68 SOME SINGAPORE BOLETIXAE. 



shown in such drawings. Even the simple process of drying, which 

 was uniform for all the species, brought out various striking differ- 

 ences. /For instance in Boletus spinifer and Boletus umbrinellus, 

 as well as in most of the other species, the flesh is very firm and 

 holds its form well while drying, whereas in Boletus retisporus and 

 Strobilomyces porphyrins, the flesh softens very rapidly, collapse 

 taking place before drying is accomplished. On the other hand, 

 one species, Boletus tristis, dried out very readily and rapidly with- 

 out the aid of heat, just as it lay, on an open table. 



The characterisations of all the species under consideration are 

 presented herewith in synoptical form, using for separation, where 

 possible, the most readily recognizable characters, so that other 

 students may easily follow up the work and make more extensive 

 comparisons of living material and of material from other parts of 

 the Peninsula. 



Section I. Young plants with a distinct veil, and a persistent 

 or evanescent, fibrous or gelatinuous, annulus; springing from 

 white mycelium (Boletopsis). 



A. Veil gelatinous ; pileus pale brown, radially irregularly shallow- 

 ly corrugate, and centrally short tomentose, the outer half vis- 

 cid; hymenium pale yellow; stipe brownish, paler above, short 

 shaggy and covered with gelatinous droplets ; flesh cream 

 colored, with a reddish tint near upper surface of pileus ; pileus 

 4 — 1.5 cm. in diameter; stipe 6 — 12 mm. x (5 em. : spores ellip- 

 tical, very pale, nearly white, 12 x 5 microm. ; tomentum of 

 pileus forming an erect pile, 100 — 300 microm. in height; 

 plant occurring in large tufts (Xo. 5003). 



Boletopsis corrugatus, sp. nov. 



AA. Veil fibrous. 



B. A^eil thick, arachnoid, bright yellow; annulus appressed 

 and adherent, ragged scaly : pileus and stipe sulphur yel- 

 low, mealy, opaque; hymenium pale leather colored; stipe 

 becoming minutely brownish scaly; flesh of pileus white, 

 of stipe yellow; pores shallow, minute, subterete, septa 

 thick and dark lined: hy menial surface narrowly and 

 slightly sinuate where it joins stipe: pileus 2.5 — 3 cm. in 

 diameter; stipe 3 — 5 mm. x 4 — 5.5 cm.; spores elliptical, 

 smooth, pale in color, 8 — 14 x -1 — 5 microm. ; hyphal 

 threads of the veil with brown granulations (No. 4991). 



Boletopsis icterinus, sp. nov. 



BB. Veil thin, membraneous, viscid, at first white, finally leav- 

 ing a completely separated and ragged and evanescent an- 

 nulus; pileus smooth, shining, slightly viscid, and light 

 bay in color ; hymenium sordid yellow, stipe shining light 

 bay, pale above; flesh of pileus faintly yellowish, of stipe 

 white changing: pores large, dee]) very irregular, with 



Jour. Straits Branch 



