268 PROCEEDINGS OP THE AMERICAN ACADEMY 



said, since they are all readily separable. As stated by Prof. FarloW; 

 G. conicum, previously referred to claoipes, must be added to our list 

 of species. It is very common in this vicinity, forming the famil- 

 iar bird's-nest distortions on Juniperus Vlrginiana appearing on the 

 leaves and stem, and apparently identical with the European form on 

 J. communis, though as yet it has not been observed upon this host 

 in America. 



G. clavipes, although a very common species in this vicinity on 

 J. Virginiana, and further eastward on J. communis, is more likely 

 to escape notice than other Gymnosporangi.a, from the fact that the 

 distortion produced is inconspicuous ; while the sporiferous masses, 

 although more brightly colored than in the other species, are small and 

 only slightly protruded when moist. The spores are characteristic, 

 from their rounded outline and inflated pedicels, the latter as broad as 

 the spores themselves, together with their peculiar method of germina- 

 tion, which takes place invariably from either extremity, as was shown 

 by a large number of cultures in which no exception was noticed. 



G. clavariceforme I have found common in this vicinity where 

 J. communis occurs, and further to the eastward in great abundance ; 

 as at Kittery, where it is often difficilt to find a juniper that is free 

 from its attack. It precedes the other species in its date of maturity. 



If my conclusions regarding its Rcestelia are correct, G. tiiacropns 

 must be regarded as autonomous, thus disposing of Schroeter's theory 

 of its identity with clavariceforme, which seems, however, scarcely ten- 

 able on other grounds. 



G. biseptatum appears to be common wherever C. thyoides occurs, 

 and I found its distortions abimdant at Greenland, N. H., near Ports- 

 mouth. 



G. ElUsii, besides its well-known peculiarities of structure, differs 

 from the other sjiecies in its date of maturity, which is later than any 

 of the others. At Greenland, where it occurred together with the 

 last-mentioned species, it was in the best condition for cultures about 

 June 10, and in the vicinity of Boston perhaps a week earlier. 



A comparison of the geographical range of the Gymnosporangia 

 and Rcestelice in those localities where I have had an opportunity of 

 observiniT them is not as instructive in indicating their relations as one 

 might suppose, and often the reverse is true. 



At Kittery, for instance, a locality on the sea-shore at the south- 

 ernmost point of Maine, there is a certain correspondence, the form 

 lacerata, x, with clavariceforme, and aurantiaca with clavipes, being the 

 most abundant. R. cornuta, if I rightly refer to this species the form 



