In the previous paper,1•`3) we isolated four new indole alkaloids, roquefortine A, B, C and D together with festuclavine from the cultures of Penicillium roqueforti. Recently, we isolated a Penicillium strain having the ability to produce at least four alkaloids I, II, III and IV in the course of screening fungi for their alkaloid productivity. By close investigation on morphological characteristics, this strain was identified as Penicillium corymbiferum. In this paper, we report the isolation and identification of these four alkaloids. Alkaloid I and II were isolated in crystalline form from the culture filtrates (ca. 5.4 liters) in the yields of 45 and 30 mg, respectively, by the routine procedure using silica gel column chromatography. Alkaloid III was obtained at first as crude powder containing alkaloid IV from the said culture filtrates by the same technique. This powder was purified repeatedly by the use of silica gel column chromatography, giving pure crystals of III and IV in the yields of 240 and 210 mg, respectively. I and II were identical with roquefortine C1,2) and D,3) respectively, not only in the physico- and spectro-chemical properties but also in the mixed melting point with authentic samples. III and IV were identical with cyclopenol4,5) and cyclopenine,4,5) respectively, which were isolated from the cultures of Penicillium cyclopium, not only in the physico and spectro-chemical properties but also in the mixed melting point with authentic samples. Judging from the assumed biosynthetic route6) of roquefortine C and D, and from that7) of cyclopenol and cyclopenine, these four alkaloids seem to be biosynthesized in used Penicillium in the correlation as shown in Fig. 1. In further screening tests, it was found that roquefortine C was produced also by Penicillium expansum IFO 5854 and Penicillium urtica IFO 7010 together or independently with roquefortine D.