44 Setchell. — An Examination of the Species 
Subgenus 3. Doassansiopsis. Central portion of the sorus 
consisting of a mass of parenchymatous cells. Spores in a 
single layer, not separable at maturity. Cortex distinct. 
7. D. occulta (Hoffm.), Cornu. 
D. occulta var. Farlowii (Cornu.). 
8. D. Martianoffiana (Thuem.), Schroeter. 
9. D. deformans , sp. n. Species often forming large distortions. 
Sori nearly^ globular, 100-140 /x in diameter, pale. Spores 
8-12 [x by 4-6 / u. Cells of the cortex flat, distinct. Pro- 
„ mycelium obconical, about 12 ft long. Sporidia in a whorl of 
5 to 6, short, broadly fusiform, conjugating either at the base or 
at the tip and producing an irregular germ-tube. 
On petioles and ribs of the leaf, on peduncles, pedicels and 
ovaries of Sagittaria variabilis. 
Norwich, Conn. ! Cambridge, Mass. ! 
Species known to me only from description : — 
10. D. comar i (B. & Br.), De Toni et Massee. 
11. D. punctiformis. Winter. 
12. D. lythropsidis , Lag. 
Species to be excluded from Doassansia : — 
D. Niesslii, De Toni. 
D. limosellae (Kunze), Schroeter. 
D. decipiens , Winter. 
Genus II. Burrillia, gen. n. Central portion of the sorus 
consisting of a mass of parenchymatous cells. Spores in 
several irregular, compact layers. Cortex absent. 
B. pustulata, sp. n. Spot none or very indistinct. Sori at length 
causing small pustules on the lower surface of the leaf and 
finally rupturing the epidermis. Ellipsoidal, 200-300 /x by 
150-180 ix. Central portion a mass of polyhedral cells. Spores 
in two to six rows, polyhedral, 4-6 /x in diameter. Germination 
occurring in the leaf. Promycelium cylindrical. Sporidia in 
whorls of 4 to 5. About 16 fx long by 3 /x wide. 
The leaves of Sagittaria variabilis. 
Dixon, 111 ., Mr. G. P , Clinton ! Madison, Wise., Prof. W. 
Trelease ! 
