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MARYLAND GEOLOGICAL SURVEY

DEVONIAN

PLATES

MARYLAND

ii

GEOLOGICAL SURVEY

DEVONIAN

PLATES

SCIENCES
UMAtf

BALTIMORE, MD., U. S. A.

DEVONIAN

LOWER

270267

NOTE

Plates I to XVI, illustrating the Geological and Paleontological Relations
of the Lower Devonian, are bound with the text volume. The following plates
illustrate the Systematic Paleontology of the Lower Devonian of Maryland.

All drawings cited from New York formations, in the following descriptions
of plates, are from the Paleontology of New York, and are after Hall or Hall
and Clarke. Only in cases where Hall figured material from Maryland is
acknowledgment made in the descriptions.

PLATE XVII

PAGE

Figs. 1-4. HINDIA SPH^ROIDALIS Duncan 195

1. Exterior view.

2. Radial section of sponge.

3. Tangential section showing tubes. X 4.

4. Radial section showing spicules and tubes. X 4.

Helderberg formation, Keyser member, Cash Valley.

Figs. 5-9. STREPTELASMA STKICTUM Hall 198

5. 6. Lateral and posterior views of corallum.

7. Transverse section.

New Scotland formation, New York.

8. Interior of calyx.

9. Transverse section of corallum.

Helderberg formation, New Scotland member, Cherry Run.
W. Va.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XVII

CCELENTERATA — ANTHOZOA

PLATE XVIII

PAGE

Figs. 1, 2. STREPTELASMA CUMBEELANDICA Swartz n. sp 199

1. Exterior of weathered corallum.

2. Longitudinal section of same individual.

Helderberg formation, near Cumberland.

Figs. 3-7. ZAPHRENTIS RCEMERI M. Edwards and Haime 200

3. Side view of corallum, questionably referred to this species. Oris-

kany formation, Ridgely member, Cumberland.

4. Side view of corallum.

5. 6. Transverse sections of corallum.
7. Longitudinal section of corallum.

New Scotland formation, New York.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XVIII

CCELENTERATA — ANTHOZOA

PLATE XIX

PAGE

Figs. 1-4. ZAPHRENTIS KEYSERENSIS Swartz n. sp 201

1. Side view of type.

2, 3. Transverse sections.

4. Longitudinal section of a small individual.

Helderberg formation, Keyser member, Keyser, W. Va.

Pigs. 5-9. CYATHOPHYLLUM CLARKI Swartz n. sp 201

5. Side view of type.

6. Interior of calyx of same. Martin Mountain, Allegany County.

7. Transverse section. X 2. Cumberland.

8. Longitudinal section. Martin Mountain, Allegany County.

9. Side view of corallum showing deep annular constrictions. Same

locality.
Helderberg formation, Keyser member.

Figs. 10, 11. CYATHOPHYLLUM OHERNI Swartz n. sp 203

10. Side view of two individuals. The corallum on right side is in-

complete.

11. Interior of calyx of one of preceding.

Helderberg formation, Martin Mountain, Allegany County.

Figs. 12-17. CYATHOPHYLLUM RADICULUM Rominger ? 202

12-14. Side views of three coralla.
15-17. Calices of same individuals.

Helderberg formation, Keyser member, Cumberland.

to

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XIX

f

11

13 14 15 16

CCELENTERATA — ANTHOZOA

17

PLATE XX

PAGE

Figs. 1-4. CYATHOPHYLLUM INEQUALE (Hall) 205

1. Transverse section of coralla.

2, 3. Portions of same. X 2 and X 5.

4. Longitudinal section. X 2.

Helderberg formation, Keyser member, Flintstone.

Figs. 5-9. CYATHOPHYLLUM SCHUCIIEBTI Swartz n. sp 203

5. Cluster of branching coralla. Devil's Backbone.

6. Single stem. Cash Valley, Lower Stromatopora bed.

7. Calyx. Same locality.

8. 9. Transverse and longitudinal sections. Devil's Backbone.

Helderberg formation, Keyser member.

n

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XX

CCELENTERATA — ANTHOZOA

PLATE XXI

PAGE

Figs. 1, 2. CYATHOPHYLLUM MARYLANDICUM Swartz n. sp 204

1. Portion of a branch. Hyndman, Pennsylvania.

2. View of calyx. Cash Valley, Lower Stromatopora bed.

Helderberg formation, Keyser member.

Figs. 3-6. HEUOPHYLLTJM CF. COKNICULTJM Lesueur 206

3. 4. Side view and calyx. Martin Mountain, Allegany County.

5, 6. Small individual, questionably referred to this species. Cumber-
land.

Helderberg formation.

Figs. 7-9. CYSTIPHYLLUM FASCICTJLATUM Swartz n. sp 207

7. Side view of several corallites.

8. Transverse section of same.

9. Transverse section of a single corallite.

Helderberg formation, Cumberland.

Figs. 10, 11. COLUMNARIA ? HELDERBERG I.E Swartz n. sp 207

10. Longitudinal section of type.

11. Longitudinal section of same. X 5.

Helderberg formation, Keyser member, Warrior Mountain,
Allegany County.

12

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXI

CCELENTERATA — ANTHOZOA

PLATE XXII

PAGE

Fig. 1. FAVOSITES HELDERBERGI^E Hall 208

Corallum showing hemispherical form. New Scotland formation,
New York.

Figs. 2-7. FAVOSITES HELDERBERGI.E VAR. PR^CEDENS Schuchert 209

2. Corallum of lobate form. Keyser, W. Va.

3. Corallum of clavate form. Near Seymour, W. Va.

4. Corallum of dendroid form. Keyser, W. Va.

5, 6. Tangential and radial sections. X 2%. Lower Stromatopora

bed, Devil's Backbone.

7. Corallum possessing yery small cells. Cash Valley.
Helderberg formation, Keyser member.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXII

CCELENTERATA — ANTHOZOA

PLATE XXIII

PA6E

Figs. 1-4. FAVOSITES PYRIFORMIS Hall 211

1. Transverse section. X 1.

2. Same. X 2.

3. Longitudinal section. X 1.

4. Same. X 2.

Helderberg formation, Keyser member, Cumberland.

Figs. 5-7. FAVOSITES CONICUS Hall 212

5. 6. Side view and base of characteristic form.

7. Longitudinal section of several cells. X 2.

Helderberg formation, Becraft member, cut of B. & O. R. R.
through North Mountain, W. Va.

Figs. 8, 9. FAVOSITES BASALTICUS Goldfuss 212

8. Portion of corallum.

9. Enlargement of several cells. X 2.

Helderberg formation, Cumberland.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXIII

CCELENTERATA ANTHOZOA

PLATE XXIV

PAGE

Figs. 1, 2. FAVOSITES FAVOSUS VAR. INTEGRITABULATUS Swartz n. var 214

1. Weathered corallum.

2. Longitudinal section of several cells.

Helderberg formation, Keyser member, Warrior Mountain,
Allegany County.

Figs. 3-6. FAVOSITES ? SCHRIVERI (Herzer) 214

3. 4. Upper and side views of enlarged base of corallum.
5, 6. Fragments of brandies.

Oriskany formation, Ridgely member, opposite Keyser, W. Va.

15

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXIV

CCELENTERATA — ANTHOZOA

PLATE XXV

PAGE
Figs. 1, 2. STRIATOPORA BELLA Swartz n. sp 215

1. Portion of a corallum.

2. Branching corallum. X 2.

Helderberg formation, New Scotland member, Cherry Run,
W. Va.

Fig. 3. STBIATOPORA sp 216

Fragment of a corallum. Helderberg formation, Keyser member,
Devil's Backbone.

Figs. 4-7. CLADOPOBA RECTILINEATA Simpson 216

4. Slab covered with numerous branches. Keyser, W. Va.

5. A branching corallum. Pinto.

6. Longitudinal and transverse sections. X 4. Four miles northeast

of Cumberland.

7. Transverse sections. X 4. Same locality.

Helderberg formation, Keyser member.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXV

CCELENTERATA ANTHOZOA

PLATE XXVI

PAGE

Fig. 1. PiEURODicTYUM LENTICULARE (Hall) 218

Portion of a corallum. Helderberg formation, New Scotland member,
near Cumberland.

Figs. 2, 3. AULOPORA SCHOHARI.E Hall 219

2. Branching corallum attached to a brachiopod.

3. Several branches. X 3.

Helderberg formation, Becraft member, Ernstville.

Figs. 4, 5. AULOPORA SCHUCHERTI Swartz n. sp 219

4. View of type.

5. Enlargement of several branches. X 4.

Helderberg formation, Keyser member, Cash Valley.

Figs. 6, 7. CERATOPORA ? MARYLANDICA Swartz n. sp 220

6. Slab covered with numerous branches.

7. Transverse section of a single branch. X 5.

Helderberg formation, Keyser member, Keyser, W. Va.

Fig. 8. HALYSITES CATENULATUS Linne 220

Corallum showing chain-like branching. Niagara formation, New
York.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXVI

CCELENTERATA — ANTHOZOA

PLATE XXVII

PAGE

Figs. 1-6. STROMATOPORA CONSTELLATA Hall 221

1, 2. Type A. Tangential and radial sections. X 10. Lower Stroma-
topora bed, Devil's Backbone.

3. Type B. Tangential section. X 10. Keyser, W. Va.

4. Type B. Tangential section. X 10. Cash Valley.

5. 6. Type C. Tangential and radial sections. X 10. East bank of

Potomac River opposite Pinto.
Helderberg formation, Keyser member.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXVII

'

•

,. a <,.•

'

•"•

>

''

"' '

CCELENTERATA HYDROZOA

PLATE XXVIII

PAGE

Figs. 1, 2. STROMATOPORA CONSTELLATA Hall 221

Type C. Tangential and radial sections (thin sections). Showing
very large and intricately branched astorhizae. Helderberg
formation, Keyser member, Cumberland.

Figs. 3, 4. SYRINGOSTROMA BARRETTI Girty 224

3. Section obliquely tangential. X 10.

4. Section obliquely radial. X 10. Branch of Cladopora rectilineata

(Simpson) at edge.

Helderberg formation, Keyser member, Cookerly, Stromato-
pora bed.

Figs. 5, 6. SYRINGOSTROMA CENTROTUM Girty 225

5. 6. Tangential and radial sections. X 10. Helderberg formation,

base of Keyser member, Warrior Mountain, Allegany County.

19

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXVIII

m

"

5 6

CGELENTERATA — HYDROZOA

PLATE XXIX

PAGE

Fig. 1. STROMATOPORA CONSTELLATA Hall 221

Type A. Portion of a reef formed of this species. X %. Helderberg
formation, Keyser member, Cumberland.

20

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXIX

CCELENTERATA HYDROZOA

PLATE XXX

PAGE

Fig. 1. STROMATOPORA CONSTELLATA Hall 221

Type C. View of surface showing mamelons and astorhizae. Helder-
berg formation, Keyser member, Devil's Backbone, Stromato-
pora bed.

Fig. 2. SYRIXGOSTROMA CENTRQTUM Girty 225

View of surface showing numerous small mamelons. Helder-
berg formation, Keyser member, Warrior Mountain, Allegany
County.

•21

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXX

CCELENTERATA — HYDROZOA

PLATE XXXI

PAGK

Figs. 1-5. CAMAROCRINUS STELLATUS Hall 227

1-3. Three transverse cuts through the same bulb; the letters indicate
the same wall in the different sections; M, the medio-basal
chamber. X %.

4. Another specimen cut through the center longitudinally; M, medio-

basal chamber. X %.

5. A second bulb cut through the center longitudinally. X %.

Helderberg formation, Keyser member, Keyser, W. Va.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXXI

ECHINODERMATA — CYSTOIDEA

PLATE XXXII

PAGE

Figs. 1-3. ANOMALOCYSTITES ? DISPARILIS Hall 228

1. Anteal or concave side, showing the deeply arched or crescentic

form of base with the succeeding plates.

2. Posteal or convex side, showing the form and arrangement of plates.

3. Lateral view of the same specimen.

Oriskany formation, Ridgely member, Cumberland.

Figs. 4-7. LEPOCRINITES GEBHARM Conrad 229

4. The anterior side, showing the pectinated rhombs at the base.

5. The posterior side, showing the ovarian aperture with the sur-

rounding plates removed.

6. The left side of the same specimen. The prominence of the ovarian

side over the opposite is well seen.

7. Base of column, showing slight evidences of rings.

Coeymans formation, New York.

Figs. 8, 9. LEPOCRINITES MANLIUS Schuchert 231

Two views of type. X 2. Helderberg formation, Keyser member,
Keyser, W. Va.

Figs. 10, 11. TETRACYSTIS CHRYSALIS Schuchert 232

10. View showing upper left-hand pectinirhomb. X 2.

11. Same specimen from the antanal side. X 2.

Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 12-16. J^KELOCYSTIS HARTLEYI Schuchert 233

12. View of type; a large specimen. Anal opening to the right. X 2.

13. A smaller specimen with the anal opening to the left. X 2.

14. Camera-lucida drawing of the oral end to show the arrangement

of the ambulacral plates, the ambulacralia (somewhat re-
stored), brachiole attachments, and the plate with the madre-
porite; the latter lies in the depression of the large plate on the
left of the figure. X 2.

15. The anal pyramid; the positions of the bounding plates, 7, 8, 13,

14, are indicated. X 8.

16. Plates 14 and 15, with the discrete-pectinirhombs; the dichopores

on plate 14 are deeply situated and do not show on the surface.
X 8.
Helderberg formation, Keyser member, Keyser, W. Va.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXXII

12

ECHINODERMATA — CYSTOIDEA

PLATE XXXIII

PAGE

Figs. 1, 2. J^KELOCYSTTS PAPILLATUS Schuchert 234

1. Anal view. X 2.

2. Antanal view of the type; pectinirhomb 14-15 is faintly indicated

on the left. X 2.

Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 3, 4. .LEKELOCYSTIS AVEIXANA Schuchert 235

3. View of type, with the anal opening to the left and pectinirhomb of

plates 14-15 to the right. X 3.

4. Same specimen from above, showing the two small discrete-pectini-

rhombs, the central madreporite, and the large anal opening.
X 3.
Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 5-9. PSEUDOCRINITES GORDONI Schuchert 236

5. 6. Two views of type, a specimen somewhat larger than usual.

7. Another specimen.

8. A smaller but adult individual of the rounder variety.

9. An elongate individual, somewhat abnormal in having the ambu-

lacra drawn over on the anal side more than is usual.
Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 10-12. PSEUDOCRINITES ABNORMALIS Schuchert 238

10. View of the sides having the abnormal position of the lower

pectinirhomb.

11. Opposite side of the same specimen.

12. End view of same.

Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 13, 14. PSEUDOCRINITES STELLATUS Schuchert 239

Two side views of type. Helderberg formation, Keyser member,
Keyser, W. Va.

Figs. 15-18. PSEUDOCRINITES CI.ARKI Schuchert 240

15-17. Three views of type, an average adult individual.
18. A very large specimen of this species. The plates around the
pectinirhomb are somewhat broken.
Helderberg formation, Keyser member, Keyser, W. Va.

24

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXXIII

17

18

ECHINODERMATA CYSTOIDEA

PLATE XXXIV

PAGE

Figs. 1, 2. PSEUDOCRINITES SUBQUADRATUS Schuchert 237

Two views of type. X 2. Helderberg formation, Keyser member,
Devil's Backbone.

Pigs. 3, 4. PSEUDOCRINITES ELQNGATUS Schuchert 241

Two views of the type. Helderberg formation, Keyser member, Martin
Mountain, Bedford County, Penna.

Figs. 5-7. PSEUDOCRINITES PERDEWI Schuchert

5. Side view of a young specimen. X 2.

6, 7. Two views of type.

Helderberg formation, Keyser member, Keyser, W. Va.

242

244

Figs. 8-10. TRIMEROCYSTIS PECULJAKIS Schuchert

8. View of type from anal side.
9, 10. Same specimen from side.

Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 11, 12. SPH^EROCYSTITES MULTIFASCIATUS Hall 245

11. A large specimen, from anal side; most of the sculpturing con-

sists of the ambulacral branches. X 2.

12. The same individual from above. X 2.

Helderberg formation, Keyser member, Cash Valley.

Figs. 13, 14. SPH^ROCYSTITES GLOBULARIS Schuchert 247

The type seen from anal side and above. X 2. Helderberg formation,
Keyser member, Keyser, W. Va.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXXIV

12

ECHINODERMATA CYSTOIDEA

PLATE XXXV

PAGE

Figs. 1-4. SPH^BOCYSTITES MUI/TIFASCIATUS Hall 245

1. The two circles of plates composing the anal pyramid; the numbers

indicate the bounding thecal plates. About X 5.

2. Part of an ambulacrum, showing one row of ambulacral plates, the

ambulacralia, and remnants of brachioles. About X 10.

3. An incomplete brachiole. About X 10.

4. Deltoid 23, with the madreporite and hydropore closed by its

pyramid. About X 10.

Figs. 5, 6. SPH^EROCYSTTTES GLOBUT..ARIS Schuchert 247

5. The anal pyramid and the bounding thecal plates indicated by

numbers. About X 5.

6. 'Part of an ambulacrum, showing the ambulacral and ambulacralia
plates, and the points of attachment for the brachioles. About
X 5.

Fig. 7. PSEUDOCRINITES STELLATUS Schuchert 239

Part of an ambulacrum, showing one row of ambulacral plates, the
brachiole facets, and the ambulacralia with their intermediate
large plates. About X 5.

Figs. 8-10. PSEUDOCRINITES PERDEWI Schuchert 242

8. Deltoid 23, with the madreporite and the small hydropore; the

double row of small plates and the ambulacralia. About X 5.

9. Portion of an ambulacrum in a young specimen. About X 5.

10. Same as fig. 9; seen from the side to show the high elevation of
ambulacralia. About X 5.

Figs. 11-13. PSEUDOCRINITES GORDONI Schuchert 236

11. Portion of an ambulacrum. About X 5.

12. A nearly complete brachiole. About X 5.

13. Deltoid 23 crowded into the ambulacral plates, showing the madre-

porite and hydropore. About X 5.

Fig. 14. PSEUDOCRINITES CLARKI Schuchert 240

Plate 13 on the left and the incomplete circle of 7 small plates bounding
the anal pyramid of 7 pieces. About X 5.

Figs. 15-16. LEPOCRINITES MANLIUS Schuchert 231

15. An ambulacrum near the oral opening. About X 5.

16. The two circles of pieces composing the anal pyramid. About X 5.

M

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXXV

ECHINODERMATA — CYSTOIDEA

PLATE XXXVI

PAGE

Fig. 1. SPH^ROCYSTITES GLOBULARIS Schuchert 247

The entire stalk, terminating in the roots at one end, and at the other
preserving a few of the thecal plates, seen from the interior.
Helderberg formation, Keyser member, Devil's Backbone.

Fig. 2. SPH^EROCYSTITES GLOBULARIS VAR. OVALIS Schuchert 248

Specimen seen from the side. X 2. Helderberg formation, Keyser
member, Keyser, W. Va.

Figs. 3-7. THYSANOCRINUS ETJGENIUS Ohern, n. sp 249

3, 4. Side and inferior view of calyx.

5. Side view of calyx showing bases of arms.

6. Exterior view of an arm.

7. Interior view of bases of arms.

Oriskany formation, Ridgely member, Cumberland.

Figs. 8, 9. TECHNOCRINUS STRIATUS (Hall) 250

8. Plate belonging to this species.

9. The basal plates anchylosed together with a small portion of the

column attached, and also one first radial plate.

Oriskany formation, Ridgely member, Cumberland. (After
Hall.)

Figs. 10, 11. TECHNOCRINUS SCULPTUS Hall 250

Basal and lateral view of the lower part of the body. Oriskany forma-
tion, Ridgely member, Cumberland. (After Hall.)

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXXVI

11

10

•••••••i"

ECHINODERMATA — CYSTOIDEA — CRINOIDEA

PLATE XXXVII

PAGE

Figs. 1, 2. TECHNOCBINUS SPINULOSUS (Hall) 251

1. The body and bases of the arms with a portion of the column

attached.

2. Diagram of the structure of the body to the base of the arms, as far

as determined.

Oriskany formation, Ridgely member, Cumberland. (After
Hall.)

Figs. 3-5. TECHNOCRINUS ? LEPIDTJS Ohern n. sp 252

3. Inferior view of calyx.

4. Cast of interior of calyx.

5. Side view of interior of calyx.

Oriskany formation, Ridgely member, near Berkeley Springs,
W. Va.

28

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXXVII

ECHINODERMATA — CRINOIDEA

PLATE XXXVIII

Fig. 1. TECHNOCRINUS ? LEPIDUS Ohern n. sp

Side view of calyx and lower part of arms.
Ridgely member, near Hancock.

Oriskany formation,

PAGE

. 252

Fig. 2. TECHNOCRINUS ANDREWS: (Hall) ' 251

Side view of calyx and base of arms. Oriskany formation, Ridgely
member, Hancock.

2!J

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXXVIII

ECHINODERMATA — CRINOIDEA

PLATE XXXIX

Fig. 1. TECHNOCRINUS ? LEPIDUS Ohern n. sp

Nearly complete specimen showing calyx and arms, x %. Oriskany
formation, Ridgely member, Berkeley Springs, W. Va.

PAGE
252

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XXXIX

ECHINODERMATA — CRINOIDEA

PLATE XL

PAGE

Figs. 1-3. CALCEOCRINUS MARYLANDICUS Ohern n. sp 253

Three views of calyx and base of arms. Oriskany formation, Ridgely
member, opposite Keyser, W. Va.

Figs. 4, 5. HOMOCRINUS PROBOSCIDALIS Hall 255

4. View of calyx and base of arms.

5. Enlargement of same. X 2.

Oriskany formation, Ridgely member, Cumberland. (After
Hall.)

Fig. 6. HOMOCRINUS HARTLEY: Ohern n. sp 255

Side view of calyx. Oriskany formation, Ridgely member, Cumber-
land.

Figs. 7-12. EDRIOCRINUS SACCULIIS Hall 25G

7-9. Three views of calyx and arms.

10-12. Three views of calyx and arms of a larger specimen.
Oriskany formation, Ridgely member, Cumberland.

Figs. 13-15. EDRIOCRINUS POCILLIFORMIS Hall 257

13. Basal view of a large individual, the proportional length being

greater than usual.

14. Lateral view of the same.

15. Interior of the same.

New Scotland formation, New York.

Fig. 16. CORNULITES CINGUL.ATUS Hall 258

Small specimen, enlarged. Helderberg formation, New York.

31

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XL

12

ECHINODERMATA CRINOIDEA

PLATE XLI

PAGE
FigS. 1-5. FlSTULIPORELLA CUMULATA U. Sp 263

1. Side view of a zoarium, natural size.

2. Tangential section. X 20.

3. A portion of the same tangential section, X 40, showing the

characters of the mature zone.

4. Several zooecia of the same section, X 40, from a less mature

portion.

5. Vertical section, X 20, showing several layers of zoarium.

Helderberg formation, Keyser member, Keyser, W. Va.

FigS. 6-8. FlSTtTLIPORELLA QUINQUEDENTATA n. Sp 264

6. Tangential section, X 20, of the type specimen.

7. A zocecium of the same, X 50, showing the structure of the lunarium.

8. Vertical section of the type, X 20.

Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 9-12. CHILOTRYPA MICROPORA n. sp 268

9. Zoarium, natural size, with end view of same, showing sack-like
form.

10. Tangential section, X 20, exhibiting the very small zocecia and

the rather wide interzooecial spaces.

11. Vertical section, X 20, through portion of a zoarium illustrating

the variation in diameter of the central tube.

12. A portion of the same vertical section, X 40, showing the more

minute structure of the zooecia (zocec) and vesicles.
Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 13-17. CERAMOPORA ? IXCONDITA n. sp 260

13. A tangential section, X 12, passing through the mature zone

where the zocecia and mesopores are most irregular in shape
and arrangement.

14. A similar section, X 12, through an immature portion of the same

zoarium.

15. A vertical section, X 12, through both zones of a thin incrusting

zoarium in which diaphragms appear to be wanting.
16, 17. Vertical sections, X 12, showing the usual characters of the
mature region.
Helderberg formation, Keyser member, Devil's Backbone.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XLI

12 13

MOLLUSCOIDEA — BRYOZOA

«r X\

PLATE XLII

PAGE

Figs. 1-4. STROMATOTRYPA GLOBULARIS n. sp 279

1, 2. Two vertical sections, X 10, one showing the usual features and
the second illustrating the closing of a mesopore as the surface
is approached.

3. A tangential section, X 20, with rounded zocecia and rather numer-

ous acanthopores and mesopores.

4. A few zocecia, X 20, of a tangential section in which mesopores are

few.
Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 5-9. CYPHOTRYPA CORRUGATA (Weller) 269

5. Tangential section, X 20, showing the simple polygonal zocecia.

6. 7. Several zocecia of the same section, X 50, illustrating the minute

structure of the walls and acanthopores.

8. A vertical section through an immature and mature zone, X 20.

9. Surface of a zoarium, X 9.

Helderberg formation, Keyser member, Keyser, W. Va.

Fig. 10. PTILODICTYA TENEIXA n. sp 288

Tangential section, X 20, illustrating the shape of the zocecia and
showing also the inferior hemiseptum as a sharp transverse
line in most of the zocecia. Helderberg formation, Keyser
member, Devil's Backbone.

Figs. 11-16. STENOPORA ? INCRUSTANS n. sp 275

11, 12. Tangential sections, X 20, showing slight variations in the

wall structure.
13, 14. Several zocecia in thin sections, X 50, illustrating the structure

of the acanthopores and the minute dotting of the walls.

15. Vertical section, X 20, through a single layer of zocecia.

16. Surface of a specimen, X 20.

Helderberg formation, Keyser member, Cash Valley.

MARYLAND GEOLOGICAL SURVEY

I I

LOWER DEVONIAN, PLATE XLII

MOLLUSCOIDEA — BRYOZOA

PLATE XLIII

PAGE

Figs. 1-4. LJOCLEMA SUBRAMOSUM n. sp 273

1. Vertical section, X 20.

2, 3. Tangential section, X 20, through the mature zone, and a small

portion of the same, X 50, illustrating the structure of the walls
and acanthopores.

4. A tangential section, X 20, through an early stage of the mature

zone where the acanthopores are undeveloped and the zoo3cia
are thin walled.
Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 5-8. ERIDOTRYPA PARVULIPORA n. sp 272

5. A tangential section, X 20.

6. A portion of another tangential section, X 20, in which the acantho-

pores are more numerous.

7. Several zocecia of a thin section, X 50.

8. A vertical section, X 20.

Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 9-12. LJOCLEMA PULCHEIXUM, n. sp 274

9, 10. Tangential section, X 20, and a portion, X 35, passing through
the mature zone.

11. A vertical section, X 20.

12. Surface of the type, X 9.

Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 13-16. FiSTULiPORELLA MINIMA n. sp 265

13. Side view of a zoarium, natural size.

14. Tangential section, X 20.

15. A zooBcium of the same section, X 50.

16. A vertical section, X 20, through two layers of zocpcia.

Helderberg formation, Keyser member, Keyser, W. Va.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XLIII

MOLLUSCOIDEA — BRYOZOA

PLATE XL IV

PAGE

Figs. 1-3. CEBAMOPORA ? INCONDITA n. sp 260

1. View of a small zoarium, X 1.5, incrusting a Favosites.

2, 3. Surface of same, X 3 and X 9, respectively.

Helderberg formation, Keyser member, Devil's Backbone.

Fig. 4. CYPHOTBYPA COBBUGATA (Weller) 269

Side view of a hemispheric zoarium with the edge broken away, X 1.25.
Helderberg formation, Keyser member, Pinto.

Fig. 5. LIOCLEMA SUBBAMOSUM n. sp 273

Fragment of a zoarium, X 1.5. Helderberg formation, Keyser mem-
ber, Keyser, W. Va.

Fig. 6. STENOPOBA ? INCBUSTANS n. sp 275

A zoarium, incrusting a specimen of Favosites, X 1.25. Helderberg
formation, Keyser member, Cash Valley.

Figs. 7-8. ERIDOTBYPA PABVULIPORA n. sp 272

7. Portion of small slab, X 1.25, showing several fragments of this

species.

8. Surface of one of the specimens, X 9.

Helderberg formation, Keyser member, Keyser, W. Va.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XLIV

MOLLUSCOIDEA BRYOZOA

PLATE XLV

PACK

Figs. 1, 2. BATOSTOMELLA INTERPOROSA n. sp 270

1. Vertical section, X 20, through the center of a branch.

2. Tangential section, X 20, showing the numerous acanthopores and

mesopores.

Helderberg formation, Keyser member, Devil's Backbone,
Maryland.

Figs. 3-6. DIPLOSTENOPORA SILURIANA (Weller) 277

3. Tangential section, X 20, cutting both mature and immature

region.

4. Portion of mature region of the same section, X 35.

5. Vertical section, X 20, with a second layer of zooecia on the left.

6. One-half of the same, X 35, illustrating the wall structure and

perforated diaphragms in more detail.
Helderberg formation, Keyser member, Devil's Backbone.

Fig. 7. SEMICOSCINITJM PLANUM n. sp 285

Transverse section of the type specimen, X 12, introduced to show the
expanded carina. Helderberg formation, Keyser member,
Hyndman, Penna.

FigS. 8-11. FlSTULIPOREIXA MARYLANDICA n. Sp 266

8. Portion of a rather narrow zoarium, natural size.

9. Tangential section, X 20, passing through a macula and adjoining

zooecia.

10. Several zorecia of the same section, X 35, exhibiting granular

structure of lunarium.

11. Vertical section, X 20, showing a portion of a solid branch.

Helderberg formation, Keyser member, Cash Valley.

Figs. 12-14. ORTHOPORA RHOMBIFERA Hall 286

12. Tangential section, X 20, illustrating quincuncial arrangement

and rhomboidal shape of zooscia in an average example.

13. Tangential section of an old zoarium, X 30.

14. Vertical section, X 20.

Helderberg formation, Keyser member, Devil's Backbone.

Fig. 15. FENESTELLA (CYCLOPORINA) ALTIDORSATA n. sp 282

Transverse section, X 12, showing the carinated obverse and reverse
sides and the ovicell-like structure on the sides of the carina.
Helderberg formation, Keyser member, Devil's Backbone.

36

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XLV

f 10

MOLLUSCOIDEA BRYOZOA

11

PLATE XL VI

PAGE

Fig. 1. RHOPALONARIA ATTENUATA Ulrich and Bassler 259

The excavations left by a portion of a colony upon an auloporoid, X 9.
Helderberg formation, Keyser member, Cash Valley.

Fig. 2. ASCODICTYON SILURIENSE Vine 260

Eight groups of vesicles, X 9, attached to a brachiopod. Helderberg
formation, Keyser member, Cash Valley.

FigS. 3-7. FlSTULIPORELLA MAYNARDI n. Sp 266

3. A slightly oblique tangential section, X 20, illustrating the struc-

ture of the outer ridge-like walls on one edge of the drawing
and the usual zocecia and mesopores elsewhere.

4. Tangential section, X 20, through the outermost part of the

zoarium.

5. Vertical section, X 20, through two layers of zooacia but not includ-

ing the outer ridge-like wall in either layer.

6. Surface view of zooecia, X 9, with crested walls and overarching

lunaria well developed.

7. View of another portion of the same specimen, X 9, in which the

ridge-like outer wall is shown only in one corner.
Helderberg formation, Keyser member, Cash Valley.

Figs. 8-9. STROMATOTRYPA GLOBULARIS n. sp 279

8. Side view of a zoarium, natural size, showing a portion of the

wrinkled base.

9. Surface of zoarium, X 9.

Helderberg formation, Keyser member, Keyser, W. Va.

37

MARYLAND GEOLOGICAL SURVEY

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MOLLUSCOIDEA BRYOZOA

PLATE XLVII

PAGE

Figs. 1, 2. FENESTEIXA CUMBERLANDICA n. sp 280

1. Obverse face, X 5.

2. Reverse face, X 5.

Helderberg formation, Keyser member, Cash Valley.

Fig. 3. POLYPORA DICTYOTA n. sp 283

Reverse face of the type specimen, X 5. Helderberg formation, Keyser
member, Devil's Backbone.

Figs. 4-6. THAMNISCUS KEGULARIS n. sp 286

4, 6. Celluliferous and non-celluliferous face respectively of the two

type specimens, X 1.5.
6. Enlargement of a portion of fig. 4, X 5.

Helderberg formation, Keyser member, Devil's Backbone.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XLVII

MOLLUSCOIDEA — BRYOZOA

PLATE XLVIII

PAGE

Figs. 1-3. DIPLOSTENOPORA siLURiANA (Weller) 277

1. An incomplete zoarium of average size, X 1.5, with low monticules.

2. A more robust incomplete, smooth zoarium, X 1.5.

3. Surface of specimen shown in fig. 1, X 9.

Helderberg formation, Keyser member, Cash Valley.

Fig. 4. FlSTULIPORELLA MARYLANDICA n. Sp 266

Surface of a zoarium, X 6, exhibiting the well-marked solid maculae.
Helderberg formation, Keyser member, Cash Valley.

Fig. 5. BATOSTOMELLA INTERPOROSA n. sp 270

One of the type specimens, X 5. Helderberg formation, Keyser
member, Devil's Backbone.

Fig. 6. ORTHOPORA RHOMBIFERA Hall 286

Surface of a slab, X 5, showing numerous fragments of this species.
Helderberg formation, Keyser member, Cash Valley.

Figs. 7, 8. PTILODICTYA TENELLA n. sp 288

7. Incomplete specimen, X 5.

8. Surface of same, X 9.

Helderberg formation, Keyser member, Devil's Backbone.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XLVIII

MOLLUSCOIDEA — BRYOZOA

PLATE XLIX

PAGE

Figs. 1-3. FENESTELLA (CYCLOPORINA) ALTIDORSATA n. sp 282

1. An incomplete, well-preserved frond, X 1.5.

2. Surface of a slab, X 2, with specimens showing both obverse and

reverse sides.

3. A third specimen, X 5, exhibiting the celluliferous face.

Helderberg formation, Keyser member, Devil's Backbone.

Fig. 4. SEMICOSCINIUM PLAXUM n. sp 285

Portion of the non-celluliferous face of the type specimen, x 5. Helder-
berg formation, Keyser member, Hyndman, Penna.

40

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XLIX

MOLLUSCOIDEA — BRYOZOA

PLATE L

PAGE

Figs. 1-4. MONOTRYPA TABTJLATA (Hall) 278

1. Vertical fracture of a zoarium, natural size, showing corrugated

zooecial walls.

2. A portion of the same enlarged.

3-4. Vertical and tangential sections, X 6.

New Scotland formation, New York.

Figs. 5-8. CALLOTKYPA STRIATA (Hall and Simpson) 271

5. A fragment of limestone with small examples of this species, natural

size.

6, 7. A small fragment and a portion of the same enlarged.

8. A further enlargement (X 18), showing the arrangement of the
zooacia and mesopores and the prominent spine, at the posterior
end of the zooacium.
New Scotland formation, New York.

Figs. 9, 10. CALLOTRYPA MACROPORA (Hall) 271

A branching fragment and a portion of the same enlarged. New Scot-
land formation, New York.

Figs. 11, 12. ERIDOTRYPA CORTICOSA (Hall) 273

A fragment, natural size, and a portion of the same enlarged showing
the thick walled zocecia. New Scotland formation, New York.

Figs. 13-15. CHILOTRYPA CONSTRICTA (Hall) 269

13. A small piece of limestone with fragments of this species.
14, 15. Two fragments enlarged, the first showing the regular arrange-
ment of the zooecia and the second showing several maculae.
New Scotland formation, New York.

Figs. 16-18. ORTHOPORA OVATIPORA (Hall) 288

16, 17. A fragment, natural size, and an enlargement of the same.
18. Surface of a fragment, X 18.

New Scotland formation, New York.

41

MARYLAND GEOLOGICAL SURVEY

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MOLLUSCOIDEA — BRYOZOA

PLATE LI

PAGE

Figs. 1, 2. FISTULIPORA MACULOSA (Hall) 262

1. A complete zoarium, natural size, showing the characteristic

maculae.

2. Surface of a zoarium magnified.

New Scotland formation, New York.

Figs. 3-5. SEMICOSCINIUM CORONIS (Hall) 285

3. A fragment, natural size.

4. An enlargement of the non-celluliferous face.

5. Celluliferous face enlarged, showing the characteristic, expanded

carina.
New Scotland formation, New York.

Figs. 6-8. FENESTELLA PHJLIA Hall 281

6, 7. A fragment showing the non-celluliferous face, X 1, and an
enlargement of the same.

8. Enlargement of the celluliferous side.

New Scotland formation, New York.

Figs. 9-11. POLYPORA COMPACTA ( Hall) 284

9. A fragment, natural size.

10, 11. Enlargements of the non-celluliferous and celluliferous faces
of this species.
New Scotland formation, New York.

Figs. 12-14. STICTOPORA ? PAPILLOSA Hall 289

12. Fragments, natural size.

13-14. Surface of specimen, X 6 and X 18.

New Scotland formation, New York.

Figs. 15-17. ORTHOPORA REGULARIS (Hall) 287

15. A specimen showing a rectangular mode of branching, X 1.
16, 17. Surfaces of two specimens, X 6, showing variations in the
thickness of the zocecial walls.

New Scotland formation, New York.

Fig. 18. ORTHOPORA RHOMBIFERA (Hall) 286

Enlargement of a specimen showing arrangement and form of the
zofficial apertures. New Scotland formation, New York.

42

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LI

11

10

MOLLUSCOIDEA — BRYOZOA

PLATE LI I

PAGE

Figs. 1, 2. CYPHOTRYPA CORRUGATA (Weller) 269

1. Vertical section, showing the characteristic crenulated walls and

the distribution of diaphragms. X 20.

2. Tangential section illustrating the range in size of the macular and

intermacular zorecia. X 20.

Decker Ferry formation, New Jersey.

Figs. 3, 4. DIPLOSTEXOPORA SILURIANA (Weller) 277

3. A vertical section illustrating the bifoliate method of growth and

the characteristic perforated diaphragms. X 20.

4. Several zocecial tubes of the same section. X 35.

Decker Ferry formation, New Jersey.

Figs. 5-8. MONOTRYPA SPH.ERICA (Hall) 278

5. Side view of a zoarium, natural size.

6. A vertical fracture, natural size.

7. An enlargement of the celluliferous surface.

8. Vertical section illustrating the distribution of the diaphragms.

X 4.
New Scotland formation, New York.

Figs. 9-11. FENESTELLA ? IDALIA Hall 281

9. A funnel-shaped frond, natural size.

10. An enlargement of the non-celluliferous face of the same.

11. An enlargement of another specimen with stouter branches.

New Scotland formation, New York.

13

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE Lll

Mm lit <iiif«;

nil

MOLLUSCOIDEA — BRYOZOA

PLATE LI 1 1

PAGE

Figs. 1, 2. ORBICULOIDEA BCEDERI Schuchert n. sp 290

1. Exterior of dorsal valve.

2. Exterior mold of ventral valve.

Oriskany formation, Ridgely member, Cash Valley.

Figs. 3-5. OBBICULOIDEA AMPLA (Hall) 291

3. Cast from a mold of the dorsal valve.

4. Side elevation of same.

5. Partially exfoliated ventral valve.

Oriskany formation, New York.

Figs. 6, 7. ORBICULOIDEA SCHUCHEBTI Swartz n. sp 292

6. Exterior of dorsal valve.

7. Exterior of ventral valve.

Helderberg formation, Keyser member, Dawson, W. Va.

Figs. 8, 9. PHOLIDOPS MULTILAMELLOSA Schuchert n. sp 293

8. Exterior of ventral ? valve partially exfoliated, showing interior

muscular scars. X 2.

9. Exterior of dorsal valve. X 2.

Oriskany formation, Shriver member, Cash Valley.

Figs. 10-12. PHOLIDOPS OVATA Hall 294

10. Exterior of dorsal valve. X 3. New Scotland of New York.

11. Interior of dorsal valve. X 5.

12. Exterior of dorsal valve. X 5.

Helderberg formation, Keyser member, % mile southwest of
Rawlings.

Fig. 13. PHOLIDOPS TUMIDA Schuchert n. sp 294

Exterior of dorsal valve. X 3. Oriskany formation, Shriver member,
Winchester road.

Figs. 14-19. LIXGULAPHOLIS TERMINALIS (Hall) 296

14. Exterior of ventral valve.

15. Exterior of dorsal valve.

16. Exterior of dorsal ? valve of another specimen. X 2.

17. Profile outline of same, showing both valves in position.

18. Interior of ventral valve. X 2.

19. Interior of ventral valve. X 3.

Oriskany formation, Ridgely member, Cumberland. (Figs.
14, 15, 19, after Hall.)

Figs. 20-23. ORTHOSTROPHIA STROPHOMENOIDES (Hall) 297

20. 21. Internal casts of ventral and dorsal valves.
22, 23. Dorsal and cardinal views.

New Scotland formation, New York.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE Llll

MOLLUSCOIDEA — BRACHIOPODA

PLATE LIV

PAGE

Figs. 1-6. DALMANELLA PLANICONVEXA (Hall) 298

I, 2. Dorsal and ventral shells. X 11A. Helderberg formation, New

Scotland member, 21st Bridge.

3. Ventral valve. Helderberg formation, Becraft member, Cherry Run,

W. Va.

4. The interior of dorsal valve of a smaller individual.

5. Interior of ventral valve.

6. Cardinal view of a larger individual. New Scotland formation, New

York.

Figs. 7-10. DALMANELLA CLARK i Maynard n. sp 300

7. Interior of ventral valve. X 21/&.

8. Dorsal valve. X 2.

9. Ventral valve. X 2.

10. Interior of dorsal valve. X 2.

Helderberg formation, Keyser member, Cash Valley.

Figs. 11-13. DALMANELLA CONCINNA (Hall) 301

II. Ventral valve.

12. Surface ornamentation. X 7.

13. Dorsal valve.

Helderberg formation, Keyser member, Cumberland.

Figs. 14-23. DALMANELLA PERELEGANS (Hall) 299

14, 15. Ventral and dorsal valves. Helderberg formation, New Scot-
land member, Corriganville.
16-19. Ventral, dorsal, side, and cardinal views.

20. Interior of ventral valve.

21. Internal cast of ventral valve.

22. Internal cast of dorsal valve.

23. Interior of dorsal valve.

New Scotland formation, New York.

Figs. 24-26. DALMANELLA EMINENS (Hall) 299

24. Dorsal view.

25. Profile outline of same.

26. Interior of ventral valve.

Helderberg formation, New Scotland member, Corriganville.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LIV

12

13

14

15

'-''•^^^^^

10

11

21

22

25

MOLLUSCOIDEA — BRACK IOPODA

PLATE LV

PAGE

Figs. 1-8. RHIPIDOMELLA EMARGINATA (Hall) 302

1-4. Illustrations of the form and character of this variety.
5, 6. Interior of ventral and dorsal valves.
7, 8. Cast of the ventral and dorsal valve.

Helderberg formation, Keyser member, Cumberland. (After
Hall.)

Figs. 9-16. RHIPIDOMELLA OBLATA (Hall) 303

9, 10. Ventral and dorsal valves.

11. Profile of same.

12. A small dorsal valve.

13, 14. Interior of ventral and dorsal valves.

15. Internal cast of the ventral valve, showing the muscular and

vascular impressions.

16. Cast of the dorsal valve, with impressions of the cardinal and

brachial processes.

New Scotland formation, New York.

Figs. 17-19. RHIPIDOMELLA ASSIMILIS (Hall) 304

17. Ventral valve.

18. Dorsal view of a large shell.

19. Interior of ventral valve.

Helderberg formation, Becraft member, North Mountain, W.
Va.

Fig. 20. RHIPIDOMELLA MVSCULOSA (Hall) 305

Cast of interior of dorsal valve. Oriskany formation, New York.

Figs. 21, 22. RHIPIDOMELLA MUSCULOSA VAR. ARCTISIXUATA Schuchert n.

var 306

21. Dorsal view.

22. Ventral view of same.

Oriskany formation, Ridgely member, Cumberland.

Fig. 23. RHIPIDOMELLA MARYLANDICA Schuchert n. sp 306

Interior cast of ventral valve. Oriskany formation, Ridgely member,
Williams road, near Cumberland.

46

MARYLAND GEOLOGICAL SURVEY

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21 22

MOLLUSCOIDEA — BRACHIOPODA

23

PLATE LVI

PAGE

Figs. 1-4. RHIPIDOMELLA MUSCULOSA (Hall) 305

1. Exterior of dorsal shell.

2. Lateral view of the conjoined valves.

3. Interior of dorsal valve.

4. Interior of ventral valve.

Oriskany formation, Ridgely member, Cumberland. (After
Hall.)

Figs. 5-8. SCHIZOPHORIA MULTISTRIATA (Hall) 307

5. 6. Dorsal and side views of shells.

7, 8. Internal cast of ventral and dorsal valves.
New Scotland formation, New York.

Figs. 9-12. SCHIZOPHORIA ORISKANIA Schuchert n. sp 307

9, 10. Dorsal and side views. The discontinuous striae in the drawing

are due to the pseudomorphous nature of the specimen.
11, 12. Internal casts of ventral and dorsal valves.

Oriskany formation, Ridgely member, Cumberland.

Figs. 13-17. LEPT^NA RHOMBOIDALIS (Wilckens) 308

13, 15. Ventral and dorsal views.
14. Ventral valve.

16. Interior of dorsal valve, showing some variety of character.

17. Internal cast of ventral valve.

New Scotland formation, New York.

Fig. 18. LEPT.ENA RHOMPXHDAOS VAR. VEXTRICOSA (Hall) 309

Interior view of dorsal valve. Oriskany formation, New York.

47

MARYLAND GEOLOGICAL SURVEY

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PLATE LVII

PAGE

Fig. 1. LEPT^EXA RHOMBOIDALIS VAR. VEXTRICOSA (Hall) 309

Interior of ventral valve. Oriskany formation, Ridgely member,
Cumberland. (After Hall.)

Figs. 2-6. LEPT^NISCA CONCAVA (Hall) 310

2. Ventral exterior.

3. Dorsal aspect.

4. Enlargement of the surface, showing the finer longitudinal striae.

New Scotland formation, New York.

5. Exterior of ventral valve. X 2.

Helderberg formation, New Scotland member, Devil's Back-
bone.

Fig. 6. STROPHEODONTA COEYMANENSIS Swartz n. sp 313

Ventral valve showing exterior save in center where muscular scars
of interior are seen. Helderberg formation, Coeymans member,
Devil's Backbone.

Figs. 7-10. STROPHEODOXTA ARATA (Hall) 311

7. Side view.

8. Ventral valve more or less exfoliated.

9. The surface showing ridges and striae.

New Scotland formation, New York.

10. Small ventral valve. Helderberg formation, Coeymans member,
Devil's Backbone.

Fig. 11. STROPHEODOXTA DEMISSA (Conrad) 313

Internal cast of ventral valve. Oriskany formation, Ridgely member,
Pendleton County, W. Va.

Figs. 12, 13. STROPHEODOXTA (LEPTOSTROPHIA) BECKII (Hall) 314

12. Ventral exterior.

13. Ventral interior.

New Scotland formation, New York.

Figs. 14-16. STROPHEODOXTA (LEPTOSTROPHIA) PLAXULATA (Hall) 315

14. An individual showing faint concentric undulations.

15. Ventral valve partially exfoliated.

Coeymans formation, New York.

16. Ventral valve differing from usual form.

Helderberg formation, Becraft member, Licking Creek,
Penna.

Figs. 17, 18. STROPHEODOXTA (LEPTOSTROPHIA) BIPARTITA (Hall) 316

17. Exterior of ventral valve. Pinto.

18. Interior of ventral valve. Devil's Backbone.

Helderberg formation, Keyser member.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LVII

18

12

MOLLUSCOIDEA — BRACHIOPODA

PLATE LVIII

PAGE

Fig. 1. STROPHEODONTA (LEPTOSTROPHIA) ARCTIMUSCULA Schuchert n. sp. . 317
Interior of ventral valve. Oriskany formation, Shriver member, 21st
Bridge.

Figs. 2-5. STROPHEODONTA (LEPTOSTROPHIA) MAGNIFICA (Hall) 318

2. Exterior of ventral valve.

3. View of dorsal valve.

4. Ventral interior.

5. Interior of dorsal valve.

Oriskany formation, Ridgely member, Cumberland. (Figs.
3-5 after Hall.)

Figs. 6-8. STROPHEODONTA (LEPTOSTROPHIA) MAGNIVENTRA (Hall) 319

6. Internal cast of ventral valve. Oriskany formation, New York.

7. Interior of dorsal valve.

8. Exterior of ventral valve.

Oriskany formation, Ridgely member, Cumberland. (Fig. 6
after Hall.)

49

MARYLAND GEOLOGICAL SURVEY

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MOLLUSCOIDEA — BRACHIOPODA

PLATE L1X

PAGE

Figs. 1, 2. STROPHEODOXTA VAKISTRIATA Conrad 312

1. Ventral valve. Striae are nearly equal or alternating in size.

2. Individual with alternating striae.

Manlius formation, New York.

Figs. 3-5. STROPHOXELLA GENICULATA (Hall) 321

Ventral, dorsal, and side views of a small individual. Helderberg
formation, Keyser member, Cumberland. (After Hall.)

Figs. 6, 7. STROPHOXELLA LEAVEXWORTHANA (Hall) 322

Dorsal and side views. New Scotland formation, New York.

Figs. 8-10. STROPHOXELLA PUNCTULIFERA (Hall) 323

8. Dorsal valve.

9. Side view of the dorsal valve.

10. Interior of a more gibbous dorsal valve.
New Scotland formation, New York.

Fig. 11. STROPHOXELLA KEYSERENSIS Swartz n. sp 324

Interior of dorsal valve. Helderberg formation, Keyser member,
Tonoloway.

Fig. 12. STROPHONELLA HEADLEYANA (Hall) 325

Exterior of a ventral valve, showing the peculiar interrupted striation.
New Scotland formation, New York.

Figs. 13, 14. STROPHOXELLA UNDAPLICATA Swartz n. sp 326

13. Dorsal valve.

14. Small ventral valve.

Helderberg formation, New Scotland member, Dawson, W. Va.

50

MARYLAND GEOLOGICAL SURVEY

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13

MOLLUSCOIDEA — BRACHIOPODA

PLATE LX

PAGE

Figs. 1-3. SCHUCHERTELLA FROLiFicA Schuchert n. sp . . 4 327

1. Ventral valve.

2. Interior of dorsal valve.

3. Two small overlapping ventral interiors.

Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 4-9. SCHUCHERTELLA WOOLWORTHANA (Hall) 328

4. Dorsal view.

5. Ventral valve.

6. Interior of a large ventral valve.

New Scotland formation, New York.

7. Dorsal valve. Helderberg formation. New Scotland member,

Cedar Cliff, W. Va.

8. 9. Internal cast of ventral and dorsal valves. New Scotland forma-

tion, New York.

Figs. 10-12. SCHUCHERTELLA BECRAFTEXSIS (Clarke) 329

10, 11. Two dorsal valves.
12. Interior of ventral valve.

Oriskany formation, New York.

Figs. 13-16. SCHUCHERTELLA DECKERENSIS (Weller) 329

13, 14. Ventral valves.

15. Cardinal view.

16. Dorsal valve.

Helderberg formation, Keyser member, Keyser, W. Va.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LX

MOLLUSCOIDEA — BRACHIOPODA

PLATE LXI

PAGE
FigS. 1, 2. SCHUCHERTELLA DEFORMIS (Hall) 331

1. View of the dorsal valve and area of the ventral valve.

2. Ventral valve of the same specimen, showing the contracted and

distorted beak.

Helderberg formation, Keyser member, Cumberland. (After
Hall.)

Figs. 3, 4. SCHUCHERTELLA sixuATA (Hall and Clarke) 331

Dorsal and cardinal views. Helderberg formation, Keyser member,
Cumberland. (After Hall and Clarke.)

Figs. 5-9. SCHVCHERTEIXA MARYLAxniCA Maynard n. sp 332

5, 6, 7. Ventral, dorsal, and cardinal views of type specimen.
8, 9. Partially exfoliated dorsal valves, Keyser, W. Va.

Helderberg formation, Keyser member, Cumberland.

Figs. 10-13. HIPPARIOXYX PROXIMITS Vanuxem 333

10, 11. Dorsal and ventral valves.

12, 13. Interior ventral and dorsal valves.

Oriskany formation, Ridgely member, Cumberland. (After
Hall.)

Fig. 14. CHOXETES ROWEI Schuchert n. sp 336

Ventral valve. Oriskany formation, Ridgely member, Miller's Spring,
near Cumberland.

Fig. 15. CHOXETES HTJDSOXICUS Clarke 337

Ventral valve. The umbo is cracked. Oriskany formation, Ridgely
member, Winchester road.

Fig. 16. CHOXETES SUBACUTIRADIATUS Schuchert n. sp 335

Ventral valve. Helderberg formation, New Scotland member, Miller's
Spring, near Cumberland.

Figs. 17-19. CHOXETES JERSEYEXSIS Weller 338

17. Ventral valve of a young individual, Tonoloway.
18, 19. Ventral and dorsal valves, Flintstone.

Helderberg formation, Keyser member.

Fig. 20. CHOXETES JERSEYEXSIS VAR. SPIXOSUS Maynard n. var 339

Ventral valve. Helderberg formation, Keyser member, Hancock.

Fig. 21. AXOPLIA HELDERBERGI^ Schuchert n. sp 340

Ventral valve. X 3. The median furrow is due to a fracture. The
shell is uniformly convex. Helderberg formation, New Scotland
member, 21st Bridge.

Figs. 22-24. AXOPLIA XUCLEATA (Hall) 340

22. Exterior of dorsal valve. X 3.

23. Interior of dorsal valve. X 2.

24. Cardinal view of the internal cast of the ventral valve.

Oriskany formation, New York.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LX I

MOLLUSCOIDEA — BRACHIOPODA

PAGE

Figs. 1, 2. CHONOSTROPHIA COMPLANATA (Hall) 341

1. Exterior of ventral valve.

2. Internal cast of ventral valve.

Oriskany formation, New York.

Fig. 3. CHONOSTROPHIA HELDERBERGI/E Hall and Clarke 342

Ventral valve. Helderberg formation, New Scotland member, Dawson.

Figs. 4-7. GYPIDULA (SIEBERELLA) COEYMANENSIS Schuchert n. name 342

4. Interior of ventral valve.

5-7. Dorsal, anterior, and side views.

8. Dorsal view of large individual.

Coeymans formation, New York.

Figs. 9-11. GYPIDULA (SIEBEREJXA) COEYMANENSIS VAR. PROGNOSTICS

Schuchert n. var 344

9, 10. Ventral and side views of unusually large individual.
11. Ventral view of individual of usual size.

Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 12-18. GYPIDULA (SIEBERELLA) COEYMANENSIS VAR. CORRIGANENSIS

Maynard n. var 345

12-15. Anterior, side, dorsal, and ventral views of a large individual.

Cumberland.

16-18. Dorsal, ventral, and side views of type. Devil's Backbone.
19. Dorsal view. Keyser, W. Va.

Helderberg formation, Keyser member.

Figs. 20-22. GYPIDULA SUBGLOBOSA Maynard n. sp 346

Ventral, side, and dorsal views. Helderberg formation, Keyser
member, Pinto.

Figs. 23, 24. RHYNCHOTRETA CUMBERLANDIA Rowe n. sp 347

Dorsal and side view of a large specimen. Oriskany formation,
Ridgely member, Cumberland.

Figs. 25-29. STENOCHISMA FORMOSA Hall 349

25, 26. Dorsal and ventral views of a large individual.

Becraft formation, New York.
27-28. Side and ventral view of smaller individual.
29. Dorsal view of young specimen.

New Scotland formation, New York.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LXII

19

20

21

22

^^m^ 26 27 28

MOLLUSCOIDEA — BRACHIOPODA

13

29

PLATE LXIII

PAGE

Figs. 1-4. STEXOCHISMA DECKEREXSIS (Weller) 349

1-3. Ventral, side, and dorsal views.

4. Dorsal view of a smaller specimen.

Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 5, 6. CAMAKOTCECHIA ? ALTIPLICATA (Hall) 351

5. View of ventral valve.

6. Side view of same.

New Scotland formation, New York.

Figs. 7, 8. CAMAROTCECHIA ORISKANIA Rowe n. sp 351

Dorsal and side views of shell. Oriskany formation, Ridgely member,
Cumberland.

Figs. 9, 10. CAMAROTCECHIA ? LAMELLATA (Hall) 352

Dorsal and ventral views of shells. Cobleskill formation, New York.

Figs. 11-14. CAMAROTCECHIA LITCHFIELDEXSIS Schuchert 353

Anterior, side, ventral, and dorsal views. Helderberg formation,
Keyser member, Cookerly.

Figs. 15, 16. CAMAROTCECHIA GIGANTEA Maynard n. sp 354

Dorsal and ventral views. Helderberg formation, Keyser member,
Devil's Backbone.

Figs. 17-19. CAMAROTCECHIA (PLETHORHYNCHA) CAMPBELLANA (Hall) .... 354
Ventral, anterior, and side views. New Scotland formation, New York.

Figs. 20, 21. CAMAROTCECHIA (PLETHORHYNCHA) PR.ESPECIOSA Schuchert

n. sp 355

20. View of a dorsal valve.

21. Side view of shell.

Helderberg formation, Becraft member, near Covington, Va.

Figs. 22-27. CAMAROTCECHIA (PLETHORHYNCHA) SPECIOSA (Hall) 356

22. 23. Dorsal and side views of a medium sized specimen.
24, 25. Dorsal and side views of a large example.

26, 27. Interior of ventral and dorsal valves.

Oriskany formation, Ridgely member, Cumberland. (After
Hall.)

MARYLAND GEOLOGICAL SURVEY

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25

MOLLUSCOIDEA — BRACHIOPODA

PLATE LXIV

PAGE

Fig. 1. CAMABOTCECHIA (PLETHORHYXCHA) SPECIOSA VAR. RAMSAYI (Hall). 358
Dorsal view of the type specimen. Oriskany formation, Ridgely mem-
ber, Cumberland. (After Hall.)

Figs. 2, 3. CAMAROTCECHIA ( PLETHORHYXCHA ) BARRANDII (Hall) 359

2. Internal cast of ventral valve.

3. Anterior view of a very gibbous specimen.

Oriskany formation, New York.

Figs. 4, 5. CAMAROTCECHIA (PLETHORHYNCHA) BARRAXDII VAR. FITCHANA

(Hall) 359

Dorsal and side views of internal cast. Oriskany formation, New
York.

Fig. 6. CAMAROTCECHIA (PLETHORHYXCHA) PLEIOPLEURA (Conrad) 360

Dorsal valve. The drawing is much restored on the left. Oriskany
formation, Ridgely member, Cumberland.

Figs. 7-10. UXCIXULUS VELLICATUS (Hall) 362

7-9. Dorsal, cardinal, and anterior views.

10. Plications of fold and sinus enlarged to show their linear median
furrows and zigzag lines of growth.
New Scotland formation, New York.

Figs. 11, 12. UNCINULUS ABRUPTUS (Hall) 363

Dorsal and ventral views. New Scotland formation, New York.

Figs. 13-15. UNCIXULUS GLOBULUS Schuchert 364

13, 14. Dorsal and side views.

15. Anterior view of a larger specimen.

New Scotland formation, New York.

Figs. 16, 17. UXCIXULUS NUCLEOLATUS (Hall) 365

Ventral and side views. Helderberg formation, Keyser member,
Keyser, W. Va.

Figs. 18-20. UXCIXULUS NUCLEOLATUS VAR. AXGULATUS Maynard n. var. ... 366
Side, ventral, and dorsal views of type specimen. Helderberg forma-
tion, Keyser member, Cumberland.

55

MARYLAND GEOLOGICAL SURVEY

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MOLLUSCOIDEA ERACHIOPODA

||

PLATE LXV

PAGE

Figs. 1-6. UXCIXULUS GORDOXI Maynard n. sp ........................... 367

1, 2. Dorsal and ventral views.

3, 4. Anterior and ventral views of a smaller specimen.

5, 6. Anterior and side views of a gibbous form. .

Helderberg formation, Keyser member, Cash Valley.

Figs. 7, 8. UXCIXULUS KEYSEREXSIS Schuchert n. sp .................... 368

Dorsal and side views. Helderberg formation, Keyser member,
Keyser, W. Va.

Figs. 9-14. UXCIXULUS CONVEXORUS Maynard n. sp ...................... 368

9. Dorsal view of individual with coarse plications.
10-13. Side, dorsal, ventral, and anterior views.
14. View of large ventral valve with fine plications.

Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 15-17. WILSOXIA GLOBOSA Weller ................................. 369

Side, dorsal, and ventral views. Helderberg formation, Keyser
member, Cash Valley.

Figs. 18-20. WILSOXIA CF. GLOBOSA Weller .............................. 370

Side, ventral, and dorsal views. Helderberg formation, Keyser mem-
ber, Tonoloway.

Figs. 21, 22. EATOXIA SIXGULARIS (Vanuxem) ......................... 371

Dorsal and ventral views. Helderberg formation, New Scotland mem-
her, Corriganville.

Figs. 23-28. EATOXIA PECULIARIS (Conrad) ............................. 372

23, 24. Dorsal and ventral views.

25, 26. Interior of dorsal and ventral valves. (After Hall.)
Oriskany formation, Ridgely member, Cumberland.
27, 28. Ventral and dorsal views of internal cast. New Scotland forma-
tion, New York.

Figs. 29, 30. EATOXIA WHITFIELDI Hall ................................ 373

29. Ventral valve. X 2.

30. A water-worn dorsal valve. X 2.

Oriskany formation, Ridgely member, Cumberland.

Figs. 31-35. EATOXIA MEDIALIS (Vanuxem) ............................ 374

31. Dorsal view of a large specimen.

32. 33. Ventral and side views.

34, 35. Dorsal and ventral views of internal cast of a small individual.
New Scotland formation, New York.

Figs. 36-38. EATOXIA SINUATA Hall .................................... 375

36, 37. Dorsal and ventral views.
38. Interior of ventral valve.

Oriskany formation, Ridgely member, Cumberland.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LXV

37

MOLLUSCOIDEA — BRACK IOPODA

PLATE LXVI

PAGE

Fig. 1. EATONIA SINUATA Hall 375

Internal cast of ventral valve. Oriskany formation, Ridgely member,
Cumberland. (After Hall.)

Figs. 2, 3. EATONIA HARTLEYI Schuchert n. sp 376

Dorsal and side views. Oriskany formation, Ridgely member, Martin
Mountain, Allegany County.

Fig. 4. RHYNCHONELLA ( ?) BIALVEATA Hall 377

Dorsal view. X 2. New Scotland formation, New York.

Figs. 5, 6. RENSSEL^RIA MUTABILIS (Hall) 378

Dorsal and ventral views. Helderberg formation, Keyser member,
Cumberland.

Figs. 7-9. RENSSEL^ERIA MUTABILIS VAR 378

Ventral, dorsal, and side views. Helderberg formation, Keyser
member, Tonoloway.

Figs. 10-12. RENSSEL^RIA SUBGLOBOSA Weller 379

10. Ventral valve.

11, 12. Ventral and side views of an average individual.

Helderberg formation, Becraft member, Cherry Run, W. Va.

Fig. 13. RENSSEL.ERIA SUBGLOBOSA VAR. AVUS Schuchert n. var 380

Ventral valve, slightly distorted. Helderberg formation, Becraft
member, Cherry Run, W. Va.

Fig. 14. RENSSEL^ERIA SUBGLOBOSA VAR, CRASSA Schuchert n. var 381

Ventral valve showing the coarser striae. Helderberg formation,
Becraft member, Licking Creek, Pa.

Figs. 15-17. RENSSEL^RIA CIRCULARIS Schuchert n. sp 381

Ventral, dorsal, and side views. Oriskany formation, Ridgely mem-
ber, Cumberland.

Figs. 18-24. RENSSEL^ERIA MARYLANDICA Hall 382

18, 19. Dorsal and side views of a small specimen.
20, 21. Dorsal and side views of an average specimen.

22. Interior of ventral valve.

23. Interior of dorsal valve to show the large crural plates and the

pointed brachidium which supports the fleshy arms.

24. Median section of shell to show the various plates, thickening of

the posterior region of the valves, and the position of the jugum.
Oriskany formation, Ridgely member, Cumberland. (After
Hall.)

Fig. 25. RENSSEL.^RIA MARYLAXDICA VAR. SYMMETRICA Schuchert n. var. . 384
Dorsal view. Oriskany formation, Ridgely member, Cumberland.

Figs. 26-28. RENSSEL^RIA KEYSERENSIS Swartz n. sp 384

Ventral, dorsal, and side views of type. Helderberg formation, Keyser
member, % mile southwest of Rawlings.

57

MARYLAND GEOLOGICAL SURVEY

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24

MOLLUSCOIDEA — BRACHIOPODA

PLATE LXVII

PAGE

Figs. 1-3. REXSSEL.ERIA (BEACHIA) PROAVITA Schuchert n. sp 385

1. Ventral valve. X 1%.

2, 3. Dorsal and side views of another specimen. X 1%.

Helderberg formation, Keyser member, Pinto.

Figs. 4-6. RENSSEIJERIA (BEACHIA) CUMBEBLAXDM: (Hall) 386

Dorsal, ventral, and side views. Oriskany formation, Ridgely mem-
ber, Cumberland.

Figs. 7-15. RENSSEL/ERIA (BEACHIA) SUESSANA (Hall) 387

7, 8. Dorsal and side views of a small specimen.

9, 10. Same of an average specimen.

11. Dorsal view of an elongate specimen.

12, 13. Dorsal and side views of a large specimen.

14. Interior of dorsal valve.

15. Longitudinal section of valves showing crura and appendages.

Oriskany formation, Ridgely member, Cumberland. (After
Hall.)

Fig. 16. RENSSEL.ERIA (BEACHIA) SUESSAXA VAR. IMMATURA Schuchert n.

var 388

Dorsal valve. X 1%. Oriskany formation, Shriver member, Cash
Valley, Cumberland.

Figs. 17-19. RENSSEL^RIA (BEACHIA) OVALIS (Hall) 389

17, 18. Ventral and side views.
19. Internal cast of ventral valve.

Oriskany formation, New York.

Figs. 20-24. ORISKANIA LUCERNA Schuchert n. sp 390

20-22. Dorsal, ventral, and side views.

23, 24. Interior of ventral and dorsal valves. X 2.

Oriskany formation, Ridgely member, Cumberland.

Fig. 25. TROPIDOLEPTUS CARINATTJS (Conrad) 390

Ventral valve. Oriskany formation, Ridgely member, Cumberland.

Figs. 26-28. ATRYPA RETICULARIS (Linne) 392

26, 27. Dorsal and side views.
28. Interior of ventral valve.

New Scotland formation, New York.

53

MARYLAND GEOLOGICAL SURVEY

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24

MOLLUSCOIDEA — BRACHIOPODA

PLATE LXVIII

PAGE

Figs. 1-3. ATRYPA ? BICOXVEXA Maynard n. sp 393

1, 2. Ventral and dorsal views. Keyser, W. Va.

3. Dorsal view of another example. Cash Valley, Cumberland.

Helderberg formation, Keyser member.

Figs. 4-6. ATKYPINA IMBRICATA (Hall) 394

4, 5. Ventral and dorsal views.
6. Dorsal view. X 3.

New Scotland formation. New York.

• '4 f
fc^a^ovnE ^*^

Figs. 7, 8. SPIRIFER' MAdROPLEURUs (Conrad) 396

Dorsal and ventral valves. Helderberg formation, New Scotland mem-
ber, Corriganville.

Figs. 9-16. SPIRIFER CUMBERLANDI.E Hall 398

9-11. Dorsal, ventral, and side views of a small specimen.
12-14. Same views of an average specimen.
15, 16. Interior of ventral and dorsal valves.

Oriskany formation, Ridgely member, Cumberland. (After
Hall.)

Figs. 17-22. SPIRIFER MODESTUS Hall 399

17, 18. Dorsal and front view.

19-21. Dorsal, ventral, and side views of a larger individual.

22. Interior of ventral valve.

Helderberg formation, Keyser member, Cumberland. (After
Hall.)

Figs. 23, 24. SPIRIFER MODESTU s VAR. PLICATUS Maynard n. var 400

Dorsal and ventral views of type. Helderberg formation, Keyser
member, Keyser, W. Va.

Figs. 25-29. SPIRIFER OCTOCOSTATUS Hall 401

25-28. Ventral, dorsal, side, and cardinal views.
29. Interior of ventral valve.

Helderberg formation, Keyser member, Cumberland. (After
Hall.)

Figs. 30, 31. SPIRIFER PAUCICOSTATUS Schuchert n. sp 402

Internal casts of dorsal and ventral valves. X 3. Oriskany forma-
tion, Shriver member, Cash Valley.

Figs. 32, 33. SPIRIFER VAXVXEMI Hall 403

Ventral and dorsal views. Manlius formation, New York.

Figs. 34, 35. SPIRIFER VAXUXEMI VAR. PROGXOSTICA Schuchert n. var 403

Ventral and dorsal views. Helderberg formation, Keyser member,
% mile southwest of Rawlings.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LXVIII

MOLLUSCOIDEA — BRACHIOPODA

PLATE LXIX

PAGE

Figs. 1-3. SPIBIFEB VANUXEMI VAB. PROGXOSTICUS Schuchert n. var 403

1. Dorsal view of a large specimen. X 2.

2, 3. Anterior and side views of a smaller individual. X 2.

Helderberg formation, Keyser member, Pinto.

Figs. 4-6. SPIRIFEK PERLAMELLOSUS Hall 397

Dorsal, ventral and side views. Helderberg formation, New Scotland
member, Cumberland.

Fig. 7. SPIRIFEK ERIENSIS Grabau 404

Ventral valve. Helderberg formation, Keyser member, Cash Valley.

Figs. 8-10. SPIRIFER CYCLOPTERUS Hall 406

8, 9. Dorsal and side views of average specimen.
10. Ventral valve of a smaller specimen.

New Scotland formation, New York.

Figs. 11-14. SPIRIFER TRIBULIS Hall 407

11-13. Dorsal, ventral, and side views.

14. A portion of the surface lamellae much magnified to show the
finely spinose margins.

Helderberg formation, New Scotland member, Cumberland.
(After Hall.)

Figs. 15, 16. SPIRIFER ANGULARIS Schuchert n. sp 409

Dorsal and ventral views of a large specimen. Oriskany formation,
Ridgely member, Cumberland.

Figs. 17-21. SPIRIFER INTERMEDIUS Hall 409

17, 18. Ventral and dorsal views of Cumberland specimen.

19. Ventral valve with a wider sinus. Cumberland.

20, 21. Dorsal and ventral views of an average specimen from Warren

Point, Penna.
Oriskany formation, Ridgely member.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LXIX

21

MOLLUSCOIDEA — ERACHIOPODA

PLATE LXX

PAGE

Figs. 1-5. SPIRIFER MURCHISONI Castelnau 411

1. Dorsal view of an average specimen. Cumberland.

2. Internal cast of ventral valve retaining portion of shell, same

locality.

3-5. Dorsal, ventral, and side views of the form with angular plica-
tions. Warren Point, Penna.
Oriskany formation, Ridgely member.

Figs. 6, 7. SPIRIFKR MURCHISONI YAR. MARYLANDICUS Schuchert n. var. . . . 413
Dorsal and side views. Oriskany formation, Ridgely member, Cum-
berland.

Figs. 8-10. SPIRIFER HARTLEYI Schuchert n. sp . . . ; 413

Dorsal, ventral, and side views of the type. Oriskany formation,
Ridgely member, Cumberland.

Figs. 11-13. SPIRIFER PERDEWI Schuchert 414

11, 12. Dorsal and ventral views of a small specimen.

13. Dorsal view of a large specimen.

Oriskany formation, Ridgely member, Cumberland.

Figs. 14-16. SPIRIFER TRIBUARIUS Schuchert n. sp 414

14. Dorsal view.

15, 16. Dorsal and ventral views of another individual.

Oriskany formation. Shriver member, Cumberland.

61

MARYLAND GEOLOGICAL SURVEY

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MOLLUSCOIDEA — BRACHIOPODA

PLATE LXXI w

PAGK

Figs. 1-9. SPIRIFER AREXOSUS (Conrad) 415

1, 2. Dorsal and ventral views of a young individual.

3-6. Dorsal, side, cardinal and anterior views of an average specimen.

7. The spiralia silicified.

8, 9. Exterior and interior of a large ventral valve.

Oriskany formation, Ridgely member, Cumberland. (After
Hall.)

Figs. 10-16. CYRTINA ROSTRATA (Hall) 423

10, 11. Cardinal and side views of a large specimen.

12. Interior of ventral valve.

13. Dorsal valve.

14. Anterior view of an alate specimen.

15, 16. Dorsal and cardinal views of a small specimen.
Oriskany formation, New York.

Fig. 17. SPIRIFER PROAVITUS Schuchert n. sp 418

Dorsal view of type. Helderberg formation, New York.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LXXI

MOLLUSCOIDEA — BRACHIOPODA

PLATE LXXII

PAGE

Fig. 1. SPIRIFER ARENOSUS (Conrad) 415

Internal cast of ventral valve. Oriskany formation, New York.

Figs. 2, 3. SPIRIFER CONCINNUS Hall 417

Dorsal and ventral views. Becraft formation, New York.

Fig. 4. SPIRIFER COXCINNOIDEUS Schuchert n. sp 419

Internal cast of dorsal valve. Oriskany formation, Ridgely member,
Pendleton County, W. Va.

Figs. 5-7. SPIRIFER GORDONI Schuchert n. sp 420

Dorsal, ventral, and side views of the type. Oriskany formation,
Ridgely member, Cumberland.

Figs. 8-10. RETICULARIA BICOSTATA (Vanuxem) 420

8, 9. Ventral and dorsal views.

10. Dorsal view of a specimen showing stronger plications.
Niagara formation, New York.

Figs. 11, 12. METAPLASIA PYXIDATA (Hall) 422

Dorsal and ventral views. X 2. Oriskany formation, Ridgely mem-
ber, Cumberland.

Figs. 13-15. RHYNCHOSPIRA RECTIROSTRIS (Hall) 424

Dorsal, ventral, and side views of the type. Oriskany formation,
Ridgely member, Cumberland. (After Hall.)

Figs. 16-25. RHYXCHOSPIRA GLOBOSA (Hall) 425

16-18. Ventral, dorsal, and side views of an exfoliated specimen.

Tonoloway.

19. Side view of unusually large and gibbous specimen. Tonoloway.
20-22. Dorsal, ventral, and side views. Cumberland.

Helderberg formation, Keyser member.
23. Side view of gibbous specimen.
24-25. Dorsal and ventral views.

New Scotland formation, New York.

Figs. 26-30. RHYNCHOSPIRA FORMOSA Hall 426

26. Side view of doubtfully determined specimen having striae coarser
than usual, beak erect. Helderberg formation, Keyser member.
Cash Valley.

27-29. Dorsal, ventral and side views.
30. Dorsal view of individual with finer plications.
New Scotland formation, New York.

68

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LXXII

•j.

8

t
P

13

m

14 15

20

19

21

22

v,
23

26

,

27

28

11

12

16

17

18

24

25

29

30

MOLLUSCOIDEA — BRACHIOPODA

PLATE LXXIII

PAGE

Figs. 1, 2. TREMATOSPIRA SIMPLEX Hall ? 427

Dorsal and ventral views. X 2. Helderberg formation, New Scotland
member, Devil's Backbone.

Figs. 3, 4. TREMATOSPIRA MULTISTRIATA (Hall) 428

Dorsal and ventral views. Helderberg formation, New Scotland mem-
ber, Corriganville.

Figs. 5-7. TREMATOSPIRA DEWEYI (Hall) 429

Dorsal, ventral and side views. New Scotland formation, New York.

Figs. 8, 9. TREMATOSPIRA EQUISTRIATA Hall and Clarke 430

Dorsal and ventral views. Helderberg formation, New Scotland mem-
ber, Corriganville.

Figs. 10-12. NUCLEOSPIRA VENTRICOSA (Hall) 430

Dorsal, ventral, and side views. New Scotland formation, New York.

Figs. 13, 14. NUCLEOSPIRA ELEGANS Hall 431

Dorsal and ventral views. The sinus in the dorsal valve is drawn too
angularly. X 1%. Helderberg formation, New Scotland mem-
ber, Corriganville.

Figs. 15-17. NUCLEOSPIRA SWARTZI Maynard n. sp 432

Ventral, dorsal and side views. Helderberg formation, Keyser mem-
ber, Keyser, W. Va.

Figs. 18, 19. ANOPLOTHECA CONCAVA (Hall) 434

—*/*£• Dorsal and ventral views. X 3. Helderberg formation, New Scotland

I member, Corriganville.

Figs. 20, 21. ANOPLOTHECA CONCAVA VAR. TONOLOWAYENSIS Swartz n. var.. 434
Dorsal and ventral views. X 2. Helderberg formation, Keyser mem-
ber, Tonoloway.

Figs. 22, 23. ANOPLOTHECA EQUISTRIATA Schuchert n. sp 435

Dorsal and ventral views. X 2. Oriskany formation, Ridgely mem-
ber, Cumberland.

Figs. 24-26. ANOPLOTHECA DICHTOMA (Hall) 435

24, 25. Dorsal and ventral views.

26. Anterior view to show concave dorsal valve.

Oriskany formation, Ridgely member, Cumberland. (After
Hall.)

Figs. 27, 28. ANOPLOTHECA (LEPTOCCELIA) FIMBRIATA (Hall) 436

Dorsal and ventral views. Oriskany formation, Ridgely member, Cum-
berland. (After Hall.)

Figs. 29-33. ANOPLOTHECA (LEPTOCCELIA) FLABELLITES (Conrad) 438

29-31. Dorsal, ventral, and side views.
32, 33. Interior ventral and dorsal valves.

Oriskany formation, Ridgely member, Cumberland. (After
Hall.)

Figs. 34-36. WHITFIELDELLA ( ?) PROSSERI Grabau 439

Ventral, dorsal, and side views. Helderberg formation, Cherry Run,
W. Va.

Figs. 37-40. WHITFIELDELLA ( ?) NUCLEOLATA Hall 441

37. Dorsal view of small specimen.
38-40. Ventral, dorsal, and side views.

Cobleskill formation, New York.

Figs. 41, 42. WHITFIELDELLA (?) MINUTA Maynard n. sp 442

Dorsal and ventral views. X 5. Helderberg formation, Keyser mem-
ber, Round Top.

Figs. 43-46. MERISTELLA PR.ENUNTIA Schuchert n. sp 443

43. Dorsal view of specimen with strong median fold.
44-46. Ventral valves showing differences in development of sinuses.
Helderberg formation, Keyser member, Keyser, W. Va.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LXXIII

MOLLUSCOIDEA — BRACHIOPODA

PLATE LXXIV

PAGE

Figs. 1-4. MERISTELLA PR^ENUNTIA Schuchert n. sp 443

I. Dorsal view.

2-4. Dorsal, side, and ventral views of a large and gibbous specimen.
Helderberg formation, Keyser member, Keyser, W. Va.

Figs. 5-8. MERISTELLA ARCUATA (Hall ) 444

5, 6. Dorsal and side views.

7. Anterior view to show depth of ventral sinus.

8. Small ventral valve.

New Scotland formation, New York.

Figs. 9-11. MERISTELLA LATA (Hall) 445

9, 10. Ventral view of different specimens.

II. Dorsal view of another specimen.

Oriskany formation, Ridgely member, Warren Point, Penna.

Figs. 12, 13. MERISTELLA LENTIFORMIS Clarke 446

Dorsal and side views of type. Oriskany formation, New York.

Figs. 14, 15. MERISTELLA ROSTELLATA Schuchert n. sp 447

Dorsal and ventral views of type. Oriskany formation, Ridgely mem-
ber. Cumberland.

Figs. 16-19. MERISTELLA SYMMETRICA Schuchert n. sp 448

16, 17. Dorsal and side views of a small individual.

18. Ventral view of a large specimen.

19. Ventral view of an unusually large specimen.

Oriskany formation, Ridgely member, Cumberland.

Figs. 20-24. MERISTA TYPA (Hall) 449

20. Dorsal view.

21. 22. Interiors of ventral valves.

23. A longitudinal section of fig. 22.

24. Internal cast of ventral valve.

Helderberg formation, Keyser member, Cumberland.* (After
Hall.)

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LXXIV

MOLLUSCOIDEA — BRACHIOPODA

PLATE LXXV

PAGE

Fig. 1. GRAMMYSIA sp 450

Anterior part of left valve. Helderberg formation, Keyser member,
Keyser, W. Va.

Fig. 2. LEPTODESMA (?) sp 451

Internal cast of right valve. Oriskany formation, Ridgely member,
Rock Enon Spring, W. Va.

Figs. 3, 4. MYTILARCA MARYLANDICA Ohern n. sp 452

3. Internal cast of left valve.

4. Anterior view of internal cast.

Helderberg formation, Cumberland.

Figs. 5, 6. MYTILARCA CORUIFORMIS (Hall) 452

5. Profile view from the anterior side of the shell.

6. View of the right valve, having the posterior cardinal extension

abraded.
New Scotland formation, New York.

Fig. 7. MYTILARCA ( PLETHOMYTILUS ) ROWEI Ohern n. sp 453

Left valve. Oriskany formation, Ridgely member, Hancock.

Figs. 8-10. AMPHICCELIA TJLRICHI Maynard n. sp 453

8. Anterior view of internal cast.

9. Internal cast of right valve.
10. Left valve.

Helderberg formation, Keyser member, Keyser, W. Va

66

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LOWER DEVONIAN, PLATE LXXV

MOLLUSCA — PELECYPODA

PLATE LXXVI

PAGE

Fig. 1. PALEOPINNA LATA Ohern n. sp 454

Left valve. Oriskany formation, Ridgely member, Hancock.

Figs. 2-4. ACTINOPTERIA COMMUNIS (Hall) 455

2. Left valve of a large specimen. Helderberg formation, New Scot-
land member, Cumberland.

3, 4. Left and right valves. Oriskany formation, Ridgely member,
Cumberland.

Fig. 5. ACTINOPTERIA TEXTILIS (Hall) 456

Left valve. Helderberg formation, New Scotland member, Cumber-
land.

Fig. 6. ACTIXOPTERIA RETICULATA Weller 459

Left valve. Helderberg formation, Keyser member, Keyser, W. Va.

Fig. 7. AVICULA RECTICOSTA Hall 460

Right valve. Oriskany formation, New York.

07

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LXXVI

MOLLUSCA PELECYPODA

PLATE LXXVII

PAGE
FigS. 1, 2. ACTINOPTEKIA TEXTILIS VAR. ARENARIA Hall 457

1. External cast of left valve. X %.

2. Left valve weathered and exfoliated. X %.

Oriskany formation, New York.

68

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MOLLUSCA — PELECYPODA

PLATE LXXVIII

PAGE

Figs. 1, 2. ACTIXOPTERIA VIRGINICA Ohern n. sp 458

1. Imperfect left valve, questionably referred to this species. Hancock.

2. Left valve of type. Four miles southwest of Keyser, W. Va.

Oriskany formation, Ridgely member.

Fig. 3. AVICULOPECTEX ? CUMBERLAXDEXSIS Ohern n. sp 460

Left valve of type. Helderberg formation.

Fig. 4. AVICULOPECTEN TEXT-ILAMELLATI'S Hall 461

Right valve partly exfoliated. New Scotland formation, New York.

Fig. 5. MEGAMBOXIA LAMELLOSA Hall 462

Left valve. Oriskany formation, Ridgely member, Cumberland.

Figs. 6, 7. CYPRICARDIXIA CF. LAMELLOSA Hall 463

6. Left valve.

7. The same enlarged to nearly three diameters.

New Scotland formation, New York.

Fig. 8. CYPRICARDIXIA SUBLAMELLOSA Hall 463

Right valve. New Scotland formation, New York.

Figs. 9, 10. ILIOXIA SIXUATA Hall 464

9. The right valve of the specimen.
10. Cardinal view of the same.

Manlius formation, New York.

Figs. 11, 12. PTERIXEA HALLI Clarke 450

11. Left valve.

12. Left valve partially exfoliated.

New Scotland formation, New York.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LXXVIII

11

MOLLUSCA — PELECYPODA

PLATE LXXIX

PAGE

Figs. 1, 2. BELLEROPHOX CF. AURICULATUS Hall 465

Dorsal and ventral views. Helderberg formation, Cumberland.

Figs. 3, 4. BELLEROPHON HELDERBERGI.E Swartz n. sp 466

Side and dorsal views of the type. Helderberg formation, Keyser
member, Cash Valley.

Figs. 5, 6. CYRTOLITES EXPANSUS Hall 466

Anterior and side views. Oriskany formation, New York.

Fig. 7. LOXONEMA FITCHI Hall 467

Cast somewhat flattened. New Scotland formation, New York.

Fig. 8. LOXONEMA sp 468

Internal cast. Helderberg formation, Keyser member, Cash Valley.

Fig. 9. HoLOPEA sp 468

Ventral view. Helderberg formation, Cumberland.

Figs. 10-12. ORTHONYCHIA TORTUOSA (Hall) 469

Views of shell in different positions. Oriskany formation, Ridgely
member, Cumberland.

Figs. 13, 14. PLATYCERAS NODOSUM Conrad 469

13. Large, partially exfoliated specimen.

14. Internal cast of smaller specimen.

Oriskany formation, Ridgely member, east side Nicholas
Mountain.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LXXIX

MOLLUSC A — GASTROPODA

PLATE LXXX

PAGE

Fig. 1. PLEUROTOMARIA LABROSA Hall 465

Dorsal view of partially exfoliated specimen, preserving spiral band.
Also an enlargement of the surface markings. Becraft forma-
tion, New York.

Figs. 2-9. PLATYCERAS GEBHARDI Conrad 470

2. Lower and upper views of a large specimen.

3, 4. Upper and ventral views of small specimen.

5. Upper view of very large specimen from Warren Point, Penna.

6, 7. Ventral and upper views of specimen with free and expanded

peristome.

8, 9. Upper and lower views of specimen with free but not expanded
peristome.

Oriskany formation, Ridgely member, Cumberland. (All but
fig. 5 after Hall.)

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MOLLUSCA — GASTROPODA

PLATE LXXXI

PAGE

Figs. 1-9. PLATYCERAS GEBHAKDI VAR. VEXTRICOSUM Conrad 471

1, 2. Upper and ventral views.

3, 4. Ventral and upper views of a small individual.

5, 6. Upper and ventral views of a specimen of medium size.

7, 8. Upper and ventral views of a large specimen with contiguous

volutions.
9. Upper view showing a broad sinuosity in the margin.

Oriskany formation, Ridgely member, Cumberland. (After
Hall.)

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MOLLUSCA — GASTROPODA

PLATE LXXXII

PAGE

Figs. 1-6. PLATYCERAS MAGNIFICUM Hall 472

1. Ventral view of a young shell.

2, 3. Dorsal and ventral views of a larger specimen with free volutions.

4. Ventral view of a specimen with the volutions free and the peris-

tome less expanded.

5. Upper view.

6. Upper view of the spire of a large specimen in which all the parts

are symmetrical and well preserved, and the volutions are free
except at the extreme apex.

Oriskany formation, Ridgely member, Cumberland. (After
Hall.)

Figs. 7, 8. PLATYCERAS STJBFALCATUM Ohern n. sp 472

Side and dorsal views. Oriskany formation, Ridgely member, Han-
cock.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LXXXII

MOLLUSCA GASTROPODA

PLATE LXXXIII

PAGE

Figs. 1-3. PLATYCERAS SUBFALCUM Ohern n. sp 472

1. Upper view of a large specimen.

2, 3. Views of type.

Oriskany formation, Ridgely member, Hancock.

Fig. 4. PLATYCERAS PATULUM Hall 473

Ventral view. Oriskany formation, Ridgely member, Cumberland.
(After Hall.)

Figs. 5, 6. PLATYCERAS REFLEXUM Hall 473

5. Ventral view of a small specimen.

6. Upper view of a larger specimen.

Oriskany formation, Ridgely member, Cumberland. (After
Hall.)

74

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MOLLUSCA — GASTROPODA

PLATE LXXXIV

PAGE

Figs. 1, 2. PLATYCEBAS REFLEXUM Hall 473

Two views of a specimen in which the aperture is obtusely quad-
rangular. Oriskany formation, Ridgely member, Cumberland.
(After Hall.)

Figs. 3, 4. PLATYCERAS ? CALLOSUM Hall 474

Dorsal and ventral views. Oriskany formation, Ridgely member,
Cumberland. (After Hall.)

Figs. 5, 6. PLATYCERAS SIXUATUM Hall ? 474

5. Upper view of a small specimen, showing the deep marginal

sinuosity and the strong wrinkled surface.

6. Upper view of a larger specimen.

New Scotland formation, New York.

Figs. 7, 8. PLATYCERAS TRILOBATUM Hall 475

Ventral and upper views. [The striae represented between the aper-
ture and the next volution do not exist in the specimen.] New
Scotland formation, New York.

75

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3 4

MOLLUSCA — GASTROPODA

PLATE LXXXV

PAGE

Figs. 1, 2. PLATYCERAS TENUILIRATUM Hall 476

Upper and dorsal views of a large individual. New Scotland forma-
tion, New York.

Fig. 3. PLATYCERAS ANGULARE Rowe n. sp 476

Dorsal view of type. Oriskany formation, Ridgely member, Warren
Point, Penna.

Figs. 4-6. PLATYCERAS MULTISINUATUM Hall 477

4, 5. Upper and dorsal views of a small specimen.
6. Upper view of a partially exfoliated specimen.
New Scotland formation, New York.

Fig. 7. PLATYCERAS PLATYSTOMUM Hall 477

View of the right side of a specimen, the apex of which is broken
off. New Scotland formation, New York.

Figs. 8, 9. PLATYCERAS SPIRALE Hall 478

Views of internal cast. Helderberg formation, New Scotland mem-
ber, Corriganville.

Figs. 10-13. PLATYCERAS GRACILE Ohern n. sp 478

10. 12. Two views of individual without plications.

11. 13. Views of strongly plicate specimen.

Oriskany formation, Ridgely member, Cumberland.

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11 12

MOLLUSCA — GASTROPODA

PLATE LXXXVI

PAGE

Figs. 1-3. PLATYCERAS SUBCONICUM Ohern n. sp 479

1, 2. Views of type.

3. Individual with low folds.

Oriskany formation, Ridgely member, Cumberland.

Fig. 4. PLATYCERAS NEWBERRYI Hall 479

Side view. Oriskany formation, Ridgely member, Warren Point, Penna.

Figs. 5-7. STROPHOSTYLUS TRAXSVERSUS Hall 480

Upper, ventral, and oblique views. Oriskany formation, Ridgely mem-
ber, Cumberland. ( After Hall. )

Figs. 8, 9. STROPHOSTYLUS MATHERI Hall 481

Dorsal and ventral views. Oriskany formation, Ridgely member, Cum-
berland. (After Hall.)

Fig. 10. STROPHOSTYLUS ANDREWSI Hall 481

Ventral view. Oriskany formation, Ridgely member, Cumberland.
(After Hall.)

FigS. 11, 12. DlAPHOROSTOMA DEPRESSUM (Hall) 482

Lower and dorsal views. New Scotland formation, New York.

Figs. 13, 14. DIAPHOROSTOMA DESMATUM Clarke 483

Upper and ventral views. Oriskany formation, New York.

77

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13

t K^^k.

14

6

MOLLUSCA — GASTROPODA

PLATE LXXXVII

PAGE

Figs. 1, 2. DIAPHOROSTOMA vENTRicosvM (Conrad) 482

Dorsal and ventral views of a large individual. Oriskany formation,
Ridgely member, Cumberland.

Figs. 3, 4. PLATYSTOMA NIAGARENSE Hall 483

Ventral and dorsal views. Helderberg formation, Keyser member,
Keyser, W. Va.

Fig. 5. TENTACULITES ? ACUS Clarke 484

Partially exfoliated specimen. Oriskany formation, New York.

Figs. 6, 7. TENTACULITES ACULUS Hall 485

6. Specimen from the Helderberg formation. New York.

7. Same. X 5.

Figs. 8-10. TENTACULITES ELONGATUS Hall 485

8. An individual of medium size.

9. An exfoliated individual.

10. A portion of the same enlarged, showing the appearance of the annu-
lations. X 4.
New Scotland formation, New York.

Fig. 11. TENTACULITES GYRACANTHUS (Eaton) 486

A shell. X 5. Helderberg formation, Keyser member, Keyser, W. Va.

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MOLLUSCA — GASTROPODA

PLATE LXXXVIII

PAGE

Figs. 1-3. OKTHOCERAS LONGICAMERATUM Hall 487

1. Longitudinal section showing curvature of septa.

2. Internal cast, doubtfully referred to this species.

Helderberg formation, Cumberland.

3. A longitudinal section of a specimen, the septa being proportionally

a little more distant. Coeymans formation, New York.

Fig. 4. OKTHOCERAS SCHUCHERTI Maynard n. sp 487

Internal cast. Helderberg formation, Keyser member, Cumberland.

Fig. 5. ORTHOCERAS RIGIDUM Hall ? 488

Fragment preserving surface ornamentation. Helderberg formation,
Keyser member, Devil's Backbone.

Fig. 6. CYRTOCERAS ? DUBIUM Swartz n. sp 488

Internal cast of type. Helderberg formation, Coeymans member,
Devil's Backbone.

79

MARYLAND GEOLOGICAL SURVEY

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MOLLUSCA — CEPHALOPODA

PLATE LXXXIX

PAGE}

Fig. 1. PROETUS PACHYDERMATUS Barrett 489

Portion of cephalon preserving glabella. X 2. Helderberg formation,
Keyser member, Cumberland.

Figs. 2-4. PROETUS CF. PROTUBERANS Hall 490

2. Cephalon.

3. The pygidium of another individual.

4. Profile of the same.

Coeymans formation, New York.

Figs. 5, 6. CORDANIA CYCLURUS Hall and Clarke 491

5. Fragment of cephalon showing lateral furrows of the glabella a

little too strongly. X 3.

6. Pygidium showing ornamentation. X 3.

New Scotland formation, New York.

Figs. 7, 8. CYATHASPIS AUSTRALIS Ohern n. sp 492

Two views of the type. X 3. Helderberg formation, Cumberland.

Fig. 9. CALYMENE CAMERATA Conrad 494

Pygidium, exfoliated. Helderberg formation, Keyser member, Pinto.

Figs. 10-12. HOMALONOTUS SWARTZI Ohern n. sp 495

10, 11. Detached pleura?.
12. Glabella.

Oriskany formation, Ridgely member, Millers Spring near
Cumberland.

Figs. 13-15. HOMALONOTUS VANUXEMI Hall 496

13, 14. Views of pygidium.
15. Nearly complete cephalon.

Oriskany formation, Ridgely member, Franklin, W. Va.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE LXXXIX

ARTHROPODA— TRILOBITA

PLATE XC

PAGE

Figs. 1, 2. HOMALONOTUS sWARTZi Ohern n. sp 495

Pygidium of type. Oriskany formation, Ridgely member, Berkeley
Springs, W. Va.

Fig. 3. HOMALONOTUS VANUXEMI Hall 496

Complete cephalon. Oriskany formation, Ridgely member, Franklin,
W. Va.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XC

ARTHROPODA — TRILOBITA

PLATE XCI

PAGE

Figs. 1-4. PHACOPS LOGANI Hall 497

1. An entire specimen which has the head compressed from above, and

the eyes slightly distorted.

2. The head of a larger individual which shows the transverse furrows*

and preserves the eyes in their proper form.

3. View of the lower side of the head of another specimen, showing

some crenulations along the marginal furrow.

4. The eye enlarged.

New Scotland formation, New York.

Figs. 5-7. PHACOPS ? sp 498

5. Cephalon exfoliated.
6,7. Pygidia.

Oriskany formation, Ridgely member, Cumberland.

Figs. 8, 9. DALMANITES KEYSERENSIS Swartz n. sp 499

8. Cephalon of the type.

9. Part of a pygidium probably belonging to the same species.

Helderberg formation, Keyser member, Tonoloway.

Figs. 10-11. DALMANITES MICRURUS (Green) 507

10. A small pygidium.

11. A larger pygidium from which the test has been removed, leaving

the cast punctate.
New Scotland formation, New York.

Figs. 12-15. DALMANITES MULTIANNULATUS Ohern n. sp 500

12. Fragments of cheeks.

13. Glabella.

14. Eye and part of cheek.

15. Genal angle.

Oriskany formation, Knobly Mountain, near Cumberland.

Fig. 16. DALMANITES ASPINOSUS Weller 499

Exfoliated pygidium. Helderberg formation, Keyser member, Cash
Valley.

MARYLAND GEOLOGICAL SURVEY

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13

ARTHROPODA — TRILOBITA

PLATE XCII

PAGE

Figs. 1-4. DALMAMTKS MULTIANXULATUS Ohern n. sp 500

1. Exfoliated pygidium showing ornamentation imperfectly.

2. Exfoliated pygidium which does not show the tubercular surface.

3. Hypostoma showing the bifurcating frontal process.

4. Genal angle.

Oriskany formation, Ridgely member, Knobly Mountain near
Cumberland.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XCII

ARTHROPODA TRILOBITA

11

PLATE XCIII

PAGE

Fig. 1. DALMAXITES MULTIANNULATUS Ohern n. sp 500

Fragment of an exfoliated pygidium. Oriskany formation, Ridgely
member, Knobly Mountain, near Cumberland.

Fig. 2. DALMANITES LATUS Ohern n. sp , 502

Imperfect pygidium of type. Oriskany formation, Ridgely member,
Cumberland.

Fig. 3. DALMANITES (SYNPHORIA) STEMMATUS Clarke 503

Exfoliated cephalon. Oriskany formation, Ridgely member, Cumber-
land.

Fig. 4. DALMANITES (CORYCEPHALUS) DENTATUS Barrett ? 505

Pygidium. Oriskany formation, Ridgely member, Evick Gap opposite
Franklin, W. Va.

Fig. 5. DALMANITES (CHASMOPS) ANCHIOPS (Green) 508

Pygidium. Oriskany formation, Ridgely member.

Figs. 6-10. DALMANITES (HAUSMANNIA) PLEUROPTYX (Green) 510

6. Imperfect pygidium. Helderberg formation, New Scotland member,

Devil's Backbone.

7. Young specimen enlarged showing the characteristic features of

species.

8. Profile of the head, showing the form and elevation of the eye.

9. Exfoliated glabella, genal angles restored.
10. A large exfoliated pygidium.

New Scotland formation, New York.

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10

ARTHROPODA — TRILOBITA

PLATE XCIV

PAGE

Fig. 1. DALMAXITES BEKKELEYENSIS Swartz n. sp 512

Pygidium of type specimen. Oriskany formation, Ridgely member, 3
miles north of Berkeley Springs, W. Va.

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ARTHROPODA — TRILOBITA

PLATE XCV

PAGE

Figs. 1-3. APARCHITES GORDON: Ulrich and Bassler n. sp 515

1. Lateral view of left valve. X 20.

2, 3. Longitudinal and vertical sections of same. X 20.

Helderberg formation, Keyser member, Cumberland.

Fig. 4. PRIMITIA POSTTURGIDA Ulrich and Bassler n. sp 515

The unique right valve on which this species is founded, showing the
flattened anterior spine and the posterior marginal swelling.
X 20. Oriskany formation, 21st Bridge.

Fig. 5, PRIMITIA ? CUMBERLANDICA Ulrich and Bassler n. sp 516

A left valve showing the subcentral pit, strongly reticulated surface
and elevated rim. X 20. Helderberg formation, Keyser mem-
ber, Cumberland.

Figs. 6-8. PRIMITIA ? CONCENTRICA Ulrich and Bassler n. sp 517

Lateral, dorsal, and anterior views of a right valve. X 20. Oriskany
formation, 21st Bridge.

Figs. 9, 10. PRIMITIELLA VARIOLATA Ulrich and Bassler n. sp 518

Lateral and dorsal edge views of a right valve. X 20. Oriskany forma-
tion, 21st Bridge.

Fig. 11. ULRICHIA A:QUALIS Ulrich and Bassler n. sp 518

Right valve showing the usual form and obscure surface reticulation.
X 20. Oriskany formation, 21st Bridge.

Figs. 12-15. STREPULA IRREGULARIS Jones and Holl 519

12. An incomplete large left valve. X 20.

13, 14. Two right valves of the average size showing differences in the

surface ornament and outline. X 20.
15. Ventral edge view of original of fig. 13. X 20.

Fig. 16. HALLIELLA ? SEMINULUM VAR. LONGA Ulrich and Bassler n. var. . . 520
A right valve slightly injured along the margin. X 20. Helderberg
formation, Keyser member, Cumberland.

Figs. 17, 18. HALLIELLA ? TRIPLICATA Ulrich and Bassler n. sp 521

17. Right valve. X 20.

18. End view of same. X 20.

Helderberg formation, Keyser member, Cumberland.

Figs. 19-21. JECHMINA CUSPIDATA Jones and Holl 521

19. Left valve showing the extraordinary development of the spine.

X 20.

20. 21. Lateral and anterior end views of a right valve. The variation

shown in outline of body of valve is probably due to accident.
X 20.
Helderberg formation, New Scotland member, 21st Bridge.

Figs. 22-24. MESOMPHALUS HARTLEYI Ulrich and Bassler n. gen. and sp. . . 523

22. Lateral view of right valve showing the ventral swelling. X 20.

23. An average right valve without the ventral pouch. X 20.

24. Left valve of a rather small complete carapace. X 20.

Helderberg formation, Keyser member, Cumberland.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XCV

10

15

18

ARTHROPODA — OSTRACODA

PLATE XCVI

PAGE

Figs. 1-3. MESOMPHALUS HARTLEYI Ulrich and Bassler n. gen. and sp 523

1, 2. Ventral and posterior end views of a female individual. X 20.
3. Highly magnified view of the surface of original of fig. 24, pi. xcv.

Figs. 4, 5. MESOMPHALUS SUBMARGINATA Ulrich and Bassler n. sp 523

Lateral and ventral edge views of the type specimen. X 20. Helder-
berg formation, Keyser member, Cumberland.

Figs. 6-9. CTENOBOLBINA ? DENTICULATA Ulrich and Bassler n. sp 524

6. Lateral view of one of the type specimens, a left valve with a portion

of the flange broken away and the surface simply granulose.
X 20.

7. Dorsal edge view of the same specimen. X 20.

8. A right valve showing pits between the granules of the surface.

X 20.

9. Ventral edge view of same. X 20.

Helderberg formation, Keyser member, Cumberland.

Figs. 10-12. CTENOBOLBINA ? DUBIA Ulrich and Bassler n. sp 525

10. Left side of complete carapace. X 20.

11, 12. Ventral and posterior edge view of same. X 20.

Helderberg formation, Keyser member, Cumberland.

Figs. 13-15. BOLLIA AMERICANA Ulrich and Bassler n. sp 525

Lateral, ventral and posterior views of a left valve. X 20. Oriskany
formation, 21st Bridge.

Figs. 16, 17. BOLLIA CURTA Ulrich and Bassler n. sp 526

Side and ventral views of a left valve of this well-marked species.
X 20. Oriskany formation 21st Bridge.

Fig. 18. BOLLIA IRREGULARIS Ulrich and Bassler n. sp 527

Lateral view of right valve. X 20. Helderberg formation, New Scot-
land member, 21st Bridge.

Fig. 19. BOLLIA JUGALIS Ulrich and Bassler n. sp 527

A left valve showing the ventral coalescence of the median and mar-
ginal ridges. X 20. Oriskany formation, 21st Bridge.

Figs. 20-22. BOLLIA UNGULA Jones 528

Lateral, ventral and posterior views of a left valve. X 20. Oriskany
formation, 21st Bridge.

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14

17

18

21

22

ARTHROPODA — OSTRACODA

PLATE XCVII1

PAGE

Figs. 1-4. KLCEDENIA CENTRICORNIS Ulrich and Bassler 529

1. Lateral view of left valve (female individual) broken anteriorly.

X 20.

2. Left valve of a complete carapace. X 20.

3. 4. Posterior and ventral views of same specimen. X 20.

Figs. 5-7. KLCEDENIA FIMBRIATA Ulrich and Bassler 529

5. Lateral view of a perfect left valve. X 20.

6, 7. Ventral and end views of same specimen. X 20.

Coeymans formation, Herkimer County, New York.

Figs. 8, 9. LEPEKDITIA ALTOIOES Weller 513

8. Left valve. X 2^.

9. Right valve. X 2%.

Decker Ferry formation, Flatbrookville, New Jersey.

Fig. 10. LEPERDITIA GIGANTEA Weller 514

A left valve, natural size. Rondout formation, Nearpass Quarry, New
Jersey.

Fig. 11. LEPERDITIA ELONGATA Weller 514

A right valve. X 2. Rondout formation, Nearpass Quarry, New
Jersey.

Figs. 12, 13. KLCEDENIA NEARPASSI (Weller) 530

Left and right valves. X 6. Decker Ferry formation, Nearpass Quarry,
New Jersey.

Figs. 14, 15. KLCKDENIA SUSSEXENSIS (Weller) 532

Two left valves showing slight variations. X 4 and X 6. Decker
Ferry formation, Nearpass Quarry, New Jersey.

Fig. 16. KLCEDENIA KUMMELI (Weller) 531

A left valve. X 3. Rondout formation, Nearpass Quarry, New Jersey.

Fig. 17. KLCEDENIA BARRETTI (Weller) 532

A right valve. X 5. Decker Ferry formation, Nearpass Quarry, New
Jersey.

Figs. 18-20. KLCEDENELLA PENNSYLVANIA (Jones) 533

Left side, end and ventral views of a complete carapace. X 15. Helder-
berg formation, Pennsylvania.

Fig. 21. KLCEDENELLA CLARKEI (Jones) 533

Right valve. X 20. Helderberg formation, Herkimer County, New
York.

'Figs. 8-17 (after Weller), Figs. 18-21 (after Jones).

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XCVII

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ARTHROPODA — OSTRACODA

PAGE

Figs. 1-3. KIXEDENELLA cLARKEi VAB. PAUPERA Ulrich and Bassler 534

1. Left side of complete carapace showing the emaciated appearance

and the granules in some of the furrows.

2, 3. Ventral and anterior end views of same.

Helderberg formation, Keyser member, Cumberland.

Figs. 4-6. KLCEDENELLA TUKGIDA Ulrich and Bassler 535

4. Right valve of an unusually short specimen. X 20.

5, 6. Left and right valves of an average specimen. X 20.

Helderberg formation, Keyser member, Cumberland.

Fig. 7. KLCEDENELLA TUKGIDA VAR. VENTROSA Ulrich and Bassler 535

Left valve of a complete carapace. X 20. Helderberg formation,
Keyser member, Cumberland.

Fig. 8. THLIPSURA MTILTIPUNCTATA Ulrich and Bassler n. sp 536

Lateral view of right valve. X 20. Oriskany formation, 21st Bridge.

Figs. 9-11. OCTONARIA ? ANGULATA Ulrich and Bassler n. sp 537

Two right and a left valve showing slight variations in outline and
markings. X 20. Helderberg formation, Keyser member, Cum-
berland.

Figs. 12-18. OCTONARIA IN.EQUALIS Ulrich and Bassler n. sp 538

12-14. Left side and posterior and ventral views of a complete carapace.
X 20.

15. Right side of another specimen more elongate than usual, showing

the relatively small size and different pitting of the right valve
as compared with the left valve. X 20.

16. Left valve of a somewhat shorter form in which the two lower pits

are confluent. X 20.
17, 18. Longitudinal and ventral sections of same. X 20.

Helderberg formation, Keyser member, Cumberland.

Fig. 19. OCTONARIA SIMPLEX (Krause) 538

Left valve. X 20. Helderberg formation, Keyser member, Cumber-
land.

Fig. 20. CRATERELLINA OBLONGA Ulrich and Bassler n. sp 540

Right valve showing the crater-like anterior pit and the somewhat
irregular shape pertaining to this species. X 20. Oriskany
formation, 21st Bridge.

Fig. 21. CRATERELLINA ROBUSTA Ulrich and Bassler n. sp 539

A characteristic right valve of this large and well marked species.
X 20. Oriskany formation, 21st Bridge.

Fig. 22. BYTHOCYPRIS PUNCTULATA VAR. ARCTATUM Ulrich and Bassler n.

var 540

Lateral view of left valve. X 20. Helderberg formation, Keyser
member, Cumberland.

Figs. 23-25. PONTOCYPRIS ARCUATA Ulrich and Bassler n. sp 541

23. Right side of a complete carapace. X 20.

24, 25. Dorsal outline and posterior end view of same specimen. X 20.

Helderberg formation, Keyser member, Cumberland.

Figs. 26-28. PONTOCYPRIS MAWII VAR. BREVIATA Jones 541

26. Left valve. X 20.

27. Outline from the dorsal side. X 20.

28. Anterior outline view, showing dorsal overlap of the right valve

and ventral overlap of the left.

Helderberg formation, Keyser member, Cumberland.

Figs. 29-31. PACHYDOMELLA LONGULA Ulrich and Bassler n. sp 542

29. Right valve. X 20.

30. 31. Ventral and posterior end views of same. X 20.

Helderberg formation, Keyser member, Cumberland.

MARYLAND GEOLOGICAL SURVEY

LOWER DEVONIAN, PLATE XCVIII

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ARTHROPODA OSTRACODA

DEVONIAN

MIDDLE

NOTE

Plates I to VI, illustrating the Geological and Paleontological Relations of
the Middle and Upper Devonian, are bound with the text volume. The follow-
ing plates (Plates VII to XLIV) illustrate the Systematic Paleontology of the
Middle Devonian of Maryland.

12

PLATE VII

PAGE

Fig. 1. STEREOLASMA RECTUM (Hall) 119

Upright view of corallum. X l1/^. Romney formation, Hamilton mem-
ber, Ernstville.

Fig. 2. CF. AMPLEXUS HAMILTONI^, Hall 120

Upright view of corallum. Romney formation, Hamilton member,
Evitts Creek.

Fig. 3. HELIOPHYLLUM sp 121

Upright view of part of corallum, epitheca partly exfoliated showing
the septa. X l1^. Romney formation, Hamilton member,
Ernstville.

Figs. 4, 5. CYSTIPHYLLUM AMERICANTJM Milne-Edwards and Haime (?).. 121

4. Upright view of corallum.

5. Transverse section of the same.

Romney formation, Hamilton member, Evitts Creek.

Fig. 6. POLYGNATHUS sp. undet 122

Incomplete jaw. The tips of four or five teeth which were discernible
on the specimen are not brought out in the illustration. Tonolo-
way. (After Kindle.) Romney formation, Onondaga member.

Figs. 7-9. RHOPALONARIA TENUIS Ulrich and Bassler 123

7, 8. Two small portions of the zoarium which on account of the fre-
quent crossing of the branches do not show the characteristic
pinnate arrangement of the rows of cells. X 9.
Romney formation, Hamilton member, Evitts Creek.

9. View of one of the type specimens of this species. (After Ulrich

and Bassler.) Thedford, Ont. X 9.

Figs. 10-12. MONTICULIPORA (?) MARYLANDENSIS Ulrich and Bassler n. sp. . 123

10. Vertical section, showing tabulation. X 20.

11. Tangential section. X 20.

12. Several zorecia of same, to show structure of walls and acantho-

pores. X 35.

Romney formation, Hamilton member, Evitts Creek.

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE VII

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CCELENTERATA — ANTHOZOA, VERMES — CH^ETOPODA AND MOLLUSCOIDEA — BRYOZOA.

PLATE VIII

PAGE
FigS. 1-4. LlNGULELLA (?) PALIFORMIS Hall 124

1. Interior of dorsal valve (?). Evitts Creek.

2. Ventral valve, showing faintly the pedicle-groove. Evitts Creek.

x iy2.

3. A partly exfoliated valve. Evitts Creek. X 1%.

4. Ventral valve, the specimen showing the pedicle-groove. Williams

Road, 3% miles southeast of Cumberland. X 2.
Romney formation, Hamilton member.

Pig. 5. LINGULA DELIA Hall (?) 125

Ventral valve (?) showing strong median septum. X 1%. Romney
formation, Hamilton member, Evitts Creek.

Fig. 6. LINGULA LIGEA Hall (?) 126

Interior of partly exfoliated valve. X 2y2. Romney formation,
Hamilton member, 21st Bridge.

Figs. 7, 8. LINGULA CF. NUDA Hall 127

7. Partly exfoliated distorted valve. X 2y2. Romney formation, Onon-

daga member, Williams Road, 3% miles southeast of Cumber-
land.

8. Partly exfoliated ventral valve (?). X 1%. Romney formation,

Hamilton member, Oldtown Road, east of Cumberland.

Figs. 9, 10. LINGULA NUDA Hall 127

Separate valves showing the usual variety of form in this species.
Hamilton formation, New York.

Fig. 11. LINGULA CF. COMPTA Hall and Clarke 128

View of crushed and broken specimen. X 1*4. Romney formation,
Hamilton member, Evitts Creek.

Figs. 12, 13. LINGULA CLARKI n. sp 128

Partly exfoliated valves showing strong median convexity. X 3. Rom-
ney formation, Hamilton member, 21st Bridge.

Figs. 14-17. ORBICULOIDEA LODIENSIS VAR. MEDIA (Hall) 129

14. Interior of dorsal valve. X 2.

15. Exterior ventral valve showing the pedicle-groove. X 2.

Romney formation, Hamilton member, Evitts Creek.

16. Interior of a partly exfoliated ventral valve. The more exfoliated

portions are smooth, not striated, as indicated by figure. Bells
Gap, Va.

17. Natural cast of the exterior of ventral valve, showing concentric

striae. East of Cumberland.
Romney formation, Onondaga member. (After Kindle.)

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE VIII

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MOLLUSCOIDEA — BRACHIOPODA

PLATE IX

PAGE

Figs. 1-7. CRANIELLA HAMILTOXM: Hall 131

1. Internal impression of dorsal valve. X 1%.

2. Upper or dorsal valve from which the shell is gone near the margin.

X 2.

3. Enlargement of part of preceding showing the finely punctate shell

structure. X 6.
Romney formation, Hamilton member, Evitts Creek.

4. Interior of a lower valve attached to a Streptelasma.

5. Three individuals of different sizes, attached to the surface of

Tropidoleptus carinatus.

6. Dorsal valve.

7. Internal impression of dorsal valve. X 2.

Hamilton formation, New York.

Fig. 8. PHOLIDOPS HAMILTONI.E Hall 132

Interior of valve. X 8. Romney formation, Onondaga member, Wil-
liams Road, 3% miles southeast of Cumberland.

Figs. 9, 10. PHOLIDOPS CF. AREOLATA (Hall) 133

9. Cast of the ventral valve.

10. Internal cast of the ventral valve. The slender impressed median
line of the figure has about twice the proper length. It is con-
spicuous only near the apex of the crescent-shaped depression.
X5.

Romney formation, Onondaga member, Bells Valley, Virginia.
(After Kindle.)

Figs. 11-17. STROPHEODONTA (LEPTOSTROPHIA) PERPLAXA (Conrad) 134

11. Partly exfoliated interior of dorsal valve. Iron Bridge over Town

Creek, northeast of Oldtown.

12. Apparently exfoliated interior of dorsal valve, same locality.

13. Internal impression of small ventral valve. X 1%. Williams Road,

% mile east of Queen City Hotel, Cumberland.

14. Further enlargement of preceding specimen, showing crenulated

hinge-line. X 3.

15. Internal impression showing median ridge. Iron Bridge over Town

Creek, northeast of Oldtown.

16. Internal impression of ventral valve showing muscular impres-

sions. McCoys Ferry.
Romney formation, Hamilton member.

17. An enlargement of the striae. Hamilton formation, New York.

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE IX

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MOLLUSCOIDEA — BRACHIOPODA

PLATE X

PAGE

Fig. 1. STROPHEODONTA DEMISSA (Conrad) 136

Ventral valve. Romney formation, Hamilton member, Hancock-Har-
risonville Road, about 2 miles north of Hancock.

Figs. 2-5. STROPHEODONTA (DOUVILLINA) IN^QUISTRIATA (Conrad) 138

2. Interior of ventral valve, showing fragment of shell near lateral

margin.

3. Enlargement of same, showing striae. X 6.

4. Squeeze of No. 2.

Romney formation, Hamilton member, Evitts Creek.

5. Interior of ventral valve. Hamilton formation, New York.

Figs. 6, 7. STROPHEODONTA CONCAVA Hall 139

6. Interior of dorsal valve, showing its strongly pustulose character

and part of crenulated hinge-line. Romney formation, Hamilton
member, Evitts Creek.

7. Ventral valve which is carinate along the center. Hamilton forma-

tion, New York.

Figs. 8, 9. PHOLIDOSTROPHIA PENNSYLVANIA Kindle 141

8. Ventral valve of type. X 3. East of Cumberland.

9. Interior of ventral valve, showing short and very slender median

septum. Berkeley Springs, W. Va.
Romney formation, Onondaga member. (After Kindle.)

Figs. 10, 11. LEPT.ENA RHOMBOIDALIS (Wilckens) 141

10. Fragment of ventral valve. Romney formation, Hamilton member,

Ernstville.

11. View of dorsal valve. Hamilton formation, New York.

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE X

10

MOLLUSCOIDEA — BRACHIOPODA

PLATE XI

PAGE

Figs. 1-5. LEPT/ENISCA AUSTRALIS Kindle 143

1-3. Ventral valves. Fig. 1X2. Berkeley Springs, W. Va.

4. Type specimen, ventral valve. X 2. Berkeley Springs, W. Va.

5. Interior of dorsal valve. New Bloomfield, Pa.

Romney formation, Onondaga member. (After Kindle.)

Figs. 6-10. SCHUCHEBTELLA vARiABiLis Prosser n. sp 144

6. Dorsal valve ( ?). Williams Road, % mile east of Queen City Hotel,

Cumberland.

7. Ventral valve. X I1/!. Same locality.

8. Portion of same enlarged to show character of striae. X 4.

9. Dorsal valve (?).

10. Portion of same enlarged to show regular variation in strength of
radiating striae. X 4.

Romney formation, Hamilton member.

Figs. 11-1 7. CHONETES MUCBONATUS Hall 146

11. Ventral valve. X 2. McCoys Ferry.

12. Ventral valve, showing two spines near each cardinal angle. X 2.

Same locality.

13. Partly exfoliated interior of ventral valve, showing cardinal spine.

X 2. Same locality.

14. Interior of ventral valve showing muscular impressions and one

cardinal spine. X 2. Same locality.
Romney formation, Hamilton member.

15. Dorsal valve, showing cardinal spines. Hamilton formation, New

York.

16. Small pedicle valve. X 3. Cumberland.

17. A pedicle valve of average size and appearance, showing the long

spines. X 2. Cumberland.
Romney formation, Onondaga member. (After Kindle.)

Figs. 18-21. CHONETES COBOXATUS (Conrad) 148

18. Partly exfoliated ventral valve, showing shallow median sinus and

cardinal spines. Evitts Creek.

19. Interior of ventral valve, showing pustulose pittings toward margin

of shell. Hancock-Harrisouville Road, about 2 miles north of
Hancock.

20. Dorsal valve. Hancock-Harrisonville Road, about 2 miles north of

Hancock.

21. Interior of ventral valve showing pustulose pittings. McCoys

Ferry.
Romney formation, Hamilton member.

Figs. 22-25. CHOXETES SETIGER (Hall) 152

22. Ventral valve, partly exfoliated. X 2. Iron Bridge over Town

Creek, northeast of Oldtown.

23. Dorsal valve. X 1%. West of Tonoloway Ridge.

24. Interior of ventral valve, showing pustulose pittings toward margin

of shell. X 1%. McCoys Ferry.

Romney formation, Hamilton member.

25. Ventral valve showing cardinal spines. X 2. Hamilton formation,

New York.

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN. PLATE XI

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MOLLUSCOIDEA — BRACHIOPODA

PLATE XII

PAGE

Figs. 1-8. CHONETES SCITULUS Hall 150

1. Interior of ventral valve. X l1/^. 21st Bridge.

2. Ventral valve. X 1%. Right bank of Potomac about 4 miles south

of Cumberland.

3. Ventral valve. X \Vz- Same locality.

4. Dorsal valve of same specimen, showing cardinal area and spines of

ventral valve. X 1%.

5. Partly exfoliated dorsal valve (?). X 1%. Iron Bridge over Town

Creek northeast of Oldtown.

6. Interior of ventral valve. X 21/i. B. & O. R. R. cut opposite Han-

cock.

7. Dorsal valve (?). X 1%. McCoys Ferry.

Romney formation, Hamilton member.

8. Dorsal valve, showing cardinal area and deltidium. Hamilton

formation, New York.

Figs. 9-13. CHOXETES LEPIDUS Hall 153

9. Ventral valve partly exfoliated, showing two cardinal spines. X 3.
Evitts Creek.

10. Valve showing three cardinal spines. X 4. Evitts Creek.

11. Interior of dorsal valve (?). X 3. Iron Bridge over Town Creek,

northeast of Oldtown.

12. Interior of ventral valve, showing cardinal teeth. X 3. West of

Tonoloway Ridge.

13. Ventral valve (?). X 3. B. & 0. R. R. cut opposite Hancock.

Romney formation, Hamilton member.

Figs. 14-21. CHONETES vicixus (Castelnau) 155

14. Ventral valve. Evitts Creek.

15. Portion of the same near the umbo, showing the intercalation of

radiating and fine concentric striae. X 8.

16. Partly exfoliated ventral valve showing one cardinal spine. X 1^4'

Iron Bridge over Town Creek, northeast of Oldtown.

17. Interior of ventral valve. X 11A. McCoys Ferry.

18. Interior of dorsal valve. X 2. Hancock-Harrisonville Road, 2

miles north of Hancock.

19-20. Exteriors of ventral valves. X 2. Same locality.
21. Interior of the dorsal valve. X 3. Same locality.
Romney formation, Hamilton member.

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XII

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MOLLUSCOIDEA — BRACHIOPODA

PLATE XIII

PAGE

Figs. 1-6. CHONETES MABYLANDICUS Prosser n. sp 157

1. Partly exfoliated interior of dorsal valve. X 1V2. 21st Bridge.

2. Interior of ventral valve. X 1%. Same locality.

3. Exterior of dorsal valve. X 1%. Same locality.

4. Portion of the same enlarged, showing the bifurcating striae and the

radiating thread-like ones. X 5.

5. Partly exfoliated interior of dorsal valve. X 2. 21st Bridge.

6. Interior of ventral valve, showing rounded median ridge. X 1%.

Same locality.
Romney formation, Hamilton member.

Figs. 7-9. CHONETES BUGOSTJS Kindle 158

7. Exfoliated ventral valve, showing imperfectly the subtended proc-

esses of the mucronate spines. X 2.

8. Type, showing a ventral valve with the peculiar spines attached

latterly to the hinge line. X 2.

9. Natural mold of the exterior of a ventral valve. X 2.

Romney formation, Onondaga member, 3 miles east of Cum-
berland. (After Kindle.)

FigS. 10-13. ANOPLEA NUCLEATA 159

10, 11. Casts of two ventral valves, showing two types of medium sep-
tum, one terminating anteriorly in an indistinct Y-shaped proc-
ess. X 3.

12. Cardinal view of natural cast of pedicle valve, showing filling of

oblique cardinal tubes. X 5.

13. Pedicle view.

Romney formation, Onondaga member, Mendota, Va. ( After
Kindle.)

Figs. 14-16. STROPHALOSIA TKTJNCATA (Hall) 160

14. Exfoliated ventral valve, showing truncated umbo. X 3. Iron

Bridge over Town Creek, northeast of Oldtown.

15. Part of an exfoliated ventral valve. X 4. Same locality.

16. Exfoliated dorsal valve. X 2. Evitts Creek.

Romney formation, Hamilton member.

Fig. 17. PRODUCTEIXA CF. SPINULICOSTA Hall 162

Exfoliated ventral valve. X 2. Williams Road. */£ mile east of Queen
City Hotel, Cumberland. Romney formation, Hamilton member.

Figs. 18-20. PRODUCTELLA SPINULICOSTA Hall 162

18. Ventral valve of a small broad form.

19. Cardinal view of ventral valve.

20. Small individual imbedded in the rock and showing attached

spines.
Hamilton formation, New York.

Fig. 21. PRODUCTELLA ( ?) SCHUCHERTI Prosser n. sp 163

Imperfect ventral valve. Ernstville.

Figs. 22-25. DALMANELLA LENTICULARIS (Vanuxem) 164

22. Dorsal view. X 2.

23. Interior of a dorsal valve.

24. 25. Two fragmentary casts of ventral valves.

Romney formation, Onondaga member, Berkeley Springs, W
Va. (After Kindle.)

Figs. 26-29. RHIPIDOMELLA VANUXEMI Hall 165

26. Ventral valve. Evitts Creek.

27. Dorsal valve of same specimen.

28. Interior of dorsal valve. Williams Road, */£ mile east of Queen

City Hotel, Cumberland.

Romney formation, Hamilton member.

29. An enlargement of the surface stria?. Hamilton formation, New

York.

M

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XIII

MOLLUSCOIDEA — BRACHIOPODA

PLATE XIV

PAGE

Figs. 1-5. RHIPIDOMELLA LEUCOSIA Hall 166

1. Interior of dorsal valve. Williams Road, % mile east of Queen City

Hotel, Cumberland. Romney formation, Hamilton member.

2. Dorsal valve of specimen of ordinary size.

3. Ventral valve of the same.

Hamilton formation, New York.

4. Interior of dorsal valve showing cardinal process and dental sockets.

Little Run, near Hancock.

5. Interior of ventral valve showing muscle scars. Two miles north of

Hancock.

Romney formation, Hamilton member.

Figs. 6-9. RHIPIDOMELLA PENELOPE Hall 167

6. Broken specimen of ventral valve (?). Evitts Creek. Romney

formation, Hamilton member.

7. Interior of dorsal valve. Cumberland.

8. Enlargement of surface, showing the character of the striae, the

ordinary puncta and the elongate tubular openings.

9. Interior of ventral valve showing the muscular impressions and

cardinal teeth.

Hamilton formation, New York.

Fig. 10. RHIPIDOMELLA CYCLAS Hall (?) 169

10. External impression of ventral valve. X 1%. Williams Road near

church, S1/^ miles southeast of Cumberland.

Figs. 11, 12. DALMAXELLA LENTICULAKIS (Vanuxem) 164

11. Dorsal valve (?). X l1^. Ernstville.

12. External impression of dorsal valve. X l1/^. Hanging Rock,

W. Va.

Romney formation, Onondaga member.

Figs. 13, 14. SCHIZOPIIOEIA STBIATULA (Schlotheim) (?) 170

13. Partly exfoliated ventral valve. Ernstville.

14. A portion of the lateral margin enlarged, showing punctate

structure. X 5.

Romney formation, Hamilton member.

Figs. 15-17. CAMAROTCECHIA CONGREGATA (Conrad) 171

15. Interior of dorsal valve. X I1/!-

16. Interior of somewhat distorted small dorsal valve. X I1/*.

17. Partly exfoliated ventral valve. X 1%. Run at eastern end of

Hancock.

Romney formation, Hamilton member.

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XIV

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MOLLUSCOIDEA — BRACHIOPODA

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PLATE XV

PAGE

Figs. 1-3. CAMABOTCECHIA PROLIFICA Hall 173

1. Exfoliated ventral valve. X 1%. Right bank of Potomac, about 4

miles south of Cumberland. Romney formation, Hamilton
member.

2. Ventral valve of an unusually large specimen.

3. Interior of dorsal valve.

Hamilton formation, New York.

Fig. 4. CAMAROTCECHIA SAPPHO Hall 174

Interior of ventral valve. Romney formation, Hamilton member.

Fig. 5. CAMAROTCECHIA sp 175

Interior of ventral valve. X l1^. Flintstone Creek in Gilpin. Romney
formation, Hamilton member.

Figs. 6-8. LIORHYNCHTJS LIMITARE (Vanuxem) 175

6, 7. Crushed and broken dorsal valves. X 1%. 21st Bridge.
8. Young specimen crushed. X 3. Same locality.
Romney formation, Marcellus member.

Figs. 9-12. LIORHYXCHUS LAURA (Billings) 177

9. Somewhat distorted and crushed exfoliated dorsal valve. X 1%.
Williams Road near church, Sy2 miles southeast of Cumberland.

10. Interior of dorsal valve. X l1^. Williams Road near church, 3^5

miles southeast of Cumberland.

Romney formation, Hamilton member.

11. Dorsal valve of typical specimen.

12. Cardinal view.

Hamilton formation, New York.

Figs. 13-17. LIORHYNCHUS CF. MYSIA 178

13-15. Dorsal, ventral and side view of shell of usual size.

16. Dorsal view of larger specimen with duplicate plications.

17. Dorsal view of large individual.

Marcellus formation, New York.

Figs. 18-23. EUNELLA LINCKL^ENI Hall 179

18. Interior of ventral valve, distorted by pressure. Iron Bridge over

Town Creek northeast of Oldtown.

19. Interior of dorsal valve of same specimen.

20. Interior of dorsal valve. Road east of Pine Hill, about 4 miles

north of Oldtown.

21. Partly exfoliated ventral valve of same specimen.

22. Enlargement showing shell structure of same. X about 20.

Romney formation, Hamilton member.

23. Brachial loop. Hamilton formation, New York.

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XV

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MOLLUSCOIDEA — BRACHIOPODA

PLATE XVI

PAGE

Figs. 1-3. CENTROXEIXA CF. OVATA Hall 179

Dorsal, side and ventral view of shell. Onondaga formation, New
York.

Figs. 4-6. ATRYPA RETICULARIS (Linn6) 183

4. Partly exfoliated ventral valve (?).

5. Dorsal valve.

6. Ventral valve.

Romney formation, Hamilton member, Evitts Creek.

Figs. 7-14. TROPIDOLEPTUS CARINATUS (Conrad) 181

7. 8. Ventral and dorsal valves of large specimen. 21st Bridge.

9, 10. Ventral and dorsal valves of medium specimen. Same locality.

11. Surface enlarged showing punct*. X 4. Evitts Creek.

12. Exterior of ventral valve.

13, 14. Interior of ventral and dorsal valves. X 2. Near Tonoloway
Ridge, Washington County.

Romney formation, Hamilton member.

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XVI

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MOLLUSCOIDEA — BRACHIOPODA

PLATE XVII

PAGE

Figs. 1-9. CYRTINA HAMILTOXEXSIS Hall 185

1. Interior of ventral valve distorted by crushing. McCoys Ferry.

2. Cardinal area of same, showing delthyrium.

3. Interior of dorsal valve. McCoys Ferry.

4. Dorsal valve. McCoys Ferry. X 1%.

5. Enlarged part of shell showing its structure. X 4. National Road

northeast of Cumberland.

6. Cardinal area of ventral valve. X 2. Near Hancock.

7. 8. Internal casts of ventral valve. Near Hancock.

Romney formation, Hamilton member.

9. Dorsal valve and cardinal area of ventral valve, showing the

elongate foramen on the deltidial plate. Hamilton formation,
New York.

Figs. 10-18. SPIRIFEB MUCRONATUS (Conrad) 187

10. Ventral valve. Evitts Creek.

11. Dorsal valve of same.

12. Interior of ventral valve. Iron Bridge over Town Creek, northeast

of Oldtown.

13. Interior of dorsal valve. Same locality.

14. Interior of partly exfoliated dorsal valve. McCoys Ferry.
15-17. Exteriors of ventral valves. Near Hancock.

18. Interior of ventral valve. Near Hancock.

Romney formation, Hamilton member.

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XVII

17 18

MOLLUSCOIDEA — BRACK IOPODA

PLATE XVIII

PAGE

Figs. 1-6. SPIRIFER GRANULOSUS (Conrad) 190

1. Ventral valve. 21st Bridge.

2. Interior of ventral valve. Flintstone Creek in Gilpin.

3. Interior of dorsal valve of same specimen.

4. Enlarged portion of surface from sinus of ventral valve, showing

the small granules. X 2. Evitts Creek.

5. Same more highly magnified. X 8.

Romney formation, Hamilton member.

6. An enlargement of the surface, showing its papillose character.

Hamilton formation, New York.

Figs. 7-9. SPIRIFER AUDACULUS (Conrad) 192

7. Ventral valve, partly exfoliated. Evitts Creek.

8. Interior of ventral valve. Warrior Mountain, east of Rush.

9. Interior of dorsal valve and cardinal area of ventral valve. West-

ern Maryland.

Romney formation, Hamilton member.

Fig. 10. SPIRIFER ACUMINATUS (Conrad) 193

Interior of broken dorsal valve. McCoys Ferry. Romney formation,
Hamilton member.

101

MARYLAND GEOLOGICAL SURVEY

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i i i
5

MOLLUSCOIDEA — BRACHIOPODA

PLATE XIX

PAGE

Figs. 1-7. SPIRIFEB TULLIUS Hall 195

1. Interior of ventral valve. Hancock-Harrisonville Road, about 2

miles north of Hancock.

2. Interior of small ventral valve. X l1/^. Same locality.

3. Exterior of ventral valve. Near Hancock.

4. Interior of dorsal valve. Little Run, near Hancock.

5. Cardinal view of ventral valve. Near Hancock.

6. Enlargement of same, showing fine striae on sinus and plications.

X 4i/2.
Romney formation, Hamilton member.

7. Dorsal valve of average specimen. Hamilton formation, New York.

Figs. 8, 9. SPIRIFER ANGUSTUS Hall 196

8. Cardinal view of internal cast. Warrior Mountain, east of Rush.

Romney formation, Hamilton member.

9. Dorsal valve of rather large individual. Hamilton formation, New

York.

Figs. 10-12. SPIRIFER (RETICULARIA) FIMBRIATUS (Conrad) 197

10. Partly exfoliated dorsal valve. Evitts Creek.

11. Cardinal view of internal cast. Hardy County, W. Va.

12. An enlargement of the surface, showing the bases of the spinules.

Romney formation, Hamilton member.

Fig. 13. SPIRIFER CF. COXSOBRIXUS (d'Orbigny) 198

Interior of ventral valve. Town Creek, 6 miles north of Oldtown.
Romney formation, Hamilton member.

Figs. 14-16. SPIRIFER SCULPTILIS VAR. MARYLANDENSIS Prosser n. var 200

14. Dorsal valve. Warrior Mountain, east of Rush.

15. Squeeze of same. X 1%.

16. Internal impression of same.

Romney formation, Hamilton member.

102

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15

MOLLUSCOIDEA — BRACHIOPODA

PLATE XX

PAGE

Figs. 1, 2. AMBOCCELIA UMBOXATA Conrad 200

1. Partly exfoliated ventral valve. X 2. Ernstville.

2. Partly exfoliated dorsal valve. X l1/^. Evitts Creek.

Romney formation, Hamilton member.
Figs. 3-6. AMBOCCELIA VIRGINIAN A Prosser n. sp 202

3. Ventral valve. X 6. 3 miles south of Green Spring, W. Va. Mar-

cellus limestone.

4. Ventral valve. X 5. Right bank of Potomac, iyz miles below Cum-

berland.

5. Dorsal valve of same specimen. X 5.

6. Cardinal area and dorsal valve of same specimen, x 5.

Romney formation, Hamilton member.
Figs. 7, 8. AMBOCCELIA PR.EUMBONA Hall (?) 204

7. Partly exfoliated ventral valve. X 1%.

8. Interior of ventral valve. X 1^4. Ernstville.

Romney formation, Hamilton member.

Figs. 9-11. AMBOCCELIA PR^EUMBONA Hall 204

9. Ventral valve.

10. Dorsal valve.

11. Profile view.

Hamilton formation, New York.
Figs. 12-15. NUCLEOSPIRA CONCINNA Hall 206

12. Interior of ventral valve (?). X IVz-

13. Interior of ventral valve. X l]/&.

Romney formation, Hamilton member, Ernstville.

14. Ventral valve.

15. A portion of surface enlarged, showing the character of the spin-

ules.

Hamilton formation, New York.
Figs. 16-23. AXOPLOTHECA (CcELospiRA) AcuTiPLiCATA (Conrad) 207

16. Ventral valve. X 1%. Williams Road near church, 3% miles

southeast of Cumberland.

17. Squeeze of same, showing appearance of ventral valve. X I1/!.

18. Dorsal valve. X 1%. Williams Road near church, 3% miles

southeast of Cumberland.

19. Squeeze of same, showing appearance of dorsal valve. X I1/*.

20. Interior of partly exfoliated dorsal valve. X l1^- Williams Road,

S1/^ miles southeast of Cumberland.

21. Squeeze of same, showing appearance of dorsal valve. X I1/!.

22. Squeeze of internal impression of dorsal valve, showing hinge-

plate, deep dental sockets and median ridge. X 1%. Williams
Road near church, 3% miles southeast of Cumberland.

23. Cast of a dorsal valve. X 2. East of Cumberland.

Romney formation, Onondaga member. (Fig. 23 after Kindle.)

Fig. 24. ANOPLOTHECA CAMILLA (Hall) 209

View of pedicle valve. Romney formation, Onondaga member, Blair

County, Penna. (After Kindle.)
Figs. 25, 26. VITULINA PUSTULOSA Hall 210

25. Exfoliated ventral valve. X 1%. National Road, northeast of

Cumberland.

26. Enlargement from an impression of the surface, showing the ap-

pearance of the pustules. X 4.
Romney formation, Hamilton member.

103

MARYLAND GEOLOGICAL SURVEY

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OP dl

^f& Jr

10

14

11

13

15

26

MOLLUSCOIDEA — BRACHIOPODA

PLATE XXI

PAGE

Figs. 1, 2. ATHYBIS SPIRIFEROIDES (Eaton) 211

1. Ventral valve.

2. Interior of same, showing the muscular markings.

Romney formation, Hamilton member, Evitts Creek.

Figs. 3, 4. MERISTELLA (?) sp 213

3. Ventral valve. X 6.

4. Dorsal valve (?). X 6.

Romney formation, Hamilton member, Iron Bridge over Town
Creek, northeast of Oldtown (?).

Figs. 5-7. PHTHONIA SECTIFROXS (Conrad) 214

5. External impression anterior end of left valve. Romney formation,

Hamilton member, Williams Road near church, 3% miles south-
east of Cumberland.

6. A large left valve narrowed by compression.

7. A large right valve, showing the form and surface characters.

Hamilton formation, New York.

Figs. 8-10. PROTHYRIS LANCEOLATA Hall 215

8. Right valve. X 1%. Romney formation, Hamilton member. Right

bank of Potomac, about 3 miles below Cumberland.
9, 10. Right and left valves. Hamilton formation, New York.

Figs. 11-13. ORTHOXOTA UNDULATA Conrad 216

11. View of broken specimen, showing anterior portion of both valves.

B. & O. R. R. cut, opposite Hancock.

12. Right valve. McCoys Ferry.

Romney formation, Hamilton member.

13. A specimen of medium size preserving both valves. Hamilton

formation, New York.

104

MARYLAND GEOLOGICAL SURVEY

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10

MOLLUSCOIDEA — BRACHIOPODA AND MOLLUSCA — PELECYPODA

PLATE XXII

PAGE

Figs. 1, 2. ORTHONOTA (?) PARVULA Hall 217

1. Both valves. X 2.

2. Dorsal view of same. X 2.

Romney formation, Hamilton member, Evitts Creek.

Fig. 3. GRAMMYSIA BISULCATA (Conrad) 218

Ventral view of distorted and crushed specimen, showing part of both
valves. Romney formation, Hamilton member, McCoys Ferry.

Figs. 4-10. GRAMMYSIA ARCUATA (Conrad) 219

4. Anterior end of right valve. McCoys Ferry.

5. Posterior end of left valve of same specimen.

6. 7. Cardinal and ventral views of a specimen vertically compressed.

Pine Hill, 5 miles north of Oldtown.
8. Right valve distorted by vertical pressure. Town Creek, about 6

miles north of Oldtown.

Romney formation, Hamilton member.
9, 10. Right and left valves. Hamilton formation, New York.

Figs. 11, 12. TELLIXOPSIS SUBEMARGIXATA (Conrad) 222

11. Left valve. Evitts Creek.

12. Part of left valve showing fine radiating striae. Right bank of

Potomac, about 3 miles below Cumberland.
Romney formation, Hamilton member.

105

MARYLAND GEOLOGICAL SURVEY

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12

MOLLUSCA — PELECYPODA

14

PLATE XXIII

PAGE

Figs. 1, 2. GRAMMYSIA CIRCULAKIS Hall 220

Right and left valves partly exfoliated, showing muscular scars and
pallial line. Hamilton formation, New York.

Fig. 3. GRAMMYSIA CIRCULARIS (?) Hall 220

Left valve. Romney formation, Hamilton member, 21st Bridge.

Fig. 4. BUCHIOLA HALLI Clarke 225

Left valve showing the conspicuous concentric ridges on the plications.
X 2. Romney formation, Hamilton member, Evitts Creek.

Fig. 5. PANENKA CF. DICHOTOMA Hall 224

View of a fragmentary right valve. Romney formation, Onondaga
member, Oldtown.

Figs. 6-10. NUCULA CORBULIFORMIS Hall 226

6. Right valve. X 1%. Right bank of Potomac River, about 3 miles

below Cumberland.

7. Left valve of same.

8. Right valve. X 1%. Same locality.

9. Cardinal view of internal impression showing hinge crenulations.

X l1/^. Same locality.

10. Right valve showing varices of growth and concentric striae. Evitts
Creek.

Romney formation, Hamilton member.

Fig. 11. PANENKA CF. MULTIRADIATA Hall 225

View of a large right valve showing strong radii. Hamilton formation,
New York.

106

MARYLAND GEOLOGICAL SURVEY

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11

MOLLUSCA — PELECYPODA

PLATE XXIV

PAGE

Fig. 1. PAXEXKA ALTERNATA Hall 223

View of a large right valve showing strong radii. Oldtown. Romney
formation, Onondaga member.

Figs. 2, 3. PAXEXKA OBSOLESCEXS Kindle n. sp 224

2. View of right valve of type. Oldtown.

3. Fragmentary right valve. Ridgeville, W. Va.

Romney formation, Onondaga member.

107

MARYLAND GEOLOGICAL SURVEY

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MOLLUSCA — PELECYPODA

PLATE XXV

PAGE

Figs. 1-5. NUCULA BELLISTRIATA (Conrad) 227

1. Right valve. X 1%.

2. Right valve, showing concentric striae and strong varices of growth.

xiy2.

3. Left valve. X 2.

Romney formation, Hamilton member, Evitts Creek.

4. Interior of right valve, showing muscular scars. X 1%.

5. Cardinal view of same. X l1/^.

Romney formation, Hamilton member, Western Maryland.

Figs. 6-8. NUCULA LIRATA (Conrad) 229

6. Left valve, distorted somewhat about the beak. Romney formation,

Hamilton member, Evitts Creek.

7. Right valve.

8. Enlarged surface showing strong concentric undulations and fine

radiating striae.

Hamilton formation, New York.

Figs. 9, 10. NUCULA LIKATA (Conrad) (?) 229

9. Interior of left valve, showing muscular scars, pallial line and

hinge crenulations. X 1%.

10. Cardinal view of same specimen, showing muscular scars and
hinge crenulations. X l1^.

Romney formation, Hamilton member, Western Maryland.

Figs. 11-16. NUCULA VARICOSA Hall 230

11, 12. Right and left valves. X l1^.

13. Left valve, showing concentric striae and varices of growth. X l1^.

14. Enlargement from same, showing the character of the concentric

striae and varices of growth. X 4.

Romney formation, Hamilton member, Evitts Creek.
15, 16. Right and left valves. Hamilton formation, New York.

Figs. 17-20. NUCULITES OBLOSGATTJS Conrad 231

17. Left valve showing fine concentric striae. Evitts Creek.

18. Small left valve also showing fine concentric striae. X 2. Evitts

Creek.

19. Interior of right valve, showing crenulated hinge and impression

of clavicular ridge. National Road, northeast of Cumberland.

20. Interior of right valve elongated by pressure. Hill in West Vir-

ginia, 3 miles south of Cumberland.
Romney formation. Hamilton member.

108

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15

MOLLUSCA — PELECYPODA

PLATE XXVI

PAGE

Figs. 1-5. NUCULITES TRIQUETEB Conrad 232

1. Small right valve. X l1^. Evitts Creek.

2. Partly exfoliated right valve. X l1^. Right bank of Potomac,

about 3 miles below Cumberland.

3. Left valve of same specimen, showing impression of clavicular

ridge. X 1%.

4. Internal impression of right valve, showing clavicular ridge. X l1^.

Hill in West Virginia, about 3 miles south of Cumberland.

5. Internal impression of right valve, distorted by pressure, showing

impression of clavicular ridge. X l^. McCoys Ferry.
Romney formation, Hamilton member.

Fig. 6. NUCULITES GRABAUI Prosser n. sp 234

Internal impression of right valve, showing impression of strong
clavicular ridge. X 1%. McCoys Ferry. Romney formation,
Hamilton member.
Figs. 7, 8. NUCULITES MODULATUS Kindle 234

7. Type specimen.

8. Another individual.

Romney formation, Onondaga member, Ridgeville, W. Va.
(After Kindle.)

Figs. 9-12. PALJEONEILO CONSTRICTA (Conrad) 235

9. Right valve, showing crenulations of hinge-line, fine concentric
striae and constriction. X la/4- Evitts Creek.

10. Right valve somewhat elongated by pressure, showing crenulations

of hinge-line, fine striae and constriction. X 1%. Evitts Creek.

11. Small right valve. X l1^. Evitts Creek.

12. Small left valve. X 1%. Williams Road, % mile east of Queen
I City Hotel, Cumberland.

Romney formation, Hamilton member.
Figs. 13-15. PAL^ONEILO PLANA Hall 237

13. Left valve, showing hinge crenulations. X 1%. Evitts Creek.

14. Small right valve, showing hinge crenulations. X 2. Evitts

Creek.

15. Right valve. X 1%. Right bank of Potomac, about 3 miles

below Cumberland.

Romney formation, Hamilton member.

Fig. 16. PAL^ONEILO MAXIMA (Conrad) (?) 238

Left valve with strong sulcus. Romney formation, Hamilton mem-
ber, Evitts Creek.

Fig. 17. PAL^ONEILO MAXIMA (Conrad) 238

Right valve with greater height than usual. Hamilton formation,

New York.
Figs. 18-21. PAL^ONEILO FECUNDA Hall 239

18. Left valve showing concentric striae, X l1^, and above that, a

portion of the surface bordering the hinge-line enlarged 3 times.
Williams Road, !/4 mile east of Queen City Hotel, Cumberland.

19, 20. Right valves.

21. An enlargement of the surface striae from fig. 20.

Romney formation, Hamilton member (figs. 19-21 after Hall).
Figs. 22, 23. PAL.EONEILO PERPLANA VAR. GRABAUI Prosser n. var 240

22. Squeeze of external impression of right valve.

23. Surface of same. X 4.

Romney formation, Hamilton member, Evitts Creek.

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10

11

15

12

13

16

14

17

20

22

21

23

MOLLUSCA — PELECYPODA

PLATE XXVII

PAGE

Figs. 1-6. PAL^ONEILO EMARGINATA (Conrad) 241

1. Left valve, showing the strong concentric ridges. Evitts Creek.

2. Left valve of shorter form. Hancock-Harrisonville Road, about

2 miles north of Hancock.

3. Right valve of same specimen.

4. External impression of right valve. McCoys Ferry.

Romney formation, Hamilton member.

5. 6. Right and left valves. Hamilton formation, New York.

Fig. 7. PAL^ONEILO TENUISTRIATA Hall (?) 242

Right valve of a broken and mostly exfoliated specimen. Romney
formation, Hamilton member, McCoys Ferry.

Figs. 8, 9. PAL^EONEILO TENITISTRIATA Hall 242

Left and right valves. Romney formation, Hamilton member, near
Cumberland. (After Hall.)

Figs. 10-13. PALVEOXEILO CLARKEI Prosser n. sp 244

10. Left valve.

11. Broken left valve, sinus at anterior end caused by crushing.

12. Right valve, shortened by the breaking away of the posterior end.

13. Interior of hinge line of No. 12 enlarged, showing the taxodont

dentition. X 2.

Romney formation, Hamilton member, right bank of Potomac
River, about 3 miles below Cumberland.

Figs. 14, 15. PAL^ONEILO ROWEI Prosser n. sp 244

14. Internal impression of left valve, showing muscular markings and.

hinge crenulations.

15. Squeeze of same specimen.

Romney formation, Hamilton member, McCoys Ferry.

Fig. 16. PAL^ONEILO MARYLAXDICA Prosser n. sp 245

Right valve. Hancock-Harrisonville Road, about 2 miles north of
Hancock. Romney formation, Hamilton member.

no

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XXVII

'

13

15

MOLLUSCA — PELECYPODA

PLATE XXVIII

PAGE

Figs. 1, 2. TANCKEDIOPSIS CLARKEI Prosser n. sp 245

1. External impression of right valve. X 1}4.

2. Squeeze of same specimen, showing external appearance of right

valve. X 1&.

Romney formation, Hamilton member, Western Maryland.

Figs. 3, 4. LEDA DIVEKSA Hall 247

3. Right valve. X 2. Romney formation, Hamilton member, McCoys

Ferry.

4. Left valve. X 2. Hamilton formation, New York.

Figs. 5-7. LEDA ROSTELLATA (Conrad) 247

5. Right valve of young specimen. X 3. Romney formation, Hamil-

ton member, National Road west of Tonoloway Ridge.

6. 7. Right and left valves. X 2. Hamilton formation, New York.

Figs. 8-12. PARALLELODON HAMILTONIJE (Hall) 248

8. External impression showing part of both valves.

9, 10. Right and left valves, margins partly broken away.

Romney formation, Hamilton member, Evitts Creek.

11. Right valve showing surface markings. Hamilton formation, New

York.

12. Left valve of an unusually large individual from near Cumberland.

(After Hall.)

Fig. 13. LIOPTERIA CF. CONRADI Hall 252

Partly exfoliated left valve. Romney formation, Hamilton member,
Iron bridge over Town Creek, northeast of Oldtown.

Fig. 14. LIOPTERIA CONRADI Hall 252

A large left valve. Hamilton formation, New York.

m

MARYLAND GEOLOGICAL SURVEY

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9

10

13

14

MOLLUSCA — PELECYPODA

PLATE XXIX

PAGE

Figs. 1-4. PTERINEA FLABELLUM (Conrad) 250

1. Left valve, showing alternation in size of radiating ribs. Evitts

Creek.

2. Internal impression of left valve, showing muscular scar and

striated ligamental area. Iron Bridge over Town Creek, north-
east of Oldtown.

3. Internal impression of left valve, broken toward the front; but

showing well the striated ligamental area. Flintstone Creek in
Gilpin.

4. Right valve, partly exfoliated. Evitts Creek.

Romney formation, Hamilton member.

Fig. 5. PTERIXEA sp. undet 251

Left valve showing surface ornamentation. Romney formation, Onon-
daga member, Little Moccasin Gap, Va. (After Kindle.)

Fig. 6. LIOPTERIA L^VIS Hall 253

Left valve. X 2. Romney formation, Onondaga member, three miles
east of Cumberland. (After Kindle.)

Figs. 7-10. LEPTODESMA ROGERSI Hall 254

7, 8. External impression X 2 and squeeze of left valve. Romney

formation, Hamilton member, Evitts Creek.
9. Block showing two right valves. X 2.
10. Left valve.

Hamilton formation, New York.

Figs. 11-13. MYTILARCA (PLETHOMYTILUS) OVIFORJIIS (Conrad) 255

11. An imperfect right valve. 21st Bridge.

12. Another imperfect right valve. Evitts Creek.

Romney formation, Hamilton member.

13. Left valve of a young shell of elongate form. Hamilton formation,

New York.

112

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XXIX

MOLLUSCA PELECYPODA

PLATE XXX

PAGE

Figs. 1, 2. CONOCARDIUM NORMALE Hall 257

Right side and cardinal view of large partial cast of exterior. Romney
formation, Hamilton member, Cumberland. (After Hall.)

Figs. 3, 4. COXOCARDIUM CUMBERLANDI.E Swartz n. sp 257

Right side and ventral view of type. Romney formation, Hamilton
member, Williams Road, 3% miles east of Cumberland.

Figs. 5-8. ACTINOPTER.IA DECUSSATA Hall 258

5. Partly exfoliated left valve.

6. Left valve.

7. External impression of a portion of a left valve, showing the char-

acter of the surface markings.

Romney formation, Hamilton member, road east of Pine Hill,
about 4 miles north of Oldtown.

8. A large right valve. Hamilton formation, New York.

Figs. 9, 10. ACTINOPTERIA BOYDI VAR. GiBBosA Prosser n. var 259

9. Right valve.
10. Left valve of same specimen.

Romney formation, Hamilton member, Town Creek, 4 miles
northeast of Oldtown.

Fig. 11. ACTINOPTERIA sp 260

Left valve, surface markings mostly obliterated over the umbonal
region. Romney formation, Hamilton member, Iron Bridge over
Town Creek, northeast of Oldtown.

113

MARYLAND GEOLOGICAL SURVEY

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16

PLATE XXXI

PAGE

Figs. 1-5. MODIELLA PYGM.EA (Conrad) 261

1. Right valve upon which the fine radiating striae are faintly shown.

X 2. Evitts Creek.

2. External impression of right valve. X 2. Evitts Creek.

3. Internal impression of left valve, showing anterior muscular scar

and oblique sinus. X 1%. Hill 3 miles south of Cumberland in
West Virginia.

4. Cardinal view of same specimen. X I1/!-

Romney formation, Hamilton member.

5. Left valve showing fine radiating stria?. X 2. Hamilton formation,

New York.

Fig. 6. NYASSA ABGUTA Hall (?) 262

Internal impression of a broken left valve, showing impressions of
posterior lateral teeth. Romney formation, Hamilton member,
McCoys Ferry.

Figs. 7-9. NYASSA ARGUTA Hall 262

7, 8. Right and left valves.

9. A squeeze showing the appearance of the interior of the right valve.

Hamilton formation, New York.

Figs. 10, 11. AVICULOPECTEN PRINCEPS (Conrad) 263

10. A specimen preserving both valves.

11. A large left valve, much extended posteriorly.

Hamilton formation, New York.

Fig. 12. AVICULOPECTEN sp 266

An incomplete right valve. Romney formation, Hamilton member,
near Hancock.

MARYLAND GEOLOGICAL SURVEY

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11

MOLLUSCA PELECYPODA

PLATE XXXII

PAGE

Figs. 1, 2. AVICULOPECTEN PRIXCEPS (Conrad) 263

1. External impression of a broken left valve.

2. Left valve with broken margins.

Romney formation, Hamilton member, Williams Road, %
mile east of Queen City Hotel, Cumberland.

Figs. 3, 4. AVICULOPECTEX EQUILATERA (Hall) 265

Two left valves showing variation in erectness of the shell. X 2.
Romney formation, Onondaga member, Blair County, Penna.,
and Ridgeville, W. Va. (After Kindle.)

Figs. 5-9. MODIOMORPHA CONCENTRICA (Conrad) i 266

5, 6. Right and left valves. Evitts Creek.

7, 8. Internal impression of right and left valves. Williams Road,

east of Evitts Creek.

9. Internal impression of right valve elongated by pressure, showing
anterior muscular scar. Western Maryland.
Romney formation, Hamilton member.

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PLATE XXXIII

PAGE

Figs. 1-6. MODIOMORPHA SUBALATA (Conrad) 268

I, 2. Right and left valves.

3. Right valve.

4. Left valve of small specimen. X 2.

5. Probably right valve of young specimen. X 2.

6. An imperfect right valve.

Romney formation, Hamilton member, Evitts Creek.

Fig. 7. MODIOMORPHA MYTILOIDES (Conrad) (?) 269

Left valve from which umbonal region is broken.

Romney formation, Hamilton member, Evitts Creek.

Figs. 8-10. MODIOMORPHA MYTILOIDES (Conrad) 269

8, 9. Right and left valves.
10. Young specimen showing both valves.
Hamilton formation, New York.

Figs. 11-13. GONIOPHORA HAMILTON ENSIS Hall 271

II. Partly exfoliated right valve, showing sharp umbonal ridge. Rom-

ney formation, Hamilton member, Hancock-Harrisonville Road,
about 2 miles north of Hancock.
12, 13. Right and left valves. Hamilton formation, New York.

Figs. 14-16. PHOLADELXA RADIATA (Conrad) 272

14, 15. Right and left valves. Hancock-Harrisonville Road, about 2

miles north of Hancock.
16. Cardinal view of a specimen. Cumberland.

Romney formation, Hamilton member (fig. 16, after Hall).

116

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13

14

10

15

MOLLUSCA — PELECYPODA

PLATE XXXIV

PAGK

Figs. 1-4. CYPRICARDELLA BELLISTRIATA (Conrad) 273

1. Right valve. Evitts Creek.

2. Interior of left valve (?) with broken anterior end. Evitts Creek.

3. Left valve. Evitts Creek.

4. Cardinal view of small specimen preserving both valves. Cum-

berland.
Romney formation, Hamilton member (fig. 4, after Hall).

Fig. 5. CYPRICARDELLA TENUISTRIATA (Hall) 275

Left valve. Romney formation, Hamilton member, Williams Road,
% mile east of Queen City Hotel, Cumberland.

Figs. 6-10. CYPRICARDINIA IXDENTA (Conrad) 276

6. Right valve. X 2. Evitts Creek.

7. External (?) impression of right valve. X 2. 21st Bridge.

8. A squeeze from the same specimen. X 2.

Romney formation, Hamilton member.

9. Right valve showing surface markings.
10. Left valve.

Hamilton formation, New York.

Figs. 11-14. PARACYCLAS LIRATA Conrad 277

11. Right valve of small specimen. Great Cacapon.

12. Left valve elongated by pressure. McCoys Ferry.

13, 14. Right and left valves somewhat distorted. Western Maryland.
Romney formation, Hamilton member.

Fig. 15. PARACYCLAS LIRATA Conrad var. (?) 278

Left valve somewhat broken along the hinge line. Romney formation,
Hamilton member, McCoys Ferry.

Figs. 16, 17. PARACYCLAS TENTHS Hall 278

Interior of right valves. X IV2. Romney formation, Hamilton mem-
ber, Evitts Creek.

Fig. 18. PAL^OSOLEX MINUTTJS Prosser n. sp 279

Both valves, ventral margin of left broken^ X 1%. Romney forma-
tion, Hamilton member, Williams Road, x/i mile east of Queen
City Hotel, Cumberland.

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11

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12

13

15

16

17

MOLLUSCA — PELECYPODA

PLATE XXXV

PAGE

Figs. 1-5. PLEUROTOMARIA (BEMBEXIA) SULCOMARGWATA Conrad 280

1. Ventral view of specimen. Warrior Mountain, east of Rush.

2. View of spire and upper part of body whorl. Right bank of Potomac,

about 3 miles below Cumberland.

3. 4. External and internal impressions. Western Maryland.

Romney formation, Hamilton member.

5. Dorsal view of specimen, showing surface character. Hamilton

formation, New York.

Figs. 6-8. PLEUROTOMARIA (GYROMA) CAPILLARIA Conrad 282

6. Dorsal view, showing surface markings. X 1^4.

7. Body whorl showing the surface markings but shell is exfoliated

from the spire. X 1*4.
Romney formation, Hamilton member, Evitts Creek.

8. Enlarged specimen, showing surface characters. X 2. Hamilton

' formation, New York.

Figs. 9, 10. PLEUROTOMARIA (TREPOSPIRA) ROT ALIA Hall (?) 283

9. Part of body whorl, showing surface markings. X 1%. National
Road, west of Tonoloway Ridge.

10. Internal impression of body whorl. X 11A. McCoys Ferry.

Romney formation, Hamilton member.

Figs. 11, 12. PLEUROTOMARIA (EURYZONE) ITYS Hall (?) 284

11. Dorsal view of internal impression. Robinson farm, 2 miles south

of Patterson Depot, W. Va.

12. Ventral view of internal impression. Western Maryland.

Romney formation, Hamilton member.

Fig. 13. PLEUROTOMARIA (EURYZONE) ITYS Hall 284

View of an internal impression retaining traces of the surface charac-
ters toward the aperture. Hamilton formation, New York.

Fig. 14. BELLEROPHON ( PATELLOSTIUM ) PATULUS Hall (?) 287

Dorsal view of smooth internal impression from which the margins are
broken. Romney formation, Hamilton member, Western Mary-
land.

Fig. 15. BELLEROPHON (PATELLOSTIUM) PATULUS Hall 287

Dorsal view of specimen. Hamilton formation, New York.

113

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XXXV

MOLLUSC A — GASTROPODA

PLATE XXXVI

PAGE

Figs. 1-3. BELLEROPHON (BUCANOPSIS) LEDA Hall 285

1. Dorsal view, showing surface markings. X la/4. Romney forma-

tion, Hamilton member, Evitts Creek.

2. Dorsal view of specimen with finely preserved surface. X 2.

3. View of one side of dorsal surface, showing surface markings. X 3.

Hamilton formation, New York.

Figs. 4-7. CYRTOLITES (CYRTONELLA) MITELLA Hall 288

4. Dorsal view of specimen which is crushed on right side. X 1^4.

5. Dorsal view of smaller specimen which is distorted toward the

front. X l1^.

Romney formation, Hamilton member, road east of Pine Hill,
about 4 miles north of Oldtown.

6. Dorsal view of partly exfoliated specimen.

7. Side view of the type, an internal impression.

Hamilton formation, New York.

Figs. 8, 9. CYCLONEMA LIRATUM VAR. GRABAUI Prosser n. var 290

8. Squeeze from an external impression, showing part of the body

whorl, the spire and surface markings. X 1%.

9. Probably the internal impression of the body whorl of the same

specimen. X 1^4.

Romney formation, Hamilton member, Williams Road, about
3^ miles southeast of Cumberland.

Fig. 10. CYCLONEMA ( ?) MARYLANDENSE Prosser n. sp 292

Side view, showing the surface markings. Romney formation, Hamil-
ton member, right bank of Potomac River, 4 miles below Cum-
berland.

Fig. 11. NATICOPSIS sp. undet 293

Lateral view. X 4. Romney formation, Onondaga member, Ridge-
ville, W. Va.

Figs. 12-15. MACROCHILUS HAMILTONI^; Hall 293

12, 13. Dorsal and ventral views of internal impression. Romney

formation, Hamilton member, Western Maryland.
14, 15. Views of the opposite sides of the type. Hamilton formation,

New York.

Figs. 16-19. LOXONEMA HAMILTONI.E Hall 294

16. Dorsal view, showing strong longitudinal striae. X 1%. 4^ miles

northeast of Oldtown.

17. Body whorl, showing longitudinal striae. X 2. Evitts Creek.

Romney formation, Hamilton member.

18, 19. Dorsal and ventral views of specimen of usual size. Hamilton
formation, New York.

119

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN PLATE XXXVI

12

13

14

11

17

15

PLATE XXXVII

PAGE

Pigs. 1-3. PLATYCERAS ERECTUM Hall (?) 296

1. Lateral view of partly exfoliated specimen. X 1*4.

2, 3. Two views of exfoliated specimen, wrinkled by crushing toward

the margin. X 1*4.

Romney formation, Hamilton member, Hancock-Harrisonville
Road, about 2 miles north of Hancock.

Figs. 4, 5. PLATYCERAS ERECTUM Hall 296

Two views of specimen from Hamilton formation of New York.

Fig. 6. PLATYCERAS CF. SYMMETRTCUM Hall 297

Dorsal view of partly exfoliated specimen. Romney formation, Hamil-
ton member, Evitts Creek.

Figs. 7-12. DIAPHOROSTOMA LINEATUM (Conrad) 298

7. Lateral view.

8. Enlarged portion of same to show surface markings. X 7.

Romney formation, Hamilton member, Ernstville.

9. The aperture and spire of a symmetrical specimen.

10. Lateral view of the same.

11. Side view of a specimen preserving the surface in great perfection.

12. Enlargement of the surface of the preceding.

Hamilton formation, New York.

Figs. 13-15. PLATYSTOMA CF. EUOMPHALOIDES Conrad 299

Upper, side and lower views. Hamilton formation, New York.

Fig. 16. (?) GASTROPOD.

Squeeze from external impression (?). X 10. Romney formation,
Hamilton member, road east of Pine Hill, about 4 miles north
of Oldtown.

Figs. 17-20. STYLIOLIXA FISSURELLA ( Hall) 300

17. Lateral view of small specimen. X 6.

18. Similar view of larger specimen. X 6.

Romney formation, Hamilton member, Iron Bridge over Town
Creek, northeast of Oldtown.

19. Specimen strongly striated longitudinally. X 6.

20. Specimen showing transverse and longitudinal striae. X 6.

Marcellus formation, New York.

Fig. 21. TENTACULITES ATTEXUATUS Hall 301

Specimen showing internal impression for larger end and external
impression for the remainder. X 5. Romney formation, Hamil-
ton member, National Road, west of Tonoloway Ridge.

Figs. 22-25. TENTACULITES BELLULUS Hall 302

22. External impression. X 3.

23. Same enlarged to show annulations and fine transverse striae. X 8.

Romney formation, Hamilton member, Iron Bridge over Town
Creek, northeast of Oldtown.

24. A specimen showing the general features of the species.

25. Enlargement of the same showing annulations and encircling

striae.

Hamilton formation, New York.

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XXXVII

21

19 20

24

23

25

MOLLUSCA — GASTROPODA

PLATE XXXVIII

PAGE

Figs. 1-3. TENTACULITES BELLULUS VAR. POTOMACENSIS Prosser n. var 303

1. View of external impression. X 1%.

2. Squeeze of same, showing the external appearance of the species.

xi%.

3. Same specimen enlarged to show annulations and transverse striae.

X 4.
Romney formation, Hamilton member, McCoys Ferry.

Fig. 4. CONTJLARIA UNDULATA Conrad 304

Side view of shell. Hamilton formation, New York.

Figs. 5-8. COLEOLUS TENUICINCTUS Hall 305

5. Two specimens, showing concentric striae; median longitudinal

groove due to fracture.

6. Part of right hand specimen of preceding enlarged, showing appear-

ance of transverse striae. X 3.

Romney formation, Hamilton member, Evitts Creek.

7. An imperfect specimen.

8. A fragment enlarged.

Hamilton formation, New York.

Fig. 9. BACTRITES ACICULUS 320

Fragment of tube. Romney formation, Onondaga member, Sassin, Va.
(After Kindle.)

Figs. 10, 11. ORTHOCERAS BEBRYX Hall (?) 307

10. Internal impression of part of an individual. Oldtown Road near

Cumberland.

11. Enlargement showing surface markings. X 4. Great Cacapon.

Romney formation, Hamilton member.

Fig. 12. ORTHOCERAS BEBRYX Hall 307

A much compressed and weathered fragment, with the siphuncle ex-
posed. Hamilton formation, New York.

121

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN PLATE XXXVIII

\

MOLLUSCA — GASTROPODA AND CEPHALOPODA

if,

PLATE XXXIX

PAGE

Figs. 1, 2. ORTHOCERAS SUBULATUM Hall (?) 308

1. Partly exfoliated living chamber.

2. Septum of the same, showing position of siphuncle.

Romney formation, Hamilton member, right bank of Potomac,
3 miles below Cumberland.

Figs. 3, 4. ORTHOCERAS SUBULATUM Hall 308

3. The apical portion of a specimen, showing the regular increase in

the depth of the air-chambers from the apex to the larger ex-
tremity.

4. A septum, showing the position of the siphuncle.

Hamilton formation, New York.

Figs. 5-8. ORTHOCERAS CONSTRICTUM Vanuxem 309

5. Partly exfoliated living chamber. Romney formation, Hamilton

member, Oldtown Road near Cumberland.

6. A fragment retaining a portion of the living chamber and twenty-

one air-chambers.

7. A fragment of the living chamber, with two of the attached air-

chambers.

8. A septum, showing position of siphuncle.

Hamilton formation, New York.

Fig. 9. ORTHOCERAS CF. EXILE Hall 310

Specimen showing seven air-chambers. Romney formation, Hamilton
member, Evitts Creek.

Figs. 10, 11. ORTHOCERAS EXILE Hall 310

10. Living chamber with two air-chambers.

11. Septum of same, showing the circular, transverse section of the

tube and the excentric position of the siphuncle.
Hamilton formation, New York.

122

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XXXIX

11

MOLLUSCA — CEPHALOPODA

PLATE XL

PAGE

Figs. 1-4. ORTHOCERAS TELAMON Hall (?) 311

1. Internal impression of living chamber.

2. Septum of preceding, showing excentric siphuncle.

3. A specimen showing five air-chambers.

4. Septum of preceding, showing excentric siphuncle.

Romney formation, Hamilton member, Robinsons farm, 2
miles south of Patterson Depot, W. Va.

Figs. 5, 6. OKTHOCERAS TELAMON Hall .". 311

5. Small fragment showing depth of air-chambers and gradual en-

largement of tube.

6. A septum, showing very excentric position of siphuncle.

Hamilton formation, New York.

Fig. 7. ORTHOCERAS EMACERATUM Hall (?) 313

Internal impression, showing six air-chambers. Romney formation,
Hamilton member, right bank of Potomac, 3 miles below Cum-
berland.

Fig. 8. ORTHOCERAS CF. ATJLAX Hall 313

Portion of living chamber, showing surface markings. Romney forma-
tion, Hamilton member, road east of Pine Hill, about 4 miles
north of Oldtown.

Fig. 9. ORTHOCERAS AULAX Hall 313

Fragment of living chamber, showing the prominent, regular trans-
verse furrows and ridges of the surface. Hamilton formation,
New York.

123

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XL

-/

MOLLUSCA — CEPHALOPODA

PLATE XLI

PAGE

Figs. 1-5. SPYBOCERAS CROTALUM (Hall) 314

1. Fragment, showing the prominent annulations and longitudinal

striae.

2. Enlargement of same. X 2.

Romney formation, Hamilton member, Western Maryland.

3. Internal impression of portion of living chamber, showing absence

of annulations near aperture and striate surface.

4. A small, septate fragment, preserving the characteristic fine, longi-

tudinal striae over the exterior of the tube.

5. A small, slightly compressed specimen, showing the surface mark-

ings and the increase in prominence of the annulations toward
the larger end.

Hamilton formation, New York.

Figs. 6-8. SPYROCERAS XUXTIUM Hall 316

6. Partly exfoliated fragment, showing the surface striae.

7. Shell of same enlarged, showing surface striae. X 6.

Romney formation, Hamilton member, right bank of Potomac,
3 miles below Cumberland.

8. A compressed specimen showing annulations and longitudinal striae.

Hamilton formation, New York.

Figs. 9-11. SPYROCERAS CLARKEI Prosser n. sp 317

9. 10. Two views of fragment, showing five annulations and surface

markings.

11. Same enlarged, showing the longitudinal and concentric stria?.
X3.
Romney formation. Hamilton member, Ernstville.

124

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XLI

11

MOLLUSCA — CEPHALOPODA

PLATE XLII

PAGE

Figs. 1, 2. CF. GOMPHOCERAS PINGUE Hall 318

1. Part of living chamber.

2. Septum of preceding, showing position of siphuncle.

Romney formation, Hamilton member, Western Maryland.

Fig. 3. GOMPHOCERAS PINGUE Hall 318

Fragment showing ventricose form and curvature of living chamber
toward aperture. Hamilton formation, New York.

Fig. 4. BACTRITES ACICULATUS (Hall) 319

Part of an individual. X 1%. Romney formation, Hamilton member,
21st Bridge.

Fig. 5. BACTRITES ACICULUM Hall 320

Shell slightly crushed. Genesee formation, New York.

Fig. 6. AGONIATITES EXPANSUS (Vanuxem) 321

Outline figure showing character of surface stria?. Romney formation,
Onondaga member, Cumberland. (After Kindle.)

Figs. 7, 8. PARODICERAS DISCOIDEUM (Conrad) 323

Lateral and ventral views. Marcellus formation, New York.

Fig. 9. CYPHASIS CF. STEPHANOPHORA Hall 326

Fragmentary glabella. X 5. Romney formation, Onondaga member,
Berkeley Springs, W. Va. (After Kindle.)

125

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XLH

'II

xs

MOLLUSCA — CEPHALOPODA AND ARTHROPODA — TRILOBITA

PLATE XLIII

PAGE

Figs. 1-7. HOMALONOTUS DEKAYI ( Green) 328

1. A young, distinctly trilobate and nearly entire individual.

2. An enrolled and uncompressed individual.

3. The hypostoma.

4. An enlargement of the under surface. X 5.

Hamilton formation, New York.

5. Dorsal view of a pygidium.

6. A smaller and somewhat crushed pygidium, showing the reflexed

apex.

7. An enlargement of a portion of the surface of same. X 10.

Romney formation, Hamilton member, road east of Pine Hill,
about 4 miles north of Oldtown.

Figs. 8-12. PHACOPS RANA (Green) 329

8. Dorsal view of cephalon. 21st Bridge.

9. The eye of same. X 3.

10. Pygidium. X 2. Evitts Creek.

Romney formation, Hamilton member.

11. A small individual.

12. The eye of a slightly weathered specimen enlarged.

Hamilton formation, New York.

Figs. 13-15. PHACOPS CBISTATA Hall 331

13. Cephalon and part of the thorax of an enrolled specimen, showing

axial and genal spines. Alinda, Penna.

14. Lateral view of an enrolled specimen with a partly crushed gla-

bella, showing genal spine base. Alinda, Penna.

15. Fragmentary thorax and pygidium, showing axial spines. Ridge-

ville, W. Va.
Romney formation, Onondaga member. (After Kindle.)

Figs. 16, 17. PHACOPS CRISTATA VAR. PIPA Hall 332

16. Fragmentary enrolled thorax. Alinda, Penna.

17. Pygidium, showing duplicate character of pleural anntilations.

Near New Bloomfield, Penna.

Romney formation, Onondaga member. (After Kindle.)

126

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XLIII

12

17

'ARTHROPOD A — TRILOBITA

PAGE

Figs. 1-4. DALMANITES (CRYPH^US) BOOTHI (Green) 333

1. Partly exfoliated pygidium with marginal spines. X 1%.

2. Another partly exfoliated and smaller pygidium. X 2.

3. A pygidium and part of one side of a thorax. X 1%.

Romney formation, Hamilton member, Evitts Creek.

4. Internal surface of a pygidium, in which the spines are broad and

flat. Hamilton formation, New York.

Fig. 5. DALMANITES MARYLANDICUS Prosser n. sp 334

Partly exfoliated pygidium, showing the pustulose surface and two
spines at the apex. Romney formation, Hamilton member,
Ernstville.

Fig. 6. LEPEKDITIA ? SUBROTUNDA ; 335

Right valve. X 20. Romney formation, Onondaga member, Little
Moccasin Gap, Va. (After Kindle.)

Figs. 7, 8. BOLLIA UNGULA Jones 336

7. Cast of a left valve. X 20. Rees Tannery, Mineral County, W. Va.

8. Dorsal view of a slightly distorted specimen. X 20. Berkeley

Springs, Ridgeville, W. Va.

Romney formation, Onondaga member. (After Kindle.)

Fig. 9. BOLLIA OBESA Ulrich 337

Cast of left valve. X 20. New Bloomfield, Penna. Romney formation,
Onondaga member. (After Kindle.)

MARYLAND GEOLOGICAL SURVEY

MIDDLE DEVONIAN, PLATE XLIV

XZO

ARTHROPODA — TRILOBITA AND OSTRACODA

DEVONIAN

UPPER

NOTE

The following plates (Plates XLV to LXXIII) illustrate the Systematic
Paleontology of the Upper Devonian of Maryland.

17

PLATE XLV

PAGE

Pigs. 1, 2. ZAPHRENTIS MARYLANDICUS n. sp 539

1. Cast of calyx of type specimen as seen from below.

2. Side view of preceding showing its relation to outline of corallite.

Jennings formation, Chemung member, National Road, Polish
Mountain, 2714.1

Figs. 3-6. ZAPHRENTIS CHEMUNGENSIS n. sp 540

3. Side view of cast of interior of calyx, showing its relation to shape

of corallum.

4. Lower surface of preceding.

5. View of type specimen, similar to fig. 3.

6. Lower surface of same individual.

Jennings formation, Chemung member, Polish Mountain, 2714.

Figs. 7, 8. HELIOPHYLLUM SCRUTARIUM n. sp 540

7. Branching corallum showing calyxes.

8. Specimen similar to preceding.

Jennings formation, Chemung member ?, Sideling Hill Creek,
Washington County.

Fig. 9. FAVOSITES sp 541

A small corallum showing size of the cells. Jennings formation, Che-
mung member ?, Sideling Hill Creek, Washington County.

Figs. 10, 11. AULOPORA REPENS Knorr and Walch 542

10. Corallum attached to shell of Rhipidomella vanuxemi.

11. Corallum similarly attached, showing some difference in propor-

tion of corallites.

Jennings formation, base of Parkhead member, hill-top south
of Potomac River, 2V2 miles southeast of Cumberland.

1 The figures following localities indicate the altitude in feet above the base
of the Jennings formation at which the specimens were found.

128

MARYLAND GEOLOGICAL SURVEY

UPPER DEVONIAN, PLATE XLV

11

CCELENTERATA — ANTHOZOA

PLATE XLVI

PAGE

Figs. 1, 2. CLADOCHONUS HUMIIJS n. sp 542

1. Corallum, natural size. Hancock-Harrisonville Road, 2 miles north

of Hancock, 725.

2. Cast of interior of corallite, showing imprints of spinules. X 5.

National Road, east of Hancock, 690.

Jennings formation, Woodmont member, Ithaca fauna.

Figs. 3, 4. PALEASTER CLARKI n. sp 543

3. Ambulacral surface, showing the character of the thecal plates,

and some of the adambulacral plates. The mouth parts are not
clearly retained. X 1%.

4. Abactinal surface, showing the character of the three rows of plates

on the arms, the fine intercalary plates of the median row and
the large and mammillated body plates. X 1%.
Jennings formation, Chemung member, near Oakland.

Fig. 5. SPIRORBIS GYRUS n. sp 544

An attached tube, showing the tubercled surface. X 5. Jennings
formation, Chemung member ?, Sideling Hill Creek, Allegany
County.

Fig. 6. PTERIDICHNITES BISERIATUS n. sp 545

Track made by animal. Jennings formation, Woodmont member,
Naples fauna, Woodmont.

129

MARYLAND GEOLOGICAL SURVEY

UPPER DEVONIAN, PLATE XLVI

COELENTERATA — VERMES — ECHINODERMATA

PLATE XLVII

PAGE
Figs. 1-5. LINGULA OHERNI n. sp 546

1. Small shells probably young of this species.

2. Single valve from preceding group. X 6.

3-4. Exteriors of valves showing slight differences of form.

5. Interior of valve.

Jennings formation, Parkhead member, Williams Road, S1/^
miles east of Cumberland, 1393.

Figs. 6, 7. LINGULA LIGEA Hall 547

6. Exterior of valve. X 3.

7. Exterior of valve which differs slightly in form. X 3.

Jennings formation, Woodmont member, National Road, east
of Hancock, 1564 to 1599.

Fig. 8. LINGULA SPATULATA Vanuxem 548

Exterior of valve. X 6. Jennings formation, Woodmont member,
Ithaca fauna, National Road, east of Hancock, 1149 to 1274.

Figs. 9, 10. OEBICULOIDEA CF. MEDIA (Hall) 549

9. Dorsal valve. Chemung formation, New York.

10. Dorsal valve somewhat distorted. Jennings formation, Parkhead
member, Williams Road, 3% miles east of Cumberland, 1393.

Figs. 11-13. CBAINELLA HAMILTOXI^E Hall 549

11. Cast of interior of dorsal valve. The vascular markings are visible
upon cast, but are not shown in figure. Jennings formation,
Parkhead member, Williams Road, Polish Mountain, 1660.
12, 13. Exterior and cast of interior of dorsal valve. Jennings forma-
tion, Chemung member, Ellerslie, Penna., 1474.

Fig. 14. STBOPHEODONTA DEMISSA (Conrad) 551

Dorsal view of shell. Jennings formation, Woodmont member, Ithaca
fauna, Hancock-Harrisonville Road, 2 miles north of Hancock,
882.

Figs. 15-18. STROPHEODONTA MAYNARDI n. sp 551

15. Ventral valve of type.

16. Dorsal valve.

17. Enlargement of cast of portion of interior of dorsal valve. X 2.

18. Enlargement of a portion of a cast of the interior of the ventral

valve showing hinge and muscular scars. X 2.

Jennings formation, Chemung member, Town Creek, 2391.

130

MARYLAND GEOLOGICAL SURVEY

UPPER DEVONIAN, PLATE XLVII

3

10

11

12

13

18

MOLLUSCOTDEA — BRACHIOPODA

PLATE XLVIII

PAGE

Figs. 1-4. LEPTOSTROPHIA PEBPLAXA VAR. NERVOSA (Hall) 552

1. The interior of a ventral valve.

2. Ventral valve showing the character of the surface.

3. Internal cast of an average ventral valve showing muscular scars

and denticulate hinge.

4. Interior of the dorsal valve showing the double cardinal process,

muscular fulcra, and pustulose patches about the muscular area.
Jennings formation, Chemung member, from localities near
Deer Park and Oakland.

Figs. 5, 6. LEPTOSTROPHIA PERPLANA VAR. ALTERNATA n. var 553

5. Cast of exterior of ventral valve, hinge-line imperfect.

6. Enlargement of striae. X 5.

Jennings formation, Chemung member, Town Creek, 2391.

Fig. 7. LEPTOSTROPHIA INTERSTRIALIS (Vanuxem) 554

Ventral valve. Striae of shell are less regular than shown and some-
what nodose. Jennings formation, Woodmont member, Ithaca
fauna, National Road, east of Millstone, 795.

Figs. 8-17. DOUVILLINA CAYUTA (Hall) 555

8. A small ventral valve of average proportions.
9, 10. Two broader ventral valves.

11. External cast of dorsal valve.

12. Dorsal valve.

13. Interior of ventral valve showing the clearly defined brachial de-

pressions in front of the muscle scars.

14. A characteristic internal cast of the ventral valve showing mus-

cular scars and crenulate hinge.

15. Internal cast of a larger ventral valve.

16. Internal cast of ventral valve.

17. Enlargement of the cardinal portion of the dorsal valve.

Jennings formation, Chemung member, Deer Park, Oakland
and Altamont.

131

MARYLAND GEOLOGICAL SURVEY

UPPER DEVONIAN, PLATE XLVIII

It ,

15

14

MOLLUSCOIDEA — BRACHIOPODA

PLATE XLIX

PAGE

Figs. 1, 2. DOUVILLINA CAYUTA (Hall) 555

1. Interior of dorsal valve.

2. Enlargement of internal cast of dorsal valve. X 2.

Jennings formation, Chemung member, Oakland and Deer
Park.

Figs. 3-13. DOUVILLINA CAYUTA VAR. GBACILIORA n. var 556

3. Ventral valve. X 3.

4. Ventral valve represented somewhat too concave at the umbo.

5. Ventral valve.

6. Dorsal view of shell. X 3.

7. 8. Internal casts of ventral valves.

9. Dorsal view of a larger specimen. X 2.
10. Ventral valve similar to fig. 1.

11, 12. Upper and profile views of a characteristic ventral valve. X 2.
13. Profile view of ventral valve.

Jennings formation, Chemung member, Deer Park and Oak-
land.

Figs. 14-17. DOUVILLIXA ARCUATA (Hall) 557

14, 15. Upper and profile views of a typical ventral valve. X 2. From
Upper Devonian of Lime Creek, Iowa. (Introduced for com-
parison with following.)

16, 17. Upper and profile views of a ventral valve believed to be of this
species.

Jennings formation, Chemung member, National Road, 6
miles west of Frostburg.

Fig. 18. STROPHOXEIXA CF. REVEKSA (Hall) 557

The interior of a dorsal valve showing the reversed convexity, cardinal
process, hinge and median sinus. Jennings formation, Che-
mung member, Trout River, near Oakland.

Figs. 19-22. SCHUCHERTELLA CHEMUNGENSis (Conrad) 559

19. Interior of small dorsal valve. Deer Park.

20. Dorsal valve. Wills Creek Station.

21. 22. Upper and cardinal views of a ventral valve. Two miles east

of Oakland.

Jennings formation, Chemung member.

132

MARYLAND GEOLOGICAL SURVEY

UPPER DEVONIAN, PLATE XLIX

.<"i!i!ij;:.'.;i-:M

3?ar

18

MOLLUSCOIDEA — BRACHIOPODA

PLATE L

PAGE

Figs. 1-3. SCHUCHERTELLA CHEMUNGENSis (Conrad) 559

1. Dorsal valve. Deer Park.

2. Dorsal valve showing impress of cardinal process. Top of Polish

Mountain.

3. Internal cast of a very broad ventral valve. Near Deer Park.

Jennings formation, Chemung member.

Fig. 4. SCHUCHERTELLA ELLIPTICA n. Sp 560

Cast of interior of ventral valve. Jennings formation, Chemung mem-
ber, Town Creek, 4631.

Fig. 5. SCHUCHERTELLA (?) PONDEROSA n. SP 560

Cast of interior of a distorted ventral valve showing muscular scars.
Jennings formation, Chemung member, National Road, east of
Millstone, 2444.

Figs. 6-10. CHONETES LEPIDIFORMIS n. sp 561

6. Ventral valve retaining long cardinal spines and showing the sur-

face characters. X 3. National Road, Polish Mountain.

7. Internal cast of ventral valve. X 2. Same locality as preceding.

8. Very large ventral valve. X 2.

9. Internal cast of ventral valve. X 3.

10. More transverse ventral valve. X 3. Figs. 8, 9, and 10 are from
National Road, east of Millstone.

Jennings formation, Parkhead member.

Figs. 11-13. CHONETES SCITULUS Hall 563

11. Ventral valve. X 2. Near base of Parkhead member, cut of

Baltimore and Ohio Railroad, Rocky Run, 7 miles southeast of
Cumberland.

12. Cast of interior of ventral valve showing papillose surface. X 2.

Same locality.

13. Ventral valve having finer striae. Williams Road, Polish Mountain,

1422.
Jennings formation, Parkhead member.

Figs. 14-18. CHONETES OAKLANDENSIS n. sp 562

14-16. Three ventral valves. X 2.
17, 18. Two dorsal valves. X 2.

Jennings formation, Chemung member, Green Glade Run,
near Deer Park.

Fig. 19. CHONETES ROWEI n. sp 563

Ventral valve showing irregular bifurcating spinulose plications. X 3.
National Road, east of Millstone. Jennings formation, Park-
head member.

Figs. 20-22. PRODUCTEIXA LACHRYMOSA (Conrad) 564

20. Ventral valve of typical form. Sideling Hill Creek, 2% miles above

mouth, 1700.

21. Ventral valve of small individual. Williams Road, Polish Moun-

tain, 1660.

22. Ventral valve upon which spines are somewhat closer than usual.

Same locality as preceding.
Jennings formation, Parkhead member.

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17

18

21

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PLATE LI

PAGE

Figs. 1-3. PRODUCTELLA LACHRYMOSA (Conrad) 564

1. Small cast of ventral valve.

2. Ventral valve.

3. Sculpture cast of ventral valve.

Jennings formation, Chemung member, top of Polish Moun-
tain.

Figs. 4-9. PRQDUCTELLA LACHRYMOSA VAR. MARYLAXDICA n. var 565

4. A large ventral valve which differs somewhat from the remaining

specimens. Williams Road, Polish Mountain, 2042.

5. 6. Interiors of dorsal valves.

7-9. Ventral valves showing sparsely spinulose surface. Polish Moun-
tain.
Jennings formation, Chemung member.

Figs. 10-12. PRODUCTELLA LACHRYMOSA (Conrad) var 565

10, 11. Ventral valves.

12. Portion of surface of valve shown in fig. 10, enlarged X 5.

Jennings formation, Chemung member, 3% miles south of
Oakland.

Figs. 13-15. PRODUCTELLA SPECIOSA Hall 566

13. Ventral valve. Hancock-Harrisonville Road, 2 miles north of Han-

cock, 1213.

14. Ventral valve showing spinules. Woodmont, 1067.

15. Dorsal valve. National Road, east of Millstone, 795.

Jennings formation, Woodmont member, Ithaca fauna.

Figs. 16-19. PRODUCTELLA HYSTRICULA (Hall) 567

16, 17. Dorsal valves.

18. Ventral valve.

19. Ventral valve showing spinules.

Chemung formation, New York.

Fig. 20. PRODUCTELLA NAVICELLIFORMIS n. sp 567

Ventral valve of type. Jennings formation, Parkhead member, Town
Creek, 2228.

Figs. 21-23. PRODUCTUS (MARGINIFERA ?) HALLANUS Walcott 568

21, 22. Ventral and dorsal views of a typical specimen from the Upper

Devonian of Lime Creek, Iowa. X 2.

23. External cast of the dorsal valves showing the lamellose, spineless
surface.

Jennings formation, Chemung member, Green Glade Run,
near Deer Park.

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20

18

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PAGE

Figs. 1-4. DALMANELLA TIOGA (Hall) 569

1. Small ventral valve.

2. Cast of interior of ventral valve.

3. Cast of interior of dorsal valve showing muscular scars.

4. Portion of surface of preceding. X 4.

Jennings formation, Chemung member, Ellerslie, Penna.
Figs. 1, 2, at 1316. Figs. 3, 4, at 1474.

Fig. 5. DALMAXELLA CARINATA (Hall) 570

Cast of interior of dorsal valve. Jennings formation, Chemung mem-
ber, west of Ellerslie, Penna.

Fig. 6. DALMAXELLA sp 572

Ventral valve. X 3. Jennings formation, Chemung member, National
Road, Polish Mountain.

Figs. 7-11. RHIPIDOMELLA VAXUXEMI (Hall) 572

7. Ventral valve. Hill south of Potomac River, 2% miles southeast of

Cumberland.

8, 9. Ventral and dorsal valves. Hinge line is shorter and cardinal

angles more acute than in fig. 7. Same locality.

10. Enlargement of interior of dorsal valve showing hinge. X 2.

Williams Road, Polish Mountain, 1371.

11. Cast of interior of ventral valve showing muscular scars. Base of

Parkhead member, hill south of Turners Run Road, 9 miles
southeast of Cumberland.
Jennings formation, Parkhead member.

Figs. 12, 13. RHIPIDOMELLA VAXUXEMI VAR.

12. Ventral valve.

13. Cast of interior of dorsal valve.

Jennings formation, base of Parkhead member, B. & O. R. R.
cut, Rocky Run, 7 miles southeast of Cumberland.

Figs. 14-18. SCHIZOPHOKIA STRIATULA (Schlotheim) 572

14. Cast of interior of ventral valve of an unusually large individual

showing deep muscular scars. Western Maryland Railroad, 2
miles west of Pawpaw, 1300.

15. Cast of interior of ventral valve. Same locality as preceding.

16. Cast of interior of dorsal valve, preserving striae. Yellow Springs

Road, 3 miles east of Berkeley Springs, West Virginia, 660 feet
west of beginning of section.

17. Cast of interior of dorsal valve. National Road, west of Tonoloway

Ridge.

18. Cast of interior of ventral valve of young individual. Same

locality as fig. 16. 310 feet west of beginning of section.
Jennings formation, Woodmont member, Ithaca fauna.

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PLATE LIII

PAGE

Fig. 1. SCHIZOPHOBIA STRIATULA ( Schlotheim) 572

Cast of interior of ventral valve which approaches the next variety.
Jennings formation, Chemung member, Ellerslie, Penna., 1474.

FigS. 2-9. SCHIZOPHORIA STRIATULA VAR. MARYLANDICA n. Var 574

2-4. Internal casts of dorsal valves.
5. Internal cast of ventral valve.
6-8. Three ventral valves.
9. Dorsal valve.

Jennings formation, Chemung member, Deer Park and vi-
cinity.

Fig. 10. SCHIZOPHORIA STRIATULA (Schlotheim) ? 572

Internal cast of ventral valve. Jennings formation, Parkhead mem-
ber, Rocky Run, 7 miles southeast of Cumberland.

Figs. 11-16. CAMAROTCECHIA CONGREGATA VAR. PARKHEADENSIS n. var 575

11. Ventral valve more elongate than usual. Parkhead member,

National Road, east of Hancock, 1600.

12. Cast of interior of ventral valve. Associated with fig. 11.

13. Dorsal valve. Associated with preceding.

14. Posterior view of cast of interior. Chemung member, National

Road, Polish Mountain above 7th turn.

15. Cast of interior of dorsal valve. Associated with fig. 14.

16. Cast of interior of ventral valve. X 2. Associated with preceding.

17. Cast of interior of ventral valve approaching C. sappho in form.

Base of Parkhead member, road 1 mile north of Rocky Run. 6
miles southeast of Cumberland.
Jennings formation.

Figs. 18-20. CAMAROTCECHIA CONTRACTA (Hall) 577

18. Ventral valve of typical form showing sharp angular plications.

Allegany Grove, 2957.

19. 20. Ventral valves possessing less angular plications, approaching

C. congregata var. parkheadensis. National Road, Polish Moun-
tain, above 7th turn.

Jennings formation, Chemung member.

Fig. 21. CAMAROTCECHIA CONTRACTA (Hall) var 577

Cast of interior of ventral valve. Jennings formation, Chemung mem-
ber, National Road, east of Millstone, 3116.

Figs. 22-25. CAMAROTCECHIA HORSFORDI (Hall) 578

22. Ventral valve, doubtfully referred to this species. Chemung

member, National Road, Polish Mountain above 7th turn.

23, 24. Cast of interiors of ventral and dorsal valves. Parkhead mem-

ber. 2% miles north of mouth of Sideling Hill Creek, 1700.

25. Anterior view of shell. Parkhead member, Western Maryland

Railroad, 2 miles west of Pawpaw.
Jennings formation.

Figs. 26, 27. CAMAROTCECHIA ORBICULARIS (Hall) 579

26. Cast of interior of dorsal valve. 2% miles southwest of Mountain

Lake Park.

27. Side view of dorsal valve. Jennings Run Road, 1 mile east of

Barrelville.

Jennings formation, Chemung member.

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26 27

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PAG0

Figs. 1-4. CAMAROTCECHIA EXIMIA (Hall) 579

1. Ventral valve. Town Creek, 4596.

2. Cast of interior of ventral valve. Allegany Grove, 1860.

3. Cast of interior of dorsal valve. Western Maryland Railroad, 2

miles west of Pawpaw, 4703.

4. Anterior view showing slight development of sinus. X 2. Town

Creek, 4596.
Jennings formation, Chemung member.

Figs. 5-8. LIORHYNCHUS MESACOSTALE Hall 581

5. Ventral valve.

6. Cast of interior of ventral valve.

7. Cast of interior of ventral valve of young individual.

8. Cast of interior of ventral valve of a somewhat crushed individual.

Jennings formation, Parkhead member, Williams Road, 3%
miles east of Cumberland, 1393.

Fig. 9. LIORHYNCHUS CF. MUI/TICOSTUM Hall 581

Exterior of ventral valve. Jennings formation, Parkhead member (?),
National Road, west side of Green Ridge.

Figs. 10-16. LIORHYNCHUS GLOBULIFORME (Vanuxem) 582

10-12. Dorsal, anterior and ventral views of an internal cast of an
unusually elongate individual. Yellow Springs Road, 3 miles
east of Berkeley Springs, W. Va., 1124.

13. Enlargement of muscular scars and hinge of ventral valve. X 3.

National Road, east of Millstone, 1122.

14. Cast of interior of dorsal valve of usual form. Western Maryland

Railroad, 2 miles west of Pawpaw, 1300.

15. Enlargement of hinge and muscular scars of fig. 14. X 4.

16. Cast of interior of dorsal valve. Locality not known.

Jennings formation, Woodmont member, Ithaca fauna.

Figs. 17-22. PUGNAX PUGNUS VAR. ALTUS Calvin 583

17-19. Ventral, dorsal and side views of internal cast. Woodmont, 1000.

20. Cast of interior of a dorsal valve bearing more pronounced angular

plications.

21. Enlargement of muscular scars and hinge of ventral valve. X 3.

Same locality as figs. 17-19.

22. Enlargement of hinge of dorsal valve. X 3. Yellow Springs Run

Road, 3 miles east of Berkeley Springs, West Virginia, 510 feet
west of beginning of section.
Jennings formation, Woodmont member, Ithaca fauna.

Fig. 23. CRYPTONELLA CF. EUDORA Hall 584

Internal cast of a ventral valve. Jennings formation, Chemung mem-
ber (?), Williams Road, Polish Mountain.

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10

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16

20

23

PLATE LV

PAGE

Figs. 1-5. TROPIDOLEPTUS CARINATUS (Conrad) 585

1. Ventral valve. Williams Road, 3% miles east of Cumberland, 1466.

2. Cast of interior of ventral valve. Sideling Hill Creek, 2% miles

above mouth, 1700.

3. Dorsal valve. Two miles north of mouth of Town Creek, 1949.

4. Interior of dorsal valve. Same locality as preceding specimen.

5. Enlargement of hinge of fig. 4. X 4.

Jennings formation, Parkhead member.

Figs. 6-11. ATRYPA RETICULARIS (Linne") 586

6. Ventral valve showing alation about margin unusually well. Jen-

nings formation, Woodmont member, Ithaca fauna, National
Road, east of Hancock, 690.

7. Enlargement of hinge of cast of interior of ventral valve. X 2.

Same specimen as fig. 6.

8. Enlargement of hinge of cast of interior of dorsal valve. X 3. 2y2

miles northeast of Pratt.

9. Cardinal region of the dorsal valve enlarged, showing the crenulate

dental sockets. Polish Mountain.

10. Ventral valve retaining parts of concentric lamellae. Near Deer

Park.

11. Ventral valve. Oakland.

Jennings formation, Chemung member.

Figs. 12, 13. ATRYPA SPINOSA Hall 587

12. Ventral valve.

13. Cast of interior of dorsal valve.

Jennings formation, Chemung member, Ellerslie, Penna,, 1524.

Figs. 14-19. ATRYPA HYSTRIX Hall 589

14. A young ventral valve. National Road, 5 miles west of Frostburg.

15. Cast of interior of ventral valve with very coarse plications. %

mile southwest of Gortner.

16. Ventral valve. Trout Creek, Oakland.

17. Dorsal valve. Near Oakland.

18. Enlargement of surface showing the lamellae enfolding into spines.

X 2.

19. Ventral valve. Trout Creek, Oakland.

Jennings formation, Chemung member.

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MOLLUSCOIDEA — BRACHIOPODA

PLATE LVI

PAGE

Figs. 1-3. CYRTINA HAMJ.LTONENSIS Hall 591

1. Cast of interior of ventral valve. Chemung member, road from

Oakland to Deer Park.

2. Cast of interior of ventral cardinal area. Same locality.

3. Dorsal valve. X 2. Woodmont member, Ithaca fauna, National

Road, west of Tonoloway Ridge.
Jennings formation.

Figs. 4-6. RETICULARIA L^EVIS (Hall) 592

4. Cast of interior of dorsal valve.

5. Interior of ventral valve. Portage formation, New York.

6. Cast of interior of ventral valve showing muscular scars.

Jennings formation, Woodmont member, Ithaca fauna, Na-
tional Road, east of Hancock, 690.

Figs. 7-14. SPIBIFEB DISJTJNCTUS Sowerby 593

7. Ventral valve. National Road, Polish Mountain.

8, 9. Ventral valves. Near Deer Park.

10. Ventral valve with extended cardinal angles. National Road, near

top of Polish Mountain.

11. Ventral valve with extended cardinal angles. Near Deer Park.

12. Interior of dorsal valve. Near Oakland.

13. Internal cast of ventral valve. National Road, Polish Mountain.

14. Enlargement of cardinal portion of internal cast of ventral valve.

X 2. Town Creek, 2122.
Jennings formation, Chemung member.

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PLATE LVII

PAGE

Fig. 1. SPIKIFEB DISJUNCTUS Sowerby 593

Internal cast of conjoined valves with extremely extended cardinal
angles. Jennings formation, Chemung member, near Deer Park.

Figs. 2-5. SPIRIFEB MESASTEIALIS Hall 596

2. Cast of interior of ventral valve. Near Pawpaw, W. Va.

3. Cast of interior of dorsal valve. National Road, east of Millstone,

2444.

4. Enlargement of portion of surface of dorsal valve. Wills Creek

Station, Penna.

5. Dorsal valve. National Road, east of Millstone.

Jennings formation, Chemung member.

Figs. 6-10. SPIKIFEB MARCYI VAR. SUPERSTES n. var 597

6. Portion of cast of interior of dorsal valve, enlarged X 2, showing

muscular scars and hinge. B. & O. Railroad cut, Rocky Run, 7
miles southeast of Cumberland.

7. Enlargement of a portion of surface showing granulose plications.

X 5. National Road, Polish Mountain.

8. Cast of interior of dorsal valve. National Road, Polish Mountain,

above sixth turn.

9. Cast of interior of dorsal valve with shorter wings. National Road

on Green Ridge, 2690.

10. Posterior view showing cardinal area of ventral valve with partially

filled delthyrium. Associated with fig. 9.

11. Posterior view of cast of interior of ventral valve showing strength

of dental plates. Associated with fig. 9.

Jennings formation, Figs. 6, 7 from near base of Parkhead
member, Figs. 8-11 from Chemung member.

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PLATE LVIII

PAGE

Figs. 1-10. SPIRIFER MUCRONATUS VAR. POSTERUS Hall and Clarke 599

1. Ventral valve of medium size. National Road, east of Hancock,

1149 to 1274.

2. Dorsal valve with extended cardinal angles. National Road, west

of Tonoloway Ridge.

3. Dorsal valve. Associated with fig. 2.

4. Cast, of interior of a very large dorsal valve. Woodmont, 1032.

5. Cast of interior of ventral valve of medium size. There is no

median septum but muscular scar is divided by an impressed
line. Yellow Springs Road, 3 miles east of Berkeley Springs, 660
feet west of beginning of section.

6. Cast of interior of large ventral valve with greatly extended ex-

tremities. Woodmont, 1032.

7. Cast of interior of dorsal valve differing from prevailing form.

Woodmont, 1000.

8. Enlargement of cast of interior of dorsal valve showing muscular

scars. X 3. Western Maryland Railroad, 2 miles west of
Pawpaw, 1300.

9. Cast of interior of ventral valve of young individual. National

Road, east of Hancock, 690.

10. Enlargement of a portion of exterior of valve of young individual
showing ornamentation. X 10. National Road, east of Mill-
stone, 795.

Jennings formation, Woodmont member, Ithaca fauna.

Figs. 11-23. SPIRIFER (DELTHYRIS) MESACOSTALIS Hall 601

11. Ventral valve of a very small individual. Near Deer Park.

12. A larger ventral valve. National Road, Polish Mountain.

13. Enlargement of a part of surface of ventral valve showing median

rib and sharp lamellose concentric markings. X 2. Same
locality.

14. Small dorsal valve. Same locality.

15. Small ventral valve. X 2. The ribs are made to appear too sharp

and the concentric lines too angular. Near Pawpaw, W. Va.

16. Small dorsal valve. Near Deer Park.

17, 18. Cast of interior of small ventral valves. X 2. Same locality.

19. Cast of interior of small dorsal valve. X 2. Same locality.

20. Cast of interior of ventral valve. Mountain Lake Park.

21. 22. Cast of interiors of ventral and dorsal valves of usual size.

Williams Road, Polish Mountain, 1660.

23. Cast of interior of large ventral valve having extended cardinal
angles. 4700 feet northeast of Sunnyside.

Jennings formation, figs. 21, 22 Parkhead member, balance
Chemung member.

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PLATE LIX

PAGE

Figs. 1, 2. SPIBIFEB (DELTHYRIS) MESACOSTALIS Hall 601

1. Cast of interior of large dorsal valve with greatly extended cardinal

angles. 1 mile southeast of Sunnyside.

2. Cast of interior of ventral valve of usual size. X 2. National Road,

Polish Mountain.
Jennings formation, Chemung member.

Figs. 3-7. AMBOCCELIA UMBONATA (Conrad) 602

3. Ventral valve. X 2. Polish Mountain.

4. Dorsal valve. X 2. Same locality.

5. Internal cast of dorsal valve. X 2. Same locality.

6. Exterior of ventral valve. X 2. Same locality.

7. Internal cast of ventral valve. X 2. Near Deer Park.

Jennings formation, Chemung member.

Figs. 8-10. ATHYRIS ANGELICA Hall 604

8. Dorsal valve.

9, 10. Ventral valves.

Jennings formation, Chemung member, Allegany Grove, 2941.

Figs. 11, 12. GRAMMYSIA EIXIPTICA Hall 606

Two views of a right valve. Jennings formation, Chemung member, 1
mile east of Barrelville.

Fig. 13. GRAMMYSIA SUBARCUATA Hall 606

Left valve. Chemung formation, New York.

Figs. 14, 15. GRAMMYSIA COMMXTNIS Hall 607

Right and left valves. Jennings formation, Woodmont member, Ithaca
fauna, Yellow Springs Run Road, 3 miles east of Berkeley
Springs, W. Va., 1124.

Figs. 16, 17. PAL^ANATINA ANGUSTA 609

16. A small right valve.

17. Cast of interior of right valve.

Jennings formation, Chemung member, Town Creek, 4596.

Figs. 18, 19. SPHENOTUS CONTRACTUS Hall 610

18. Sculpture cast of left valve. Chemung formation, New York.

19. Right valve doubtfully determined. Jennings formation, Chemung

member, Wills Creek Station, Penna.

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16

15

17 18 19

MOLLUSCOIDEA — BRACHIOPODA AND MOLLUSCA — PELECYPODA

PLATE LX

VAGE
FigS. 1-3. BUCHIOLA RETROSTRIATA (V. Buch) 613

1. A large right valve, somewhat flattened. X 3. Barrelville Road, y2

mile west of Corriganville.

2. A very small right valve with few broad flat ribs with coarse re-

curved surface markings. X 5. Town Creek, Gilpin.

3. An enlargement showing the smooth embryo shell and the abrupt

introduction of the radial ornament in secondary growth, x 10.
Wolfe Mills, near Cumberland.

Jennings formation, Genesee member.
Figs. 4-6. BUCHIOLA CONVERSA Clarke 615

4. Right valve of type showing the elevated margins and concave sur-

face of the ribs. X 3. Lower Falls of the Genesee River, New
York. Naples shales.

5. 6. Left and right valves. X 5.

Jennings formation, Woodmont member, Naples fauna, Town
Creek, Gilpin.
Figs. 7, 8. BUCHIOLA MARI.E n. sp 615

7. Right valve. X 4.

8. Smaller right valve. X 3.

Jennings formation, Genesee member, Williams Road, Cum-
berland.

Figs. 9-12. BUCHIOLA ? LIVONIA Clarke 616

9. Right valve showing the numerous flattened ribs. X 4. Jennings
formation, Woodmont member, Naples fauna, National Road,
east of Town Creek, Gilpin.

10. The two valves, normally expanded. Romney Road, 3% miles

southeast of Burlington, W. Va. Jennings formation, Genesee
member.

11. Right valve. X 4. Same locality as fig. 10.

12. Left valve of the type specimen showing the fine concentric linea-

tion of ribs. X 3. Styliola limestone of Genesee shales, Livonia
salt shaft, New York.
Figs. 13-16. PARACARDIUM DORIS Hall 617

13. A small right valve. X 4. Wolfe Mills, near Cumberland.

14. Both valves. X 4! Wolfe Mills, near Cumberland.

15. A large right valve. X 4. West of Corriganville.

16. The right valve. X 4. Same locality as fig. 15.

Jennings formation, Genesee member.
Figs. 17, 18. PARACARDIUM DELICATULUM Clarke 618

17. A valve with normal characters, somewhat deformed about the

hinge. X 10. This is the type specimen. Styliola limestone of
the Genesee shale (Naples fauna). Canandaigua Lake, New
York.

18. A right valve showing the extremely fine radial ribs, which are

crossed by concentric lines, though these are made much too
strong in the drawing. X 10.

Jennings formation, Genesee member, Wolfe Mills, near Cum-
berland.
Figs. 19-23. NUCULA CORBULIFORMIS Hall. . , 619

19. Cast of interior of left valve. X 2. Woodmont member, Ithaca

fauna, National Road, west of Tonoloway Ridge.

20. Cast of interior of left valve. X 2. Woodmont member, Ithaca

fauna, same locality as fig. 19.

21. Enlargement of portion of exterior. X 8. Woodmont member,

Ithaca fauna, Berkeley Springs, West Virginia, 1058.

22. Right valve. Parkhead member, 2 miles north of mouth of Town

Creek, 1716.

23. Enlargement of cast of interior showing hinge. Parkhead member,

Williams Road, Polish Mountain, 1352.
Jennings formation.

Fig. 24. PAL^ONEILO PETILA Clarke ? 624

Right valve. X 2. Jennings formation, Woodmont member, Naples
fauna, Williams Road, 3% miles east of Cumberland, 406.

Fig. 25. PAL^EONEILO MAXIMA (Conrad) ? 622

Cast of interior of right valve. 2 miles north of mouth of Town
Creek, Parkhead member, 1282.
Jennings formation.

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13

19

20

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25

PLATE LXI

PAGE

Figs. 1-3. PAL^ONEILO PLANA Hall 621

1. Cast of interior of left valve. National Road, east of Millstone, 2322.

2. Left valve. Associated with preceding.

3. Cast of interior of a very elongate left valve probably of this species.

Near Mr. Cheney's, 2% miles northeast of Pratt, at base of
section.

Jennings formation, Chemung member.

Figs. 4-6. PAI/^EONEILO BREVIS Hall 622

4. 5. Casts of interiors of right and left valves. Parkhead member,

Western Maryland Railroad, 2 miles west of Pawpaw, 1763.

6. Cast of interior of left valve. Woodmont member, Ithaca fauna,

Woodmont.

Jennings formation.

Figs. 7-10. PAi/y£ONEiix> CONSTRICTA (Conrad) 620

7. Cast of interior of right valve. Jennings formation, Woodmont

member, Ithaca fauna, Woodmont, 710.
8,9. Sculpture casts of right and left valves. Hamilton formation,

western New York.

10. Cast of left valve. Jennings formation, Chemung member, Green
Ridge.

Figs. 11, 12. PAL^ONEILO FILOSA (Conrad) 623

Two right valves. X 2. Jennings formation, Chemung member, near
Wills Creek Station, Penna.

Fig. 13. PAI^EONEILO ANGUSTA Hall 624

Left valve. Jennings formation, Chemung member, 1 mile southeast
of Sunnyside.

FigS. 14, 15. PALyEONEILO CKASSA n. Sp 625

14. Cast of interior of right valve of type.

15. Dorsal view of internal cast.

Jennings formation, Chemung member, Town Creek, 3584.

Figs. 16, 17. LEDA CF. DIVERSA Hall 626

16. Cast of interior of left valve. X 2. Town Creek, 3760.

17. Cast of interior of left valve. X 2. Town Creek, 3870.

Jennings formation, Chemung member.

Fig. 18. MACRODON CHEMUNGENSIS Hall 627

Cast of interior of left valve. Jennings formation, near base of Park-
head member, White Sulphur Branch, 4 miles southeast of Pratt.

Figs. 19-21. PTERINEA NODOCOSTA n. sp 628

19. A large left valve showing the coarse nodose ribs and finer inter-

vening ones. Oakland.

20, 21. Two rather imperfect and small left valves. Near Deer Park

and Oakland.

Jennings formation, Chemung member.

Fig. 22. PTERINEA CHEMUNGENSIS (Conrad ) 629

22. A left valve of normal character. Jennings formation, Chemung
member, National Road, 7 miles west of Frostburg.

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PAGE

Figs. 1-3. LUNULICARDIUM ENCRiNiTUM Clarke 630

1. Left valve showing the finely lineate surface. X 3. Town Creek,

Gilpin, Allegany County.

2. Same. X 2. Wolfe Mills, near Cumberland.

3. Same. X 3. Allegany County.

Jennings formation, Genesee member.

Fig. 4. LUNULICARDIUM CYMBULA n. sp G31

The single valve observed. X 5. Jennings formation, Genesee mem-
ber, near Corriganville.

Figs. 5-7. PTEROCH^NIA FRAGILIS (Hall) 632

5. Right valve showing the smooth concentrically lined surface and

the sica. X 3. Jennings formation, Woodmont member, Naples
fauna, Town Creek, Gilpin.

6, 7. Right and left valves. X 3. Jennings formation, Genesee mem-

ber, west of Corriganville.

FigS. 8, 9. ECTENODESMA BIROSTRATUM Hall 633

8. Cast of interior of left valve. The wings of this specimen are

broken. Jennings formation, Woodmont member, Ithaca fauna,
Little Orleans, Wagon Road, north of Western Maryland R. R.

9. Left valve. Chemung formation, New York.

Figs. 10-12. LIOPTERIA BIGSBYI Hall 634

10, 11. Left and right valves. Hamilton or Ithaca, Schoharie, New

York.

12. Left valve doubtfully referred to this species. Jennings forma-
tion, Chemung member, National Road, Polish Mountain, 2714.

Figs. 13, 14. LIOPTERIA MARYLAXDICA n. sp 635

Casts of interior of two left valves. Jennings formation, Chemung
member, Town Creek, 2023.

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PLATE LXIII

PAGE

Fig. 1. LIOPTERIA AURICULATA n. sp 636

Exterior of left valve. The anterior ear is made too large in drawing.
Jennings formation, Woodmont member, Ithaca fauna, National
Road, east of Millstone, 795.

Fig. 2. LIOPTEBIA sp.

A small suberect left valve with short posterior wing and concen-
trically lined surface. Jennings formation, Chemung member,
Trout River, 2 miles south of Oakland.

Fig. 3. LEPTODESMA ROGERSI Hall 636

Right and left valves. Ithaca beds, Norwich, N. Y.

Figs. 4-8. LEPTODESMA LONGISPINUM Hall 637

4. Right valve. Chemung formation, New York.

5. Left valve with posterior spine restored. Near Oakland.

6. Left valve doubtfully referred to this species. National Road, 6

miles west of Frostburg.

7. 8. Right and left valves. Same locality.

Jennings formation, Chemung member.

Figs. 9, 10. LEPTODESMA AGASSIZI Hall 637

9. Left valve.

10. Right valve.

Chemung formation, New York.

Figs. 11-15. LEPTODESMA MEDON Hall 638

11. Small left valve. National Road, 7 miles west of Frostburg.
12, 13. Right valves. Allegany Grove, 2307.

14, 15. Left valves. Allegany Grove, about 2215.
Jennings formation, Chemung member.

Figs. 16, 17. LEPTODESMA NAVIFORME Hall 639

16. Exterior of large right valve showing faint radiating striae.

17. Exterior of right valve of somewhat different proportions.

Jennings formation, near base of Parkhead member, Williams
Road, 4 miles east of Cumberland.

Figs. 18, 19. LEPTODESMA LICHAS Hall 640

18. Left valve. Jennings formation, Chemung member, National Road,

6 miles west of Frostburg.

19. Left valve. Chemung formation, New York.

Fig. 20. LEPTODESMA ELONGATUM n. sp 640

Left valve. Jennings formation, near top of Chemung member, Keyser-
Piedmont Road, 2% miles west of Keyser, W. Va.

Fig. 21. GOSSELLETIA sp 641

Cast of interior left valve. Jennings formation, Chemung member,
Williams Road, Polish Mountain.

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11

21

MOLLUSCA — PELECYPODA

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PAGE
Fig. 1. ACTINOPTERIA CF. EPSILON Hall 642

A large left valve, showing radial lines. Ithaca beds, Ithaca, N. Y.

Fig. 2. ACTINOPTERIA BOYDI (Conrad) 642

Left valve, outline restored. Jennings formation, Woodmont member,
Ithaca fauna, Woodmont, 1170.

Figs. 3-5. SCHIZODUS CHEMUNGENSIS (Conrad) 644

3, 4. Casts of interior of right valve.
5. Cast of interior of left valve.

Jennings formation, Chemung member, Town Creek, 3453.

Fig. 6. SCHIZODUS CHEMUNGENSIS VAK. QUADRANGULARIS Hall 645

Left valve. Jennings formation, Chemung member, near Deer Park.

Figs. 7-14. SCHIZODUS OHERNI n. sp 646

7. Left valve.

8. Cast of interior of right valve of more circular shape than usual.
9, 10. Interior of left and right valves showing hinge.

11. Cast of interior of right valve.

Jennings formation, Parkhead member, National Road, east
of Millstone, 1781.

12, 13. Cast of interior of very large left valves.
14. Posterior view of cast of valve shown in fig. 13.

Jennings formation, Chemung member, Sideling Hill Creek.

Fig. 15. SCHIZODUS FROSTBURGENSIS n. sp 647

Cast of interior of left valve. Jennings formation, Chemung member.
National Road, 7 miles west of Frostburg.

Figs. 16-18. SCHIZODUS TRIGONALIS n. sp 647

16-17. Casts of interiors of left valves. Chemung member, Town

Creek, 2228.

18. Cast of interior of right valve, probably of this species. Parkhead
member, National Road, east of Millstone, 1781.
Jennings formation.

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PAGE

Fig. 1. LYRIOPECTEN TRICOSTATUS (Vanuxem) 649

Left valve with characteristic surface markings. Jennings formation,
Chemung member, Allegany County, near West Virginia line.

Pig. 2. MODIOMORPHA SUBANGULATA Hall var 650

Right valve. Jennings formation, Chemung member, Williams Road,
Polish Mountain, 2382.

Fig. 3. GONIOPHORA HAMILTONENSIS Hall 651

Left valve. Jennings formation, Parkhead member, Western Mary-
land Railroad, 2 miles west of Pawpaw, 1485.

Figs. 4-6. GONIOPHORA TRUNCATA Hall 651

4. Cast of interior of left valve.

5. Cast of interior of right valve.

6. Left valve.

Jennings formation, Parkhead member, Williams Road, Polish
Mountain, 1660.

Fig. 7. GONIOPHORA GLAUCA Hall 652

Right valve. Jennings formation, base of Parkhead member, White
Sulphur Branch, 4 miles southeast of Pratt.

Figs. 8-10. CYPRICARDELLA BELLISTRIATA (Conrad) 653

8. Left valve.

9. Right valve.
10. Left valve.

Hamilton formation, New York.

Figs. 11-15. CYPRICARDELLA MARYLANDICA n. sp 654

11. Right valve.

12. Right valve somewhat distorted.

13. Internal cast of right valve.

14. Left valve of normal outline.

15. Right valve expressing the correct characters of the exterior. X 2.

Jennings formation, Chemung member, Deer Park.

Figs. 16-18. CYPRICARDELLA GREGARIA (Hall) 654

Internal casts of left valves. Jennings formation, Parkhead (?) mem-
ber, National Road, west of Green Ridge.

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15

PLATE LXVI

PAGE

Figs. 1-5. CYPRICABDELLA TENUISTRIATA (Hall) 656

1. Cast of interior of left valve. Sideling Hill Creek, 2y2 miles above

mouth, 1700.

2. Right valve. Two miles north of mouth of Town Creek, 1716.

3. Right valve, somewhat questionably referred to this species, upon

which concentric striae of umbo are nearly obsolete. Two miles
north of mouth of Town Creek, 1632.
Jennings formation, Parkhead member.

4. Large left valve. Hamilton formation, New York.

Figs. 6-12. CYPRICARDELLA NITIDULA n. sp 656

6. Left valve showing the well marked umbonal slope and strong

concentric ridges. X 2.

7. Internal cast of left valve showing muscle scars and hinge. X 2.

8. Gutta-percha squeeze of hinge of left valve. X 2.

9, 10. Two left valves of an elongate finely lined shell, with posterior
umbonal ridge close upon the margin. These shells resemble in
outline C. tenuistriata Hall except for the position of the pos-
terior ridge.

11. Gutta-percha squeeze showing interior of right valve. X 2.

12. The interior of a small left valve of the same species.

Jennings formation, Chemung member, figs. 6-11 Deer Park,
fig. 12 National Road, west of Frostburg.

Fig. 13. CYPRICARDELLA CUMBERLAND!^ n. sp 657

Cast of interior left valve. Jennings formation, Chemung member,
Allegany Grove.

Figs. 14-20. CYPRICARDELLA CRASSA n. sp 657

14, 15. Left valves.

16. Cast of interior of right valve.

17. Cast of interior of left valve.

18. Right valve.

19. Interior of right valve.

20. Hinge of right valve enlarged X 2.

Jennings formation, Chemung member, National Road, east of
Millstone, 2761.

Fig. 21. CYPRICARDINIA ELEGANS n. sp 659

Left valve of type. Jennings formation, Chemung member, National
Road, 300 feet west of schoolhouse, Belle Grove.

Figs. 22-24. CYPRICARDINIA ELEGANS VAR. ANGUSTA n. var 659

22. Cast of interior of left valve.

23. Dorsal view of internal cast. The valves are not equal in convexity

as the figure seems to indicate.

24. Right valve.

Jennings formation, Chemung member, Town Creek, 3584.

Fig. 25. PARACYCLAS MARYLANDICA n. sp 660

Right valve of type. Jennings formation, Chemung member, Town
Creek, 3870.

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PLATE LXVII

PAGE

Figs. 1-3. PLETJROTOMARIA (GYKOMA) CAPILLARIA Conrad 661

1. Ventral view of large individual. X 2. Hamilton formation, New

York.

2. Dorsal view of small shell. Jennings formation, Parkhead member,

Sideling Hill Creek, 2% miles above mouth, 1700.

3. Exterior of portion of shell showing ornamentation and slit band.

Associated with preceding.

Fig. 4. HOBMATOMA BisTRiATA n. sp 663

Dorsal view of type. X 2. Jennings formation, Parkhead member,
Sideling Hill Creek, 2% miles above mouth, 1700.

FigS. 5-8. ECTOMAHIA MARYLANDICA n. SP 663

5. Dorsal view of shell. X 2. The apical angle is too large in drawing.

Western Maryland Railroad, 2 miles west of Pawpaw, 1597.

6. Dorsal view of shell. X 2. Sideling Hill Creek, 2y2 miles above

mouth, 1700.

7. Dorsal view of type specimen. Western Maryland Railroad, 2 miles

west of Pawpaw, 1597.

8. Cast of exterior of shell. The apical angle is much too small, due to

cast. Same locality.
Jennings formation, Parkhead member.

Figs. 9-12. ECTOMARIA ECCLESI.E n. sp 664

9. A group of shells, natural size. Near Oakland.

10. Dorsal view. X 3. Deer Park.

11. Part of the spiral with the concentric striae obsolete. X 5. Near

Oakland.

12. An enlargement of part of the spire showing the surface orna-

mentation. X 5. Polish Mountain.
Jennings formation, Chemung member.

Figs. 13-16. BELLEROPHON NACTOIDES n. sp 665

13-15. Dorsal, ventral, and side views of cast of exterior. National

Road, west of Tonoloway Ridge.
16. Enlargement of portion of surface. X 3. Same locality.

Jennings formation, Woodmont member, Ithaca fauna.

Figs. 17-20. BELLEROPHON CLARKI n. sp 666

17-18. Dorsal and side view of type specimen. X 1%. Williams Road,
Polish Mountain, 1660.

19. Dorsal view. Western Maryland Railroad, 2 miles west of Paw-

paw, 1597.

20. Enlargement of exterior showing ornamentation. Polish Moun-

tain.

Jennings formation, Parkhead member.

Figs. 21, 22. BUCANOPSIS M^RA (Conrad) 667

Dorsal and side view of shell. Chemung formation, New York.

Figs. 23-25. STRAPAROIXUS MARYLANDICUS n. sp 668

23. Internal cast of type, dorsal view.

24. Lower surface of specimen illustrated in fig. 23, showing large

umbilicus. Sideling Hill Creek, 2% miles above mouth, 1700.

25. Upper view of small shell. Williams Road, Polish Mountain, 1661.

Jennings formation, Parkhead member.

Fig. 26. PH^XEROTINUS LAXUS (Hall) 669

Internal cast. Parkhead member, Sideling Hill Creek, 2V2 miles above
mouth, 1700.

Figs. 27-29. CYCLONEMA COXCIXNUM Hall 670

27. Dorsal view showing ornamentation. Chemung member, Town

Creek, 2228.

28. Dorsal view of smaller specimen. Parkhead member, Western

Maryland Railroad, 2 miles west of Pawpaw, 1597.

29. Internal cast. Parkhead member, Sideling Hill Creek, 2l/2 miles

above mouth.

Jennings formation.

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MARYLAND GEOLOGICAL SURVEY

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M OLLU SC A — GASTROPODA

24

PLATE LXVIII

PAGE

Figs. 1-4. CYCLONEMINA CRENULISTRIATA n. sp 671

1. Dorsal view.

2. Portion of the surface of a shell enlarged. X 3.

3. Dorsal view of individual showing great thickness of the shell.

4. Dorsal view showing aperture. Type.

Jennings formation, Chemung member, Town Creek, 2228.

Fig. 5. CYCLONEMINA CKENUXJSTRIATA VAR. OBSOLESCENS n. var 672

Shell preserving portion of test, showing ornamentation. Jennings
formation, Chemung member, Town Creek, 2228.

Figs. 6-10. CYCLONEMINA MITLTISTRIATA n. sp 672

6. Dorsal view of type. Sideling Hill Creek, 2~y2 miles above mouth,

1700.

7. Enlargement of a portion of the surface showing ornamentation.

X 5. Same locality.

8. Dorsal view of a shell of slightly different proportions. Same

locality.

9. Cast of interior. Same locality.

10. Internal cast of a very large shell. Williams Road, Polish Mountain,
1600.

Jennings formation, Parkhead member.

Figs. 11, 12. TURBO CORONOLA n. sp 673

11. Profile from a replica. The original cast of this is somewhat

imperfect or distorted about the lower edge of the aperture.

12. A part of the exterior drawn from a gutta-percha squeeze.

Jennings formation, Chemung member, National Road, 6 miles
west of Frostburg.

Fig. 13. TROCHONEMA (GYRONEMA) LIRATUM (Hall) 674

Dorsal view. Jennings formation, Chemung member, National Road,
east of Hancock, 2223.

Figs. 14, 15. MACROCHILINA PULCHELLA n. sp 675

14. Internal cast of the only specimen observed. X 5.

15. Exterior of the same. X 5.

Jennings formation. Chemung member, Williams Road, Polish
Mountain.

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MOLLUSCA — GASTROPODA

PLATE LXIX

PAGE

Figs. 1, 2. LOXONEMA HAMILTONI,E Hall 676

1. Dorsal view of a small specimen. X 2. Western Maryland Railroad,

2 miles west of Pawpaw, 1597.

2. Dorsal view of a larger individual of the usual proportions. Same

locality, 1485.
Jennings formation, Parkhead member.

Figs. 3-7. LOXONEMA TEREBRUM Hall 676

3. Dorsal view of a nearly complete example. National Road, 6 miles

west of Frostburg.

4. Dorsal view of a small shell. Same locality.

5. A portion of the exterior. Same locality.

6. Part of an internal cast. Glade Run.

7. External and internal cast of a specimen. Same locality.

Jennings formation, Chemung member.

Figs. 8-10. LOXONEMA STYLIOLUM Hall 676

8. 9. Dorsal view of exteriors of shells upon which ornamentation is

not preserved.

10. Internal cast of apical portion.

Jennings formation, Chemung member, Town Creek, 2238.

Figs. 11-14. LOXONEMA ( ?) GLABRUM n. sp 677

11. Internal cast. Williams Road, Polish Mountain, 1660.

12. Dorsal view of exterior. Same locality.

13. Internal cast. Sideling Hill Creek, 2l/2 miles above mouth, 1700.

14. Dorsal view of exterior of a shell probably of this species. Wil-

liams Road, Polish Mountain.

Jennings formation, Parkhead member.

Figs. 15, 16. TRACHYODOMIA PRECURSOR (Clarke) 678

Ventral and dorsal views of shell. X 1%. This is a barite replacement
of the fossil from the Portage formation, Naples beds, Honeoye
Lake, New York.

Figs. 17, 18. HOLOPEA ROWEI n. sp 679

17. Internal cast of a large specimen.

18. Dorsal view.

Jennings formation, Chemung member, Williams Road, Polish
Mountain.

Figs. 19, 20. HOLOPEA MARYLANDICA n. sp 680

Dorsal views showing variations in form. Jennings formation, Che-
mung member, Williams Road, Polish Mountain.

Fig. 21. HOLOPEA HUMILIS n. sp 680

Internal cast of type. Jennings formation, Parkhead member, 2 miles
north of mouth of Town Creek, 1716.

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15

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21

18

PLATE LXX

PAGE

Figs. 1-3. PLATYCERAS COMPKESSUM n. sp 683

Three views of type. Jennings formation, Chemung member, west of
Green Ridge, near Pennsylvania line.

Figs. 4-6. ORTHONYCHIA PROSSERI n. sp 681

Three views of internal cast. Jennings formation, Chemung member,
National Road, 6 miles west of Frostburg.

Figs. 7-9. ORTHONYCHIA UNGUICTJLATA n. sp 682

Three views of type. Jennings formation, Parkhead member, Williams
Road, Polish Mountain, 1660.

Figs. 10, 11. ORTHONYCHIA sp 682

Enlargement of internal cast. X 2. Jennings formation, Parkhead
member, Sideling Hill Creek, 2l/2 miles above mouth, 1700.

Figs. 12-16. PLATYCERAS MARYLANDICUM n. sp 683

12, 13. Two views of a small individual. Parkhead member, Williams

Road, Polish Mountain, 1660.

14-16, Three views of type specimen. Chemung member, same locality,
2042.
Jennings formation.

Figs. 17-19. DIAPHOROSTOMA LINEATUM (Conrad) 684

17, 18. Two views of same shell.

19. Portion of surface enlarged X 7.

Jennings formation, Chemung member, west of Green Ridge,
near Pennsylvania line.

Figs. 20-23. TENTACULITES DESCISSUS n. sp 686

20. A full grown example showing the subequal rings of early growth

and the alternation in size in later stages. X 2. Green Ridge,
Allegany County.

21. A small example. Western Maryland.

22. 23. Fragments of the apical parts of the tubes with only the sub-

equal rings present. X 5.

Jennings formation, Chemung member, Deer Park.

Fig. 24. TENTACTTLITES SPICTJLUS Hall 687

Shell enlarged X 5. Jennings formation, Woodmont member, Ithaca
fauna, National Road, east of Millstone, 795.

153

MARYLAND GEOLOGICAL SURVEY

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MOLLUSCA GASTROPODA

PLATE LXXI

PAGE

Figs. 1-3. STYLIOLINA FISSURELLA (Hall) 685

1. Surface of fragment of shale covered with shells, natural size.

2. Fragment enlarged. X 3.

3. Single individual. X 6.

Genesee formation, New York.

Figs. 4-6. COLEOLUS TENUICIXTUS Hall 687

4. Cast of interior of shell of unusually large size. Maryland-Pennsyl-

vania state line, east of Ragged Mountain.

5. 6. Apices of two specimens. X 6. One-half mile north of Pawpaw.

Jennings formation, Parkhead member.

Figs. 7-9. HYOLITHES ACLIS Hall 688

Three views of cast of interior. X 2. Jennings formation, Parkhead
member, Sideling Hill Creek, 2l/2 miles above mouth, 1700.

Fig. 10. PHARETREIXA TENEBROSA Hall 690

Specimen showing ornamentation. Genesee formation, New York.

Fig. 11. BACTRITES ACICTJLUS (Hall) 692

A specimen showing the usual crushed and incomplete condition of the
fossil. Jennings formation, Genesee member, Williams Road,
near Cumberland.

Figs. 12, 13. ORTHOCERAS FILOSUM Clarke 691

Specimens showing the surface characteristics. Jennings formation,
Woodmont member, Naples fauna, Town Creek, Gilpin.

Figs. 14, 15. ORTHOCERAS DEMUM Hall 691

14. Chamber of habitation.

15. A part of shell showing septa.

Jennings formation, Chemung member, National Road, east of
Hancock, 2223.

Figs. 16-18. ORTHOCERAS CONSORTAI.E Hall 690

16. Cast of a portion of shell showing septa.

17. Portion of shell showing chamber of habitation.

18. Septum showing siphuncle.

Jennings formation, Chemung member, Williams Road, Polish
Mountain, 2043.

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MOLLUSCA — GASTROPODA AND CEPHALOPODA

PLATE LXXII

PAGE

Figs. 1-3. MANTICOCERAS PATERSONI (Hall) 693

1. Shell upon which sutures are not preserved. Chemung member,

Williams Road, Polish Mountain, 2042.

2. Transverse section of shell shown in fig. 1.

3. Smaller individual preserving suture lines.

Portage formation, Naples fauna, New York.

Figs. 4, 5. PROBELOCERAS LUTHERI Clarke 695

Two small specimens neither showing septa, tentatively referred to
this species. Fig. 4X3; fig. 5 natural size. Jennings forma-
tion, Genesee member, Wolfe Mill, Allegany County.

Fig. 6. TORNOCERAS UNIANGULARE (Conrad) 696

A small flattened specimen showing the characteristic septal sutures.
X 2. Jennings formation, Genesee member, Williams Road,
Cumberland.

Fig. 7. SANDBERGEROCERAS CHEMUNGENSIS (Vanuxem) 697

Part of a single volution. Jennings formation, near base of Parkhead
member, White Sulphur Branch, 4 miles southeast of Pratt.

Figs. 8, 9. PHACOPS RAX A (Green) 699

8. Glabella. Sideling Hill Creek, 2% miles above mouth, 1700.

9. Pygidium. Road leading northeast from Pratt, % mile west of

15-mile Creek.
Jennings formation, Parkhead member.

155

MARYLAND GEOLOGICAL SURVEY.

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MOLLUSCA— CEPHALOPODA AND ARTHROPODA— TRILOBITA

PLATE LXXIII

PAGE

Figs. 1-3. GLYPTASPIS EASTMANI n. sp 700

1. Antero-ventro-lateral plate showing surface ornamentation. Jen-

nings formation, base of Parkhead member, Horse Ridge, south-
west of Hancock, 1600.

2. Right postero-ventro-lateral plate showing surface ornamentation.

Jennings formation, Parkhead member (?), west of Green
Ridge, near Pennsylvania line.

3. Fragment of an undetermined plate from the same locality as fig. 1.

J53

MARYLAND GEOLOGICAL SURVEY

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