224 MYCOLOGY 



in their being less awl-shaped and pointed. /. obliquus on stumps, /. 

 carneus on tulip poplar, I. fusco-violaceus on pine trunks are American 



species. 



Family 7. Polyporace^.— The fruit body of the fungi of this 

 family are of various substance and shape. The hymenium lines the 

 inner surface of pores, or grooves, or is spread over the under surface of 

 the fruit body. The depressions are either united vein-like grooves, 

 tubes, or honeycombed cells, or twisted passages. Concentrically 



Fig. 87. — Fruit-body of Hydnum erinaceum. (After Patterson, Flora W., and 

 Charles. Vera K., Bull. 175. U. S. Dept. Agric, pi. xxxii. .ipr. 29. 1915.) 



formed lamellae are found rarely. The consistency of the fruit bodies 

 of these fungi is leathery, fleshy and succulent, while in some the fruit 

 bodies are wood}- and perennial. The family is naturally divided into 

 four subfamilies, as follows: Merulioide^, Polyporoide^, Fistulin- 

 oiDE.E, BoLETOiDE^. Each of these subfamilies includes fungi which 

 are important economically. 



Meruloide^. — This subfamily includes two genera of interesting 

 fungi: Mertdhis and Mycodendron. Merulius is represented by sixty- 



