Plate D. Fig. 3, the exposed inner surface of the cap, should be _smooth_, not _ridged_, as the straight lines in the engraving might suggest. Plate V. For Lactarious read Lactarius. PART 3. Plate VIII. The red on the upper surface of the cap is too bright in tint. It should be a dull brick-red. Plate IX. Fig. 6. The spores should be a deeper tint or brownish purple. The spores as delineated on the plates represent a magnification of from 400 to 500 diameters. Transcriber's Notes. To avoid confusion, corrections noted above were not made to the plates or their captions. "Membranaceous," "membraneous" and "membranous" all appear multiple times; I left them as is. Similarly for "Hynesboro" and "Hynesbury," "sebaceus" and "sebaeceus," "subglobose" and "sub-globose," "center" and "centre," "net-work" and "network." Both "Huseman" and "Husemann" appear; perhaps they refer to the same person, but I couldn't be sure, so I left them as is. There is little consistency about when names are italicized or placed in quotes. Except where noted below, I left them as typeset in the original. Changed "filamentose" to "filamentous" on page 7 of part 1: "filamentous network." Changed "sub generas" to "subgenera" on page 9 of part 1: "of the subgenera." Changed "Pratelę" to "Pratellę" on page 11 of part 1, in Dr. M. C. Cooke's subdivisions. Changed "puffball" to "puff-ball" on page 13 of part 1: "and the puff-ball." Changed "II" to "I" on page 17 of part 1 to match the illustrations: "illustrated in Plate I." Changed "mycophogists" to "mycophagists" on page 18 of part 1: "with most mycophagists." Changed "micaceous" to "micaceus" on page 19 of part 1: "Coprinus micaceus." Changed "plain" to "plane" on page 20 of part 1: "then nearly plane." Changed "parsely" to "parsley" on page 22 of part 1: "with parsley chopped." Changed "channeled" to "channelled" on page 23 of part 1: "_Canaliculate_, channelled." Changed "Channeled" to "Channelled" on page 23 of part 1: "_Channelled_, hollowed out like a gutter." Changed "clustured" to "clustered" on page 24 of part 1: "little clustered grains." Changed "charactertistics" to "characteristics" on page 3 of part 2: "the distinguishing characteristics." Changed "mushroon" to "mushroom" on page 5 of part 2: "common field mushroom." Changed "paraphesis" to "paraphyses" on page 7 of part 2: "spore sack and paraphyses." Changed "Saac." to "Sacc." on page 8 of part 2: "Mitrula vitellina Sacc." Changed "tetrasporus" to "tetrasporous" on page 9 of part 2: "being entirely tetrasporous." Changed "agaricus" to "Agaricus" on page 16 of part 2: "Agaricus arvensis." Changed "mid-western" to "midwestern" on page 17 of part 2: "and midwestern States."