aon ees
Zansenian InstityeS
7 N
\
fd
ty
Honal Musee®7
PROFESSIONAL PAPERS OF THE ENGINEER DEPARTMENT, U.S. ARMY.
No. 18.
REHPORT
OF THE
GEOLOGICAL EXPLORATION OF THE FORTIETH PARALLEL,
MADE
BY ORDER OF THE SECRETARY OF WAR ACCORDING TO ACTS OF
CONGRESS OF MARCH 2, 1867, AND MARCH 3, 1869,
UNDER THE DIRECTION OF
BRIG. AND BVT. MAJOR GENERAL A. A. HUMPHREYS,
CHIEF OF ENGINEERS
BY
CLARENCE KING,
U. S. GEOLOGIST.
I-IT
Rte,
wis
UNITED STATES GEOLOGICAL EXPLORATION OF THE FORTIETH PARALLEL.
oe CLARENCE KING, GEOLOGIST-IN-CHARGE.
PART I.
PALAONTOLOGY.
F. B. MEEK.
PART IL. |
PAL HONTOLOGY.
BY
JAMES HALIL AND R. P. WHITFIELD.
PARY Il.
ORNITHOLOGY.
ROBERT RIDGWAY.
SUBMITTED TO THE CHIEF OF ENGINEERS AND PUBLISHED BY ORDER OF THE SECRETARY OF
WAR UNDER AUTHORITY OF CONGRESS.
ILLUSTRATED BY XXIV PLATES.
WASHINGTON:
GOVERNMENT PRINTING OFFIOE.
1877. v-VI
TABLE OF CONTENTS.
Page
TINTEAOIDUOICEAr TOOT Ber. /5 ee ceca) 0s 9a ae ee Oe eee ar eer anim ae XI
NT eee AON TOMOG Noe ly ar VRBO Ss ft se ee ea ues ee eee 1
INTRODUCTORY REMARKS....--..-- ee RSM aye els te alts Se ay 3
DESCRIPTIONS OF FOSSILS—SILURIAN SPECIES.....--....--.-----. ile
DEVCNIAN SPECIES ....-- Boece 25
CARBONIFEROUS SPECIES .-....-. ..-. 50
DRUASSIOU SPECIES! 382-22 Meck essa - Se 99
JURASSIC OSPE OMNS)4, Yiecn gutses asic oe eee 130
CRELACEOUSISPECINSm soa. see ese eee: 140
I'RESH AND BRACKISH-WATER SPECIES. 163
IHR PUAR SoNPE CUR Sie fc ic tides ne! aceon 182
Part IJ. PALZONTOLOGY, BY JAMES HALL AND R. P. WHITFIELD .......... 198
GCRINIE YANG SI Ey MENG See ee eecrgmariy eo Aas SAM leat rete iaeuse eles oe 199
OSS SLOP NEUE MA OMS DYAIV Ie ete pene, fais arch brace ls rretey Se tres asin ee eet 205
OVERS TODA see eee ies een cy See eae 252
HB) AV OOINITEANN ere eee ral UNG, So lected s) ) AG
VV PANV AEN Vga cetera ter sole ins 5,0 eM esc wwe Rea a he 251
HOWHE OMB ONENEROUS™. -oc. s.c5 28 agiecbe ace nee 265
CoAL-MEASURES AND PERMO-CARBONIFEROUS..-. 273
UNG STOR aN ee een en ee kee 280
AUIUA SST Cpa etn, aerate irks ones ea pin ce, 284
PAnT tik ORNITHOLOGY, BY ROBBER RIDGWAY . 2: - << 25-25-25 fee oes ea 303
> GETS: GVRACOLOISE DING Si ol oc nen Mn et 305
PGE BELO PURO AN SMUG SION Ms fae Acs bo ale cicle= sine nia apataeyetioie e's = 2s 307
DESCREE TION TORRE a OWNS we sans 2 ate eae Sere eMeeaels Geese one o 309
PHYSICAL PHATURES, OF THE GREAT BASIN 2.0: 2. 4... 5- 00% oc 245. 313
LDF) CUANIG AG TIESASWIINCAUE tee Ree ae ey eel rae ate ee eee eee ark 316
WHSCRIETIONSONCAIPS 2.0). 2 exes baer eon hn ews be Sane 328
GENERAL REMARKS ON THE BASIN AVIFAUNZ .... .:-.-... ----.- 317
COUGH NTE OYE OF DOU DUS) 25 OO) DISD aie, ca eae cS 0) gee en 386
EO GEIR Aly SROVIION eee mk ae BE rea. cratic oie gas weasel uc o one 391
ANE XO se ATMs orem coe TOC a Ge ee 5 hit clétic: SLES CE SO On Sa a 645
TRTDISNG THO) TEATRO Ls Re Aras canons eer eS aura Ree an ee ee a 649
ALENT NeO le AVE ESNet cram tone a aihny 3 eine eerae IE Rd SDE. be Sctehouleen nk on 652
VII-VIII
Fig.
Vig.
z=)
11. DALMANITES (undt. sp.)
. CONOCORYPHE KING. Upper view, natural size
SPEIDNON DEALT J oINONENSTSp aaciclc cis cine ae eis aie See eee ese aE See ae eee
PLATE I.
Page.
. OPHILETA COMPLANATA, var. NANA..---...----- eee eee AAs (eae Oe ac eao toa eas 17
1. An upper view of a specimen, natural size, as seen lying in the matrix.
1a. The same, enlarged.
1b. Profile view, enlarged.
b IRV NEENRONU) THOMEMTIMONNIG) 5a52 055052 co02 Decors bans SoSes0 sa2gee onDES Seoeco seSace ceee 18
2. View of upper side, natural size.
2a. Profile view of same.
2b. Under side of same, magnified. [In the specimen, the umbilicus is filled with rock,
though its subangular margins are exposed. |
¢ RAPHISTOMAST ERO CHISCUS Ee: he: eae wea siacteenieint ne ictae een ie CET ee eee eee ER eC eeae 19
3. Upper side, natural size.
3a. Profile.
3b. Under side, enlarged. [The umbilicus is filled with rock in the specimen, but its
margin is clearly seen. ]
[The specimen is accidentally compressed so as to spread cut the posterior extremities of
the cephalic shield more than is. natural. Broken edges of the crust are also in
the figure wrongly made to look like small nodes at the ends of the segments of
the mesial lobe. ]
. PARADOXIDES? NEVADENSIS. Shows upper side of a part of thorax and pygidium ....-.... 23
ig. 6.
HAV OSTBES | (Udit SPs)! eects-eesee aimee air iste Shape cies eis ekesie epee ee marcas Seaeee iSaptestes 20
PPAR VEP AUR TIC Wi MRTG ss, 5 5,0:.5.6:5 5, e)e 015 tain asco en eve ate tm siete telerare ore = oe ape ye Siemois loreterele ears etenc tale eel eee meets : 38
7. Dorsal view.
Za. Side view.
mates 46
8. Side view of a large specimen, natural size.
8a. Opposite view of a smaller specimen.
L SPITE AP INO NENSIGs <.< So sece cise tere seo mice a eisse is aemiciojale wieieatel Gunielal els lyatsie /srelotene loners eter Enea 45
9. Dorsal view, natural size.
9 a. Profile view of same.
9b. Ventral view of same.
10; AP ROSCUSSDENTICULATUB Ss. cists ac os Sonsis one eee ee Ss Sloe ec ACIS Dene eee eee eee 49
10. The glabella embedded in the matrix (enlarged two diameters).
10a. Pygidium, enlarged two diameters. cay
10. One of the thoracic segments seen in profile (enlarged two diameters).
Beck eae te Sn een aareie Serer men ANE 8 as ees na Goss 48
11. A monld of the pygidium.
1la, Another specimen of same.
wes ¢ ol. Expl. 40 Parallel Silurian and Devonian Plate I.
. S. Geol. Expl. 4
ower Oilurian
J.Bien Jit.
ELW. Elliott del.
PW AC Amey alee
Hig, PLY CHOPMYECUN GNNUNDIGUIE UM: -aeeeineeete testis Sanne eee ee eee ee ee eee eee
1. A longitudinal section, showing the depth of the calice, with the unfundibuliform
plates, and apparences of a columella.
la. An upper view of another specimen.
1b. A side view of a third specimen.
Hig.2. CYATHORM Ya UN PALMERG jec=-/srvearc oe cle -teee seine SAE ee er ee eee ee ee Serre
View of upper side, showing the young corallites at places growing in the middle of the
calices of the old.
Bigs; Spe AVOSERES) POT: YAN O12 HA teeta re eer ee eee BoEOenEd dcbone a quandas oHbcobesleos
Motte IDOE SEB ae KOMI N IOKIKOS CEM IUOINIS Docs cseede ceoo nbs noeu ocoo cocanquscueocebe secu nHoe noma Dooe
4. Aside view of a bundle of the corallites, imperfect at both ends, and showing them
to coalesce at intervals.
4a. A longitudinal section of onc of same, enlarged, showing the wide inner area occupied
by broad, slightly arching tabula (without any traces of a columella), and the
very narrow, outer vesicular area.
4b. A transverse section of same, enlarged.
JENS De NCI PACIENIDHA IPISINTEAGONUA Cote oba5 ope uobose etecop nesa Saco Tes tenN Qbsc conse anse ce s3 55 ce
5. View of upper side, showing corallites, natural size.
5a. A transverse section of a few of the corallites, enlarged.
Bigs6. SMUneia TEMNINAMIU; ERS oor crereiciey cis = ciciovs sis teiz a pars ce ce clare ersiers Sieretene ere alana Severe ee = acai owteleravarmlernaieiare
6. View of surface, showing corallites, natural size.
6 a. Transverse section of same, enlarged.
Big. 7)., ATV BOUIRES, “IMU L I AU EITIAS ra, scars Sere iste i Scns ois ele potatoe teres =e ee ENT ep SEI oie he eee eet
7. View of a flat, vertical, weathered section.
7a. A portion of same, polished and magnified, so as to show the num rous, thin, crowded
tabule, and the mural pores; the latter being seen through the transparent
calcareous matter filling the interior.
7b, A transverse section of the same, showing the forms of the corallites, magnified.
Fig; 8. (\ORTHOCHRAS KINGU jo. a sc:s -eteticoe soe ose hem see ie se Ese) See oe se ee eee
Figt 2) ORDHOCERASI(UNGt: SP!)) o-ce aeaec dos cae es ee eee eee ee een = aorta eee eee
33
27
28)
3l
32
47
48
U.S. Geol. Expl. 40 Parallel Devonian Plate IL.
HW. Elliott del. ; =a
J. Bien jith..
s
am cabegiinn tn’ borne ctw
is te, Bees ee PES!
PU AC a Se
Hie SOPURTCER MU MALTON STS se ee eee eee
1. An antero-ventral view, natural size.
1a. Dorsal view of same specimen.
1b. A side view of a smaller specimen.
1c. A cardinal view of another specimen, showing area and foramen.
1d. Cardinal view of the ventral valve of the largest specimen seen.
le. An antero-ventral view of same.
Fig. 2. HEMIPRONITES CHEMUNGENSIS, var. ARCTOSTRIATA
2. View of ventral valve, with an oblique view of area.
Hig. (3. SPIRIPER ENGEEMANND cs acer scenes “Se ce= Bee ee eae see me hee eee ee eee eee Eee eonee
3. A cardinal view, showing area and foramen.
3a. A side view of saine.
3b. Dorsal view of same.
3c. An antero-ventral view.
3d. A ventral view of another specimen apparently of this species.
3 e. Dorsal view of last.
Fig. 4, SPrrRIrER ARGENTARIUS
4. i Ae aE av eile
J Oiifets ioe Un ats KOSH ROMO NVIEvEUNION AL Sook c5bods pansdesoSoon FScecd bosebu cone eae acsoooorsagocce
1. cane eee taeee ne chiens clerniciomreincie te eitaiaeeere 85
1. Dorsal view of the original typical specimen.
La. Ventral view of same.
16. An outlive profile of same.
1c. An internal cast of the ventral valve, showing the slit left by the rostral septum.
1d. A dorsal view of another very gibbous specimen.
le. An outline profile of same.
Fig: 2. PRODUCTUS NEVADENSIS iadscsau cies acueeieckees cee eee eset eae Soares yes osicen coal 64
2. Ventral view of a specimen, with the ears broken away.
2a. Cast of the exterior of a ventral valve of same species.
2b. Ventral aspect of another specimen, turned so as to give a more direct view than
fig. 2.
2c. Internal cast of ventral valve.
2d. Aside view of same.
2e. A longitudinal section of a specimen with the valves united.
Hig. o.s PRODUCTUS: MULTIST RVARUS 20 cise Ree een seeine ns) ieee oisl ye isiera i= eeeree steerer 76
3. Ventral view of a rather large specimen, with the free margins Shier away.
3a. Side view of same.
36. Ventral view of a smaller specimen, with one ear and much of the margins broken
away.
3c. Dorsal view of last.
3d. Side view of same.
3e. Internal view of a dorsal valve, too much worn to show internal markings, but
showing the very abrupt geniculation of the anterior and lateral margins around
the flattened visceral region.
IDEs Gl JENOWIGOIN US) WORKERS Soo sob cho 565 sooa5s bbomno oo Ssc5 anoobs yessse On sond Sase0 see7 S500 78
4. Aside view.
4a. Veutral view, with ears partly broken away.
JOT; Gy, SMO MIs IAEA CHMIlis S]Dy))ooo5 aeosoo Sessa becess ce Se5c aog5ne Pando cobs DSDOnD Oy ooBaNS GoDSSe 84
5. Dorsal view of a specimen, with lateral extremities imperfect.
5a. Antero-ventral aspect of same.
5b. A side view of same.
LDCs PATTI MS NOLL ENTE TENG A oes mB nee AR Oo Meee geo Ske cocseoae Sobade sos sop eSecou Joasca casos canoe 83
6. Dorsal view.
6a. An outline profile of same.
Plate VII.
Carboniferous
U. S. Geol. Expl. 40 Parallel
J.Bien hth.
FLW. Elliott del. .
Eun vi irle US SENS RY Sig Zt"
Write #9) At
exc tdy See TPP epee
TE oleae Wao teeth. in putes 2 at hm,
abe AF Fe Par’;
Fig.
Fig.
Fig.
Fig.
Fig.
Fig.
(Sai
PLATE IX.
A WPIRINERYSCOBINA,
tion with the preceding one is very narrow and slight, leaving the inner
ones projecting on the sides of the shell, exposing the greater part of each
volution. :
Surface of the shell marked by rather distinct transverse lines of
growth, which are sometimes grouped so as to form slight transverse undu-
lations on the larger part of the shell. These lines have a slight outward
convexity on that portion within the carina of the upper ‘side, and on the
outer portion a somewhat retral curvature as they cross the body of the
volution. :
The species is of the type of Huomphalus pentangularis Sow., and
somewhat closely resembles S. similis var. planus M. & W. (Geol. Rept. IIls.,
vol. ii, pl. 19, fig. 5), but differs in the sharp carina of the upper side, and in
having the volutions coiled more decidedly in the same plane. This shell
also attains a much greater size than that one is known to do; the largest
specimen observed having a diameter of nearly an inch and two-thirds.
It is also related to S. planodorsatus of the same authors (loc. cit., pl. 24,
fig. 2), but is readily distinguished by the form of the upper surface of the
volution.
260 PALHONTOLOGY.
Formation and locality—In limestone near the base of the Wahsatch
limestone, of the age of the Waverly group, at Dry Cafion, Oquirrh Mount-
ains, Ogden and Logan Cations, Wahsatch Range, Utah. Collected by J.
Ki. Clayton and 8. F. Emmons. |
KUOMPHALUS LAXUS.
Plate IV, figs. 24-25.
Euomphalus lacus White, MSS. Lieut. Wheeler’s Rept. of Geograph. and Geol. Surv.
and Expl. W. of 100th Meridian.
Shell subdiscoidal; the height of the spire above the body of the last
volution equal to from one-third to about one-half its diameter, the inner
volutions being scarcely elevated above the general plane. Umbilicus
broad and proportionally deep, exposing all the inner whorls. Volutions
three or more, seldom, however, exceeding four; rather slender in their
proportions; the last one more rapidly increasing in size than the others;
obscurely pentangular in transverse section; the periphery being obtusely
angulated just below the middle, slightly flattened above the angle, and dis-
tinctly so on the upper surface. The lower side of the volution is gently
rounded on the’ outer part, but more sharply curved at the edge of the
broad open umbilicus.
Surface of the shell marked by distinct, somewhat irregular, lines of
growth, parallel to the margin of the aperture, their direction being nearly
at right angles to the axis of the shell, with a very slight sinuosity as they
cross the upper flattened surface of the volution.
The species is a well-marked one, and appears to be quite characteristic
of beds near the lower part of the Wahsatch limestone, Wahsatch Range, ~
Utah. It bears a strong resemblance to specimens of H. laxus H. from the
Burlington limestones, but the volutions increase much more rapidly, and
the flattened space on the upper side is narrower in proportion to the diam-
eter of the volution than in those specimens, and it is also a much smaller
form. It also bears considerable resemblance to an angulated form in the
Burlington sandstones, usually referred to EZ. cyclostomus H., but probably
distinct. There is also a species in the Chemung group of New York very
closely resembling this one, but which does not show the angularity of the
FOSSILS OF THE WAVERLY GROUP. 261
periphery, although flattened on the top of the volution. The individual
figured is somewhat smaller than the specimen used and figured by Dr. C.
A. White in Lieutenant Wheeler’s Report above cited, but possesses all the
characters of those specimens.
Formation and locality—tIn limestones near the base of the Wahsatch
limestone, of the age of the Waverly group of Ohio, at Dry Cation, Oquirrh
Mountains, and Logan Carion, Wahsatch Range, Utah. Collected by S.
F. Emmons and J. HE. Clayton.
EUOMPHALUS (STRAPAROLLUS) OPHIRENSIS 0. sp.
Plate IV, figs. 26-27.
Shell of medium size, broadly conical or subtrochiform; height equal
to two-thirds the greatest transverse diameter of the base; composed of
four and a half to five volutions, which are closely coiled, so as to rest nearly
upon the surface of the succeeding ones; four of the volutions obliquely
compressed on the outer upper portion, and sharply rounded on the periphery
and below, giving a somewhat convex trochiform. aspect to the coils.
Umbilicus broad and deep, exposing more than one-half of each of -the
preceding whorls, which are strongly rounded and full. ‘Transverse section
of the volution obliquely and irregularly ovate, narrow, and somewhat
pointed at the upper end at the junction of the volutions, rounded on the
inner, and obliquely flattened or depressed-convex on the outer surface.
Surface of the shell marked only by very fine transverse lines of
growth, which have a slightly backward curvature as they cross the volu-
tion.
This species has something of the form and general appearance of S.
umbilicus M. & W., from the Coal-Measures (see Geol. Rept. Ils., vol. ii, pl.
27, fig. 1), but is more depressed and proportionally broader, without the
horizontal flattening on the upper surface of the volutions, which are instead
obliquely compressed nearly in the direction of the slope of the spire.
Formation and locality—In limestones of the age of the Waverly group,
at Dry Canon, Oquirrh Mountains, Utah. Collected by J. E. Clayton.
~ Tes
262 PALZ ONTOLOGY.
CRUSTACEA.
Genus PROETUS Stein.
PROETUS PEROCCIDENS 2. sp.
Plate IV, figs. 28-32.
One of the most persistent and characteristic fossils of this formation
at the several localities where it has been recognized, and one that will
probably serve to identify it at other localities, owing to its marked features,
is a small species of Trilobite of the genus Proetus. Although specimens
of the pygidium have been obtained at all the localities yet recognized, no
other parts of the animal have been noticed except from one locality.
These were collected, and sent, among other species, by J. E. Clayton, esq.,
of Salt Lake City, from Dry Cation, Oquirrh Mountains, Utah. They
consist of some detached and imperfect examples of the glabella and cheeks;
-and as there are no other forms of Trilobites yet known from the locality,
and these occurring in the same blocks with the pygidia, it is reasonable to
infer that they belong-to the same species.
The glabella is conico-cylindrical in form, once and a half as long as
wide, very gently narrowing from the base forward, and rounded-truncate
in front; very depressed-convex throughout, and marked by four pairs of
transverse furrows; the posterior ones strongest, curving backward at their
inner ends, nearly surrounding the posterior lobes, forming rounded convex
tubercles, each of which is equal in width to one-third that of the entire
glabella. The other three pairs are faintly marked, and reach nearly one-
third across the glabella; the anterior one transverse and very obscure,
distant from the anterior end of the glabella, equal to its width at the furrow;
second and third pairs distinct, slightly curving backward at their ends.
Occipital ring narrow, depressed-convex, and not strongly marked. Fixed
cheeks narrow; palpebral lobe small, situated a little more than one-third
of the distance from the posterior border of the head, angular in outline.
Frontal border thickened and rounded, well defined, but not distinctly
separated from the glabella in front. Posterior lateral limbs not preserved,
but narrow at their junction with the fixed cheeks. Suture-line cutting the
frontal margin, with a slight curvature at a point distant from the sides of
FOSSILS OF THE WAVERLY GROUP. 263
the glabella equal to one-half its width at the anterior end, and rounding
inward with a gentle curvature to the anterior side of the palpebral lobe,
the cheek being very narrow at this point, thence passing along the top
of the eye to the junction of the posterior lateral limb. Surface of the
glabella and cheeks smooth, except a few granules near the base of the
glabella. |
Movable cheeks of medium size in proportion to the glabella, flattened _
convex from the base of the eye to the narrow, thickened, and chamfered
marginal rim; occipital furrow narrow, not strongly marked, and reaching
nearly to the depression within the marginal rim; posterior angles of the
cheeks extending backward in the form of short angular spines.
Thoracic segments unknown.
Pygidium paraboloid in outline, highly convex, abruptly so at the
sides and posteriorly. Axial lobe forming a little less than one-third of the
entire width, and reaching nearly to the posterior margin, rounded and
strongly elevated throughout; gradually tapering posteriorly and narrowly
rounded at the extremity; marked by from fifteen to seventeen annulations
in different individuals exclusive of the anterior articulating ring. Lateral .
lobes well marked, very convex, slightly flattened near the axis, but very
abrupt at the sides and behind; marked by from fourteen to sixteen very
sharply elevated angular ribs, which occupy the entire border, extending
beyond the end of the axial lobe, and reaching almost to the margin, leaving
only a narrow plain space at the edge. ‘The surface of the annulations is
marked by a series of small nodes, or pustules, along their crests, arranged
in four longitudinal rows on the axial rings, and an indefinite number,
closely arranged, occur on those of the lateral lobes.
The species in some of its features resembles P. macrocephalus Hall of
the shales of the Hamilton group of New York, especially in the markings of
the pygidium ; but it differs in the more elongate form and number of ribs
of this part, while the glabella is proportionally narrower and the sides
more nearly parallel; the fixed cheeks and anterior border are narrower,
and the movable cheeks terminate in spines, which is not the casé with that
one. ‘The surface of the glabella and head is also destitute of the strong
pustules which characterize that species.
264. PAL ONTOLOGY.
Formation and locality.—In limestones of the age of the Waverly group
of the Mississippi Valley, at Ogden and Logan Canons, Wahsatch Range,
and Dry Cafion, Oquirrh Mountains, Utah. Collected by S. F. Emmons
and J. EH. Clayton.
PROETUS LOGANENSIS 2. sp.
Plate IV, fig. 33.
The pygidium of a small species differing very materially from the
preceding occurs at Logan Carion, associated with that one. The form is
more nearly semicircular, being but very slightly paraboloid. The axial
lobe is highly convex, rapidly tapering below and terminating abruptly a
little within the posterior margin; anterior end forming fully one-third of
the entire width of the shield. Lateral lobes moderately convex, with a
slightly thickened, scarcely elevated border of moderate width, on which
the ribs become nearly obsolete. Axial lobe marked by nine rounded and
distinct annulations, exclusive of the terminal ones; strong in front and
rapidly decreasing in size posteriorly. The ribs of the lateral lobes are ten
in number on each side; simple, highly rounded, and continuing entirely
around the posterior margin of the shield, the most posterior ones being
very faintly marked.
This species differs conspicuously from the corresponding parts of
P. peroccidens in its shorter form, small number of ribs, and in being desti-
tute of the surface ornamentation which characterizes that one. —
Formation and locality—In limestones of the age of the Waverly group,
at Logan Cafion, Wahsatch Range, Utah. Collected by S. F. Emmons, esq.
Wi
FOSSILS OF THE LOWER CARBONIFEROUS. 265
FOSSILS OF THE LOWER CARBONIFEROUS.
BRACHIOPODA.
Genus ORTHIS Dalman.
ORTHIS RESUPINATA ?.
= ' ‘ Plate 5, figs. 1-2.
Orthis resupinata Martin sp.
Shell of moderate size, transversely elliptical or quadrate-elliptical ;
valves ventricose, the dorsal quite rounded and almost evenly ventricose,
sometimes a little fuller on the umbone; middle of the valve slightly
impressed with a broad, shallow, mesial sinus, extending from near the beak
to the front of the valve; beak proportionally large and full, somewhat
incurved, and projecting beyond the line of the hinge; area moderately
large, extending about half the length of the valve, the plane of its surface
nearly in the direction of the plane of the valve. Muscular impression
large, extending to about two-fifths of the length of the shell, distinctly
flabellate and lobed. Ventral valve unknown. Surface marked by moder-
ately strong, rounded, radiating strie and concentric lines of growth.
The species is represented in the collection only by dorsal valves, but
the specific characters are unmistakable and easily recognized. |
Formation and locality—In Lower Carboniferous limestone, near the
base of the formation, at Dry Canon, Oquirrh Mountains, Utah. Collected
by J. E. Clayton.
Genus PRODUCTUS Sowerby.
PRODUCTUS FLEMINGI var. BURLINGTONENSIS Hall.
Plate 5, figs. 9-12.
Productus Flemingi var. Burlingtonensis Hall, Geol. Rept. Iowa, vol. i, part ii, p. 598,
pl. 12, fig. 3.
Shell of medium size, wider than long; height and length subequal, or
a little longer than high, except in old individuals, where the front is much
produced, giving additional height; hinge-line as wide, or a little less than
the width of the shell below. Ventral valve strongly arcuate, more abruptly
curving just posterior to the middle of the valve; auriculations distinct when
266 PALMONTOLOGY.
well preserved, and in some cases strongly separated from the body of the
valve; sides of the valve a little straightened; front rounded on the lateral
portions, but strongly emarginate in the center by the rather strong, some-
times abruptly depressed, mesial sinus, which extends from near the beak to
the front of the shell; beak moderately strong, extending beyond the hinge-
line and incurved. Dorsal valve nearly flat over the cextral area, with a
slight concavity in the region ef the beak, the margins abruptly geniculated
to conform to the curvature of the opposite valve. The mesial constriction
is as strongly marked, but a little wider than that of the ventral valve, and
extends nearly to the beak. - |
Surface of the shell marked by rather even, rounded strize of moderate
strength, except near the front of the shell, where they become indistinctly
fasciculate or blended; also, on the rostral half of the shell by numerous,
distinct, closely arranged, concentric, undulating wrinkles, but which seldom
extend beyond the point of greatest geniculation. A few scattered spines
mark the front and sides of the shell, while several stronger ones are observ-
able on the cardinal auriculations. On the dorsal valve, the concentric
wrinkles are more distinct, and occupy the entire flattened area of the valve,
while the radiating striz are found to be more strongly bifurcating.
_ The specimens bear a very close resemblance to those from Burlington,
Iowa, in their general form and characters. There are a few unimportant
differences noticed, but not such as can be considered of specific importance.
There is also considerable resemblance to Prod. mesialis Hall (Geol. Lowa,
p. 636, plate 19, fig. 2); but that shell is much wider in proportion to the
length than any of those from the more western locality.
Formation and locality—In dark-blue limestone of Lower Carboniferous
age, north of Snowstorm Hill, Dry Canon, Oquirrh Mountains, Utah. Col-
lected by J. E. Clayton.
PRODUCTUS LAVICOSTUS ?.
Plate 5, figs. 7-8.
Productus levicostus White?, Jour. Bost. Soc. Nat. Hist., 1860, p. 230.
Shell below the medium size, subtriangular in general outline, rapidly
increasing in width from the small, narrow, and rather pointed beak to near
‘FOSSILS OF THE LOWER CARBONIFEROUS. 267
the front of the shell, which is broadly rounded and destitute of any mesial
depression; hinge-line short, scarcely more than half as wide as the body of
the shell. Ventral valve strongly arcuate in the upper part. Dorsal valve
unknown.
Surface of the ventral valve covered by very fine, even, rounded,
thread-like striae, seven to eight of which may be counted in the space of
an eighth of an inch on the front of the shell, but are much finer near the
beak. The striz have been marked by numerous fine, slender spines, the
bases of which can be seen protruding through a portion of shale adhering
to the surface of one of the specimens; but they are so fine as to make
scarcely any perceptible scar on the surface of the striz when denuded.
The species is of the general form of many of those usually referred to
_P. Prattenanus Norwood, but differs materially from the original specimen
used and figured by Dr. Norwood in the finer strize and short hinge-line.
It does not appear to be positively identical with any of the forms figured
by De Koninck as P. Cora, but is a very closely representative species.*
Formation and locality—tIn limestone in the higher parts of the Lower
Carboniferous, north of Snowstorm Hill, Dry Canon, Oquirrh Mountains,
Utah. Collected by J. EK. Clayton.
PRODUCIUS SEMIRELICULATUS Martin.
Plate 5, figs. 5-6.
The specimens of this species in the collection have very much the
form and characters of those of the species which occur in the Burlington
and Keokuk beds in Iowa and Illinois, represented by the specimen figured
in the Geological Report of lowa (vol. i, part 2, plate 19, fig. 4), except that
they are only about two-thirds as large as that individual. The shell is
rather narrow and strongly arcuate; the beak narrow and rather pointed,
and distinctly separated from the body of the shell; the hinge-line appears
to have been about equal in length to the width of the shell below; the
sides of the shell abrupt, flattened, and squarish, while the middle of the
*The original specimen of P. levicostus is from the base of the Lower Carbon-
iferous, and from the beds at Burlington, lowa, referred to the Waverly group; but
there aie forms of very similar character in other beds of the formations at other places
that cannot be readily distinguished from those above referred to.
268 PALA ONTOLOGY.
valve is marked by a rather distinct depression, extending from near the
beak to the front of the shell, but most marked on the middle of the valve.
The striz are rather coarse, somewhat irregular, and present a rugose,
knotty appearance; while the upper half of the shell is very distinctly
marked by strong, irregular, concentric wrinkles, a little less marked in the
central depression. A few of the transverse wrinkles are seen marking the
front half of the shell in one specimen, and are broad and less deep than
those above.
The specimens are proportionally longer and narrower than the typical
forms of P. semireticulatus; but the form is such a variable one that it is
somewhat difficult to define the limits of its characters.
Formation and locality—tIn the limestone of Lower Carboniferous age,
north of Snowstorm Hill, Dry Canon, Oquirrh Mountains, Utah. Collected
by J. E. Clayton.
PRODUCTUS ELEGANS.
Plate 5, figs. 3-4.
Compare Productus elegans N. & P., Jour. Acad. Nat. Sci. Phila., iii, p. 11, fig. 7.
There are two specimens of a Productus associated with the preceding, ~
having so much the form and characters of P. elegans N. & P., that, unless
from a larger number of individuals other and different features shall be
obtained, cannot well be considered as distinct from that one. The form is
narrow in the upper part, the hinge-line shorter than the width of the shell
below; beak rather small and appressed; auriculations not very marked;
ventral valve sharply arcuate above and gently curving throughout, with a
slight, scarcely defined depression extending from beak to base. Surface
of the valve marked by moderately fine but distinctly radiating strize, which,
on the better preserved specimen, have an irregular, knotty appearance,
caused by the thickening of the strie at the spine-bases. The radiating
strie are marked by very fine transverse lines of growth on the forward
part of the shell, and on the upper part of the beak and sides of the
shell a few obscure transverse wrinkles may be detected.
There are some slight differences between the specimens, one of them
being a little more compressed, giving it a broader form, while the striz are
FOSSILS OF THE LOWER CARBONIFEROUS. 269
a little finer and more even than on the other; but the differences are even
less than occur among specimens of P. elegans from the typical locality.
Formation and locality—In limestone of Lower Carboniferous age, north
of Snowstorm Hill, near Dry Catton, Oquirrh Mountains, Utah. Collected
by J. E. Clayton.
Genus SPIRIFERA Sowerby.
SPIRIFERA STRIATA.
Plate V, figs. 13-15.
Anomites striatus Martin; Spirifer striatus Sowerby and others.
Shell rather above the medium size, transversely oval or semi-elliptical,
the hinge-extremities either rounded or slightly extended beyond the width
of the shell below. Valves moderately convex, or in some cases rather
strongly rounded; the ventral valve most rotund and marked by a broad
mesial depression, the margins of which are not strongly defined; front of
the valve in the depression somewhat extended and bent upward; beak
small, pointed, and closely incurved; area small, poorly defined, the mar-
gins rounding to the body of the shell. Dorsal valve most ventricose in
the upper part; the sides gradually sloping to the margins, and the center
strongly elevated, forming a distinct, sharply rounded mesial fold, which is
narrow in the upper part but expands very rapidly as it approaches the
front of the shell.
Surface of the valves marked by moderately strong, radiating plica-
tions, which are distinct and subangular on the upper part of the shell, but
frequently bifurcate and become flattened toward the margin, often forming
fascicles of three, four, or more on the extension of the valves, while those
near the middle are usually in pairs, but not uncommonly simple.
The species is extremely variable in form and surface-markings as it
occurs in the collections examined, representing two quite distinct types,
which appear to characterize two different horizons of the geological section
of the district in which they were found. Although these differences are
easily detected on close examination, still they are not sufficiently strong
and marked to be considered as of specific or even varietal importance,
and, in their extremes, are not-nearly so great as those ascribed to the species
270 PALDONTOLOGY.
by European authors. ‘The specimens from the lowest horizon are gen-
erally more extended on the hinge-line, and sometimes quite elongated;
while those from the lower beds are seldom much longer than the width of
the shell below, and in some stages of growth appear to have been short
and rounded at the cardinal extremities. There is also a perceptible
difference in the character of the striz; those from the higher beds being
more finely marked, more angular, and more distinctly fasciculate than the
others.
Formation and locality.—In limestone of the Lower Carboniferous age,
near the base of the section, at Dry Camion, and in the higher beds at Snow-
storm Hill, Oquirrh Mountains, Utah. Collected by J. E. Clayton.
SPIRIFERA SETIGERA.
Plate 5, figs. 17-18.
Spirifer setigeras Hall, Geol. Rept. Iowa, vol. 1, pt. 2, p. 705, pl. 27, fig. 4.
Shell rather below the medium size, transversely oval or elliptical,
with ventricose valves, and a short, scarcely defined hinge-line and rounded
extremities. Ventral valve more ventricose than the dorsal, most strongly
arcuate in the upper part; beak small, somewhat pointed and strongly or
closely incurved; area small, the margins not distinctly defined, but rounded
almost imperceptibly into the general curvature of the valve. Center of
the valve marked by a moderately distinct, but narrow mesial depression,
traceable from beak to base. Dorsal valve rather gently and evenly convex,
the center elevated in a narrow, not distinctly defined, rounded elevation
corresponding to the depression of the opposite valve.
Surface of the shell marked by numerous, rather closely-arranged
concentric varices, marking stages of growth at irregular distances, and also
by fine, closely-arranged, setose, radiating lines, most distinct just below
each concentric line, but becoming indistinct before reaching the next one
below. These lines on the natural surface have been elevated and rounded,
forming spines at the concentric ridges, but on the exfoliated surface have
the appearance of interrupted radiating lines, scarcely raised on the surface
of the shell.
The specimen figured is somewhat imperfect and much distorted by
FOSSILS OF THE LOWER CARBONIFEROUS. . ATES t
compression, but the features of the species are so well and distinctly
represented on it that it is impossible to doubt its identity.
Formation and locality—tIn limestone of Lower Carboniferous age,
north of Snowstorm Hid, Dry Canon, Oquirrh Mountains, Utah. Collected
by J. E. Clayton.
SPIRIFERA — sp. 2.
Plate 5, fig. 16.
Compare Spirifera imbrex Hall, Geol. Iowa, vol. 1, pt. ii, p. 601, pl. 13, fig. 2.
The figure is of a fragment of a cast of the ventral valve in chert, from
a fragment of the Weber quartzite, a rock usually destitute of all organic
remains, and it is for this reason only that the specimen has been figured.
It is of a species possessing numerous sharply-elevated, angular plications,
simple on the sides of the shell, and apparently bifureating in the mesial
sinus; although the example does not furnish positive evidence of such
bifurcations, still the direction and number would indicate such to be the
ease. The plications have been crossed by closely-arranged, strong, zigzag,
concentric lines; which give a strongly roughened surface to the cast. The
only species having strong affinities with it is S. ambrex Hall from the Bur-
lington limestone of the Lower Carboniferous formations, at Burlington,
Iowa (lowa Geol. Rept., vol. 1, pt. ii, p. 601, pl. 13, fig. 2), and it is even
probable that it may be identical; but, as the ventral valve of that species
is unknown to us, we are unable to determine positively. The plications
of that species often bifurcate on the upper part of the shell, while these
are simple; but this feature may not hold good on all specimens of the same
species where the bifureations are but few.
Formation and locality—tIn the Weber quartzite, Bear River, Uinta
Range, Utah. Collected by Clarence King, esq.
Genus ATHYRIS McCoy.
ATHYRIS SUBQUADRATA ?.
Plate 5, figs. 19-20.
Athyris subquadrata Hall, Geol. Iowa, vol. 1, pt. ii, p. 703, pl. 27, fig. 2.
Shell of medium size, varying from irregularly circular to distinctly
quadrate in outline, with more or less ventricose valves; length usually
272 : PALMHONTOLOGY.
somewhat exceeding the width, though often less; point of greatest widtha
little below the middle of the shell, the margins nearly straight from this
point to the beak above and to the front below, giving the quadrangular
outline. Dorsal valve ventricose, more distinctly elevated along the middle,
forming the proportionally narrow mesial fold, which is often more sharply
elevated and sometimes prolonged in front. Ventral valve marked along
the center with a narrow depression, corresponding to the fold on the dorsal
valve, but narrower, abruptly marked, and extending nearly to the beak;
body of the valve ventricose, especially in the upper half; beak strong,
sharply incurved, and slightly truncate. |
Surface of the valves marked by strong concentric lines of growth at
unequal distances, most numerous and crowded near the margin of the shell.
The specimens examined are all more or less imperfect from exfoliation;
consequently, the true surface-features cannot be ascertained. The species,
however, closely resembles specimens of A. subquadrata from the Chester
limestones of Illinois and Kentucky, differing mostly in the less distinctly
marked and narrower mesial depression of the ventral and corresponding
fold of the dorsal valve. The front is also sometimes much produced, but
not more so than is often the case with those. The species as found at
Chester, Illinois, and elsewhere, is quite variable, and among twenty or
thirty individuals from the typical localities specimens could be selected
that would correspond in form to any of those presented in this collection.
Formation and locality —tIn dark-colored limestone of Lower Carbonif-
erous age; the Wahsatch limestone, at Snowstorm Hill, near Dry Cajon,
Oquirrh Mountains, Utah. Collected by J. E. Clayton, of Salt Lake City.
COAL-MEASURE AND PERMO-CARBONIFEROUS FOSSILS. 273
FOSSILS OF THE COAL-MEASURES AND PERMO-
CARBONIFEROUS.
LAMELLIBRANCHIATA.
Genus AVICULOPECTEN McCoy.
AVICULOPECTEN WEBERENSIS D. sp.
Plate VI, fig. 5.
Shell of medium size or smaller, suborbicular in outline, the length
and height being subequal, anterior side of the shell larger than the posterior,
giving a slight obliquity to the valves; hinge-line straight, nearly two-thirds
as long as the greatest length of the shell, anterior portion forming rather
more than one-third of the length. Left valve very convex, the depth equal
to about one-ihird the height when not compressed. Auriculations not dis-
tinetly limited, anterior one small, with a shallow rounded sinus below,
extremity rounded; posterior side of moderate size, the sinus faintly marked;
extremity obtusely angular.
Surface marked by somewhat irregular radiating -coste, which vary
much in size, some of them being moderately strong and distant, with from
one to four smaller ones between, most prominent and distinct on the
median portion of the valve, becoming gradually smaller on the sides and
wings. There are also fine concentric striz crossing the radii, giving a
slightly roughened surface. Right valve unknown.
The species resembles in some of its characters many of those referred
to Eumicrotis Hawni M. & H., but differs in the size and form of the wings
and in the finer radii of thé surface. ‘The character of the auriculations
would prevent it from being classed as Eumicrotis.
Formation and locality—In limestones of the Upper Coal-Measures
(Permo-Carboniferous), foot-hills southeast of Salt Lake City, Wahsatch
Range, Utah. Collected by 8. F. Emmons, esq.
AVICULOPECTEN CURTO-CARDINALIS N. sp.
Plate VI, fig. 4.
Shell of small size, broadly ovate in outline, and nearly equilateral,
widest just below the middle of the height; hinge-line short, not exceeding
18 PR
274. PALA ONTOLOGY.
half the width of the shell below, and sloping somewhat rapidly from the
center to the extremities on each side of the beak. Left valve highly con-
vex, becoming almost subangular on the umbone; auriculations subequal,
quite small and indistinctly separated from the body of the shell by very
slight, rounded depressions, extending from the beak to the margin on each
side, in which they cause slight sinuosities, the anterior one most distinet.
Beak small, somewhat pointed, and slightly projecting beyond the cardinal
line. Surface of the valve marked by fine, even, rounded, thread-like radi-
ating striz, scarcely visible without the aid of a lens; also by finer concen-
tric lines. Right valve not observed.
The species presents much the appearance of many forms of Lima, and —
it is possible it should be so referred; but there is no other evidence of a
cardinal area on the left valve than the sloping of the hinge-line, while the
wings and sinuosities are more like those of Aviculopecten.
We know of no species so closely related to this one as to be readily
mistaken.
Formation and locality—In limestone of the Upper Coal-Measures
(Permo-Carboniferous), foot-hills southeast of Salt Lake City, Wahsatch
Range, Utah. S. F. Emmons, collector. |
AVICULOPECTEN PARVULUS 0. sp.
Plate VI, fig. 6.
Shell quite small, equilateral, broadly ovate in outline, a little higher
than wide; sides and base rounded, slightly prolonged on the postero-basal
side, and obscurely angular near the middle of the anterior margin. Hinge-
line two-thirds as long as the greatest width ef the shell, longest on the
anterior side, and very moderately sloping from the beak. Left valve
highly convex; wings moderate, not distinctly separated from the body of
the shell; anterior one largest, the margins nearly rectangular to each other,
the sinus scarcely perceptible, forming only a broadly-curved indentation
below the angle; posterior wing small, the margins forming an obtuse
angle. Surface of the valve highly convex; beak small and obtusely
pointed, barely projecting* beyond the cardinal line. Body of the valve
marked by alternating larger and smaller radii, the stronger ones extending
COAL-MEASURE AND PERMO-CARBONIFEROUS FOSSILS. 275
to the beak, while the smaller are added at irregular distances; wings
marked by finer radii of nearly equal strength. A few irregular concentric
undulations cross the radii at unequal distances. Right valve unknown.
This species differs from the preceding (A. curtocardinalis) in the stronger
radii, in being higher in proportion to the width, and in the longer hinge-
line. It differs from A. occidaricus Meek, plate 12, fig. 13, of his report,
with which it is associated, in being a smaller shell, more highly convex,
aud in having a greater number of strong radii, with a smaller number of
intermediate ones; this having usually but one instead of from two to four,
as in that species.
Formation and locality—In limestone of the Upper Coal-Measures
(Permo-Carboniferous), foot-hills southeast of Salt Lake City, Wahsatch
Range, Utah. Collected by S. F. Emmons, esq.
Genus MYALINA De Koninck.
MYALINA AVICULOIDES.
Plate VI, fig. 8.
Myalina aviculoides M. & H., Proc. Acad. N. Sci. Phil., May, 1860, p. 184; Pal. Up.
Mo., p. 51, pl. 2, fig. 8.
Shell of rather more than average size, mytiliform, ovate or triangularly
ovate in outline, half as high again as long; beak prolonged, narrow, and
somewhat curved; body of the shell nearly erect, highly convex, and
obtusely angular along the umbonal ridge, which is placed near the anterior
border and parallel to it; anterior face of the shell nearly vertical; posterior
surface rapidly and regularly sloping from the crest of the ridge to the pos-
terior margin; hinge-line nearly as long as the shell below the prolongation
of the beak; anterior border sinuous above and nearly rectangular to the
hinge-line below; base narrowly rounded; posterior margin broadly rounded.
Surface marked by rather strong, concentric lines, indicating stages of growth.
The shell is somewhat peculiar for the form of the beak, which is slender
and greatly prolonged anteriorly beyond the body of the shell, with a slightly
upward curvature near the point. It is also remarkable for the great con-
vexity of the valves along the umbonal ridge, which gives an almost vertical
anterior face. ‘These features readily distinguish this from all other species.
276 PALAHONTOLOGY.
_ Formation and locality.—In limestones of Permo-Carboniferous age, foot-
hills southeast of Salt Lake City, Wahsatch Range, Utah. Collected by
S. F. Emmons, esq.
MYALINA PERMIANA.
Plate VI, fig. 7.
Mytilus (Myalina) Permianus Swallow, Trans. St. Louis Acad. Sci., vol. 1, 1858, p. 17.
Mytilus (Myatina) concavus (Swal.) Meek, ib., p. 18.
Myalina Permianus (Swal.) Meek, Pal. Missouri, p. 52, pl. ii, fig. 7.
Shell of medium size, elongate triangularly-ovate, much higher than
long, suberect; hinge-line shorter than the width of the shell below;-ante-
rior margin concave; base sharply and narrowly rounded; posterior margin
broadly rounded, sloping abruptly forward in the upper part to meet the
hinge-line, considerably contracting the length of the shell at this point.
Surface of the valves highly convex near the front border, and somewhat
gradually sloping toward the posterior margin; umbonal ridge rounded;
beaks obtuse, nearly or quite terminal. Surface of the shell marked by
concentric lines of growth, obscurely preserved on the casts.
This species differs from the last (JZ. aviculoides), with which it is asso-
ciated, in the less convexity of the valves and more rounded umbonal ridge,
as well as in wanting the narrow and prolonged beak of that species. The
example used and figured differs from those figured by Mr. Meek (loc. cit.)
only in having the hinge-line a little shorter. This feature, however, varies
much among the specimens in the collection.
Formation and locality—Occurs with the preceding.
Genus SEDGEWICKIA McCoy.
SEDGEWICKIA ? CONCAVA.
Plate VI, fig. 3.
Sedgewickia ? concava Meek & Hayden, Pal. Up. Missouri, p. 41, pl. 1, fig. 8, 1864.
Iyonsia concava M. & H., Trans. Albany Inst., vol. iv, March, 1858.
Among specimens on a yellowish-brown sandy shale from the Wahsatch
Mountains, near Salt Lake City, is one so nearly resembling the figure cited
above that we cannot hesitate in considering it as specifically identical.
The specimen is about one-third longer than the figure cited, being about
nine-tenths of an inch long. The form is transversely elongate-elliptical,
COAL-MEASURE AND PERMO-CARBONIFEROUS FOSSILS. 277
a little more than twice as long as high, with the posterior extremity rounded
and recurved; beak large, prominent, and situated at about the anterior
third of the length; anterior end rounded, and longest below the middle;
basal line slightly convex, more abruptly directed upward for the posterior
third of its length; cardinal line concave; valve convex, becoming slightly
more compressed posteriorly; marked by slight concentric undulations of
growth parallel with the margins. :
Formation and locality—Upper Coal-Measures (Permo-Carboniferous),
foot-hills, southeast of Salt Lake City, Wahsatch Range, Utah. Collected
by S. F. Emmons. .
Genus CARDIOMORPHA De Koninck.
CARDIOMORPHA MISSOURIENSIS.
Plate VI, figs. 1-2.
Cardiomorpha Missouriensis Swallow, Trans. Acad. Sci. St. Louis, vol. 1, p. 207, 1858.
Shell rather below the medium size, transversely elongate and sub-
quadrangular in general outline; valves ventricose, or even gibbous, pre-
senting an almost cylindrical form. Hinge-line more than half the length of
the shell, very slightly arcuate and abruptly rounding into the posterior
extremity, which is obliquely rounded, and longest below; basal margin
nearly straight in the middle, curving more abruptly at each extremity;
anterior end short, rounded; beaks tumid and enrolled, situated rather
within the anterior third of the length; umbonal prominence faintly sub-
angular; cardinal slope narrow and abrupt. Surface of the shell marked
with fine concentric strize of growth and stronger undulations. Substance
of the shell very thin.
The specimens described differ so litttle from examples of the species
received from the Coal-Measures of Canton, Illinois, that they are not readily
distinguished when placed together; the most marked difference being the
slightly greater length of the anterior end, and somewhat more prominent
beaks. The shell is also a little more excavated in front of the beaks; but
these differences are not strong enough to be deemed of specific importance.
Formation and locality—In black shale of Coal-Measure age, near
Eberhardt Mills, White Pine. Collection of Arnold Hague, esq.
278 PALHONTOLOGY.
CEPHALOPODA.
Genus CYRTOCERAS Goldf.
CYRTOCERAS CESSATOR 0. sp.
Plate VI, fig. 15.
Shell of rather small size, moderately curving throughout its length,
and rapidly expanding from below upward; the specimen measured show-
ing an increase of diameter from less than half an inch to about eight-tenths
of an inch in a length of only about nine-tenths of one inch; section circu-
lar. Surface marked by strong, rather distant, rounded annulations, which
are separated by concave interspaces. The annulations are directed slightly _
upward or forward in crossing the back of the shell, and become gradually
more distant with the increased growth of the individual; four of these
annulations occupy a length of the shell equal to its diameter at the upper-
most of those counted. Septa equal in number to the annulations, their
extreme outer margins reaching nearly to the crest of the ridges in some
cases; others are more distant. Siphuncle small, submarginal, situated a
little to the right of the dorsal line (perhaps only an accidental feature).
Surface of the shell marked by fine, crowded, thread-like, encircling
striz on both ridges and interspaces.
The species closely resembles in many of its characters that figured
by Meek and Worthen (Geol. Ills., vol. ii, plate 24, fig. 3), under the name
of Orthoceras annulato-costatum, but differs in its circular section, more rapidly
expanding tube, and longitudinal curvature. The latter feature, together
with the dorsally-situated siphuncle, would place the species under the
genus Cyrtoceras, and we strongly suspect the Illinois shell will also prove
to belong to the same genus when its true characters are ascertained. The
O. Chesterensis of Swallow (Trans. St. Louis Acad. Nat. Sci., vol. ii, p. 98)
is still further removed from this one by its closely-arranged annulations,
though it is not stated if it be curved or straight.
Formation and locality—tIn black shales of probably Coal-Measure age,
near Eberhardt Mill, White Pine, Nevada; associated with Gomatites Kingu
and Cardiomorpha Missouriensis. Collected by Arnold Hague, esq.
COAL-MEASURE AND PERMO-CARBONIFEROUS FOSSILS. 279
Genus GONIATITES De Haan.
GONIATITES KINGII 2. sp.
Plate VI, figs. 9-14.
Shell rather below the medium size, subglobose, the length and breadth
being about as three to two; composed of from four to six volutions, which
are broadly rounded over the dorsum and subangular at the margin of the
broad open umbilicus, into which the sides slope abruptly, forming an angle
of about forty-five degrees to the axis of the shell. Each volution em-
braces the preceding one to near the lateral angle, leaving a very narrow
surface exposed within the umbilicus. Extreme width of the volution equal
to three times the length, measured from the ventral to the dorsal surface,
at the center of the volution.
Surface of the shell and umbilicus marked by fine, subequal, trans-
verse lines of growth, often becoming crowded, and forming incipient un-
dulations on the back of the shell. Surface of the internal casts sometimes
marked by transverse constrictions, caused by the thickening of the inner
surface of the lip at stated periods of growth, as if for the purpose of strength-
ening its substance. ‘Two of these constrictions occur in the | space of one
volution, bringing them on opposite sides of the cast Septa rather closely
arranged and deeply lobed. The dorsal lobe is longer than wide, and deeply
divided, forming two long, slender, lanceolate branches, with a shorter, trun-
cated, central projection; dorsal saddle broadly conical, rounded above, and
slightly inclined toward the dorsal lobe; lateral lobes as long as the dorsal
saddle, obconical, pointed at the lower extremity; lateral saddles broader
-and shorter than the dorsal saddles. |
The shell is somewhat remarkable for the great extent of the outer
chamber, appearing from fractured individuals to consist of two complete
volutions, and in some cases even more. It does not appear to attain a very
large size; the largest fragment observed indicating a specimen of not more
than two inches in diameter.
The species is of the type of G. sphericus Sow., but is less globose and
the umbilicus much larger. There are several American species of the type
known, as G. Nolimensis Cox and G. globulus and G. Iowensis M. & W. from
280 | PALAONTOLOGY.
the Coal-Measures, but our shell differs from all of them in the proportionate
size of the whorls, in the form of the umbilicus, and in the form and dispo-
sition of the septa to such an extent as to be not readily mistaken.
Formation and locality—In black shale of the Coal-Measures, near
Eberhardt Mill, White Pine, associated with Cyrtoceras cessator and Cardio-
morpha Missouriensis. Collected by Arnold Hague, esq.
FOSSILS OF THE TRIASSIC FORMATION.
RADIATA. |
' ECHINODERMATA.
Genus PENTACRINITES Miller.
PENTACRINITES ASTERISCUS ?.
Plate VI, fig. 16. ;
? Pentacrinites asteriscus M. & H., Proc. Acad. N. Sci. Phil., 1858, p. 49; 1860, p. 419;
Pal. Up. Missouri, p. 67, pl. 3, fig. 2.
Several specimens of the separated disks of a Pentacrinites very simi-
lar in character to P. asteriscus M. & H., but differing somewhat in form,
but more particularly in their larger size, have been noticed among the col-
lections from Dun Glen Pass, Pah-Ute Range. When compared with speci-
mens of that species from localities of Jurassic age, they differ: slightly in
the more obtuse points of the star, and the filling up of the angles between
the points, and also in the broader form of the elliptical figures on the ar-
ticulating surfaces of the disks. As these features, however, are not constant
among any considerable number of specimens of that species, even when
found together on the same block, we hesitate to consider them of specific
importance. The large size is the most noticeable feature of these speci-
mens, some of which exceed one-fourth of an inch in diameter, while those
of that species seldom reach one-fifth of an inch, and are usually much
smaller. It is possible that this may prove to be a very distinct form when
FOSSILS OF THE TRIASSIC FORMATION. 281
more and better material shall have been examined, but at present we hesi-
tate to so consider it.
Formation and locality—In limestone of supposed Triassic age, asso-
ciated with Spiriferina Homfrayi and Terebratula Humboldtensis Gabb., near
Dun Glen Pass, Pah-Ute Range, Nevada. Collected by Arnold Hague, esq.
BRACHIOPODA.
Genus SPIRIFERINA D’Orb.
SPIRIFERINA HOMFRAYI ?.
Plate VI, fig. 18.
? Spirifer Homfrayi Gabb, Geol. Sur. Cal., Pal., vol. 1, p. 35, pl. 6, fig. 38.
It is with considerable hesitation that we refer to the above species
some very imperfect fragments in the Dun Glen collections. They con-
sist of two imperfect dorsal valves, and some still more fragmentary ventrals;
the latter altogether too imperfect for illustration. The dorsal valves are
depressed-convex, with slightly rounded cardinal extremities; the mesial
fold is simple, broad, and rounded, the front forming a little more than one-
fourth of the entire width of the valve, measured along the hinge-line. The
sides of the shell are each marked by seven or eight simple, scarcely angu-
lar plications, rapidly decreasing in size from the middle outward; front
margin nearly semicircular in outline. The ventral valve has been erect
and pointed at the beak; the plications appear more angular than those of
the dorsal, and the area of considerable height. 2
The specimens are badly exfoliated, thus rendering the surface-charac-
ters obscure. The texture of the shell cannot be distinctly made out, but
appears to have been punctate, and for this reason we have classed it
under the genus Spiriferina, although it may possibly not be properly
referred.
Formation and locality—In dark-colored limestone of Triassic age, one
and a half miles south of Dun Glen Pass, Pah-Ute Range, Nevada. Col-
lected by Arnold Hague, esq.
SPIRIFERA (SPIRIFERINA ?) ALIA D. sp.
Plate VI, fig. 17. :
Shell of medium size, transversely broad-ovate ; the width about one-
282 PALF ONTOLOGY.
sixth greater than the length, measuring on the ventral valve. Valves
rotund, with rounded hinge-extremities. Beak of the ventral valve obtuse,
incurved, and rounded; area of only moderate height; middle of the valve
marked by a well-defined mesial depression, the front of which is equal to
more than one-third of the entire width of the valve. Dorsal valve not
observed. Surface marked by numerous, rather fine, slightly angular, radi-
ating cost, which do not appear to bifurcate except on the mesial fold.
There are eight plications marking the mesial sinus, near the front margin,
on the specimen figured, and about twenty may be counted on each side of
the valve. Interior unknown.
We know of no species of Spirifera or Spirvferina in rock of this age
resembling the one under consideration or with which it can be confounded.
The substance of the shell, like all those from the same locality, is badly
exfoliated, and has apparently undergone some change, which has to some
extent obliterated the natural features, so that we are not able to say defi-
nitely if it be punctate or not, consequently are in some doubt in regard to
its generic relations.
Formation and locality——In dark-colored limestone of Triassic age, one
and a half miles south of Dun Glen Pass, Pah-Ute Range, Nevada. Col-
lected by Arnold Hague, esq.
Genus TEREBRATULA (Llhwyd.) Brug.
TEREBRATULA HUMBOLDTENSIS.
Plate VI, figs. 22-24.
Terebratula Humboldtensis Gabb, Geol. Survey Cal., Pal., vol. 1, p. 34, plate 6, fig. 35.
Shell of medium size, elongate-oval or ovate, widest above or below
the middle in different specimens; front of the shell truncate, marked by a
simple fold and sinus on the front margin, or by a double fold on the dorsal,
with a sinus between, and corresponding elevation and depression on the ven-
tral side. Ventral valve usually slightly flattened across the middle; beak
strong and broad, scarcely incurved, truncated by a rather large perfora-
tion; cardinal borders broad, strongly inflected and flattened, so as to form
an angularity along the edge of the beak.
Surface of the shell marked by strong, irregular, concentric varices of
FOSSILS OF THE TRIASSIC FORMATION. 283
growth, but without other visible markings. The substance of the shell
appears to have been finely punctate; but, owing to some chemical change,
the structure is usually obliterated.
The species is a very variable one, both in general form and in the
features of the front margin; sometimes being entirely plain, or having a
simple elevation and sinus, or being biplicate on the dorsal side, and appar-
ently triplicate on the ventral. These features seldom mark the young or
half-grown shells, and on the older specimens are usually confined to the
anterior third of the valves.
Formation and locality—tIn limestone of Triassic age, near Dun Glen
Pass, Pah-Ute Range, Nevada. Collected by Arnold Hague, esq.
LAMELLIBRANCHIATA.
Genus EDMONDIA De Koninck.
EDMONDIA MYRINA DN. sp.
Plate VI, fig. 19.
Shell rather below the medium size, transversely ovate, the length
nearly one-third greater than the height exclusive of the beaks. Valves
very convex, becoming almost inflated near the anterior end and on the
umbones; beaks proportionally large and tumid, situated near the anterior
end, and projecting largely above the hinge-line; anterior extremity short
and rounded; basal line gently convex; posterior extremity more broadly
rounded than the anterior; cardinal line nearly two-thirds the length of
the shell and gently curved throughout. Surface marked by obscure lines
of growth; interior features not determined.
The specimens consist of internal casts, preserving but fragments of
the shell in a highly crystalline condition, and do not reveal the true sur-
face of the shell, nor the exact generic relations of the species.
Formation and locality—In limestone of Triassic age, at Dun Glen, Pah-
Ute Range. Collected by Arnold Hague, esq.
284 PALA ONTOLOGY.
FOSSILS OF THE JURASSIC PERIOD.
BRACHIOPODA.
Genus RHYNCHONELLA Fischer.
RHYNCHONELLA MYRINA lh. Sp.
Plate VII, figs. 1-5.
Shell of medium size, very broadly ovate, being wider than long; the
greatest diameter below the middle, valves depressed-convex, the dorsal
much the deepest and nearly evenly convex from beak to base, and also
transversely. Ventral valve somewhat unevenly convex, slightly flattened
toward the sides, and moderately depressed in front to form the proportion-
ally broad mesial extension; beak rather large, pointed, strongly curved
upward, and projecting considerably beyond the dorsal valve.
Surface marked by from thirty-two to thirty-four low, rounded plica-
tions, eight to ten of which are elevated on the dorsal valve forward of the
middle of the shell, forming the rather wide but only moderately elevated
mesial fold and a corresponding number impressed on the ventral valve.
Minute surface-structure of the shell finely but evenly marked with con-
centric lines of growth.
This is a very pretty species, and is characterized by the moderately
fine plications of the surface, which are of nearly equal strength on all
parts of the shell, those of the mesial elevation being hardly perceptibly
larger than those on the sides. The species bears considerable resemblance
to Rhynchonella varians Schl. of the Inferior Oolite from Whitby, England,
but differs in the more evenly convex valves and in the rounded plications,
those of that species being slightly angular in the specimens examined.
Formation and locality—In light-colored limestones of Jurassic age, at
Flaming Gorge, Uinta Range, Utah.
RHYNCHONELLA GNATHOPHORA 2.
Plate VII, fig. 6. |
Rhynchonella gnathophora Meek ?, Geol. Surv. Cal., Pal., vol. 1, p. 39, pl. 8, fig. 1.
A few individuals referred with doubt to this species occur in the
collections from Flaming Gorge. The reference, however, is very unsatis-
FOSSILS OF THE JURASSIC PERIOD. 285
factory, and, on examining specimens of that species, appears even more
uncertain; still, the differences are not so great as to positively preclude
the possibility of specific identification. The individual represented on
plate 7, fig. 6, is perhaps as closely related to Meek’s species as any one
seen, but differs very materially in the strength of the plications on the
lateral parts of the shell, there being from two to four on each side more
than on the most finely marked individuals referred to that species by its
author; the shell is also less rotund and more slender and delicate in habit.
Genus TEREBRATULA (Llhwyd.) Brug.
TEREBRATULA AUGUSTA nD. sp.
Plate VII, figs. 7-10.
Shell small, broadly ovate, the widest part being : a little below the
middle of the length; width of the shell less than the length; valves
depressed-convex, the dorsal sometimes nearly flat, but usually two-thirds
as convex as the ventral; beak small, minutely perforate, and strongly
incurved; cardinal slopes angular; margins of the shell acute. Surface
marked by lines of growth without perceptible structure except the very
fine puncte of the shell. |
The species of this genus, when of the same general type, are so.
similar that it is extremely difficult to point out specific differences or insti-
tute satisfactory comparisons, and the shells now under consideration belong
to a form which is so often repeated, both in this and several other genera,
that it would be useless to enter into any discussion of specific characters ;
therefore we shall rely upon the figures to tell their own story.
Formation and locality.—In limestones referred to the Jurassic, at
Shoshone Springs, Augusta Mountains, Nevada.
LAMELLIBRANCHIATA.
Genus OSTREA Linn.
OSTREA sp. 2.
Plate VII, fig. 12.
Compare O. Engelmanni Meek, Proc. Acad. Nat. Sci. Phila., 1860, p. 311; Pal. Upper
Missouri, p. 73, figs. A and B.
A single example, an impression of an upper valve, found associated
with the following species, appears to be entirely distinct. It is a much
286 PALMONTOLOGY.
larger shell, and possesses all the features of a true Ostrea. The form is
irregularly ovate in outline, moderately convex, and slightly curving poste-
riorly ; length and breadth about as four to three, the expansion of the
valve being most rapid on the posterior side below the middle; posterior
border concave in the upper part, and sharply rounded below; anterior
border regularly and broadly rounded; adductor muscular scar small, sub-
marginal, situated above the middle of the length; the area embraced
above the pallial line being not more than one-fourth as great as that
below.
The specimen under consideration was at first supposed to be the young,
or a small individual, of O. Engelmanni Meek, but there is not the slightest
evidence of plications, the shell is proportionally longer, and the muscular
imprint proportionally smaller and more nearly submarginal; yet the
resemblance to that species is quite strong, and it is possible that in such
variable shells such changes may take place in the same species.
Formation and locality—In rocks of Jurassic age, northwest of Raw-
lings Station, Wyoming.
Genus GRYPH AA Lam.
GRYPH4A CALCEOLA var. NEBRASCENSIS.
Plate VII, fig. 11.
Gryphea calceola var. Nebrascensis M. & H., Proc. Acad. Nat. Sci. Phila., 1861, p. 437;
Pal. Upper Missouri, pp. 74-75, pl. 3, fig. 1.
Among the Jurassic fossils of the collection are numbers of a small
Oyster-like shell, which we suppose to be identical with many of those
referred to the above-named variety of Quenstedt’s species G. calceola. ‘The
specimens are mostly small and of variable form, the prevailing feature
being broadly and irregularly reniform, or curved-ovate; more or less
truncate at the posterior end; the smaller valve being extremely shallow
and scarcely convex, while the attached valves are very irregular and
variable in depth and convexity, most of them being flattened and attached
over the greater part of their extent, with the edges abruptly curved
upward, to give the requisite depth, others scarcely showing any mark of
attachment, and still others are squarely and vertically truncate at the
upper extremity, similar to those represented in the Pal. Upper Missouri,
FOSSILS OF THE JURASSIC PERIOD. ., 287.
pl. 3, figs. 1 bande. The most general feature seems to be their small
size, although they differ in this respect, for while the majority of the speci-
mens range from half to three-fourths of an inch in length, other examples
are found attaining a length of an inch and a half.
It will be seen, by reference to the remarks of Messrs. Meek & Hayden
on this species, that they have met with all these various phases and varia-
tions among their specimens, although they speak of examples of much
larger size, where the attached valves are deep and strongly arcuate, with
large, strongly incurved beaks. These they term ‘‘normal forms” of the
variety, although it would seem that from some of their localities these
forms are nearly or quite absent, and that the flattened forms prevail.
Among the examples examined by us there are none of these ‘normal
forms”, but all are of the irregularly convex, the squarely truncate, or the
flattened forms above referred to; and it seems to us that these forms are
much more likely to prove an entirely distinct species from the so-called
‘normal forms” than that they are merely individual differences. In fact,
from the specimens before us, and from the figures above referred to, it
appears that there is but little reason for considering the forms under con-
sideration as belonging to any other genus than Ostrea; while those
referred to as ‘‘normal forms” are unquestionably true Gryphea.*
In the flattened and almost wholly attached examples, the form and
_ characters are so exactly similar to Ostrea congesta Conrad, from the Creta-
ceous formations, that it is nearly or quite impossible to say wherein they
differ, except, perhaps, that they are not so Ce or so densely packed
together as that species often is.
. Formation and locality.—In shaly limestone of Jurassic age, at Sheep
@kéck: Uinta Range, Utah, associated with Camptonectes bellistriatus, Penta-
crinites asteriscus, &c.; and on Ashley Creek, Uinta Range, associated with
Camptonectes? extenuatus, Bellemnites densa, &c. Collected by S. F. Em-
mons, esq.
* Since the above paragraph was written, Dr. C. A. White has described these
small shallow forms under the name Ostrea strigilecula (see Pal. Rep. Geograph. and
Geol. Surv. and Expl. West of 100th Merid., Lieut. Wheeler in charge, by C. A .White,
p. 168, pl. xiii, fig. 3).
288 —C PALAONTOLOGY.
Genus AVICULOPECTEN McCoy.
AVICULOPECTEN (EUMICROTIS?) AUGUSTENSIS D. sp.
Plate VII, figs. 14-16.
Shell small, broadly ovate, higher than wide; length of the hinge equal
to about half the height of the shell, the anterior side straight and forming
two-thirds of the entire length, posterior side slightly declining from the
beak; left valve moderately convex, most prominent on the umbone; beak
small, obtusely pointed and but slightly projecting beyond the hinge-line;
auriculations depressed, but not distinctly separated. from the body of the
shell, the anterior one of moderate size, posterior one quite small. Surface of
the valve marked by simple rounded ribs of equal strength, except on the
left auriculation, where they are finer, somewhat corrugated, and strongly
curved upward to the margin. Right valve flat or very slightly convex;
beak depressed and not extending beyond the hinge-line; ears much more
distinctly marked than on the left valve, the lines separating them from the
body of the shell, strong, nearly straight, and rapidly diverging from the
beak, inclosing an angle of about ninety degrees; anterior auriculation
large, rounding inward from the extremity. Byssal notch more than a third
as deep as the length of the ear, broad and rounded at the bottom. Suirface-
markings similar to those of the opposite valve.
The specimens from ‘which the description is taken are slightly exfoliated
and do not present the natural surface-markings; but another fragment
presenting a weathered surface shows concentric strie, which are strongly
vaulted in crossing the radii, but not distinctly marked in the depressions.
The species has much resemblance, especially the left valve, to many
of those referred by Mr. Meek to his genus Eumicrotis, in general form and
surface-markings, but differs strongly in the large anterior auriculation and
byssal notch of the right valve, corresponding in this respect more nearly
with Aviculopecten, and we are eee as to which genus these ought
properly to be referred.
Formation and locality—In limestone referred to the Jurassic, Shoshone
Springs, Augusta Mountains. Collected by S. F. Emmons, esq. —
FOSSILS OF THE JURASSIC PERIOD. 289
Genus EUMICROTIS Meek.
EUMICROTIS CURTA.
Plate VII, fig. 24.
Avicula curta Hall, Stans. Rept. Salt Lake, p. 412, pl. 2, fig. 1.
Avicula (Monotis) tenuicostatus M. & H., Proc. A. N. Sci. Phil., 1858, p. 50.
Monotis curta M. & H., Proc. A. N. Sci. Phil., 1860, p. 418.
Eumicrotis curta M. & H., Smithsonian Check-List N. Am. Invert. Foss., 1864.
Humicrotis curta M. & H., Pal. Upper Missouri, p. 81, pl. 3, fig. 10.
Shell small, suborbicular or obliquely ovate, a little higher than long,
or height and length subequal; valves convex, the left one the most rotund.
Hinge-line short, compressed behind and forming a small, obtusely-angular
wing; anterior side very short, scarcely forming a wing, the anterior margin
rounding nearly to the beak; posterior margin gradually sloping backward
from the extremity of the hinge to a point below the middle of the valve,
whence it is rather sharply rounded to the junction with the basalline. Base
slightly prolonged on the posterior side of the median line, giving a little
obliquity to the shell. Right valve apparently less convex than the left.
Surface marked by distinct radiating lines or ribs, which are narrower
than the spaces between, and usually become obscure or obsolete before
reaching the beaks. On the right valve, the radii are much less strongly
marked, while the concentric stria become more distinct.
Among a large number of specimens there are no right valves in a con-
dition to show the hinge-features or byssal notch, and we are therefore left
somewhat in doubt concerning these features. The shells appear to possess
all the essential characters of E. curta, but vary so much among themselves
as to give rise to some doubt.
Formation and locality—In calcareous beds of Jurassic age, apo the
gypsum beds at Ashley Creek, Uinta Range, Utah. Collected by S. F.
Emmons, esq.
Genus CAMPTONECTES Agassiz.
CAMPTONECTES BELLISTRIATUS Meek.
Plate VII, fig. 13.
Camptonectes bellistriatus Meek, Pal. Upper Missouri (Smithsonian Contributions to
Knowledge), p. 77, figs. A-D.
“Shell very thin, ee eaicaln suborbicular in outline; valves
19 PR
290 - PALZONTOLOGY.
nearly equally convex; hinge-line equaling two-fifths to one-half the trans-
verse diameter of the valves; posterior ear very short, or nearly obsolete,
flat, and obliquely truncated; anterior ear larger, flattened, and marked by
rather distinct lines of growth in the right valve, separated from the adjacent
margin by a more or less angular sinus, one-third to one-half as deep as the
length of the ear, measuring from the beak. Surface striae very fine, regu-
lar, sharply impressed, and increasing in number by the intercalation of
others between as they diverge in extending from the umbonal region, so
strongly arched as to run out on the hinge-line near the beaks; concentric
strie fine, regular, closely arranged, and often nearly or quite obsolete on
the impressed spaces between the impressed radiating strize, to which latter
they impart a subpunctate appearance.”
The above is a transcript of Mr. Meek’s description of this species.
Although there are quite a number of specimens in the collection which are
referable to it, there are none which give the entire characters of the shell;
nor are there any from which a figure could be made without some resto-
ration. Still the characters of the species are, nevertheless, shown so dis-
tinctly as to leave no doubt as to the correct reference. The specimens
are generally smaller than the figures given by Mr. Meek, and some of
them are a little more oblique in outline, while the characters of the sur-
face vary from being nearly smooth to those strongly cancellated; while
on some the concentric striz are strongest, and on others nearly obsolete.
Formation and locality—Jurassic; specimens have been recognized from
northwest of Rawlings Station, Wyoming, and from Sheep Creek, and
Flaming Gorge, Uinta Range, Utah. Collected by 8. F. Emmons, esq.
CAMPTONECTES EXTENUATUS Meek.
Plate VII, fig. 18.
Camptonectes ? extenuatus Meek, Pal. Upper Missouri (Smithsonian Contributions to
Knowledge), p. 78.
Camptonectes ? pertenuis M., ib., pl. iii, explanations of fig. 6.
Shell small, erect, broadly ovate, a little higher than wide, the point of
greatest width being near the middle of the sheli; hinge-line short, about
half as long as the width of the valve; ears small, the anterior one slightly
FOSSILS OF THE JURASSIC PERIOD. 291
obtuse at the outer angle, the posterior margin sloping gently backward
toward the body of the shell, the posterior wing not fully determined. Body
of the (right?) valve convex, most prominent, and almost subangular toward
the umbo; beak small, pointed, scarcely projecting beyond the hinge-line;
margin of the shell broadly rounded anteriorly and posteriorly, and some-
what acutely rounded at the base. 3
Surface of the valve in the specimen seen marked by fine, concentric,
impressed lines, and by stronger radiating lines. ‘These latter seem to be
composed of rows of fine dots, or punctures, and are strongly divergent, so
as to curve abruptly upward toward the margin on the sides of the valve,
the increase being entirely by interstitial addition.
The shell differs from C. bellistriata Meek in its smaller size, convex
valves, more erect form, and in the proportional height and width of the
valve, this being higher than wide, while the reverse is true of the other.
There can be no doubt that this is the shell to which Mr. Meek gave
the above names, although he had not seen the radiating strize of the
surface so plainly as to feel sure of their existence. On the specimen used
in the above description, the striz: are very distinct, and have exactly the
character of that of C. bellistriata; consequently, there can be no doubt of
its correct reference to the genus Camptonectes, although in our specimens
the anterior wing and sinus have not been satisfactorily determined, that
part in the figure having to be made from analogy.
Formation and locality.—In light-colored shales of Jurassic age, Acide
west of Rawlings Station, Wyoming.
CAMPTONECTES PERTENUISTRIATUS 2. sp.
Plate VII, fig. 17.
Shell small, very broadly ovate, the point of greatest width being about
the middle of the length, width equal to about four-fifths of the height;
base and sides of the shell regularly rounded. . Right valve very depressed-
convex or almost flattened; hinge-line short, the anterior side equal to a
little more than one-third of the width of the valve below; posterior side
unknown, the specimen being mutilated in this part. Beak small, pointed,
not rising above the line of the hinge; cardinal slopes nearly straight from
292 PALHZ ONTOLOGY.
the beak to a little above the middle of the length, and embracing an angle
of about ninety degrees; anterior wing narrow, separated from the body of
the shell by a deep, sharply rounded notch, which extends about half-way
to the center of the valve; a strongly-depressed sinus passes from the base
of the notch to the beak, separating the upper part of the wing from the
body of the shell.
Surface of the shell marked by rather distinct, concentric lines of
growth, which are crossed by exceedingly fine, radiating strize, imperceptible
except by the aid of alens. The strize diverge rapidly from the median
line, and curve upward rather more strongly toward the sides of the shell.
The shell differs from C. ? eatenuatus Meek and Hayden (Pal. Upper
Missouri, p. 78, plate iu, fig. 6) in its more attenuated beak, Hameed valve,
finer strize, and more elongate form.
Formation and locality—In limestone of Jurassic age, northwest of
Rawlings Station, Wyoming.
Genus LIMA Brug.
LIMA (PLAGIOSTOMA) OCCIDENTALIS 0D. sp.
Plate VII, fig. 23.
Shell of medium size or smaller, very broadly ovate, the height slightly
exceeding the greatest width; widest point about one-third of the height
from. the basal extremity, below which the margin is regularly and evenly
rounded, and above the posterior border is more rapidly rounded and con-
tracted to the extremity of the short hinge-line, with which it blends with-
out perceptible angle. Valves strongly convex, most ventricose near the
middle of the anterior border, from which point the surface declines to the
postero-cardinal and postero-basal margins; beaks apparently small, incon-
spicuous, and somewhat appressed (?). Anterior wing minute, posterior
wing small, but alated, not distinctly separated from the body of the shell;
ligamental area not observed. Anterior border of the shell strongly con-
cave, the concavity extending more than half the height of the shell.
Surface of the shell marked by simple, strong, rounded radii, about
sixty in number, posterior to the junction of the anterior and basal borders,
with a few incipient radii observable on the anterior slope. The radii are
FOSSILS OF THE JURASSIC PERIOD. 293
strongest near the middle of the basal border, and decrease very slightly in
size anterior to this point; but posteriorly they decrease more rapidly, and
on and near the posterior alation are quite fine. Interspaces narrow and
concave.
This species is closely allied to Lima lineata Gold. (= Plagiostoma lineata
of authors, ) but differs in being more regularly rounded on the basal and pos-
tero-basal borders, as well as in being more erect, that species having con-
siderable obliquity, the longest point of the base being much nearer the
anterior side. The beak is also shorter, and not nearly so prominent, and
the greatest convexity of the shell nearer the anterior margin, while that
one is most prominent near the middle of the valve, and nearly evenly
rounded in both directions from this point. The posterior wing of this
species is more alate than in that one, and more finely ribbed, giving about
fifteen additional ribs over and above the number counted on that species.
This character is perhaps the most distinctly marked feature of the species,
and one that will serve to readily distinguish them, although the general
resemblance of the shells is very great.
Formation and locality —In cherty limestones of J urassic age, at Flam-
ing Gorge, Uinta Range, Utah. Collected by S. F. Emmons, esq.
Genus TRIGONIA Brug.
TRIGONIA QUADRANGULARIS 2. sp.
Plate VIL, fig. 22.
Shell small, subquadrangular in outline, with depressed convex valves
and flattened inconspicuous beaks; length of the shell a little greater than
the height; anterior end broad and rather squarely truncate; the margin
but slightly rounded; basal line somewhat straightened or but slightly con-
vex, more strongly rounded behind; posterior end obliquely truncate, long-
est below; cardinal border short, not more than two-thirds the length of
the valve, very little concave, and subparallel with the basal margin.
Surface of the valve marked by a flattened, distinctly elevated ridge,
which rises from behind the beaks, and passes along the umbonal slope,
extending beyond the posterior margin of the valve in a squarish projec-
tion, equal in extent to the elevation of the ridge. Above the ridge, the
294 | _ PALAIONTOLOGY.
cardinal slope is narrow and depressed, marked only by transverse lines of
erowth. The surface of the ridge is marked by irregular transverse lines
of nodes. The body of the shell is marked by a series of low, rounded
ridges or undulations, which originate in a point at the edge of the flattened
- umbonal ridge, and extend in the direction of the postero-basal angle of the
shell, where they are again bent forward, forming a series of acute angles
marking the umbonal line of the shell, and are directed with a slightly
downward tendency to the anterior margin. Along the umbonal ridge of
the valve the undulations are broad and rounded, Se narrow aga
in their anterior extension. :
The strong undulations of the body of the shell of this species is a
distinguishing feature, and one by which it will be readily recognized. It
differs greatly in this feature from T. Conradi M. and H. (Pal. Upper Missouri,
p- 83, pl. 3, fig. 11) from the Jurassic of the Black Hills, as well as in the
subquadrangular form of the shell, that species being of a subtriangular
form.
Formation and locality —In light-colored, somewhat shaly, limestones of
Jurassic age, near Como, Laramie Plains, Wyoming, associated with Penta-
crinites asteriscus M. and H. and other Jurassic species. Collected by
Arnold Hague, esq. |
Genus SEPTOCARDIA n. gen.
Shell bivalve, equivalve, inequilateral, cardiform. Hinge strong; right
valve with a strong, recurving, hooked tooth under the beak, and a deep
cavity below and exterior to it, which is profoundly excavated in the
thickened substance of the shell. In the left valve, a large, deep cavity
corresponds to the tooth of the right valve. Lateral teeth obsolete. ‘Liga-
ment external, situated in a groove formed by a thickened, overlapping
portion of the shell posterior to the tooth and corresponding cavity. Ante-
rior adductor muscular scar very large and deep, separated from the general
cavity of the shell by a calcareous plate, or septum, extending across the
anterior end of the valve on the inner side of the scar, thereby forming a
distinct chamber in each valve. Posterior adductor scar much smaller,
situated within the posterior cardinal margin. Pedal scars not observed..
FOSSILS OF THE JURASSIC PERIOD. 295
Surface of the shell marked, in the typical species, by strong, elevated,
radiating ribs, with ornamented surfaces similar to many of the recent
species of Cardium. ‘Type S. typica.
The shells for which the above generic name is proposed are small,
few specimens of the typical species exceeding three-eighths of an inch in
their greatest diameter. Externally they closely resemble the Eocene forms
of Cardita, but the hinge-structure separates them at once from all other
known forms. The cardinal border of the right valve appears almost as if
composed of two distinct lamellee of shell, an inner and an outer one, the
inner one originating on the inside of the umbonal cavity, and rising to the
level of the valve margin, coalescing with the outer portion posteriorly, and
diverging considerably anteriorly, so as to leave a gradually-widening space
between the two, the anterior end of which is partitioned off, forming the
anterior muscular scar, or pit, and leaving a smaller, somewhat triangular,
cavity posterior to it. From the inner lamella bounding this cavity, the
recurved, hooked tooth rises, overarching the cavity beneath. In the left
valve, the two lamelle are less distinct; the whole cardinal border being
thickened, and the cavity into which the tooth of the right valve fits is
excavated in its substance, immediately in front or against the beak of the
valve. There are no lateral teeth in either valve. The septum bounding
the inner margin of the anterior muscular scar is similar to that of Cucullea
or Idonearca, except that it borders the anterior instead of the posterior
muscle as in those genera, and in the species S. typica reaches almost to the
basal margin of the valve.
The type-species occurs in rocks referred with some doubt to the
Jurassic, although the general appearance of the shells would indicate a
much more recent date.
SEPTOCARDIA TYPICA ND. Sp.
Plate VII, figs. 26-29.
Shell small, subrhomboidal in outline, the united valves angularly cor-
diform and very gibbous. Valves longer than high, oblique, and widening
posteriorly; beaks strong, angularly tumid and enrolled, situated near the
anterior end .of the shell; cardinal line arcuate, slightly elevated posteri-
296 PALAMONTOLOGY.
orly; anterior end short and obtusely pointed; basal line gently rounded ;
posterior end broadly truncate and slightly rounded. Body of the valves
very ventricose, subangular along the umbonal ridge, marked by strong
radiating coste, separated by equally wide, flattened interspaces; six or
eight of these costes occupy the postero-cardinal slope, and from twelve to
sixteen may be counted on the body and anterior portion of the shell. The
costee are flattened on the summit, and marked by closely-arranged, recurved,
transverse ridges, or nodes, which become more crowded and stronger with
the increased age of the shell. Interior margin of the valves strongly den-
ticulate from the squarely-depressed grooves, corresponding to the external
ribs, and which extend to nearly one-third of the width of the shell.
Formation and locality—In limestones referred to the Jurassic, at Sho-
shone Springs, Augusta Mountains, Nevada. Collected by S. F. Emmons,
esq.
SEPTOCARDIA CARDITOIDEA 0. sp.
Plate VII, fig. 25.
Shell of medium.size, subrhomboidal in outline, longer than high, nar-
row anteriorly, and widening behind. Valves ventricose, very angular
along the umbonal bridge, rapidly sloping to the postero-cardinal margin,
and more gently toward the anterior end of the shell; beaks large, promi-
nent, and strong; placed well toward the anterior end, which is narrowly
rounded; basal line broadly rounded; posterior extremity obliquely trun-
cate, longest at the postero-basal angle. Internal features unknown. Sur-
face marked by numerous, strong, sharply-elevated, angular, radiating
coste, with sharply V-shaped interspaces, the exact number not deter-
mined; those on the postero-cardinal slope near the basal angle count-
ing about five in the space of half an inch, giving about a tenth of an inch
from crest to crest; toward the cardinal line they become gradually finer.
Those on the body of the shell appear to have been of nearly equal strength
with those on the posterior part, becoming finer toward the anterior
extremity. The costz are crossed transversely by fine, closely-arranged,
zigzag lines, strongly arched upward in crossing the ribs. Greatest length
of the specimen, 1# inches; height, 14 inches.
This species differs from S. typica not only in its greater size, but in
FOSSILS OF THE JURASSIC PERIOD. 297
being proportionally longer, but most notably in the angular form of the
ribs and interspaces, as well as in the different style of transverse orna-
mentation. ‘The specimen presents much the appearance of an Eocene
Cardita, and closely resembles C. alticostata Conrad (C. transversa Lea) of
the Claiborne beds in Alabama, except that it is narrower anteriorly.
Formation and locality.—In limestone referred to the Jurassic, Shoshone
Springs, Augusta Mountains, Nevada. Collected by 8. F. Emmons, esq.
Genus ASTARTE Sowerby.
ASTARTE? ARENOSA 0. Sp.
Plate VII, figs. 20-21.
Compare Tancredia Warrenana Meek and Hayden, Pal. Upper Missouri, p. 96, pl. 3,
fig. 7.
Shell small, the largest specimens not exceeding half an inch in length,
by a height about two-thirds as great; form transversely suboval, or
quadrangularly oval; cardinal line arcuate, but little more than half as long
as the body of the shell, gradually and moderately declining posteriorly ;
anterior end constricted in front of the beaks, and rather sharply rounded
below; basal line broadly convex; posterior end narrow and obliquely
truncate, being longest below at the junction with the basal border; beaks
small, incurved, moderately ventricose, and situated at about one-fourth of
the length from the anterior end. Valves ventricose throughout, with a per-
ceptible fullness along the umbonal slope, above which the shell declines
more rapidly to the cardinal border. Features of the hinge and muscular
system unknown. Surface of the shell smooth, so far as can be determined
from the specimens examined.
At first, we were inclined to consider this shell as identical with Tan-
credia Warrenana M. (loc. cit.), but on closer comparison with figures and
description it would seem to be distinct. At least, it is not a Tancredia, and
may be equally distant from Astarte; but, in the absence of all generic
features in the specimens beyond the external form, it is impossible to say
definitely to what genus it does belong. It is an abundant species in some
localities, the rock being literally filled with the impressions. It differs
specifically from the above-named shell in being less distinctly triangular
298 PALZONTOLOGY.
and in the more anterior position of its beaks, as well as in the want of
convexity in the curvature of the antero-cardinal boudes, as would be
required were it a species of Tancredia.
T’ormation and locality.—In red sandstones of Triassic or Jurassic? age,
North head of Chalk Creek, lens Picked up in the débris, and of no
stratigraphical importance. |
GASTEROPODA.
Genus NATICA Lam.
NATICA? LELIA 0. sp.
Plate VII, figs. 19-21.
Shell small, globose; height and width about equal, and seldom exceed-
ing a fifth of an inch in measurement. Volutions two and a half to three,
the last one very rapidly expanding and ventricose, constituting almost the
entire bulk of the shell; inner volutions minute, moderately elevated above
the surface of the body-whorl, and somewhat regularly rounded, forming a
very low spire; suture distinct but not channeled; aperture subpatulose or
pear-shaped, higher than wide, largest below the middle, pointed at the
upper extremity and rounded below, except near the junction with the col-
umella, where it is almost subrimate; outer lip thin and sharp. Columella
arcuate, rounded, without any appearance of a callus or thickening of any
kind as far as can be determined from any of the examples in hand. (This
portion of the shell is more or less concealed by adhering rock in all the
individuals, so that this feature cannot be satisfactorily determined.) The
strize, however, appear to pass from the body of the shell directly upon and
over the solid, slightly-twisted, and non-umbilicated columella.
Surface of the shell smooth, appearing almost polished, except for the
very fine strive of growth which are directed backward across the body of
the volution.
The species has nearly the size and eeneral appearance of Naticopsis
nana Meek and Worthen, from the Coal-Measures of Lllinois and the West,
but differs in the columella being less straightened and prolonged below,
not giving so great a basal extension to the aperture. The differences of
the character of the columella are too distinct to require comparison. The
FOSSILS OF THE JURASSIC PERIOD. . 299
shell is most probably not a true Natica, and may possibly not belong to
the same family; but as the real features of this portion cannot be satis-
factorily determined, it remains a matter of doubt. It closely resembles, in
general form, shells of the genus Neritopsis except for the smooth surface.
It differs also from Neritoma Morris in wanting the peculiar callus of that
genus and from Narica Reel. in the smooth surface and want of umbilicus.
Formation and locality —In a greenish white limestone supposed to be of
Triassic age,* northwest of Rawlings Station, Wyoming, and on the Kast
Fork of the Duchesne River, Uinta Range, Utah. Collected by 8. F.
Emmons, esq.
*I do not myself believe this to be Triassic, but it has been so referred by
others.—R. P. W.
wt be) oe
‘
*alue
* ee
ands! peri Ok cin ae
=
CLASSIFIED LIST OF THE FOSSILS DESCRIBED. IN THIS REPORT.
Order. | Family.
Genus and species.
Formation.
CCELENTERATA.
Actinozoa.......-. 4 Zoantharia ........ | Favositide .....- | Michelina sp. undet............ saoccsesaossos | Waverly group.
ANNULOIDA.
Echinodermata ae Crinoidea ..... eal Pentacrinidze el Pentacrinites asteriscus? M. & H........ a Triassic.
MOLLUSCOIDA (ARTICULATA?).
Obolidze
Se cckteresne
btaie AOeratsejanislee
Lingulepis Mera n. sp .-.---..2--c0---------- Potsdam group.
Lingulepis minuta n. sp.-.----------+-------- ----do.
Lingulepis Ellan. sp......------------------- Quebec.
Obolella discoida n. sp.---.------------------ Potsdam group.
Kutorgina minutissima n. Sp .--.------------- .---do.
Orthis Pogonipensis n. sp...--.-------------- Quebec group.
Orthis resupinata? Martin...... nooopdeceseses Lower Carbonif.
Strophomena Nemia n.sp..----..--.------+-- Quebec group.
Strophomena rhomboidalis Wilckins....-..--. Waverly.
Streptorhynchus equivalvis Hall ..........--. sons
-| Streptorhynchus inflata W. & W. .-.-.-..-----|....do.
Strophodonta Canace H. & W..........----- Devonian.
-| Leptzena Melita n.sp.--..---- ence eee ee eens Quebec group.
Chonetes Loganensis n. sp .-.---.------------ Waverly.
-| Productus Flemingi var. Burlingtonensis Hall Lower Carbonif.
Productus leevicostus ? White. ...------------|_._.do.
Productus semireticulatus Martin ....-..-.-.. peeedoe
Productus elegans? N. & P........--.-----.- pee doe
Spirifera Alba-pinensis n. sp.--.------------- Waverly.
Spirifera? (Spiriferina) Alia n. sp ..---.---.-- | Triassic.
-| Spirifera centronata Winchell ........-..----- Waverly.
Spirifera imbrex? Hall.............---------- Lower Carbonif.
Spirifera setigera Hall ..............--- ere: ~==-d0. 1
Spirifera striata Martin .............------- eeudow
Spititerinay Alia Speeeessceesnese asec Triassic.
Spiriferina Homfrayi Gabb..........--------- SEeEdOs
Athyris Glayitoniiespeee-ceneseceeseatese ae Lower Carbonif.
Athyris planosulcata? Phillips........-------- Peeedor
Athyris subquadrata ? Hall.....-.-.---------. eidor
Rhynchonella Emmonsi n. sp...------------- Devonian.
Rhynchonelia gnathophora Meek.......-..-- Jurassic.
-| Rhynchonella Myrina n. sp ..-..--- ------.--. ----do.
Rhynchonella pustulosa? White ...-...... --- Waverly.
Porambonites obscurus Nl. Sp ...---.--------- Quebec.
-| Terebratula Augustensis n. sp .--...-----.--- Jurassic ?.
Terebratula Humboldtensis Gabb.-....---.-. Triassic.
MerebratwlanUlahoneispiesseesee sete eee , Waverly.
LUSCA.
-| Ostrea sp. ? ? =O. Engelmanni Meek ....-.. Jurassic.
Gryphea calceola var. Nebrascensis M. & H.|....do.
Aviculopecten (Eumicr. ?) Angustensis n.sp.|... do.
Avicuiopecten curtocardinalis n. sp..-------- Permo-Carbonif.
Aviculopecten parvulus n. sp ...-...--------.|--- do.
Aviculopecten Weberensis n.sp .....--.---- .-- do.
TUMICTOLSicurtalalleeeseeneeecs eeeen es cee. Jurassic.
302 CLASSIFIED LIST OF FOSSILS.
Class. Order. Family. i Genus.and species. _ Formation.
MOLLUSCA.
Camptonectes bellistriatus NMCekeeeateseetteean mL LASSICS
Camptonectes extenuatus M. & H........... eon);
Camptonectes pertenuistriatus n. sp .......- eeonG),
Lima (Plagiostoma) occidentalis n. ‘sp eeeeaeee soo CDs
Myalina aviculoidesM. & H ..........-...-. Permo-Carbonif.
Myalina Permiana Swallow. .........--..--.- Seca lo)e
Nuculites triangulatus n. sp .--...---.-.....- Devonian.
Doetacceweosenber oes Onsen ce eee Trigoniidae sianee Trigonia quadrangularis'n. sp Jurassic.
Doz. ccakaceeneases Ose essee eee Cardiomorphidz.| Cardiomorpha Missouriensis Swallow........ Coal-Measures.
IDotatese ee teeees GO! Seesnrcciees Fepe(s ORs aeaanacres Edmondia? Myrina n. sp .-....-------- .ee-.| Driassic.
Cardiidze .....--. Lunulicardium fragosum Meek .....-.-...... Devonian.
SaceSooNecs Septocardia Carditoidea n. sp ..-..---.----.--| Jurassic ?.
Eeciotala een Septocardia typica n. sp ...:.--.-. ----do.
Lucinide.....-.. Paracyclas peroccidens n.sp Devonian.
AStartidze) eee] 25] eAStantersarenosal miaSpesee= ee eaer ee eeseee eee Triassic ?; loose.
Anatinidse?...... Sedgewickia ? concava Meek ..........-...- Permo-Carbonif:
Fasciolariide --.| Fusispira compacta 0. Sp ---..-----..--- ..--.| Quebec.
.| Naticide......--| Natica? Lelia n. GO cocscecesecooesoncosescee Triassic ?.
-| Solariide.......-| Raphistoma acuta n.Sp .-.-..---..--..--.---- Quebec.
ae) OW esnsieeaa Euomphalus laxus White ....---.......-.---- Waverly.
peed Oy ason siemens Euomphalus Utahensis n. sp..--...-.-------- ----do.
shoe ids eceosooas Euomphalus (Strap.) Ophirensis n. sp..-.--- ----do.
Maclurzeidze ....| Maclurea miniman. sp ....-.-..------------- Quebec.
Bellerophontidz | Bellerophon Neleus n. sp..---.-----.-------- Devonian.
s2ecO® eesscoseone Cyrtolites sinuata n. sp ..... Goosoucaqononess|| OME DRE.
.| Cyrtoceratidze...| Cyrtoceras cessator n. sp ..--.--------------- Coal-Measures.
Goniatitidze ..... Goniatites Kingii ny Sp) -2---.--eseeeseneee- = 555. 6(0)5
ARTICULATA.
Crustacea..-...... Aualopitaeccess— == Calymenide..... Conocephalites subcoronatus n. sp .-.-.--..- Quebec.
Calymenidze ?...| Conoceph. (Pterocephalus) laliceps n. sp .-. | Potsdam group.
Paradoxidz ?....| Crepicephalus (L.) Anytus n. sp..----.-...--]---- do.
Seed Ouest eae Crepicephalus (L.) granulosus n. sp ......-..|---- do.
.---do .......-.--| Crepicephalus (L.) Haguei n.sp .----..-----.|----do.
boad@) occceaactes Crepicephalus maculosus n. sp.....-.--..---- ee eaOs
250500 ssoscdsocns Crepicephalus nitidus n. sp....-....-..------ aEeECOls
ise dO seer ee Crepicephalus (L.) quadrans n. sp .....-..--- Quebec.
Mero loy Pema ae Crepicephalus (L.) simulator n. sp .......---- Potsdam group.
smendOrwesecemece Crepicephalus (L.) unisulcatus n. sp ..--.-.-- pee dor
se teGO! co -wtene nee Crepic. (Bathyurus?) angulatus n. sp .--..--. poe CKO)
Paradoxidze ..-..| Ptychaspis pustulosa n. SP .------------------ scent)
Pre One cece Chariocephalus tumifrons n.Sp --...-..-..--- Rend Or
epenGl®) sccaotosecs Dikellocephalus bilobatus n. sp ---.--- eB eaee Pasctes
----do .....-..--.] Dikellocéphalus flabellifer n. sp -.--.---.---. saendor
Apa Craaaeecescce Dikellocephalus gothicus n. sp..----.---...-- Quebec.
soccttl®) ese noscoass Dikellocephalus multicinctus n. sp -----...--. Potsdam group.
socedl).4 nadssesnor Dikellocephalus quadriceps n. sp ------------ Quebec.
ie dO es aemecen Dikellocephalus Wahsatchensis n, sp ---..---].--. do.
Asaphidze ....... Ogygia parabola n. sp..----------------.--- Potsdam group.
s5e00® coseesssoss Ogygia producta n. sp -- -------------------.|_=-. do.
1Di8) sscesodouce||soSocc GO) EGachoosa8e SaeudOie cise seater Bathyurus Pogonipensisn. sp .----------- -- Quebec.
1D)0) sconce sqsoea)sossoc GIO) ses tGandse Preetidee .......-| Proetus Loganensis n. sp
poonthe) Soneqogsaas Prceetus peroccidens n. sp
Agnostidz ....-- Agnostus communis n. sp
SSAC} spaces ase) AVENTIS INGoyisal, So) -sossasosseobossssasSsesf[oooc
pao) somocuecces Agnostus prolongus n, sp
sconele) Stdeanac ...| Agnostus tumidosus n. sp ..-.--.-0.---------|---- do.
EXPLANATION OF PLATE I.*
Page.
QOBOLELLA DISCOIDEA ..<.220--2s2cesecee soos ESSE CCAD BoIpercoe SORES Scena a Cspaee ae neeron SIROBSUO 205
Fig. 1. View of a dorsal valve, enlarged, showing the orbicular form.
2. View of a ventral valve, showing the truncated beak. Enlarged.
DEIN GUE PIS 2, IMMN UMA en oes reais soe nem ne eaicicie iels eis miata tial cilasem sien Sin ees ye wla\el= Sie iciay alge an Sete cise 206
Fig. 3. View of a cast of the shorter valve, enlarged, showing muscular scars.
4. View of the cast of a long valve enlarged, showing the muscular scars more spreading
than jn the other valve.
LINGULEPIS MaRA....-.----...- ooscoc Pee ee oe RIS RST ci ici atat acai erenle ica parcioie Smheres ren Thiwicieareiate 206
Fig. 5. View of a supposed ventral valve showing the extended beak.
6. A larger valve having a shorter beak. This may be a dorsal valve.
7. Outline showing the relative gibbosity and length of the two valves.
DATING JOGO Ss Sa Sane aU COOH IA OO COCOE GORI BIS EES e eRe eee Sere een rare Seep re 232
Fig. 8. View of a dorsal (?) valve showing the truncation of the beak. Enlarged to two
diameters.
Ortuis POGONIPENSIS..---. JESS SEC OOS UEC SOO EIT OS SESS EE ORES ee Oo he ae Sie ere eee eens 232
Fig. 9. View of a dorsal valve of rather more than the ordinary size. Enlarged.
10. A ventral valve of the ordinary size, and of an elongate form, showing the elevation
of the beak.
KUTORGINA MINUTISSIMA.......-----.---+- Seer PN Sree ah ema cn ee a 207
Fig. 11. View of a dorsal valve, greatly enlarged, showing ‘the peculiar stris and the faint
radiations on the surface.
12. A ventral valve having a more elongate form. '
BRP TASNUN, MITA eieeteeisisna'steiciaiainiote ee me i a | a peel oa) Spat vie eats 208
Figs. 13-14. Views of two different individuals, showing variation in the surface-characters.
SINR ONE TA OMMIEINT ASN [ENVIS Ae ape ee eialsteta ns a (eainio tare a ate saie aaylainian siiaral=inies aletas rl ae Siafoloaarniaisinina we maiele clea ac a/e/s= 233
Fig. 15. View of the specimen described, showing the general form and surface-striz.
PORAMBONITES OBSCURUS.---..------ oe ee ee amie a SIBATS Hine ate atelcioansie sieve c cies momineae 234
Fig. 16. View of the exterior of a ventral valve, showing the lamella projecting inward from
the beak.
BVEAC@ TUR Aly NEDNTRUUAS = orate olotn =) oiler sinters Seadodgéogbo nee ad cance Aoteeee ROH ACB EAE See 4 eer tee 230
Fig. 17, View of the spire of an internal cast of aspecimen. Enlarged.
18. View of the flat side of the same individual.
19. Profile view of the specimen, showing the depth of the shell.
*Theline drawn by the side of figures indicates the natural size.
RAP HISTOMA ACU DA 2% css Bo ous slic on Cardle Be Sees risinr ee cia ainiee een eee sees teen see Soe eam eee
Fig. 20. Profile of a specimen, showing the elevation of the spire.
21 and 22. Upper and lower surfaces of the same individual.
CXYRTOLITES: SINUATUS: «0 2 sc shoo crohns oieisese Sabi aren eeae ci eeces Ccee tease ee meee eee eeeee
Figs. 23-24, Lateral and profile views of a specimen, showing the features of the shell. Enlarged.
FUSISPIRA COMPAOUTA ak. oSeo sd Sat eset hoe ee eae Ose reine Stee titans eis eee eee nea e
Fig. 25. View of the specimen described, which is imperfect at both ends; the outline shows
the probable form of the anterior end.
AGNOSTUS NISON sus. -s dance com eae a weseleeie belo een Ss EEO ee Sern SIC Eine wae eee eee nalcee ere
Figs. 26-27. View of the cephalic and caudal shields, greatly enlarged, showing the features
as seen on the specimens.
AGNOSTUS COMMUNIS...-- 'sssjmusTaie idle: i tS asian te ispais ws marche a Sah oS SiS ee eels ahetole ere elena CEM recto ein ie rete
Fig. 28. View of the cephalic shield, greatly enlarged, showing the ste form of the glabella
and the spine on its center.
29. Caudal shield. Enlarged.
AGNOSTUS: PROLONGUSG ecco osic os sok Sioie peters ure ole open: averey eels a aie rarcisionee srareie telbvoTn nai ese isle ia aia aeroae eee
Fig. 30. The cephalic shield, greatly enlarged, showing the great length and obscurely-marked
glabella.
3l. View of Uie caudal shield associated with the above Genanc shield.
AGNOSEUSERUMIMVOSUS eee scieemee casks seis ces eeeise erie eialaislepaiceiakc teenie alc ees eimmoshe scien ere
Fig. 32. View of the cephalic shield, with its peculiar and tumid glabella. Greatly enlarged.
IONE MAOIs LEO COMP UNIS) 5- G56 sooce6 soos sSan ese Seda osa5 soso dsonse sdoaoscose vsceso sooege soo5
Fig. 33. View of the pygidium described, showing the form and character of ribs, and the orna-
menting granules on the axial rings.
34. a of the same, showing the elevation of the specimen.
eC NW AUIS ARON TOSI so s60 pode Sogcas Soaoos Sood Says asses Ssae coed oes IOS Socas GOD0
Fig. 35. View of the glabella and one fixed cheek. The wider depressions on the glabella are
accidental depressions on the glabellar lobes.
\
te >
A Quek 24 3 Diicibtocima bet -mommews fe 2 Del ee fee ha se ee cee eee
Fig. 36. Yigw of a pygidium, showing the peculiar character of the ribs oL the lateral lobes:
Ok wes ao
QUADRICEPS... Just a8 2 oe See haececseleeeoiisc eee teees Opa oes ease see eaae
Fig. 37. Enlarged view of the glabella and fixed cheeks, showing the peculiar form of the
glabella and short frontal limb.
38. Profile of the same, showing the elevation of parts.
39. View of the pygidium, natural size.
40. Profile of the same, showing the great elevation.
228
230
241
242
240
U.S. Geol Exp]. 40Parallel . - Primordial and Silurian Plate I,
H.M.Marun Del J.Bien lith.
ye Te indy
: cle AD ang
L che
als
24 i
ae :
Phar t Ney
3 mye i
fa dh se RRR So
ke tt Lape
ae f
fe
+
af ey
% ~
' ales
rw
;
t
| i
is ta
peut .
: Poneto
a4 : BEAM
«! % is are eS
ae ' a: RAAT bee ge)
~) i Nt oe * ’ evn
\ Y ;
op eet : ten a as
. (is ‘aks
r i here as
ee ri
F +
zs _* " : o
;
é Py
¢ ;
ee
1
;
EXPLANATION OF PLATE II.
STC EEU NO HESS. SITIRCOIRON MIS) .oobe0 codons soeso5 565000 Cons dEeeoe sogson oScnde ceonSE Seeces baeE
Fig. 1. View of a glabella and fixed cheeks, showing the general characters of the species.
feats ge
GRANULOSUSieeercee steno eiseise mine cincist ence cisioajsece aseismic
Figs. 2-3. Vertical and profile views of a glabella and fixed cheeks, showing the form and
surface-markings. Enlarged.
TE "ROCEPTALUSY- THAI CHES pee eas ese syne e cio oe eels See isle sedueinereciscrseicnciowie
Fig. 4. View of the central parts of the head, showing the peculiar form of glabella and
extended frontal limb.
5. A movable cheek, with a portion of the under surface of the front of the head.
6. A part of a thoracic segment, associated with the other parts.
7. View ot) an imperfect pygidium, found in the same rock.
Hin. Cay monvrQ cae
G@REPIcEPHALUS (LOGANBEEUS)-NITIDUS BAe peie ieee ale hcla Se cete cle aes Sie wewi ae elisisreialnwatie me svecieieeecie
Fig. 8. View of the central portion of a head of the species, showing the pea gris of these
parts.
9-10. Two pygidia, showing some variations in the-details.
CREPLCBPHAEUS-CLOGANEELUS) QUADRANS ..--26 0. eo ee eee en ce ene ones Ae Aaa Sinai tacaee tse
Fig. 11. A glabella and fixed cheeks, enlarged.
12. View of a cheek, enlarged to twice the natural size.
13. View of a pygidium, enlarged to three times the natural size.
CREPICLPHATUS. CHOGENEEEGO)- HAGUE. ssis00 52 sci osccsie cscccccccees cece serces -octce cocescans
Fig. 14. View of an entire individual, enlarged to twice the natural size, showing the form and
characters of the animal.
15. A single thoracic segment (third), enlarged to show more distinctly its cone tne.
CREPIOEPHALUS-(LOGANBELUG) SIMULATOR... 22. --- eee nee e te ene ene eee eee meee cee een eenee
Fig. 16. View of the central part of a head, showing the characters of the species. The lateral
linbs have been broken off.
17. View of a movable cheek, enlarged to two diameters, showing the broad, flattened,
z marginal border.
nf me & ee of) a eee Jarger cheek, natural size (upper right-hand corner of plate).
Ge eee crin i naoeeaeo ners SO OOK CES Aon GSS R GEE aS EEO OCR E eS eas aera
Fig. 19. View of the central parts of the head of a small individual, showing the angular
glabella and strong ocular ridges. ;
20. View of a movable cheek, natural size, showing the striated surface.
21. A pygidium from the same block as the other specimens.
214
221
238
210
218
219
GrEricerHilLUs; ChOUGANBEEUS)- UNISULCATUS ct: can cnsccmemicces seeser rasicbee evisuc eSceunceceenen
Fig. 22. View of the central part of the head, deprived of the postero-lateral Jimbs,
23. View of the pygidium, associated with the above
CREPICEPHALUS (LOGANELTUS). MACULOSUS..------------ Se Meee eos ala SP arimniec ateisbe erate eae ei cera
Fig. 24. View ef the central parts of the head, showing the rounded glabella, with faintly-
marked furrows, and the postulose surface of fixed cheek, and frontal limb.
25. A movable cheek of the same species, presenting the same surface-markings.
=e. ? View of a pygidium found associated with the above parts, but not showing pustulose
ae markings.
vs iy brn x O~
12 siavsro ts), DUSED OOS Som cncesd o80sSs 9505 Howads euotinn goDEnS C5Oa Seon Boma Sos oue cn dene eseese-
Fig, 27. View of the glabella and fixed cheeks, the postero-lateral limbs having been removed.
AO )y ere fo. ~~ =) ees stains ale olen steele eee oleae
Fig. 37. View of the specimen described, showing the general form, with the margins restored
_ in outline, partly from another specimen.
, ae
CrtantockrnaLes TUMIBRONG: . Gwe cs- one eee mamane setae Moston cnet pacer eens ae eeR ee ner
Fig. 38. View of the glabella and fixed cheeks, showing the glabella projecting in front of the
anterior limb, and the two deep glabellar furrows.
39. Profile view of the same individual, showing the short frontal limb, with the glabella
projecting beyond it.
C
993
220
227
244
226
226
_
U.S. Geol Expl 40 Parallel Primérdial and Silurian
Plate I
| J. Bien ith.
H.M.Martin Del.
yy
en
= AS be bee
rye arsenal (PIR Sa 9 9
ee Tt ne wl
mea
EXPLANATION OF PLATE III.
i‘ vs
STROPHODONTA, GANACH) Sac caroc cision sce Seiemeein ine nleclieticie slereeisieterete Be eRe RCE Sern nS Se eres tare
Fig. 1. View of a very young individual.
2-3. Dorsal and ventral views of an older individual, presenting the features of the
species.
RHYNCHONELEA GEMMONSE cee sie toerclonictet seem ersioisteeeininicteeie ie ai cieste eieitee sieteeeeeie siete seieeiae ieee
Figs. 4-8. Dorsal, ventral, profile, front, and cardinal views of a full-grown and well-formed
specimen. .
EUNULICARD IONE RAG OSUMeysoreeicnies as acielsinieini sole ateine ste oes sericea aise meceesiee Wom eenine ae
Fig. 9. View of a short form, enlarged, showing strong undulations, and retaining the ante-
rior flange, of large size.
10. An elongated form, enlarged, showing a narrower anterior projection.
11. A right valve of medium proportions, showing a strong anterior flange.
NUGULIENS ERAN UBUE Lk Sok hese note ae cae ee a NS Te een cee ea ere
Fig. 12. View of a left valve, showing the surface-characters.
13. View of the same individual after having the shell removed from all but the hinge-
margin, and showing the impression of the clavicle very faintly.
PARACYCLAS (PEROCCIDENS nas cFacrseatecnecciet acne ie ieioters w/areecisns sere eiminielietsioieiniaias sinroieiere aieele meee
Fig. 14. View of a specimen, preserving a part of the external shell.
15-17. Right, left, and profile views of a cast, showing the muscular imprints and pallial
line.
BELEBROPHON: NEEBUS ciisilecn cic cleseaisiinie Lis etree re Sis Sn os Sioa a eae clea SESE ae eee aoe oer
Fig. 18. View of a fragment, showing the callus of the inner lip and a small part preserving
the external ornamentation.
19. Front view of an internal cast, showing the form of the lip and dorsal slit.
20. Profile view of the same individual, showing the axial cavity filled with the thick-
ened shell-substance.
247
249
248
248
250
U. S. Geol. Expl. 40 Parallel Devonian. Fae Ul
HM Martin Ded. J. Bien, ith.
=
EXPLANATION OF PLATE IV.
SHREPTOREVNCHUS: INEQUAUIS use < yale oem cea tee eee see cisent? eis ey see ars msciceiniciccs venice seins
Fig. 1. View of a dorsal valve, showing an unusual breadth, from Ogden Cafion.
2. View of a narrower ventral valve, showing finer and more even striz, from Logan
Cafion.
SPREE TORIMVYN CHU S. INMDAT UW Sto(t= a sheiastainie sin/eis Sai ciac le slaidam cia eiels mia mcie is aoteinlsinjamielsinialeje e oi~intienelaisieisce
Fig. 3. View of a very rotund, dorsal valve, with fine, even-strie, from Dry Caiion.
STROPMOMENA RHOMBOIDALIS...---..---- pete sat tis 2a ee eas rN I een ares IA Re teers a ah aR ae ie ya
Fig. 4. View of a specimen from Dry Cafion, showing fine, even wrinkles.
SS PUTO Aw CHNIDR ON AM Meets oe emcee oe sa cicine siseteceeeleaine wee acinscociene ketene cone selscme pecs tomes
Fig. 5. View of a large dorsal valve, showing the usual features of the species, Dry Caion.
6. A smaller ventral valve, from the same locality.
SRIRTD MRA AUB ACP DNIINGISE em sors eros cies aay eects riot w cise eres Siicis MUS Sess ceceecacceeecesen
Vig. 7. View of a ventral valve, from a siliceous layer at White Pine, Nevada, as obtained
by gutta-percha cast from the matrix. -
8. Another ventral valve, from Logan Caiion, Utah.
OTOS TMS) ILO GAINERS 5 cococo costes pesese cee cone cecoos soenoe nee Sea Ses 209 Sood ceeS cose oncses
Fig. 9. View of the specimen described.
IRDERV RISER EANGSUTC ADT Autie oclsaterne aimelelorsete mnie te sina eae lnicisie ms sie wis cele eam bee eciece mote ae Benen eS coins
Fig. 10. View of a small ventral valve from Logan Cafion.
11. A partial cast of another ventral valve from Cottonwood Cafion, Utah.
UEVANCHONDLICAY PUSTUTOSAGT Sm, = ais (cnidle waione) otcieniseusceanctiece obec dec cies esi adeinds Waarleree us
Figs. 12-13. Dorsal and front views of a specimen from Dry Caiion, Utah. Enlarged.
14. Dorsal view of the specinien, natural size.
PASE ER WRTSH OTA ARON soe aio eyare Sareea aro Sie lero lero She te ay wie are Slain) ha wielieiwic me lefeletetamiciSicwniste we: daw RG
Figs. 15-17. Dorsal profile and ventral views of a specimen of the species, showing the form of
shell and the perforation of the beak.
SUNT RESESEOANT UTA UO EAE rere ree ete ae ome eee ee eioteist = miniel ets stel imine ototeinele) sisieisto Seiaicmsicisinic icine s\sleitie sin \aieiewe
Fig. 18. View of a ventral valve, natural size.
MICHELINA BRE a stera aaa eter Ree ea ory says ial sero nS eveisidicisc iaidielersinsi@edvae ockaoecea
Fig. 19. View of the specimen referred to under the description.
257
207
256
208
251
HUOMPHADUS) (SERAPAROLEUS) WU DAEIINGIS = ciiselelseee ee enteritis eee eters
Fig. 20. View of the upper surface of a large individual fom Ogden Cation, showing the obso-
lescence of the carina on the outer volution.
21. View of a smaller individual from Dry Cafion, as obtained by gutta-percha impression
from the matrix.
22, A similar small specimen from Logan Cation. The figure is an enlarged view.
23. A view of the under side of a large specimen from near Read and Benton’s mine, Utah.
IBCOH OD FU NTOIS) THAD-QUS) co.sg 66 600056 s5o008 CHO dds Adon ndoon0 GonD oDbhbS ssaSs0 oSodab ebao Sono DOA ooeece
Figs. 24-25. Profile and vertical views of a specimen from Dry Caiion, Utah.
ECOMPHALUS (STRAPAROLLUS)) OPHIRENSISEoseeEse ee eeer eee seco e eee eee neeeeee eee eee eeae
Fig. 26. Lateral view of the specimen, restored partly from the shell and partly from gutta-
percha impression in the matrix.
27. View of the umbilicus. From Dry Caiion, Ophir, Utah.
PROETUS: PEROCCIDENS onc ciceieaciseinjene slaceintine seine tie aeenelee ne eects se Ree e ees niece eee cee
Fig. 28. View of a glabella of the species, from Dry Canon.
29. View of the left movable cheek.
30. View of a pygidium of large size, from the same locality.
31-32. View of a smaller specimen, natural size and enlarged, showing the ornamenta-
tion of the surface, from Ogden Caiion, Utah.
IPROETUS (UOGANENSIS ita o3.ca) cis o's a\niaisterotoicl atotician Siaictol oisistetatctalsinio slaatet icon ae cis aise eee eee eee eee
Fig. 33. View of the pygidium, enlarged to two diameters, showing the specific features of this
part.
260
261
262
264
U. S. Geol. Exp]. 40 Parallel
HM Marin Del.
Waverly Group
EXPLANATION OF PLATE V.
ORTHIS RESUPENATA'?. 2 5.5, .nciiberetee cae eeies be Sinise ie cot isteters Ieee ee EE eee eee meee ee Metetetletatatatater
Fig. 1. View of a dorsal valve, slightly exfoliated, but retaining the shell in great part.
2. A cast of a dorsal valve, showing the muscular imprint.
PRODUCTUS HEEGANS ee lytic eee ence sjcisinis Wace ceinisck weiss asincie oe cons ebe Rein seca Sees
Figs. 3-4. Profile and front views of a speeimen referred to this species.
IPRODUCTUSISEMIRETICULATUS saaaacacnee coe eos eee eee eee cee eee eE eee en etoeen paccecossons
Figs. 5-6. Vertical and cardinal views of a specimen referred to this species, showing the
form and surface character.
IPIRG OAC OS) IDA DNVACOSINOS xo os sooo cooce= coSoSn nse) GQ0nS5 CODesO OnOses Os950 Dose50 KONO Goeec0
Figs. 7-8. Vertical and front views of specimens having the form and character of the species.
PRODUCHUS) HOEMINGI var. BURGINGTONENSISsse seelee eta a= aie eeciceel easels see ieee eee ee
Fig. 9. View of a dorsal valve, showing the cardinal process.
10. View of a ventral valve.
11-12. Front and profile views of a similar individual, presenting the features of those from
Burlington, Iowa. zi
POUR IAI SINQUNDN, asos5q 50000 ceed ocooHa saeco s65s9 Sehab bon soo neeono Gopseraran tagSoo caso cebeee
Fig. 13. Dorsal view of a specimen somewhat crushed, but showing the specific characters
of the shell.
14. Ventral view of the same specimen.
15. Ventral valve of another individual, showing fewer bifurcations in the plications.
SPIRIFERA Sos f cseceo casa cosboe dosausegng o6n000 Geduse sees BaDNSE QUOCSCO cos CoSdbS Saos see
Fig. 16. View of the fragment referred to on page —.
POG OOAGN, SIMU CCID. Gaen coco soeeEO Deen Jooaso caccos cacesseees Sq0 BcSe Sage Sos oneae oho Ss05 SoDc
Fig. 17. View of a small specimen somewhat compressed, but preserving the surface char-
acters and somewhat the general form.
18. View of a larger dorsal valve, showing the form.
ATEVRIS! SUBQUADIRATAGT eet saree exc o/s Sree rete ate ee tere ere ee aero oto is coreintel char) ers Rerstaeaee eaten
Fig. 19. View of the dorsal side of a specimen referred to this species.
20. Ventral valve of the same, showing the sinus as well as the general form of the shell.
268
269
271
271
J. Bien lith
Lower Carboniferous
U.S. Geol. Expl. 40 Parallel
HM Marin Da.
oe
a
4
eS ASR RM el ty
ae
ih ed +84 ie -
A, ‘
el Ate rae jaded
4
ie
2
-
7 «
' = ; ; é. ‘ heer 4 ie; 4 ie
Sed U4 1p FOO Ca + he Pein? & ets eT a ee j
.
~ a < ” e he
PAL WM gat i itis
2 ; >
. - s é
pelea g el ty 0 }
af cy a ‘
4 ; & . x caf Me Pa €
y AS ;
id)
Se a* ‘ - , ~ i
®
\s > ia } ¥ ay
8 os AMS ERIS Tiga :
ApS atc eee began shes | :
} ~ eh ctr eae Mis re
7 - ¢ n ie ae . ve oe
mre oer eet Ue Mee Uh clk ox GAL ;
¢ av s] C
ts Ui oie
EXPLANATION OF PLATE VI.
CARDIOMORPHAS MISSOURTIENSIS 2-210 oe jenn ceeiaset- ete ee Gee eee COE ee Eee Eee eee Ere oo oer Sa
Fig. 1. View of the right valve of a specimen of the usual size and form.
2. Cardinal view of the same individual.
SEDGEWICKIA? (CONCAVA, sosic om tose sis wes sat-m1s SSRIS Oe SERRE E Oe Ree EEE eee
Fig. 3. View of a right valve, as obtained by a gutta-percha impression in the natural mold.
AVICULOPECTEN CURTO-CARDINALIS ..-.-. segs oleieeaaih ce cee eer eee ee aC Serer eee .
Fig. 4. View of the specimen described, enlarged to twice the natural size.
AVICULOPECTEN, WEBERENSIG! 4-3) os is ns) ae Sore ee eee meee ele ee ee Renee eee :
Fig. 5. View of a left valve, showing the strongly alternating coarser and finer strive.
AVICULOPECTFEN PAR VULUSHeR ee tiee ace cess eon eee eee eers gaa ee e
wee ewe we eee ewe ee ee ed
Fig. 6. View of a left valve, enlarged to three times the natural size, showing the strong
elevated primary rays, with finer ones between.
MYATINA JPERMPANA 52s. cbecuemeitmae Eck oeae Biter ceremonies aerate 5
Fig. 7. View of a cast of a right valve, showing the usual form. The outline at the beak
shows the extreme of other specimens.
MY ALINA AVICULOMDES : 02... Rie bee cae ee See eee Pees Ce
Fig. 8. View of an internal cast of a left valve, with the impression of the extended beak
showing in the matrix.
(Cropsiwun ios} OG CR baeap dasooo seedsd obcoco songuo Dnnaog bes eba cosa soodeonSo5e oS5000 Catcon Sages
Fig. 9. Lateral view of a specimen of medium size, showing the deep umbilicus.
10. View of the opposite side of a similar individual, showing more distinctly the surface-
markings.
11. Profile view of the specimen fig. 9, showing the great width of the shell.
12. Sectional view, showing the proportional size of the volutions and depth of the um-
bilicus.
13. Profile view of a smaller individual, the outer volutions broken away to reveal the
lines of septa.
14. Profile of a septum from the latter, enlarged.
@YARTOCERAS (HSS R yaya eae eae tesa a ete aor eee ee
Fig. 15. Lateral view of the specimen described, showing the curvature of the tube and the
strong annulations.
LP NCMONUIS: NSTBHRISIGUS HY Goq050 ca500 soe 925008 doce cpa s00 on 3590 s00SY So 2950 one Sseaaodceace
Fig. 16. Enlarged view of a disk referred with doubt to this species. The figure is enlarged
two diameters.
SPIRIFERA (SPIRIFERINA?) ALIA ...--. 2... 222. -.-22- seccos weenn qd dngnse nonsSN Deo soMopDSoO neoTsC
Fig. 17, View of a ventral valve, showing the characters described.
SPOROMOMINAN IBOWTIRNE Yo soso noms opebon Gen5 son6 ands Hoos o500 cg0ea0 SocnoD EEOcce Sbos anezce ooEoSC
Fig. 18. View of an imperfect dorsal valve referred to this.species. .
IDTORMORIDIA WORN, sogah6 5550 agus 5005 5660 5000 5500 8500 de Hast Sato cose Soo sadO SOBs OaCeS pkdcosoos
Fig. 19. View of an imperfect left valve.
ASTARTE ARENOSA.....--- 55 cond Sosb OSes c0o00 SooSdo se Snes soon phosoS co8d Od0d S2ob See ssH ca sen Se
Fig. 20. View of a specimen of a left valve, enlarged.
21. View of a fragment of rock containing several individuals, including the above. The
species is placed with some doubt on-this plate among the Triassic forms.
LMAO GIN 1s ONIN XOMI DIONE (SS Yoooc0 o6bo bobs soasSoe BboSer osadantoonce ss bsn0 sSseonnedso4 aac See
Figs. 22-23. Dorsal and profile views of a specimen, showing strong plications on the front
of the valve.
24. Dorsal valve of another individual nearly destitute of the plications.
278
280
281
281
283
297
282
per Carboniferous and Trias
Up
Geol. Exp]. 40 Parallel
wo
J Bien lath.
EM Marin Del
EXPLANATION OF PLATE VII.
Page
REY NCMONINUEA UMMRINA S225 Gece dste se eect elec ue OR ene ee eon cieee Ee eee eee ise et 284
Figs. 1-4. Dorsal, ventral, profile, and front views of a characteristic specimen.
5. Ventral valve, showing a variation of form in the sinus. 7 p/ ©!
VRUYNCTONELLA GNADHOPHORA? ijecie ceyaia- see eee obb bndo Ad obarionodae SooooD sopdad osSond S60000 284
Fig. 6. View of the ventral valve referred with doubt to this species. ; 2 5 5 °
Pee re AUGUSTA SS 522< soca bee seSee es ase Rae ae eee ee a eee pa00 S008 285
Fig. 7. View of a ventral valve of the usual form and size. Noe
8-10. Dorsal, ventral, and profile views of a specimen, enlarged to two diameters. | ~~ RF
VGrypi#a? CALCEOLA var. NEBRASGENSIS? ........ 2-22-2202. 0-2-0000 Boos sesssesec+ ones a555 286
Hig. 11. Interior of the larger valve, showing the prevailing form which occurs in the
localities mentioned under the description. /254 Y
VOSTREA ENGELMANNI? ..-.-. -.- asd ti caie, So Sem RICA 2 etc cS Ss eee Oe et Tea eae 285
Fig. 12. View of an impression of the interior of the attached valve./2524
CAMPTONECTES ‘BELEISTRIATUS <<. o'35/5)s cnin- a Wee eats wise sie cere miom ore eee eel een eee ee eee Beton Leek
Fig. 13. View of an imperfect right valve of the size most common among those in the. collec-
tion.
AVICULOPECTEN ? (EUMICROTIS) AUGUSTENSIS ..---...----.---- et disaete susicis SSeS eer Bema -6Se 288
Fig. 14. View of a right or flat valve.
15. A left valve from the same specimen of rock.
16. Enlargement of striz from another individual, preserving the surface.
(2 SHEROSITCT Is PERTENUISUREATUS fei sosce isos ein soe sso sl aiaiere ene Soci eee oalseseieeetcceaeectee 291
Fig. 17. View of aright valve of the species, enlarged to twice the natural size; the posterior
wing restored in outline. | 9 je Ae
V CAMPTONECTES EXTENUATUS.-....---.2--2-+ -2- wis Se Boe ee ees omen Bete eo Ga aboad nia eases 290
Fig. 18. A right valve, natural size. ; 7 557.
NAWICAN? ARITA See Me ce tie o 8 oe ol ccs ain bute aiSrailsialn ehercllatnicle ey (ereysate eee e eee ere eee er ea reeeree ie eae 293
Figs. 19-21. Three views of an individual of the ordinary size eularged. ‘The line near fie. 20
shows the natural height.
~ :
TRIGONLA QUADRANGUTARIS. 2am Sci cs.anncceeatene see ae ORE EEO En ECS Een eee Lees 293
Fig. 22. View of an imperfect right valve, enlarged to twice the natural size. The outline
would seem to have been considerably extended posteriorly.7 2537
“Lima (PLAGIOSTOMA))'OCOCIDENTAMIG). 2. 20.2 gece maar tee eae aie pee eats ooh oot ore tee Se eae ete ets 292
Fig. 23. View of a left valve, slightly restored at the beak and hinge, as also on the umbone. }
COUMICROMIS | CURTAG: ssc ciat is ccica occas Se 32) 3 = =e oe ae ae eee Soe ale aotearoa eee to arias 289
bh
Fig. 24. View of a left valve, enlarged, showing the alternate size of the radii. 2 01
SEPTOCARDIA CARDITOIDHA So oa ~csc = como ae ose OR eRe One ee Cee eee eneaa teen cree 296
Vv Vig. 25. View of the posterior end of the specimen described. ; |
SEPROCARDTA TVGPTCGA: sa )ete pele jora)sie ie ietnay