164 BOTANICAL GAZETTE. [J u ty> 



quite improbable. Turning to the American forms previ- 

 ously included under the name " penicillata " it was found that 

 thev included two well-marked species, namely, R. pyrata 



and R. lacerata. 



Rcestelia pyrata, the .^Ecidium pyratum of Schweinitz, 



which was obtained from sowings of G. macropus upon Py- 



rus Malus, was found to be a peculiarly American form. 



readily separable from any known European species and not 



to be confounded with any other American species : from all 



of which it is readily distinguished by its habit alone, as well 



as bv its microscopic characters. It is distributed in Ellis' 



N. A. Fungi No. 1086 a, b, and d {not c), under the name 





>' 



My 



7-32 under the name "lacerata. It is very common on 

 Pyrus malus and often destructive, but grows most luxuri- 

 antly on P. coronaria ; and may be readily distinguished 

 from the only other Roestelia common upon Pyrus malus, by 

 its revolute peridial lacerations. I make this statement in de- 

 tail from the fact that I have subsequently been quoted as con- 

 sidering R. pyrata a form of R. penicillata, whereas my ex- 

 pressed opinion was exactly the contrary of this statement ; 

 and also for the reason that I notice the name " penicillata 

 still retained by certain American writers when referring to 

 R. pyrata, which is a manifest error. 



The second form above referred to, which has, in this 

 country, been wrongly considered a form of R. penicillata. 

 is beyond question the true 



Rcestelia lacerata. — This was obtained from sowings 

 of G. clavariaeforme on Crataegus. In its general habit it 

 bears a superficial resemblance to R. pyrata, but the peridial 

 lacerations are only slightly divergent, not revolute ; while 

 it is also readily separable microscopically. In its most typi- 

 cal form it attacks the fruit and tender shoots of Crataegus, 

 and more especially of Amelanchier ; but it also occurs upon 

 the leaves of both these plants, and has recently been found 

 by Prof. Farlow on the fruit of Pyrus arbuti folia, a hitherto 

 unrecorded host. The species is distributed in Ellis' N. A. 

 F. No. 1086 c, in my copy, {not a, b or d), under the name 

 " penicillata," and also under the names "carpophila Bagnis 

 (Myc.Un. 1326) and " lacerata" in various European exsiccati. 

 ' fc Roestelia lacerata," however, as it is commonly understood 

 in this country, is quite another thing. In my previous paper 

 I spoke of the forms referred to R. lacerata for the sake oi 

 convenience as lacerata x,y and z : " lacerata X " being used 



