50 SECTION CAMAROPHYLLOPS1S 



5. Pileus 1—1.5 cm broad, convex-umbilicate (see H. berkelci/i Orton, page 

 68, also) 5. H. buccinulus 



5. Pileus larger and convex to umbonate 6 



6. Lamellae white until maturity 7 



6. Lamellae pale yellow when young 8. H. cremicolor 



7. Spores 5-8 X 3-5 n 10. H. angustifolius 



7. Spores larger 8 



8. Spores 8-12 X 5—7 p; pileus entirely white 9. H. virgineus 



8. Spores 7.5-10 X 4—5.5 ft; pileus watery white, flushed pinkish orange 

 on one side 7. H. borealis f. salmoneus 



2 



Hygrophorus niveicolor (Murr.) Sm. & Hes. 



Lloydia 5: 23. 1942 



Clitocybe niveicolor Murr., Mycologia 3: 190. 1911. 

 Camarophijllus niveicolor (Murr.) Singer, Lloydia 5: 99. 1942. 



Pileus 3-7 mm broad, compressed-convex, snow white, smooth, 

 glabrous, appearing subtomentose when dry because of loosely-woven 

 context, margin slightly irregular, decurved. 



Lamellae decurrent, slightly arcuate, white, rather narrow, dis- 

 tant. 



Stipe 1-1.5 cm long, 1 mm thick above, 1.5 mm thick below, white, 

 cylindric, slightly tapering upward, glabrous, fleshy, fistulose. 



Spores 10-14 X 7-9 /x, ellipsoid, smooth, pale yellow in Melzer's 

 reagent. Basidia 62-76 X 9-12 /x, mostly 4-spored, a few 2-spored. Pleu- 

 rocystidia and cheilocystidia none. Gill trama interwoven, hyphae 

 broad, 8-17 /x. Cuticle of appressed, undifferentiated hyphae — a cutis. 

 No hypodermium. Pileus trama of radially disposed, interwoven, hy- 

 phae. Clamp connections present on the hyphae of the gill trama. 



Habit, Habitat, and Distbibution — On ground in a moist virgin 

 forest, Mexico, January. 



Matebial Studied — Mexico: Murrill 1058 (type, from a mountain 

 side near Motzorongo, Jan. 15, 1910). 



Obsebvations — The record of microscopic characters above is 

 based on our study of the type. Singer ( 1942 ) properly concluded that 

 this species, at first described by Murrill as Clitoci/be niveicolor, is a 

 C 'amar ophijllopsis. It differs from H. nivens in its dry pileus and larger 

 spores. 



3 



Hygrophorus lawrencei, sp. nov. 



Pileus 1-3 cm latus, late convexus, glaber, siccus, albus; graveo- 

 lens; lamellae decurrentes, latae, albidae; stipes albidus, siccus; sporae 



