159 



regarded as comprising two classes, the Acrasieae and the Myx- 

 omycetes, the Plasmodiophorales being excluded. 



The seven genera of the Acrasieae were described in some 

 detail, and the work of Van Tieghem, Brefeld and others was 

 reviewed. Following the glimpse at the historical side of our 

 knowledge of the group, the main features of the two more or 

 less distinct stages, the vegetative and the fructifying, were 

 briefly summarized. The formation and structure of pseudo- 

 plasmodium, as well as the peculiar method of formation of 

 the cellulose stalk, were especially emphasized. 



In the treatment of the Myxomycetes, representative her- 

 barium specimens were shown, illustrating various types of 

 fructifications. The early treatment of the Myxomycetes by 

 Sachs, the contentions of Prowazek, Jahn, Kranzlin, and others, 

 as to nuclear fusions were briefly reviewed, as well as the work 

 of Strasburger, Harper and Dodge, and Bisby on the formation 

 of capillitial threads. 



Dr. Marshall A. Howe exhibited cystocarpic and a tetrasporic 

 specimens of Dumontia filiformis (Huds.) G ev. from South 

 Harpswell, Maine, at which locality this red alga has been col- 

 lected by Miss Grace Dunn, of Johns Hopkins University, in 

 the late spring and early summer of 1913 and 1914. This genus 

 and species occurs on the northern shores of Europe and in 

 Alaska, but no published record of its existence on the Atlantic 

 coast of North America seems to have been made. However, 

 a letter from Mr. F. S. Collins states that sterile specimens were 

 collected near Kittery, Maine, by Professor Roland Thaxter 

 in the spring of 1914. 



Dr. Howe exhibited also living specimens of Corsinia mar- 

 chantioides Raddi from the vicinity of Austin, Texas, where it 

 was collected recently by Dr. F. McAllister, of the University 

 of Texas. This monotypic genus is of special morphologic 

 interest as one of the simplest representatives of the family 

 Marchantiaceae. It has been best known from the Mediter- 

 ranean region of Europe, though its existence in Louisiana was 

 reported by Rev. A. B. Langlois in 1887. But there had been 



