Art. XXXIV.—A Revision of the Species of the Formicidæ (Ants) of New Zealand. By Professor Dr. A. Forel. Communicated by A. Hamilton. [Read before the Wellington Philosophical Society, 1st June, 1904.] Chigny près Morges, Switzerland, 3rd April, 1904. Dear Sir,—I have received the list of the Hymenoptera of New Zealand by P. Cameron, published in your Transactions, vol. xxxv., pp. 290–299. This list contains such a large number of errors that I think it necessary to send you a revision of the New Zealand species of Formicidœ, as now known. Of the species named in the list Aphœnogaster antarcticus, Smith = Monomorium antarcticum, White, Smith named it Atta antarctica, while Cameron made an Aphœnogaster of this false Atta—the Aphœnogaster being more erroneous than the Atta. In the following paper I have given the necessary synonymy. Mr. Cameron has forgotten to include in his list many new species discovered since 1892, and has added species that do not exist. He gives no Lasius in New Zealand, and Formica zealandia = Melophorus advena, Smith. Emery suggested that my Strumigenys antarctica may be a synonym of Orectognathus perplexus, Smith, because he thinks Smith has miscounted the number of joints of the antennæ; but, as it is only a suspicion, it must wait for more material. I have no doubt that the North Island will furnish further new species after careful search, especially in vegetable mould and the hollows of trees.—Truly yours, Prof. Dr. Forel. Revision of New Zealand Species of Formicidæ. 1. Subfamily Ponerinæ, Lep., 1836. Ponera, Latr., 1804. (1.) P. (Mesoponera) Castanea, Mayr., Reise “Novara,” Zool. ii., 1, Formicidæ, 1865. P. castanea, Smith, Trans. Ent. Soc. Lond., 1876, p. 489. P. castaneicolor, Dalla Torre Cat., 1893, p. 38. (2.) P. Antipoda, Forel, Ann. Soc. Ent. Belg., 1895. Ectatomma, Smith, Cat., 1858. (3.) E. (Acanthoponera) Brounii, Forel, Mitt. Schw. Ent. Ges., 1892, p. 330.