobayashi, 1935
Genus KOOTENIA Walcott, 1889
Type species.—Bathyuriscus (Kootenia) dawsoni Walcott.
KOOTENIA, species undetermined
Plate 12, figures 14, 15
Available material_—A single, incomplete pygidium.
Description.—Pygidium of relatively low convexity. Axis wide,
moderately tapered, straight-sided, composed of six well-defined rings
plus a terminal section, reaching the posterior border furrow. All
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 43
the axial rings except the last have a median node. Pleural regions in
proximal portion not downsloping at all, convex and downsloping
only in marginal portion. Five pairs of pleural furrows very broad
and moderately deep ; narrow interpleural furrows well defined espe-
cially in the proximal portion. Border furrow broad and poorly
defined ; border flat, extended into several pairs of spines of about
equal size, evenly spaced, and directed perpendicularly to the margin.
All spines are broken and their length cannot be ascertained; the
bases of five pairs of spines are visible, but there must have been
another pair on the anterior, unpreserved portion of the border. The
distance between the spines of the sixth pair is much greater than the
distance between successive pairs.
Surface of test with ornamentation that consists of shallow puncta
on the axial rings and becomes rather of reticulate type on the pleural
regions. Length of pygidium 6.0 mm, width 10 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion—This pygidium is referred to Kootenia which it
resembles more than any other described genus, but its unusual fea-
tures might suggest a new genus if the cephalic parts were known.
Compared to the described forms of Kootenia, the axial rings are
proportionately much wider and shorter, the pleural regions are flat
rather than convex in their proximal portion, and the interpleural
furrows are unusually developed. In particular, there is little resem-
blance to the species of Kootenia or Fordaspis described from the
Lower Cambrian of the Taconic area (Lochman, 1956).
Disposition of material—Figured specimen: U.S.N.M. 146039.
Genus BONNIA Walcott, 1916
Type species.—Bathyurus parvulus Billings.
Several species of Bonnia seem to be represented by cranidia, asso-
ciated with one form of pygidium definitely referable to the genus.
It cannot be determined whether all the cranidia belong to Bonnia
rather than to Kootenia, since the two are not always generically
distinguishable in the absence of the pygidium. For these reasons
each cranidium is described as an undetermined species of Bonmia
and the pygidium is not referred to any of the cranidia.
BONNIA, species undetermined No. 1
Plate 11, figures 23-25
Represented by several examples, mostly too immature for spe-
cific identification. Entire cranidium proportionately wide and short.
44 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Glabella slightly expanded forward, with traces of lateral furrows.
Occipital furrow deep laterally, shallow medially; occipital ring but
partially preserved. Fixigenae convex and downsloping, about half
the glabellar width. Ocular ridges low and broad, paralleling the
border furrow. Border not well preserved, seemingly very narrow
at least in front of the glabella. Palpebral lobes shorter than average
for the genus; posterior area wider (tr.) than occipital ring. Surface
of test with indistinct ornamentation. Length of largest cranidium
3.5 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion—This form cannot be identified with any of the
species of Bonmia previously described, in particular with the nu-
merous species illustrated by the writer from the conglomerates of
Quebec (Rasetti, 1948). The chief characteristic is the breadth of
the cranidium, the glabella and the fixigenae.
Disposition of material—Figured specimens: U.S.N.M. 146040.
BONNIA, species undetermined No. 2
Plate 11, figure 22
Represented by an immature example. Cranidium of average shape
for the genus. Glabella but slightly expanded, of average convexity,
unfurrowed. Occipital furrow narrow but well impressed ; occipital
ring incomplete, possibly spinose. Fixigenae, palpebral lobes, and
anterior border of average form. Length of cranidium 2.7 mm. Sur-
face of test smooth.
Occurrence.—Collection cs-4, North Chatham.
Discussion—In the general proportions and lack of ornament
this form might be compared with Bonnia similis Rasetti. As far as
can be ascertained from one small, somewhat imperfect cranidium,
it seems to differ in the more posterior position of the palpebral
lobes.
Disposition of material—Figured specimen: U.S.N.M. 146041.
BONNIA, species undetermined No. 3
Plate 12, figure 16
Possibly represented by a few, incomplete examples. The descrip-
tion is based on the best specimen illustrated herein. Glabella of
average convexity, slightly expanded in posterior half, slightly tapered
anteriorly, with but traces of lateral furrows. Occipital furrow wide
and deep throughout; occipital ring long (sag.), extended into a
short, somewhat blunt spine. Fixigenae relatively narrow; anterior
border narrow in front of the glabella, wider laterally. Posterior area
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 45
not preserved. Test with shallow puncta, close together so that the
ornamentation, which is not very conspicuous, might be described
as intermediate between punctate and granulate; anterior border
with irregular raised lines. Length of cranidium 5.5 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion —This form might be compared with Bonnia busa
(Walcott) which, however, has visible glabellar furrows and stronger
ornamentation.
Disposition of material—Figured specimen: U.S.N.M. 146042.
BONNIA, species undetermined No. 4
Plate 12, figure 18
Represented by a single, incomplete, somewhat deformed example.
Glabella seemingly more convex both transversely and longitudinally
than in the preceding form, although this feature may have been
accentuated by slight lateral compression. Glabella on the average
parallel-sided, with exceedingly shallow lateral furrows. Occipital
furrow deep and broad; occipital ring incomplete, seemingly
triangular and presumably spinose. Fixigenae incompletely pre-
served ; anterior border of average width, strongly slanted backward
laterally. Surface of test finely granulate, the granules on the pos-
terior part of the glabella showing a tendency to become arranged
in irregular, transverse ridges. Length of cranidium 7.5 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion —The proportionately short and wide, strongly con-
vex, nonexpanding glabella seem to distinguish this form from de-
scribed species. It is quite possible that, were the pygidium known, this
form should be referred to Kootenia. The cranidium does not greatly
differ from Kootenia troyensis Resser, as redescribed and figured by
Lochman (1956), but no pygidia resembling that species were found
in the collection.
Disposition of material—Figured specimen: U.S.N.M. 146043.
BONNIA, undetermined pygidium
Plate 12, figure 17
Represented by a few examples, the only complete specimen being
the one illustrated. Pygidium with relatively narrow, somewhat ta-
pered axis showing three rings plus a terminal unsegmented section,
reaching the border furrow. Pleural regions with four pairs of pleural
furrows, counting the anterior border furrow, and but traces of one
pair of interpleural furrows. Border furrow shallow, border flat,
46 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
seemingly lacking the small spine at the anterolateral angle. Orna-
mentation indistinct. Length of complete pygidium 2.8 mm, width
4.6 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion—This unmistakable pygidium of Bonnia presumably
belongs to one of the cranidia described herein. It may be compared
with the pygidium of Bonnia senecta (Billings) illustrated by the
writer (Rasetti, 1948) which it resembles in the narrow axis and
well-impressed pleural furrows.
Disposition of material—Figured specimen: U.S.N.M. 146044.
FAMILY, GENUS, AND SPECIES UNDETERMINED
Undetermined pygidium No. 4
Plate 6, figures 20, 21
Available material.—Several incomplete examples.
Description.—Entire pygidium subtriangular, of moderate convex-
ity. Axis well defined, somewhat tapered, straight-sided, almost
reaching the posterior margin. Axial rings numerous, probably 13
or 14, all well defined by ring furrows that, at least in the anterior
portion of the axis, show a median backward inflection. At least the
first few rings seem to have borne a node or spine. Pleural regions
downsloping, with straight, narrow, somewhat backward-directed
pleural furrows that, at least for the first 10 segments, correspond
to the ring furrows on the axis. About 11 or 12 pleural furrows are
visible ; there is no trace of interpleural furrows. All furrows end in
a broad, poorly defined border furrow that sets off a narrow, some-
what convex border. The anterior outline of the pleural lobes shows
a sharp geniculation very close to the axial furrow; past the genicula-
tion the margin turns backward in a wide curve and finally assumes
the straight backward and inward course that gives the pygidium a
subtriangular shape. Surface of test smooth. The length of the
largest pygidium, if complete, would be about 14 mm, the maximum
width 12 mm.
Occurrence.—Collection cs-4, North Chatham.
Discussion.—This peculiar pygidium cannot be referred to any
described genus of Cambrian trilobites, and not even a plausible
family assignment is suggested. It is virtually certain that this is not
the pygidium of an Olenellid or Ptychoparioid trilobite, and it seems
unlikely that it belongs to one of the numerous Eodiscids present
in the collection.
Disposition of material—Figured specimens: U.S.N.M. 146000.
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 47
REFERENCES
Darr, T. N:
1904. Geology of the Hudson Valley between the Hoosic and the Kinder-
hook. U.S. Geol. Surv. Bull. 242, pp. 1-63.
FisHEr, Donatp W.
1962. Correlation of the Cambrian rocks in New York State. New York
State Mus. Sci. Serv., Geol. Surv., Map and Chart Series: No. 2.
HutcHinson, R. D.
1962. Cambrian stratigraphy and trilobite faunas of southeastern Newfound-
land. Geol. Surv. Canada, Bull. 88, pp. 1-156.
LocHMAN, CHRISTINA.
1956. Stratigraphy, paleontology, and paleogeography of the Elliptocephala
asaphoides strata in Cambridge and Hoosick quadrangles, New
York. Geol. Soc. Amer. Bull., vol. 67, pp. 1331-1396.
LocHMAN, CHRISTINA, and WILSON, JAMEs L.,
1958. Cambrian biostratigraphy in North America. Journ. Paleontol., vol.
32, pp. 312-350.
Pater, A. R.
1955. Upper Cambrian Agnostidae of the Eureka District, Nevada. Journ.
Paleontol., vol. 29, pp. 86-101.
1957. Ontogenetic development of two olenellid trilobites. Journ.
Paleontol., vol. 31, pp. 105-128.
PoxrovskKayYA, N. V.
1959. Trilobite fauna and stratigraphy of the Cambrian deposits of Tuva (in
Russian). Publ. Geol. Inst. Acad. Sci. Soviet Soc. Rep. (Moscow),
No. 27, pp. 1-197.
RASETTI, FRANCO.
1945. Fossiliferous horizons in the “Sillery formation” near Levis, Quebec.
Amer. Journ. Sci., vol. 243, pp. 305-319.
1946. Cambrian and early Ordovician stratigraphy of the lower St. Law-
rence valley. Geol. Soc. Amer. Bull., vol. 57, pp. 687-706.
1948. Lower Cambrian trilobites from the conglomerates of Quebec (ex-
clusive of the Ptychopariidea). Journ, Paleontol., vol. 22, pp. 1-
24,
1952. Revision of the North American trilobites of the family Eodiscidae.
Journ. Paleontol., vol. 26, pp. 434-451.
Raymonp, P. E.
1913. Quebec and vicinity. Geol. Surv. Canada, Guide Book No. 1, pt. 1,
pp. 25-47.
THEOKRITOFF, GEORGE.
1964. Taconic stratigraphy in northern Washington County, New York.
Geol. Soc. Amer. Bull., vol. 75, pp. 171-190, map.
WesTeErRGARD, A. H.
1946. Agnostidea of the Middle Cambrian of Sweden. Sveriges Geol.
Unders., ser. C., No. 477, Arsbok 40, No. 1, pp. 1-140, 16 plates.
ZEN, E-An.
1964. Taconic stratigraphic names: definitions and synonymies. U.S. Geol.
Surv. Bull. 1174, pp. 1-95.
48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
EXPLANATION OF PLATES
GENERAL STATEMENT
To avoid unnecessary repetition, locality and collection numbers
are only indicated for the few illustrated specimens that are not
part of the writer’s collection cs-4 from the North Chatham locality.
Three specimens (pl. 7, fig. 18; pl. 9, figs. 14-16; pl. 11, figs. 6, 7)
are from U.S.G.S. collection 4216 at the same locality. One specimen
(pl. 5, figs. 13, 14) was collected near Elgin Station, Quebec,
Canada.
All figured specimens show the outer surface of the test.
PLaTE 1
Page
Fig. 1. Calodiscus reticulatus Rasetti, new species . . .. .. . 24
Dorsal and lateral views of cephalon, <3.
Fig. 2. Acidiscus birdi Rasetti, new genus, new species . . . .. . Il
Lateral and dorsal views of cephalon; pygidium; 2.
Fig. 3. Bathydiscus dolichometopus Rasetti. new genus, new species . . 17
Dorsal, frontal, and lateral views of cephalon; posterior, lateral, and
dorsal views of pygdium; 4.
Fig. 4. Oodiscus subgranulatus Rasetti, new genus, new species . . . 29
Dorsal, frontal, and lateral views of cephalon; pygidium; 4.
Fig. 5. Leptochilodiscus punctulatus Rasetti, new genus, new species . . 26
Cephalon, <6.
PLATE 2
Fig. 1. Serrodiscus subclavatus Rasetti, new species . . . 31
Dorsal and oblique anterior views of cephalon; oblique pastecior ei
dorsal views of pygidium; <4.
Fig. 2. Analox bipunctata Rasetti, new genus, new species . . 15
Dorsal and lateral views of pygidium; lateral and dorsal views mee
cephalon; <6.
Fig. 3. Acimetopus bilobatus Rasetti, new genus, new species . . 14
Dorsal and lateral views of pygidium; oblique and dorsal views ios
cephalon; <4.
PLATE 3
Fig. 1. Bolboparia superba Rasetti, new genus, new species . . . . . 19
Dorsal and oblique views of cephalon, 4.
Fig. 2. Bolboparia elongata Rasetti, new species . . . .... .- 20
Pygidium, <5.
Fig. 3. Litometopus longispinus Rasetti, new genus, new species . . . 27
Dorsal and lateral views of cephalon; pygidium; 2.
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 49
Fig. 4. Stigmadiscus gibbosus Rasetti, new species . . . . . . . 37
Dorsal and lateral views of cephalon, <5.
Fig. 5. Stigmadiscus stenometopus Rasetti, new genus, new species . . 36
Dorsal and lateral views of cephalon, <3.
PLATE 4
Figs. 1-14. Acimetopus bilobatus Rasetti, new genus, new species . . . 14
1-4, Dorsal, oblique, anterior, and lateral views of cephalon, <5;
U.S.N.M. 145991, holotype. 5, Cephalon, <6. 6, Cephalon, 4.
7, Cephalon, <5. 8-10, Dorsal, lateral, and posterior views of py-
gidium, <5. 11-13, Dorsal, lateral, and posterior views of pygidium,
x5. 14, Lateral view of pygidium preserving part of axial spine, <5.
U.S.N.M. 145992, paratypes.
Piate 5
Figs. 1-6. Bolboparia superba Rasetti, new genus, new species . . . 19
1-4, Dorsal, anterodorsal, frontal, and oblique views of cephalon, SA:
U.S.N.M. 145998, holotype. 5, Thoracic segment, <5. 6, Cephalon
with broken-off glabellar spine, showing occipital ring, X5. U.S.N.M.
145999, paratypes.
Figs. 7-12. Bolboparia elongata Rasetti, new species . . 20
7-9, Lateral, dorsal, and frontal views of cephalon, x5: ‘US.NM.
146001, holotype. 10, Cephalon, 5. 11, 12, Lateral and dorsal views
of pygidium, <4. 13, Pygidium, 7.5. U.S.N.M. 146002, paratypes.
Figs. 13, 14. Bolboparia canadensis Rasetti, new species . . 21
13, 14, Dorsal and lateral views of cephalon, <8. G.S.C. 19887, Poles
type. Collected from the Charny formation near Elgin Station,
L’'Islet County, Quebec.
PLaTE 6
Figs. 1-10. Analox bipunctata Rasetti, new genus, new species . . 15
1-3, Dorsal, frontal, and lateral views of cephalon, x6; US.NM.
145993, holotype. 4, Cephalon, <6. 5, 6, Lateral and dorsal views
of pygidium, X10. 7, 8, Lateral views of two cephala, X6. 9, Dy-
gidium, <5. 10, Pygidium, 6. U.S.N.M. 145994, paratypes.
Figs. 11-19. Acidiscus birdi Rasetti, new genus, new species . . 11
11, 12, Dorsal and lateral views of cephalon, 2; U.S.N.M. 145987,
holotype. 13-15, Dorsal, lateral, and frontal views of cephalon, pad
16, 17, Dorsal and lateral views of pygidium, X2. 18, Lateral view
of pygidial doublure showing short spines, <5. 19, Portion of py-
gidium showing granulate surface, X7.5. U.S.N.M. 145988, para-
types.
Figs. 20, 21. Undetermined pygidium No. 4 . . - + + + © + + 46
20, 21, Two examples, X2.5; U.S.N.M. 146000.
50 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
PLATE 7
Figs. 1-6. Acidiscus hexacanthus Rasetti, new species :
1-3, Dorsal, frontal, and lateral views of cephalon, 3: ‘US.NM.
145989, holotype. 4, 5, Lateral and dorsal views of cephalon, x5.
6, Pygydium, *6. U.S.N.M. 145990, paratypes.
Figs. 7-11. Serrodiscus spinulosus Rasetti, new species . .
7-9, Lateral, dorsal, and frontal views of cephalon, <5: ‘U.S.N.M.
146026, holotype. 10, 11, Dorsal and lateral views of pygidium, <5;
U.S.N.M. 146027, paratype.
Figs. 12-18. Calodiscus reticulatus Rasetti, new species . .
12-14, Dorsal, frontal, and lateral views of cephalon, 4; ‘US.N.M.
146006, holotype. 15, Cephalon, <5, 16, Glabella of another specimen
showing ornamentation, X10. 17, Lateral view of the same cephalon,
<4. U.S.N.M. 146007, paratypes. 18, Incomplete cephalon, showing
occipital ring and posterior border, *5; U.S.N.M. 146008, paratype.
Piate 8
Figs. 1-9. Litometopus longispinus Rasetti, new genus, new species
1-3, Dorsal, frontal, and lateral views of cephalon, X3; U.S.N.M.
146012, holotype. 4, 5, Lateral and dorsal views of cephalon, 4.
6, Pygidium, <2. 7, Pygidium, 2. 8, Lateral view of doublure of
the same pygidium, <5. 9, Pygidium, x3. U.S.N.M. 146013, para-
types.
Figs. 10-19. Serrodiscus subclavatus Rasetti, new species .
10, 11, Dorsal and oblique views of cephalon, 4; U.S.N. M. 146022,
holonpe: 12, 13, Dorsal and lateral views of cephalon, <3. 14, Por-
tion of same cephalon, showing ornamentation and characteristic
furrow parallel to posterior margin, 7.5. 15, Lateral view of
pygidium, <5. 16, Lateral view of pygidium, with portion of axial
spine restored, 4. 17, 18, Oblique and dorsal views of pygidium,
<4. 19, Cephalon with two thoracic segments attached, X3. U.S.N.M.
146023, paratypes.
PLATE 9
Figs. 1-16. Bathydiscus dolichometopus Rasetti, new genus, new species
1-3, Dorsal, frontal, and lateral views of cephalon, *4; U.S.N.M.
145995, holotype. 4-6, Dorsal, frontal, and anterodorsal views of
cephalon, X3. 7, Portion of cephalon, <5. 8, Frontal view of the same
cephalon, <3. 9, 10, Posterior and lateral views of pygidium, 4,
exposing doublure. 11, 12, Dorsal and posterior views of pygidium,
<3. 13, Pygidium, X3. U.S.N.M. 145996, paratypes. 14-16, Lateral
dorsal, and posterior views of pygidium, <4; U.S.N.M. 145997,
paratype.
Figs. 17-21. Calodiscus fissifrons Rasetti, new species Pub bn tig fails iat
17, Cephalon, X5; U.S.N.M. 146004, holotype. 18, 19, Incomplete
cephala, 4. 20, Small pygidium, 10. 21, Pygidium, 5. U.S.N.M.
145005, paratypes.
Page
13
33
24
31
17
NO. 9 NEW CAMBRIAN TRILOBITE FAUNULE—RASETTI 51
Page
Figs. 22, 23. Calodiscus occipitalis Rasetti, new species . . 24
22, 23, Lateral and dorsal views of cephalon, x5; U.S. NM, 146003,
holotype.
PLaTE 10
Figs. 1-10. Oodiscus subgranulatus Rasetti, new genus, new species . . 29
1-3, Dorsal, frontal, and lateral views of cephalon, x5; U.S.N.M.
146014, holotype. 4, Portion of the same cephalon, showing one of
the marginal spines and ornamentation, 7.5. 5, Cephalon, x4.
6, portion of cephalon, showing positions of the marginal spines, <5.
7, Portion of pygidium showing ornamentation, 7.5, 8, Pygidium,
X3. 9, 10, Dorsal and lateral views of pygidium, x3. U.S.N.M.
146015, paratypes.
Fig. 11. Undetermined pygidium No.3 . . ar tyaigiyle feat SD
Dorsal view of specimen, *3. U.S.N.M. No. 146035.
Figs. 12-15. Serrodiscus latus Rasetti, new species. . 34
12-14, Lateral, dorsal, and frontal views of ecialon 6: ‘U.S.N.M.
146024, holotype. 15, Larger cephalon, x4; U.S.N.M. 146025,
paratype.
Figs. 16-18. Oodiscus binodosus Rasetti, new species . . 3
16-18, Dorsal, frontal, and lateral views of cephalon, <5; ‘U.S.N.M.
146016, holotype.
Fig. 19. Serrodiscus, species undetermined . . iS ous Gown, . es
Dorsal view of cephalon, 5; U.S.N.M. 146028.
Figs. 20, 21. Oodiscus longifrons Rasetti, new species . . . .. . 30
20, Cephalon, *3; U.S.N.M. 146019, paratype. 21, cephalon, x4;
U.S.N.M. 146018, holotype.
Piate 11
Figs. 1-7. Leptochilodiscus punctulatus Rasetti, new genus, new species . 26
1-3, Dorsal, lateral, and frontal views of cephalon, X7.5; U.S.N.M.
146009, holotype. 4, 5, Dorsal and oblique views of another cephalon,
7.5; U.S.N.M. 146011, paratype. 6, 7, Dorsal and frontal views of
incomplete cephalon, 7.5; U.S.N.M. 146010, paratype.
Figs. 8-11. Oodiscus, species tadetermined INOS Eas 31
8-10, Dorsal, lateral, and posterior views of preidiicn: 53, 11, Be
gidium, x4. U.S.N.M. 146020.
Figs. 12, 13. Oodiscus, species undetermined No.2 . . ... . . 3l
12, 13, Pygidia, *4. U.S.N.M. 146021.
Figs. 14-16. Undetermined pygidium Now2 2 38
14, 15, Dorsal and lateral views of specimen, x5. 16, Smaller speci-
men, <7.5. U.S.N.M. 146034.
Figs. 17-21. Undetermined pygidium No.3 . . ~ a oo
17, 18, Lateral and dorsal views of small speemer: X75. 19-21,
Posterior, lateral, and dorsal views of larger specimen, X5. U.S.N.M.
146033.
Fig. 22. Bonnia, species undetermined No.2 . . - - + + + + 5 44
Cranidium, <5. U.S.N.M. 146041.
52 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148
Page
Figs. 23-25. Bonnia, species undetermined No.1... 43
23, Immature cranidium, X10. 24, 25, Lateral and deraal views ai
cranidium, <5. U.S.N.M. 146040.
PLatTe 12
Figs. 1-7. Stigmadiscus stenometopus Rasetti, new genus, new species . 36
1, 2, Dorsal and frontal views of cephalon, 3; U.S.N.M. 146029
holotype. 3, 4, Dorsal and lateral views of cephalon, <3. 5, 6,
Dorsal and lateral views of incomplete cephalon, <3. 7, Largest
glabella observed, X3. U.S.N.M. 146030, paratypes.
Figs. 8-13. Stigmadiscus gibbosus Rasetti, new species . . 37
8, 9, Dorsal and lateral views of cephalon, 4; U.S.NM. 146031,
holotype. 10, 11, Lateral and dorsal views of cephalon slightly com-
pressed longitudinally, 5. 12, 13, Dorsal and lateral views of small
cephalon slightly compressed laterally, 7.5. U.S.N.M. 146032,
paratypes.
Figs. 14, 15. Kootenia, species undetermined . . a ee AZ
Posterior and dorsal views of pygidium, *4. U.S.N. M. 146039.
Fig. 16. Bonnta, species undetermined No. 3.0.0 3 6 3 PO 4
Cranidium, 5. U.S.N.M. 146042.
Fig. 17. Bonnia, undetermined pygidium . . SHORT PROQORI te AS
Dorsal view of specimen, *4. U.S.N.M. 146044.
Fig. 18. Bonnia, species undetermined No. 4... . . . . . . 45
Cranidium, X3. U.S.N.M. 144042.
Figs. 19, 20. Paedeumias?, species undetermined No.2 . . . . . . 4i
Incomplete cephala, *5. U.S.N.M. 146037.
Figs. 21, 22. Olenellus, species undetermined . . . . . . . +. 42
Incomplete cephala, X5. U.S.N.M. 146038.
Figs. 23-25. Paedeumias, species undetermined No.1 . . 40
23, 24, Incomplete cephala, 5. 25, Meraspid cephalon, X15, showing
small procranidial spines. U.S.N.M. 146036.
SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOL. 148 NO. 9, PLATE 1
CALODISCUS, ACIDISCUS, BATHYDISCUS, OODISCUS, AND LEPTOCHILODISCUS
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148 NO. 9, PLATE 2
SERRODISCUS, ANALOX, ACIMETOPUS
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148 NO
: cM) TUITE: St
BOLBOPARIA, LITOMETOPUS, STIG MADISCUS
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148 NO. 9, PLATE 4
EODISCIDAE (ACIMETOPUS)
(SEE EXPLANATION OF PLATES AT END OF TEXT:)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148 N
OL. 148 NO. 9, PLATE 5
EODISCIDAE (BOLPARIA)
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148 NO. 9, PLATE 6
EODISCIDAE (ANALOX, ACIDISCUS); UNDETERMINED TRILOBITE
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 1 N
- 148 NO. 9, PLATE 7
EODISCIDAE (ACIDISCUS, SERRODISCUS, CALODISCUS)
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148 NO. 9, PLATE 8
EODISCIDAE (LITOMETOPUS, SERRODISCUS)
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148 NO. 9, PLATE 9
EODISCIDAE (BATHYDISCUS, CALODISCUS)
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148 NO. 9, PLATE 10
EODISCIDAE (OODISCUS, SERRODISCUS, UNDETERMINED GENUS)
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 1
/OL. 148 NO. 9, PLATE 11
EODISCIDAE (LEPTOCHILODISCUS, OODISCUS, UNDETERMINED GENERA);
DORYPYGIDAE (BONNIA)
(SEE EXPLANATION OF PLATES AT END OF TEXT.)
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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 148 NO. 9, PLATE 12
EODISCIDAE (STIGMADISCUS); DORYPYGIDAE (BONNIA, KOOTENIA);
OLENELLIDAE (OLENELLUS, PAEDEUMIAS)
(SEE EXPLANATION OF PILATES AT END OF TFYXT)
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