OF ARTS AND SCIENCES. 17 



7. D. occulta, (Hoffm.). 



D. occulta, (HofFm.), var. Farlowii, (Cornu). 



Authentic specimens of D. Farlowii, Cornu, do not seem to me to 

 correspond exactly to Hoffmann's figures * but differ particularly 

 in having spores which are elongated in a radial direction. 

 Specimens collected by myself near Norwich, Conn,, agree better 

 with Hoffmann's figure, and are considered in these notes to 

 represent the type of D. occulta, while D. Farlowii is for the 

 present placed as a variety under it. The elongated cells on 

 the periphery of the sorus in Cornu's figure f are really the 

 spores, and the real cortex of small, radially flattened cells is not 

 shown, while the rounded cells in the centre are not immature 

 spores, but are sterile cells resembling parenchyma cells. 



In the ovaries of species of Potamogeton. 



Type. Germany ; United States ! (Norwich, Conn. !). 



Var Farlowii. Canada (Ottawa, /. B. Fletcher !). 



8. D. Martianojfftana, (Thuem.), Schroeter. 

 On leaves of species of Potamogeton. 

 Siberia ; Germany, Sweden ! ; Canada ! . 



In the specimens from Sweden, distributed by Johanson, $ there 

 appear to be conidia, almost identical in appearance with those already 

 known in some species of Entyloma. There seems to be an intimate 

 connection between the mycelium of the Doassansia and that of the 

 conidia. 



9. D. deformans, sp. nov. Species forming distortions, often of large 



size, on all parts of the host. Sori globular, 100-140//, very 

 light brown. Spores polyhedral, 8-10/^ by 4-8 /x. Cortical 

 cells polygonal, flattened radially. Promycelium somewhat ob- 

 conical, about 12 /* long. Sporidia 5 to 6, broadly fusiform, 12 /x 

 by 4-5 //, conjugating and producing a short germ tube. 



In the leaves, petioles, peduncles, pedicels, and ovaries of Sagittaria 

 variabilis. 



United States ! (Norwich, Conn. !, Cambridge, Mass. !) ; Canada 

 (London, leg. Benrness, comm. J. B. Ellis). 



A species forming large distortions on Sagittaria, nearly related to 

 the other species of the subgenus, but abundantly distinct from all the 



* Ic. Anat. Fung., Taf XVI. Fig. 3, 1862. 

 t Ann. Sci. Nat., Tom. XV. PI. XVI. Fig 6, 1883. 



X Cf, Eriksson, Fung Scand. Par., No. 264, 1888. Fazschke, Fung. Eur., 

 No. 3602, 1890. 



VOL. XXVI. (n. s xviii ) 2 



