Proceedings of the American Academy of Arts and Sciences. VOL. XLVIII. No. 20.- MAY, 1913. CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY OF THE MUSEUM OF COMPARATIVE ZOÖLOGY AT HARVARD COLLEGE.- No. 236. THE STRUCTURE OF THE GORGONIAN CORAL PSEUDOPLEXAURA CRASSA WRIGHT AND STUDER. BY WAYLAND M. CHESTER. 1. 2. 3. 4. 5. 6. 7. 8. 9. (Continued from page 3 of Cover.) VOLUME 48. BELL, LOUIS. On the Ultra Violet Component in Artificial Light. pp. 1–29. WALCOTT, HENRY P.- Alexander Agassiz. pp. 31-44. June, 1912. 30c. CHIVERS, A. H.-Preliminary Diagnoses of New Species of Chaetomium. pp. KENT, NORTON A.- A Study with the Echelon Spectroscope of Certain Lines THAXTER, ROLAND.- New or Critical Laboulbeniales from the Argentine. pp. HOTSON, JOHN WILLIAM.-Culture Studies of Fungi producing Bulbils and 10. THAXTER, ROLAND. - Preliminary Descriptions of New Species of Rickia and Trenomyces. September, 1912. pp. 363-386. 40c. 11. 12. 13. 14. 15. 16. 17. 18. WILSON, EDWIN B., and LEWIS, GILBERT N.-The Space-Time Manifold of Relativity. The non-Euclidean Geometry of Mechanics and Electromagnetics. November, 1912. pp. 387-507. $1.75. WEBSTER, D. L.-On the Existence and Properties of the Ether. pp. 509527. November, 1912. 40c. JEFFREY, EDWARD C.-The History, Comparative Anatomy and Evolution, SANGER, CHARLES ROBERT and RIEGEL, EMILE RAYMOND.-The Action of 40c. CLARK, A. L.- An Electric Heater and Automatic Thermostat. pp. 597-605. HOLDEN, RUTH.-Cretaceous Pityoxyla from Cliffwood, New Jersey. pp. TABER, HENRY. On the Scalar Functions of Hyper Complex Numbers. pp. 625-667. March, 1913. 80c. MARK, KENNETH L.- Preliminary Study of the Salinity of Sea-water in the 19. 20. HEIDEL, WILLIAM ARTHUR. - On Certain Fragments of the Pre-Socratics: 80c. 65c. Proceedings of the American Academy of Arts and Sciences. VOL. XLVIII. No. 20.— MAY, 1913. CONTRIBUTIONS FROM THE ZOÖLOGICAL LABORATORY OF THE MUSEUM OF COMPARATIVE ZOÖLOGY AT HARVARD COLLEGE.- No. 236. THE STRUCTURE OF THE GORGONIAN CORAL PSEUDOPLEXAURA CRASSA WRIGHT AND STUDER. BY WAYLAND M. CHESTER. THE MUSEUM OF COMPARATIVE ZOÖLOGY AT HARVARD THE STRUCTURE OF THE GORGONIAN CORAL BY WAYLAND M. CHESTER. Presented by E. L. Mark, March 12, 1913. Received April 5, 1913. PSEUDOPLEXAURA CRASSA is found on the reefs of Florida, of the West Indies, and of the Bermuda Islands. It is very abundant in the shallow water of the inner reefs of Bermuda, and is there one of the two or three very common sea whips; but it is found in the deeper waters of the outer reefs as well. The range in depth, to include the greater number of colonies, is from a position near the surface at low water to seven or eight meters. Ellis and Solander (1786) described this colony under the name of Gorgonia crassa. Kölliker (1872) placed under the name of Plexaura branched, sea-rod forms in which the polyps completely retract into a comparatively thick coenenchyma, in which club-shaped and spiny spindle-shaped spicules appear. The different species were divided into two groups: Plexaura durae and Plexaura molles. Hargitt and Rogers (:01, p. 285) follow Verrill ('65, p. 34) in describing this form as Plexaura crassa. Wright and Studer ('89, p. 141-143), from observations of Bermuda specimens, created for this species a new 1 Contributions from the Bermuda Biological Station for Research. No. 27. |