leathery as it is a black film with irregular, broken, longitudinal lines with more or less scaly edges.
Microscopic structure undetermined.
Observations.—The perforations in the tegument are not unlike those of the living alga Agarum turneri Post and Ruprecht, and one might imagine that a fragment of the strong frond of this species is similar to M. dorus, but the resemblance is only general; the perforations of M. dorus are more uniform than those of the beautifully perforate living alga Kallymenia perforata Agardh, which also has a far more delicate tegument.
Holotype and paratypes.—U. S. N. M., Nos. 83922, 83923a-e.
REDOUBTIA Walcott 1918
REDOUBTIA POLYPODIA Walcott
Plate 2, figs. 2-3
- Redoubtia polypodia Walcott, 1918, Smithsonian Misc. Coll., vol. 68, no. 12, p. 5, fig. 5.
The holotype is refigured since it was first published in the popular account of field explorations issued annually by the Smithsonian Institution, which does not reach paleontologists generally.
Accompanying the original figure is the following statement, "An elongate creeping holothurian with numerous tube feet and tentacles."
Whether the second specimen really represents the same species appears somewhat doubtful inasmuch as the tube feet are smaller and more numerous. The larger appendages above the specimen, as posed on the plate, are parts of another animal.
Holotype and paratype.—U. S. N. M., Nos. 83924 and 83925.
PORTALIA Walcott 1918
PORTALIA MIRA Walcott
Plate 3, figs. 2-3
- Portalia mira Walcott, 1918, Smithsonian Misc. Coll., vol. 68, no. 12, p. 6, figs. 6, 7.
Another holothurian first figured in the explorations account for 1918 is also refigured, to give it wider availability. This form differs from the preceding Redoubtia polypodia in having fewer and longer tube feet and in their apparently different grouping.
Holotype.—U. S. N. M., No. 83927.
