Author Description

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1921 Excerpt:...relatively lower, broader, and less angular calyx, and in its peculiar sculpturing by means of very fine radiating costae, which become bent and wrinkled in various ways, producing a sort of vermicular style of ornament. In most specimens a low continuous radial ridge is defined, but in some it is entirely wanting. The tegmen is remarkably constant among the specimens both of the original species and the variety, being broadly and rather deeply lobed, and covered over the entire surface with numerous small projecting tubercles. One little point peculiar to this species is a sort of overhanging lip from the edge of the tegmen between the rays; it seems to be present in all the variations. This form persisted into the Hamilton, where it increased in size, and underwent some striking changes in surface markings, while retaining with thorough constancy the chief distinguishing characters of the type. This was described by Miller and Gurley as a variety, asperatus, but in view of the difference in horizon, it is better treated as a species, and it will be listed as such under the Hamilton. Horizon and locality.--The type of D. ornatus is in Columbia University; and the species is from the Onondaga limestone at Columbus, Ohio, and in western New York. DOLATOCRINUS ROTUNDUS, new species. Plate 5, figs. 12, 13. This species is founded upon a single specimen, of a type differing from all others in having a perfectly round calyx, without angularities or projections of any kind; the surface is smooth, and there is no lobing, or depression, except a slight one for the column facet. It has 10 arms; although surface preservation is good, pinnule openings are not discoverable between the arm bases. The dimensions are 25 mm. high by 30 mm. wide, being slightly contracted v...