. College collection of palaeontology. 146 ] ECHINODERMATA. No. 447. [938, Cast]. Mariacrinus nobilissimus, Hall. This species, constituting the type of this genus, is one of the largest and finest known Crinoids in the Silurian system. It bears a general resemblance to Olyptocrinus ; but it has four basal plates, three pentagonal and one hexa- gonal. The column is round, consisting of joints, gradually growing thinner towards the body. A remarkable feature is that the main arms give origin to armlets or fingers which bear the tentacles. This magnificent specimen of a nearly entire individual
. College collection of palaeontology. 146 ] ECHINODERMATA. No. 447. [938, Cast]. Mariacrinus nobilissimus, Hall. This species, constituting the type of this genus, is one of the largest and finest known Crinoids in the Silurian system. It bears a general resemblance to Olyptocrinus ; but it has four basal plates, three pentagonal and one hexa- gonal. The column is round, consisting of joints, gradually growing thinner towards the body. A remarkable feature is that the main arms give origin to armlets or fingers which bear the tentacles. This magnificent specimen of a nearly entire individual is from the Lower Helderberg (Upper Silurian, Litch- field, N. Y. No. 448. Melocrinus (Ctenocrinus) typus, Bronn. This genus is peculiar to the Devonian. Lower Devonian, Eifel, Prussia. No. 449. [945, Cast]. Pentacrinus (Extracrinus) Briareus, Size, 2 ft. 2 in. x 1 ft. 10 in. The Extracrinoids of Aus- tin are Pentacrinoids with unequal radial plates. The majority of the individuals found are much distorted, and their arms tangled and broken by the action of the waves before they were buriedinthemud. This slab, containing a multitude of beautifully preserved bodies, is from the Lias of Whitby, England, and is now in the Ward Collection, University of Rochester. No. 450. Pentacrinus Briareus, Miller. A smaller specimen of this beautiful crinoid from Lyme-Regis, England. No. 451. Pentacrinites cingulatus, Munst. Stems. The columns of this genus are five-sided, and the articulating facets of the joints are marked by crenated ridges, making a pentapetalous figure. The column is provided with " ; Oolite, Boellert, Wurtemberg. No. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Ward's Natural Science Establishment, inc. Rochester
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