REPORT OF THE BOTANIST. 55 



state the pileus is clothed with a minute velvety villosity, but this disappears 

 with age, and the pileus becomes either uniformly black or blackish variegated 

 with paler zones, rarely wholly pale. I have met with it both on alder and 

 witch-hazel. 



Reticularia umbrina Fr. 



In Dr J. Rostafinski's Monograph of the Myxogasters, Reticularia 

 lycoperdon Bull, has been substituted for the name in common use. This 

 Monograph, being based on an entirely new system of Classification, necessi- 

 tates a change of name in numerous instances. How thoroughly different the 

 system, and how wide spread the change of names therein inaugurated, may be 

 inferred from the following facts. Of the hundred or more species given in 

 the Handbook of British Fungi less than one-fourth remain under their old 

 names. Three out of the four species of Reticularia are referred to as many 

 different genera, leaving one species only in the genus and another specific 

 name is given to that one. The generic name Fuligo takes the place of 

 JEthalium, and the two supposed species,^?, septicum and JE. vaporarium, 

 help make up a page of synonyms under the name Fuligo varians. The genus 

 Diderma is discarded and its thirteen species are distributed among three 

 genera, Chondrioderma taking the largest share. In several instances two, 

 and in one or two cases three supposed species have been united in one. The 

 genus Physarum has had its characters so modified that it now comprehends 

 species that before were found in Diderma, Didymium and Angioridium ; and 

 one of its species, Physarum nutans, with its varieties, has been transferred 

 to Tilmadoche and separated into two species. 



The adoption of so many new names at once will necessarily be attended 

 by some disadvantages, yet we think the advantages to be derived from the 

 adoption of this new method of classification will more than compensate for 

 the temporary inconvenience. One thing is quite evident to my mind, and 

 that is, that the species may be more satisfactorily referred to their proper 

 places by this system and by the descriptions, given by Rostafinski than they 

 possibly could be by the old system and descriptions. 



The following is a list of the New York Myxogasters at present known. 

 The names in the first or left hand column are those required by and 

 arranged according to the new system ; those in the second column are the old 

 names, applied to such of the species as have before been reported and 

 published as New York species : 



Present Names. Former Names. 



Physarum cinereum Batsch. Didymium cinereum Fr. 



P. contextum Pers. Diderma flavidum Pk. 



P. flavidum Pk. Didymium flavidum Pk. 



P. sinuosum Bull. Angioridium sinuosum Grev. 



P. polymorphum Mont. Didymium connatum Pk. 



P. albicans Pk. D. subroseum Pk. 



P. citrinellum Pk. Diderma citrinum Fr. 



P. luteolum Pk. 



P. inaequalis Pk. 

 P. ornatum Pk. 

 P. atrorubrum Pk. 

 P. psittacinum Dittm. 



P. pulcherripes Pk. Physarum pulcherripes Pk. 



Tilmadoche nutans Pers. P. nutans Pers. 



T. mutabile R. 



