bb. No pigment produced on agar media, c. Not acido-proteolytic. d. Utilizes urea as a sole source of nitrogen. 2. Micrococcus ureae. dd. Does not utilize urea. 3. Micrococcus freudenreichii. CO. Acido-proteolytic in litmus milk. 9. Micrococcus caseolylicus . aa. Do not utilize NH4H2PO4 as a sole source of nitrogen, b. Grow well at 25° C. c. Yellow pigment produced. 4. Micrococcus flavus- cc. No pigment produced. 5. Micrococcus candidus. bb. No growth at 25° C; grows well at 10° C. 6. Micrococcus cryophilus. 2. Nitrites produced from nitrates. a. Do not utilize chitin. Utilize NH4H2PO4 as a sole source of nitrogen. Ordi- narily found in dairy products, b. Yellow pigment produced on agar media. Not acido-proteolytic. c. Gelatin liquefied. 7. Micrococcus conglomeratus . cc. Gelatin not liquefied. 8. Micrococcus varians. bb. Usually not chromogenic. Actively acido-proteolytic in litmus milk. 9. Micrococcus caseolylicus. aa. Utilizes chitin. Found in sea water. 10. Micrococcus colpogenes. B. Pink, orange-red or red pigment produced on agar media in young cultures. 1. Not obligately halophilic. a. Gelatin liquefied slowly. Produces rose-colored pigment. 11. Micrococcus roseus. aa. Gelatin not liquefied. b. Non-motile. Produces light, flesh-colored pigment on agar slants. 12. Micrococcus rubens. bb. Motile. Produces a bright red pigment. 13. Micrococcus agilis. 2. Obligately halophilic (requires at least 12 per cent salt for growth). 14. Micrococcus morrhuae. II. Free nitrogen gas and sometimes nitrous oxide produced from nitrates. A. Will not grow in media containing more than 6 per cent salt. Produces a mixture of nitrogen and nitrous oxide gases from nitrates. 15. Micrococcus denilrificans. B. Grows in 4 to 12 per cent salt. Gas produced from nitrates is largely nitrogen. 16. Micrococcus halodenitrificans. 1. Micrococcus luteus (Schroeter, 1872) Beitr. z. Biol. d. Pflan., 1, Heft 2, 1872, 119; Cohn, 1872. (Bacleridium hileum Schroeter, Cohn, z6zd., 153; not Micrococcus Zwfews Leh-
