92 Forty- fifth Report on the State Museum. 



(E.) 



NEW YORK SPECIES OF OMPHALIA. 

 Omphalia Fr. 



Pileus thin, submembranaceous. Lamellae decurrent. Stem 

 cartilaginous, stuffed or hollow, somewhat thickened upwards. 

 Spores white. 



The species of Omphalia are generally small, the pileus rarely 

 exceeding an inch or an inch and a half in diameter. It is usually 

 umbilicate, a character which gives name to the genus, the word 

 Omphalia being derived from the Greek, 6p.<paXo<s an umbilicus. It 

 is sometimes either umbilicate or umbonate even in the same 

 species. It is- generally very thin, almost or quite membranous, 

 and most often hygrophanous, so that generally it is striate or 

 striatulate when moist. When mature, it assumes a funnel shape 

 in a few species and then simulates some species of Clitocybe, 

 but from these the species of Omphalia may be distinguished by 

 their cartilaginous stem. From species of Mycena they are sep- 

 arated by their truly decurrent, lamellae. 



They grow chiefly on decaying wood or other vegetable mat- 

 ter or on soil largely composed of such matter. They are fond 

 of moisture and are to be sought in damp shaded places or 

 in wet weather. Some occur in cold situations or at high alti- 

 tudes, and others appear to be capable of enduring great varia- 

 tions in temperature. 0. Campanella, one of our most common 

 and most abundant species may be found throughout the season. 

 It may even be found in sheltered cavities or on the under side of 

 decayed prostrate trunks when the ground is covered with snow. 

 On the other hand many species are quite rare, and some here 

 described have been found but once in many years of exploration. 

 Because of their small size the species are not regarded as 

 important for the table and none are classed as edible. 



The grouping of the species in the Friesian arrangement 

 depends upon the primary form of the pileus, the character of its 

 margin and the degree of proximity of the lamellae to each other, 

 but these characters have not appeared to me to be very sharp 

 and satisfactory and in the following pages I have disregarded 

 them. 



0. subgrisea has been found to belong to another genus, and 

 0. tubwformis is probably a large form of Marasmius salignus. 



