1. 2. 3. 4. 5. 6. VOLUME 48. BELL, LOUIS.—On the Ultra Violet Component in Artificial Light. pp. 1-29. 2 pls. May, 1912. 40c. WALCOTT, HENRY P.- Alexander Agassiz. pp. 31-44. June, 1912. 30c. PHILLIPS, H. B. and MoORE, C. L. E.-A Theory of Linear Distance and Angle. pp. 45-80. July, 1912. 50c. CHIVERS, A. H.- Preliminary Diagnoses of New Species of Chaetomium. 81-88. July, 1912. 20c. pp. KENT, NORTON A.- A Study with the Echelon Spectroscope of Certain Lines in the Spectra of the Zinc Arc and Spark at Atmospheric Pressure. pp. 91-109. 2 pls. August, 1912. 50c. KENNELLY, A. E., and PIERCE, G. W.- The Impedance of Telephone Receivers as affected by the Motion of their Diaphragms. pp. 111-151. September. 1912. 70c. 7. THAXTER, ROLAND. New or Critical Laboulbeniales from the Argentine. 155-223. August, 1912. 70c. pp. Proceedings of the American Academy of Arts and Sciences. VOL. XLVIII. No. 7.-SEPTEMBER, 1912. CONTRIBUTIONS FROM THE CRYPTOGAMIC LABORATORIES OF HARVARD UNIVERSITY. - No. LXIX. NEW OR CRITICAL LABOULBENIALES FROM THE ARGENTINE. BY ROLAND THAXTER, CONTRIBUTIONS FROM THE CRYPTOGAMIC LABORATORIES OF HARVARD UNIVERSITY. - No. LXIX. NEW OR CRITICAL LABOULBENIALES FROM THE ARGENTINE. BY ROLAND THAXTER. Presented April 10, 1912. Received July 28, 1912. THE rapid accumulation during the past six years of Laboulbeniales, which have come to me from various parts of the world and now include some hundreds of new species and genera, has forced me to abandon my intention to figure all new forms as they were published; and it has again become necessary to resort to preliminary diagnoses, a third series of which is entered on with the present paper. It is, however, my purpose to illustrate all the species described in this series as soon as the necessary figures can be prepared and published. The exotic material which is now available is not only very varied, but is in far better condition than that which has formerly been obtained from dried specimens of insects, for the reason that a majority of the hosts have been collected directly into alcohol and the parasites removed before drying. The examination of large series of forms in good condition has inevitably led to some modification of my views in regard to the limitations of certain genera and species, and while it has in some instances made clearer relationships or differences that were formerly in doubt, it has at the same time served to break down distinctions which were formerly regarded as more or less crucial, so that it has seemed best to modify the treatment of certain genera and species. Thus in the present paper, the limits of Corethromyces, for example, are considerably extended to include several genera hitherto kept distinct, and other changes will be noticed applying both to species and genera, which have seemed advisable in the light of a more complete knowledge of numerous forms. The materials here considered were collected in Argentina, chiefly in the Buenos Aires region, the host insects having been captured |