180 ILLINOIS ACADEMY OF SCIENCE 



corresponding to those given to the families of Siphono- 

 gams by Dalla Torre and Harms.^ The entire list is to 

 be found in subsequent pages. Column 13 includes the 

 localities. The countries have been omitted from the 

 descriptions, in many cases there being only the name of 

 some local town. An attempt has been made to supply 

 the countries or nations as f^r as possible. Some of 

 the species that have been quoted from a large number 

 of countries in Europe have been entered in this column 

 simply from Europe. 



CONSIDERATIOlSr OF VARIOUS GROUPS OF SPECIES 



The largest number of species from a single fam- 

 ily is reported from the Compositae, but that is be- 

 cause that family is broader in its limits than most 

 of the others. Somewhat recently authors have, in fact, 

 divided the original Compositae into a number of sep- 

 arate families. Of the 118 species from this family, 54 

 are described from Italy and Central Europe, i. e. Ger- 

 many, France, Portugal, Austria, etc.- It will be noticed 

 that in many cases species from a given country tend 

 to group themselves together under similar spore lengths. 

 In these groups other characters also correspond. For 

 instance, if we trace in the tables the species from Com- 

 positae (280), beginning with spores 20-27 mu. in length, 

 four species in succession occur from the United States. 

 A fifth species from Silphium properly belongs in this 

 group. Again, beginning with species having a spore 

 length of 25 mu. we find three species from Italy, all 

 with spore lengths between the limits of 25-30 mu. 



Among the species on Gramineae, we find the same 

 grouping by countries. It is a notable fact that many 

 of the species here listed from the Gramineae are gen- 

 eral parasites and are capable of affecting most grasses. 

 Twenty-six of the sj)ecies are included between the mini- 

 mum spore lengths of 20-24 mu. while many others lap 

 over into these limits. Septation is slightly more com- 

 mon than in the Septorias on Compositae, and there 



3 C. G. Dalla Torre et H. Harms, Genera Siphonogamarum. 



