THE ANXALS AND MAGAZINE OF NATURAL HISTORY. [FOURTH SERIEJ^.] No. 99. MARCH 1876. XIX. — On the Polytremata {Foramimfera) , especially with reference to their Mythical Hybrid Nature. By H. J. Carter, F.R.S. &c. [Plate Xm.] Synonymy o/Polytrema miniaceum. MiUeporn miniacea, Linn. 1788, Syst. Naturae, ed. Gmel. Vi. p. 3784; Esper, 1797, vol. i. tab. xvii. I MWepora rubra, Lamk. 1810, Anini. sans Vert. vol. ii. p. 202. Polytrema coralluia, Risso, 1826, Hist. Nat. Europ, merid. vol. v. p. r^40. no. 91. Polytrema miniaceum, De Blainville, 1834, Man. d'Actin. p. 410, and p. 673, pi. Ixix. fig. 4. Polytrema miniaceum^ De Blainville, 1834. PI. XIII. figs. 1-6. The true nature and position of this organism in the animal kingdom was first recognized and pointed out by the illustrious Dujardin, who, in 1841, placed it in his third family of Rhi-zopoda (Hist. Nat. des Zoophytes Infu.soires, p. 259) — con-jecturally, it is true (but such is at once the modesty and sagacity of this author that his conjectures may almost be taken as facts) ; while its pseudopodial extensions are illus-trated by those of his Vorticialis strigilata =-Folystomella {ap. cit, pi. i. fig. 1.5). I need hardly add that the genera of his Rhizopoda are respectively Arcella^ Difflugta^ Trinema^ Eu-glypha^ Gromia, Miliola, Cristellaria, and Vorticialis^ to which An7i. & Mag. N. Hist. Ser. 4. Vol. xvii. 13