Zoology 141 



There appears to be some fat-like body on the cell surface. There is no relation 

 between the degree of dissociation of an acid and its rate of penetration, but the 

 toxic acids penetrate most readily irrespective of their strength. Acids and alkalies 

 which are soluble in fatty substances penetrate living cells readily while those which 

 are insoluble are poor penetrators. Acids penetrate more rapidly than alkalies. 



Dr. Alfred G. Mayer describes 31 species of Scyphomedusse obtained by the 

 U. S. Fish Commission steamer Albatross in the Philippine Islands, 9 of which 

 were apparently new to science. He also describes 6 Hydromedusse from the 

 Murray Islands, Torres Straits, and speaks of the physiology, reactions, and habits 

 of the Scyphomedusae, and of the poverty of the region of the Great Barrier Reef 

 of Australia in comparison with that of the Philippines. 



Dr. Paul Bartsch gives an account of an extensive series of experiments in 

 transplanting Cerions from Andros Island, Bahamas, to the Florida Keys, the new 

 colonies ranging from near Miami to the Tortugas. The first generation of these 

 snails born in Florida differs from their Bahama-born parents, but the cause of 

 this sudden departure remains to be determined. 



Professor Ulric Dahlgren describes the structure and polarity of the electric 

 motor nerve-cell in various species of Torpedo. He concludes that the plasmosome 

 is the heaviest body in the nucleus, and is probably of greater specific weight 

 than any other nuclear constituent, with the possible exception of the karyosomes. 

 Thus it is due to gravity that in adult fish the plasmosomes came to occupy a 

 ventral position within the nucleus. Very strong electric currents may move this 

 plasmosome but weak currents do not affect it, and thus the author dissents from 

 Magini's theory that the electric discharge is coordinated with a ventral-ward move- 

 ment of the plasmosome. 



No. 213. Papers from the Department of Marine Biology of the Carnegie Insti- 

 tution of Washington. Vol. IX. Quarto m-f-362 pages, 105 plates, 

 14 figs. Published 1918. Price $15.00. 

 This book contains the following papers, not sold separately: 



MAYER, ALFRED G. Ecology of the Murray Island Coral Reef. 48 pp., 19 pis., 



9 figs. 

 VAUGHAN, THOMAS WAYLAND. Some Shoal-Water Corals from Murray Island 



(Australia), Cocos-Keeling Islands, and Fanning Island. 185 pp., 73 pis., 2 figs. 

 VAUGHAN, THOMAS WAYLAND. Some Shoal-Water Bottom Samples from Murray 



Island, Australia, and Comparisons of them with Samples from Florida and 



the Bahamas. 54 pp., 2 pis., 2 figs. 

 GOLDMAN, MARCUS ISAAC. Composjtion of Two Murray Island Bottom Samples 



according to Source of Material. 14 pp. 



MANN, ALBERT. Diatoms from Murray Island, Australia. 2 pp. 

 CUSHMAN, JOSEPH A. Foraminifera from Murray Island, Australia. 2 pp., i pi. 

 HOWE_, MARSHALL A. Calcareous Algae from Murray Island, Australia, and Cocos- 

 Keeling Islands. 6 pp., 2 pis. 

 DOLE, RICHARD B., and ALFRED A. CHAMBERS. Salinity of Ocean Water at 



Fowey Rocks, Florida. 16 pp., i pi., 2 figs. 

 WELLS, ROGER C. The Solubility of Calcite in Contact with the Atmosphere, and 



its Variation with Temperature. 3 pp. 

 VAUGHAN, THOMAS WAYLAND. The Temperature of the Florida Coral-reef Tract. 



20 pp., 3 figs. 

 CAKY, L. R. The Gorgonacex as a Factor in the Formation of Coral Reefs. 20 



pp., 6 pis. 



Dr. Mayer's paper gives the first statistical account of the distribution of corals 

 over reef flats and shows that more than 90 per cent of the coral heads of the 

 reef flats belong to 4 genera. Forms living near shore are generally well able to 

 resist high temperature or the effects of silt, while those living in the cooler and 

 purer waters of the outer reef are readily killed by high temperature or by silt. 

 Stream waters pouring outward from forested volcanic shores are alkaline and 

 thus can not dissolve limestone by reason of their "acidity." Thus the Murray- 

 Agassiz solution theory is not supported. Holothurians are a potent factor in dis- 

 solving reef limestones which they swallow, and the effects of currents in scouring 

 are important factors tending to deepen the water over reef flats. 



Dr. Vaughan's paper entitled "Some Shoal-water Corals from Murray Island, 

 Australia, Cocos-Keeling Islands, and Fanning Island," is based primarily on 

 three collections of living corals, ins., those made by Dr. Alfred G. Mayer at 

 Murray Island, Australia, by Dr. F. Wood Jones at Cocos-Keeling Islands, and by 

 Mr. Carl Elschner at Fanning Island. A general statement is given of the objects 



