Page:Proceedings of the United States National Museum, Volume 76.djvu/142

14 previously been described that its description and naming seems desirable.

The undivided carapace, the apparent structure features that appear as elevations on the test and its surface ornamentation all indicate that it is a merostome. If so it is considerably older than any of this group hitherto found.

Such generic characters as may be observed will be presented in the specific description.

The name is given as a slight recognition of the important work done for many years by Dr. H. Justin Roddy, now curator of the museum and professor of geology at Franklin and Marshall College, in discovering the interesting fossils occurring in the Lower Cambrian of the Lancaster region. Doctor Roddy has the happy faculty of interesting people in natural science and therefor the author, together with hundreds of others, owes much to him for his unfailing encouragement in the early years of geologic work.

Genotype.—Roddyia typa, new species.

Range.—Lower Cambrian. Southeastern Pennsylvania.

Cephalic shield undivided. The prominences noticeable in the specimen may represent a raised central portion lobed somewhat in the manner of Aglaspis. Surface covered with slightly irregular raised lines.

This form should be compared with Molaria, Habelia, and Emraldella of the Burgess shale, but none of these preserve their cephalic shields sufficiently well to make any real comparisons. So far as may be ascertained Roddyia seems to be more like Molaria than the others, but even then the similarity is only superficial.

Horizon and locality.—Lower Cambrian, Kinzers formation; (loc. 12x) near Rohrerstown, Pennsylvania.

Holotype.—Cat. No. 80480, U.S.N.M.