heat; Gr. adj. philus loving; M.L. adj. thal- pophilus warmth-loving. Vegetative growth: Grows well on organic and synthetic media, except on potato, at 50° C. Growth is colorless with yellow pig- mentation in edges; color changes to orange with age of culture. Soluble, wine-colored to light rose pigment produced in yeast- glucose agar. Aerial mycelium: Well developed, white, powdery, with tendency to form "fairy rings" on some media. Sporulating hyphae very short, 0.6 to 1.0 micron in length. Spherical conidia, 0.8 to 1.5 microns in di- ameter, are produced singly on the short sporophores or are entirely sessile. Gelatin: Liquefaction. Synthetic sucrose agar: Abundant, color- less growth. Powdery white to light gray aerial mycelium. Glucose-asparagine agar: Colorless growth with reverse white to yellow to light brown. White, powdery aerial mycelium. Considerable development of "fairy rings" in aerial mycelium. Glycerol agar: Cream-colored vegetative growth; white aerial mycelium. Yeast-glucose agar: Good, colorless growth, pigmented yellow at edges, color turning orange in older cultures. Lichenoid, white aerial mycelium. Soluble, wine to rose pigment. Potato agar: Limited vegetative growth, penetrating deep into medium. Limited, powdery, white aerial mycelium. Milk: Coagulated with limited peptoniza- tion. Starch is rapidly hydrolyzed. Nitrites weakly produced from nitrates. No growth at 28° C; good growth in 4 days at 37° C; excellent growth in 2 daj^s at 50° C. Source: Isolated from soil and high-tem- perature composts. Habitat: Presumably widely distributed in soil. 3. Thermoactinomyces monosporus (Lehmann and Schiitze, 1908) Waksman, 1953. (Actinomyces monosporus Lehmann and Schiitze, in Schiitze, Arch. f. Hyg., 67, 1908, 50; Thermoactinomyces monospora (sic) Waksman, in Waksman and Lecheva- lier, Actinomycetes and Their Antibiotics, Baltimore, 1953, 130.) mo.no'spo.rus. Gr. adj. monus single; Gr. fem.n. spora a seed; M.L. fem.n. spora a spore; M.L. adj. monosporus single-spored. Vegetative growth: Grows well in various media. Growth yellowish, compact, smooth or lichenoid. Hyphae about 1.0 micron in diameter. Aerial mj'celium: Well developed, cover- ing the whole growth, grayish green. Good sporulation on hay infusion-peptone agar; somewhat less on glycerol-peptone and lac- tose-peptone agars; none on peptone-glu- cose agar. Ellipsoidal spores, 1.0 to 1.4 by 1.5 to 1.8 microns; produced singly on sim- ple, short sporophores. Gelatin: Liquefaction. Blood serum: Good, smooth growth. Se- rum liquefied. Milk: Not coagulated. Potato: No growth. Optimum temperature, between 37° and 55° C; grows poorly at 27° and not at all at 60° C. Source: Isolated from self-heated hay. Habitat: Presumably soil. FAMILY IV. ACTINOPLANACEAE COUCH, 1955.* (Actinosporangiaceae Couch, Jour. Elisha Mitchell Scientific Soc, 71, 1955, 149; Couch, ibid., 269.) Ac.ti.no.pla.na'ce.ae. M.L. noun Actinoplanes type genus of the family; -aceae ending to denote a family; M.L. fem.pl.n. Actinoplanaceae the Actinoplanes family.
- Prepared by Prof. John N. Couch, Department of Botany, University of North Caro-
lina, Chapel Hill, North Carolina, January, 1955. The investigational work was supported by a grant from the National Science Foundation. The author gratefully acknowledges the assistance of Dr. E. K. Goldie-Smith.
