170 PROCEEDINGS OF THE ACADEMY OF [1893. 



Forming black tuberculiform tufts on the dead stems, about 

 1 mm. across and composed of closely packed chains of conidia about 

 120;/ long and 10-12//- broad, the single conidia being elliptical, 

 brown, uniseptate and constricted, about 20 x 10-12/;, placed end to 

 end without any connecting cell. 



Cercospora nicotianae E. & E. 



On leaves of tobacco, Raleigh, N. C. Oct., 1891. (com., Gerald 

 McCarthy.) 



Spots amphigenous, pale, becoming white, 2-5 mm. diam., with a 

 narrow, inconspicuous, reddish, slightly raised border, often concave 

 below. Hyphse tufted, amphigenous, 75-100 x 4-5//, 2-3-times 

 geniculate above and sometimes with a short, lateral branch brown, 

 septate. Conidia slender, 40-75 x 3-3?/*, hyaline, slightly curved, 

 multiseptate (mostly about 6-septate.) 



Cercospora nesaeae E. & E. 



On leaves of Nesaea verticillata, Milford, Del. Sept., 1892. 

 (Commons, No. 1,984.) 



Spots amphigenous, scattered, suborbicular or irregular, 2-4 mm. 

 diam., with a shaded, purple border. Hyphse epiphyllous, tufted, 

 35-45 x 2i-Bfi, continuous, olivaceous or smoky-hyaline, geniculate 

 above. Conidia clavate-cylindrical, hyaline, 3-5-(mostly 3-) septate, 

 25-75x2^-3//. 



The minute black tufts of hyphse under the hand lens resemble 

 the perithecia of some Septoria or Phyllosticta. 



Cercospora weigelae E. & E. 



On leaves of Weigelce (cult.), Newfield, N. J. Sept., 1889. Sent 

 also from Washington, D. C. by Miss E. A. Southworth. 



Spots small (1-2 mm.), white, with a broad, shaded, dark purple 

 border. Hyphse in small tufts scattered thickly over the central 

 part of the spot, geniculate and toothed above 70-90 x 32-4*//., brown, 

 continuous. Conidia terminal slender clavate, hyaline, nucleate, 

 50-75 x 2j-3 ; «. 



Cercospora crotonis E. & E. 



On leaves of Groton texensis, Rockport, Kansas. Aug., 1892. 

 .(Bartholomew, No. 359.) 



Spots indistinct, pallid, not definitely limited, finally subconfluent 

 and brownish, giving the leaf a dirty withered look. Tufts mostly 

 epiphyllous, in small but dense fascicles, appearing under the lens 

 like minute, black grains thickly scattered over the spots. Hyphse 



