USGS Logo Geological Survey Professional Paper 58
The Guadalupian Fauna

PLATES — PLATE X.

CAPITAN FORMATION, GUADALUPE MOUNTAINS.


ORTHOTETES GUADALUPENSIS n. sp. (p. 199).

FIGS. 1 to 1d.

The type specimen retaining both valves in conjunction. All the figures X 1-1/2. It was not found possible to represent quite faithfully the fineness of the lirae and their rounded shape.

1.

Ventral view.

1a.

Dorsal view.

1b.

Anterior view.

1c.

Posterior view.

1d.

Side view.

Capitan formation, Capitan Peak (station 2926).

FIGS. 2 to 2b.

A similar but somewhat irregular specimen retaining both valves. All the figures X 1-1/2.

2.

Side view.

2a.

Posterior view.

2b.

Dorsal view.

Capitan formation, Capitan Peak (station 2926).

FIG. 3.

A dorsal valve from which the shell has been largely exfoliated, so that the socket plates can be seen.

Seen from above, X 1-1/2.

Capitan formation, Capitan Peak (station 2926).

FIG. 4.

A ventral valve with the apex ground down to show the septal arrangement, X 3. The typical camerate structure is seen, but as the specimen was somewhat distorted the septum is not quite central.

Capitan formation, Capitan Peak (station 2926).

FIG. 5.

Fragment of a ventral valve which has been broken along the dental plates and septum. x, Pseudodeltidium; y, y, converging dental plates; z, median septum.

Specimen viewed obliquely downward and to the right, X 3.

Capitan formation, Capitan Peak (station 2926).


ORTHOTETES DECLIVIS n. sp. (p. 200).

FIGS. 6 to 6b.

A ventral valve taken as the type of the species. The figures of this species are not enlarged, so that its size relative to the preceding type is misrepresented.

6.

Seen from above.

6a.

Posterior view.

6b.

Side view.

Capitan formation, Capitan Peak (station 2926).

FIGS. 7 and 7a.

A fragmentary dorsal valve supposed to belong to this species, with the shell partially removed to show the long socket plates.

7.

Seen from above.

7a.

Side view in outline.

Capitan formation, Capitan Peak (station 2926).

FIGS. 8 and 8a.

A somewhat imperfect dorsal valve referred to this species.

8.

Seen from above.

8a.

Side view in outline.

Capitan formation, bill southwest of Guadalupe Point (station 2906).


ORTHOTETES DISTORTUS n. sp. (p. 201).

FIGS. 9 to 9c.

The type specimen preserving both valves in conjunction. The extremely fine liration can not be accurately represented on figures of this size. All figures nearly X 2.

9.

Posterior view.

9a.

Side view.

9b.

Anterior view.

9c.

Dorsal view.

Capitan formation, Capitan Peak (station 2926).


ORTHOTETES DISTORTUS var. CAMPANULATUS n. var. (p. 202).

FIGS. 10 to 10c.

A ventral valve; the typical specimen. All figures X 1-1/2.

10.

Anterior view, showing the great length of the septum.

10a.

Side view.

10b.

Seen from above.

10c.

Posterior view.

Capitan formation, Capitan Peak (station 2926).


DERBYA sp. a (p. 184).

FIGS. 11 and 11a.

A ventral valve provisionally referred to this species. The shell has been much exfoliated, partially obscuring the sculpture.

11.

Seen from above.

11a.

Side view in outline.

Capitan formation, Capitan Peak (station 2926).


DERBYA sp. b (p. 185).

FIG. 12.

A fragmentary ventral valve.

Posterior view.

Capitan formation, Capitan Peak (station 2966).


Plate X. (click on image for a PDF version)


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Last Updated: 05-Dec-2008