BIVERTICILLATA-SYMMETRICA 653 



recognized species in the Section. If cultural and structural individuality 

 still persists, as in the case of P. diversum., recognition of a new species 

 would seem warranted. 



Penicillium rugidosum var. atricolum (Bainier?) Thorn. (The Penicillia, p. 474. 

 1930) was recognized by Thorn in 19-30, to cover a culture received from the Bainier 

 Collection labelled P. atricolum which showed numerous characteristics relating it 

 to his P. nigulosutn, but developed colonies somewhat flocculent and colorless in 

 reverse. Careful comparative examination of this culture, now XRRL 1052, fails 

 to show any outstanding differences to separate it from typical strains of P. tardum 

 Thorn, hence continued recognition of the variety appears to be unwarranted. 



Penicillium scoiieum Takedo, Suematsu, and Xakazawa (Jour. Agr. Chem. Soc. 

 Japan. 10: 95-121 . 1934) was isolated from military equipment and described as new. 

 The type was received by Thom from Westerdijk in January 1937, and was noted at 

 that time to approximate P. pinophilum Hedgcock. Re-examination of this strain 

 upon different substrata for the current study shows it to be more closely allied to 

 P. tardum Thom since it grows very restrictedly upon Czapek and steep agars but 

 luxuriantly upon malt. Our culture, XRRL 1129, differs from most Penicillia in com- 

 monly producing conidia from Cadophora-Yike sterigmata, i.e., sterigmata within 

 which conidia appear to be formed and to be pushed out as they approach maturity. 



Pemcillium diversum Raper and Fennell, in Mycologia, 40 : 

 539-541, fig. 11. 1948. 



Colonies on Czapek's solution agar extremely slow-growing (fig. 165A), 

 2 to 5 mm. in 12 to 14 days at room temperature, consisting of a fairly 

 tough mycelial felt, surface appearing velvety or slightly granular, heavily 

 sporing in yellow-green shades near Andover green (Ridgwaj^, PL XLVII) ; 

 exudate lacking; odor suggesting sea-weed; reverse uncolored; conidiophores 

 arising from the mycelial felt, up to 200m by 2.0 to 2.5m, "^vith walls smooth 

 or nearl}^ so; penicilli typically biverticillate and symmetrical (fig. 165C), 

 regularh^ consisting of a terminal verticil of 5 to 7 or 8 metulae measuring 

 about 9 to 11m by 2.0 to 2.5m, slightly enlarged upward; sterigmata usually 

 in compact clusters of 6 to 8, mostly 8 to 10m by 1.8 to 2.2m; conidia at first 

 elliptical, becoming subglobose or broadly elliptical when mature, with 

 walls thin, smooth or delicately roughened, mostly 2.0 to 2.5m by 1.5 to 

 2.0m, borne in tangled chains up to 75 or 100m hi length. 



Colonies on steep agar essentially as on Czapek but usually lighter spor- 

 ing, conidial structures sparsely produced, often smaller than on Czapek. 



Colonies on malt extract agar spreading broadly, up to 5.0 to 5.5 cm. 

 in 12 to 14 days, velvety, plane, with vegetative mycelium largely sub- 

 merged, bearing abundant conidial structures in a dense stand (fig. 165B), 

 consistent!}^ narrowlj^ zonate, heavily sporing throughout in dull gray 

 shades near grayish olive (R., PI. XLVI); showing abundant short, en- 

 crusted and pigmented hyphae intermixed with conidial structures; exudate 



