Cordyceps nutans PATOUILLARD is known as a parasite on various species of Heteroptera, and is very abundantly found in some mountainous regions of the Province Chikugo, Northern Kyushu, though in other places it seems fairly rare. The first record of this curious fungus was published apparently by RYOCHOKU (TODO) OHARA in his posthumous work, "Todo Ihitsu", vol. iii, sheet 17 (1833), in which he gave only figures of the specimens originating from the Province of Omi. (Figure 1). The second record was given by TAKIZO UMENO and ARINOBU MITANI in their "Chikugo Chishi Ryaku" (Elementary Geography of the Province of Chikugo), sheet 29 (1879), and the authors believed that the specimens were insects during the summer and transmute into plants in the winter. (Figure 2). A French missionary then in Japan was interested in the description of the latter authors and collected the specimens from the said locality and sent them to Prance, and those specimens were later studied and described mycologically by PATOUILLARD in Bull. Soc. Mycol. France, tom. iii, p. 127-129, pl. xi, fig. 5 (1887). A list of the host-bugs is given in the present paper (pp. 225-226). (Those preceded by an are known to me only in the literature, and the figures in parentheses indicate the number of the specimens collected by me). Apparently the fungus is parasitic only on bugs of larger size such as Pentatomidae and Coreidae. The fungus is found only in shady, more or less moist places in the mountainous regions, and thus it may be of little economic importance. The parasitized insects become very hard and not at all fragile as ordinary dried specimens. In more than 90 % of the 244 specimens collected by me, the stalk of the fertile club of the fungus is projecting from between pro- and mesothorax, where the anatomical connection between two segments of the insect-body is weakest. In most specimens the stalk is only one in number in a single host, but sometimes two or more, and even six in one specimen, are projecting from a single bug.