Page:Smithsonian Miscellaneous Collections, Volume 85.djvu/128

HELMETIA Walcott 1918

HELMETIA EXPANSA Walcott

Plate 27

Helmetia expansa Walcott, 1918, Smithsonian Misc. Coll., vol. 68, no. 12, p. 7, fig. 8.

This is another of the species first published in the Smithsonian explorations pamphlet for 1917, and for that reason is here reprinted.

Holotype.—U. S. N. M., No. 83952.

EXPLANATION OF PLATES

Plate 1

			PAGE
Margaretia dorus, new species			2
Fig.	1.	Impression of outer surface.
	2.	A wider and less well defined specimen. Possibly a mutilated fragment.
	3.	Impression of surface, on which the elevations apparently were more conical and more numerous, which may indicate another species.
	4.	Unretouched photograph by reflected light of the typical form. This is again the impression of the outer surface. Compare the elongate elevations with the more conical ones in fig. 3.
	5.	Unretouched photograph of the holotype.
	6.	(✕ 2.) Another, less perfect specimen on which Doctor Walcott apparently laid stress.

Plate 2

			PAGE
Miskoia placida, new species			4
Fig.	1.	The holotype showing the annulations, the teeth around the mouth, and the manner in which the digestive tract seems to run along one side of the body, as it is compressed in the shale.
Redoubtia polypodia Walcott			3
Fig.	2.	A specimen, possibly of a different species, since it has smaller appendages. Parts of a Hymenocaris? lie above it.
	3.	(✕ 1.5.) Holotype, as illustrated previously.

Plate 3

			PAGE
Wiwaxia corrugata Walcott			6
Fig.	1.	Photograph of a very fine individual retouched to bring out the striae on the scales.
Portalia mira Walcott			3
Figs.	2, 3.	Counterparts of the holotype. A specimen of Miskoia lies nearby.