APPENDIX. We bring together here records of some species described in Germany during the war period, 1916-1918, cited from periodicals only recently received in the United States, together with a few supplementary observations upon other species described in this volume. Cereus hexagonus. (See page 4, ante.) Dr. Britton has recently studied this species on the western mainland of Trinidad and the small islands, Gasparee, Monos, and Chacachacare, adjacent. Here it inhabits rocky hillsides, attaining a height up to 15 meters; planted individuals observed were con- siderably taller. At St. Joseph large numbers of young plants up to 4 meters tall were seen growing upon branches of saman trees, evidently germinated from seeds carried by birds from the fruit of large planted specimens nearby, an interesting illustration of in- duced epiphytic habit of a typically saxicolous plant. Repeated field observations showed that this Cereus is usually 4-ridged when young, becoming 6-ridged later in life, many plants bearing some joints 4-ridged, some 6-ridged. Illustration: Loudon, Encycl. PI. 410. f. 6854, as Cactus hexagonus. Cereus chalybaeus. (See page 16, ante.) Cereus beysiegelii (Monatsschr. Kakteenk. 29: 48. 1919) is an abnormal form, similar to Cereus peruvianus monstruosus, which Mr. W. Weingart says looks like Cereus chalybaeus on account of its black spines and turquoise-green skin. Its origin is unknown.