30 



FARLOW ON THE GYMNOSPORANGIA 



finely granulated, 19^-24,1* in diameter. Spermogonia in yellowish spots on the upper 

 surface of the leaves. 



On leaves, stems, and fruit of Crataegus crus-galli, C. punctata, C. coccinea, C. tomen- 

 tosa, C. oxyacantha, and other species ; on leaves and fruit of Amelanchier canadensis, 

 and on leaves of wild and cultivated apples. 



Common from Maine (Bolles) to South Carolina (Mellichamp), and west to Missouri 

 (Engelmann). 



This is decidedly the most common species found with us, and it abounds on all wild and 

 cultivated species of Crataegus and apples. On the one hand the species approaches R. 

 cornuta, from which it is distinguished by being more slender, and when young, splitting 

 into segments which become fimbriate, and by the narrower peridial cells. On the other 

 hand, it approaches R. penicillata with which, in fact, it is united by some authors. R. 

 lacerata is more variable than most of our species, and I can distinguish the following 

 forms. On C. tomentosa and other species of Crataegus the aecidia are borne on small, 

 slightly swollen spots, and the peridia are large and diverge from one another. Our form 

 is precisely the No. 556 of Westendorp and Wallys. The form on Amelanchier is the 

 Aecidium Mespili D.C., and the swellings of the leaves are more strongly marked, and 

 the peridia shorter than in the form last described. Our smallest form is found on apple 

 leaves. The spots are bright yellow and the aecidia are few in number, often only 1-3, 

 and occupy the centre of the spot. Possibly this last form might be separated as a dis- 

 tinct species. It is, apparently, not the variety Mali of the Syn. Fung. Am. Bor. The 

 specimen in Mycotheca Universalis, No. 732, collected by Ellis at Newfield, N. J., labelled 

 R. lacerata, f. Mali, is said by Von Thumen to be synonymous with Aecidium cancella- 

 tion of the Syn. Fung. Carol. Sup., but on what authority the statement rests is uncertain. 



ROESTELIA PENICILLATA (Sow.) Fr. 



Aecidium penicillatum Pers., in Gmel. Syst. 



Aecidium Mali Schum., Fl. Saell., Vol. n, 222. 



Aecidium laceratum D. C, Flore Franchise, Vol. vi, p. 98. 



Caeoma cylindrites, var. Mali Schweinitz^Syn. Fung. Am. Bor., No. 2899. 



Aecidium pyratum Schweinitz, Syn. Fung. Am. Bor., No. 2896. 



Roestelia penicillata (Sow.) Fr., Summa Veget. Scand., Vol. n, p. 510. 



Ceratitium penicillatum E&benh., Bot. Zeit., 1851. 452. 



On leaves and fruit of Pyrus malus and Pyrus angustifolia and fruit of Amelanchier 

 canadensis. 



Eastern Massachusetts (Farlow) ; Santee Canal, S. C. (Ravenel). 



Same as P. lacerata, but aecidia smaller and frequently concentrically arranged, peridia 

 splitting to the base, the divisions very numerous, revolute, fimbriate, formed of one or 

 more rows of cells. 



The present species, if indeed it is not a form of the one last described, does not appear 

 in American Catalogues as distinct from R. lacerata. It is not uncommon and seems to 



