August 12, 1910] 



SCIENCE 



223 



Ontogeny and Paleontology: F. B. LooMis and 



Amadeus W. Gkabau. 

 Phylogeny and Paleontology : Robeet T. Jackson 



and D. P. Penhallow. 

 Paleo7itologie Evidences of Recapitulation: E. R. 



CuMiNGS and L. Hussakof. 

 Isolation in Paleontology : John M. Clarke. 

 Continuity of Development from the Paleontologic 



Standpoint: T. Wayland Vaughan. 

 Paleontology of Man: S. W. Wiixiston. 

 Varanosauru^ Species: a Permian Pelycosaur: 



S. W. WiLLiSTOJSi, Chicago, 111. 



Description with full illustrations of the com- 

 plete skeleton of Varanosaurus sp., a primitive 

 pelycosaur from the Permian of Texas; a slender 

 crawling reptile, four feet in length. The speci- 

 mens upon which the description is based were 

 found almost perfectly preseiwed in a remarkable 

 bone-bed associated with dozens of others of the 

 same and related forms. 



Discussed by H. F. Osbom, W. J. Sinclair and 

 W. J. Holland. 

 The Structure of the Sauropod Dinosaurs: with 



special reference to the recent mounting of the 



skeleton of Diplodocus carnegiei Hatcher: W. J. 



HouLAJSTD, Pittsburgh, Pa. 



This paper discussed certain recent criticisms 

 of the work of Professors Marsh, Osborn, Lull, 

 Hatcher and the writer in connection with the 

 osteology of the sauropod dinosaurs. 



Discussed by S. W. Williston. 

 Phylogenetio Position of the Genus Stegomylu-s : 



F. B. LooMis, Amherst, Mass. 

 The Armor of Stegosaurus: R. S. Luix, New 



Haven, Conn. 



Discussed by H. F. Osborn and W. J. Holland. 

 Restoration of Paleolithic Man: R. S. Lull, New 



Haven, Conn. 

 'Neio Genus of Permian Reptile: S. W. Williston, 



Chicago, 111. 

 Principal Character of the Chelydrosauria, a Sub- 

 order of Temnospondyte Amphibians from the 



Texas Permian: S. W. Williston, Chicago, 111. 

 Skull of Tyrannosaurus : H. F. Osbobn, New 



York, N. Y. 

 Anderson's Methods of Photography in Vertebrate 



Paleontology : H. F. OSBORN, New York, N. Y. 

 Correlation of the Pleistocene of Europe and 



America: H. F. Osborn, New York, N. Y. 

 Permian Floras in the Western "Red Beds": 



David White, Washington, D. C. 



Characteristic floras, found in a brief tentative 

 search of red beds at three points in Colorado and 

 New Mexico, not only prove Permian age but also 



indicate great thickness of Dyas in certain " Red 

 Beds " sections in the Rocky Mountains. Exam- 

 ination of lower middle Wichita in Texas and 

 additional collections from Chase (Wreford and 

 Winfield beds) and Wellington of Kansas and 

 from red beds within the same limits in Okla- 

 homa, confirm lower Permian correlations. 



Discussed by C. Schuchert, J. W. Beede, J. M. 

 Clarke and E. 0. Ulrich. 

 The Ordovicic-Siluric Section of the Mingan and 



Anticosti Islands, Gulf of St. Lawrence: 



Charles Schuchert and W. T. Twenhofel, 



New Haven, Conn. 



The section is a large one, beginning on the 

 Mingan Islands in the lower Ordovicic and con- 

 tinued on Anticosti, where there is a complete 

 transition from the Richmondian into the Clin- 

 ton. The succession was described and corre- 

 lations made with standard sections in the United 

 States. 



Discussed by E. 0. Ulrich and A. W. Grabau. 

 On the Persistence of Fluctuating Variations, as 



Illustrated by the Genus Rhipidomella : Henry 



S. Williams, Ithaca, N. Y. 



A summary was given of results obtained from 

 a comparison of measurements of a series of 

 specimens of the brachiopod Rhipidomella from 

 the Hamilton formation and from successive zones 

 of recurrent Hamilton faunas in the upper De- 

 vonian of central New York, representing, prob- 

 ably, over a million years of the history of the 

 genus; to which were added some remarks upon 

 the bearing of the facts on the nature of organic 

 variations. 

 Intracolonial Acceleration and Retardation, and 



its Bearing on Species: Amadeus W. Grabau, 



New York City. 



Acceleration or tachygenesis and retardation, or 

 bradygenesis, operate in differentiation of species 

 by affecting either the entire individual (geuepis- 

 tasis), or only certain organs (heterepistasis), 

 using these terms in a somewhat modified sense. 

 These principles are applicable wherever it can be 

 shown that development is orthowenetic. Intra- 

 colonial acceleration and retardation affect indi- 

 viduals within the colony so that they will either 

 become more specialized in one or more determin- 

 able directions, or will remain in a more primitive 

 stage of development than other members of the 

 colony. Thus the colony will come to consist of 

 individuals representing distinctly different steps 

 in an orthogenetic series, i. e., it will be multi- 

 specific. Examples from the invertebrates and 

 from plants were cited. 



