11.") 



Plant [lalc bulf to croani-color, slender, medium size, average 4-6 cm. wide, rarely 

 7 cm.; spores 7-8// wide. Form }.* 



In all these forms none of the characters ascribed appear to 

 be constant and intermediate forms are easily found, yet in a 

 general way the three forms are readily distinguished in the 

 field by one familiar with the habit of the plant ; but herbarium 

 specimen.s undergo so great changes in drying that it is very 

 difficult to separate these forms with any degree of satisfaction. 



Form (J. is the plant described as Hydmun wnbilicatwn by 

 C. H. Peck, Bull. N. Y. State Mus. lo : 953. //. K. f. 14-18. 

 Peck especially emphasizes the umbilicate feature of the pileus, 

 but aside from this character the plant does not appear to be 

 essentially different from those forms which he has usually re- 

 ferred to rufcscens. On this point compare Peck, Rep. N. Y. 

 State Mus. 48 : //. ^8. f. y-io. It is to be observed that in the 

 plate cited, which shows both repanditin and rufesceus, the latter 

 is represented with larger spores than the former and that actual 

 measurement of the plate on the scale of i : 400 gives as values 

 for the spores in the case of rcpandnm y—d) ix and for the variety 

 rufcscens 8.5—10/^. Peck gives for his species umbilicatuni, loc. 

 cit., spore -values equivalent to 7.5-10//, and in the accompany- 

 ing plate they are represented of corresponding size. As the 

 umbilicus hardly seems a sufficient ground upon which to estab- 

 lish a species I should regard all the forms in the plates cited as 

 belonging to one segregation, which must be known as the 

 species or variety iiudnlicata ; for even if its hould be identified 

 with H. rufcscens Pers. the latter name, as we have seen, is pre- 

 occupied by H. rufcscens Schaef. which appears to be a distinctly 

 different thing. Specimens referable to this form have been ob- 

 served in the following collections : Massachusetts, Forstcr ; New 

 Jersey, Ellis ; Carolina or Pennsylvania, ScJni'cuntz.\ It is very 

 probable that this segregation should be regarded as a distinct 

 species. 



* It has not seemed best to the writer to treat these as varieties, much less as 

 species, in the present paper. The above device has therefore been resorted to, until 

 their claims to distinction can be more clearly established. \ 



fThe specimen observed in the Schweinitz herbarium in the Acad. Sci. Phila. 

 was marked '■'^ Hydnuin rttfescens — Schaeffer, Carolina, Pa." The specimen an- 

 swered remarkably to Peck's description and plate of//", umbilicatuin. 



