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. 1910 Excerpt: ...fixed brachials forming broad, highly elevated ridges which pass insensibly into the arms. Between these ridges are profoundly depressed interradial areas, composed of minute irregular pieces. Arms 10 at their origin but usually bifurcating. Tegmen depressed-convex, consisting of very small pieces forming a ...
Read More
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. 1910 Excerpt: ...fixed brachials forming broad, highly elevated ridges which pass insensibly into the arms. Between these ridges are profoundly depressed interradial areas, composed of minute irregular pieces. Arms 10 at their origin but usually bifurcating. Tegmen depressed-convex, consisting of very small pieces forming a continuation from the interbrachials. Anal opening excentric, at top of a small protuberance. Column large, pentagonal. Ordovicic. 152. R. stellaris Billings. Ordovicic. Arms extremely short and tapering rapidly. Interbrachial depressions paved by numerous irregular pieces with a slightly stellate surface. (Type of genus.) Trenton of Ottawa. LIV. Thysanocrinus Hall. Calyx subglobose or urn-shaped. IB 5 and small, often hidden by the column. B 5, four of them equal and angular above, the fifth truncated and supporting a large anal plate. The rays marked by a ridge; surface of plates otherwise smooth or ornamented. Costals two. Arms 10 or 20, biserial. Pinnules long. Column round or obtusely 5angled (Fig. 1876). Siluric of America, England and Sweden. T- T: .. M.. 1,11. su ti c--i-Fig. 1876. Thysanocrinus. (Af 153. T. inornatus (Hall). Siluric. . v JO v' terWeller.) Calyx urn-shaped. Cross section at top of costals pentagonal and across distichals decagonal. B each with a node and hence forming a 5-lobed rim around the column. Ill-defined radiating ridges follow the median line of the rays and also branch laterally. Interbrachial spaces deeply depressed so as to give the calyx at the arm bases a prominently lobed aspect. Anus at end of a conspicuous ridge of anal plates. Tegmen depressed. Niagaran of Indiana and Wisconsin. 154. T. occidentalis Hall. Siluric. Larger than T. inornatus and with no anal ridge. Ornamentation consisting of ridges fo...
Read Less
Add this copy of North American Index Fossils, Invertebrates: Conularida to cart. $39.96, good condition, Sold by HPB-Red rated 5.0 out of 5 stars, ships from Dallas, TX, UNITED STATES, published 2015 by Arkose Press.
Choose your shipping method in Checkout. Costs may vary based on destination.
Seller's Description:
Good. Connecting readers with great books since 1972! Used textbooks may not include companion materials such as access codes, etc. May have some wear or writing/highlighting. We ship orders daily and Customer Service is our top priority!
