. Bulletin - United States National Museum. Science. DENDROID GRAPTOLITES OF HAMILTON, ONTARIO. 41 Below is given Doctor Spencer's original description, with addi- tional characters, as published by him in 1884, placed in brackets. Frond flabellatc. hut cyatbiforni in jurowing state; bifnrcatinj;; branches with dichotomous terminations; [stem terminating in a well-marl^ed bulb] ; branches (marlved with strije) more or less reticulated, and united, or overlaid bj' others. This genus is established on account of its bulbous root, which as yet has been found in no other species of this family. Th
. Bulletin - United States National Museum. Science. DENDROID GRAPTOLITES OF HAMILTON, ONTARIO. 41 Below is given Doctor Spencer's original description, with addi- tional characters, as published by him in 1884, placed in brackets. Frond flabellatc. hut cyatbiforni in jurowing state; bifnrcatinj;; branches with dichotomous terminations; [stem terminating in a well-marl^ed bulb] ; branches (marlved with strije) more or less reticulated, and united, or overlaid bj' others. This genus is established on account of its bulbous root, which as yet has been found in no other species of this family. The numerous branches closely overlie each other or are connected in the form of a network without transverse dis- sepiments, as in Dictyoncma. Fragments of these somewhat resemble species of CaJyptograptiis, but have a much more [regularly] netted appearance and the branches are much more delicate. Genotype.—Rhizograptus htdhosiis Spencer. RHIZOGRAPTUS BULBOSUS Spencer. Rhizograpsus bulbosiis Spencer, Canadian VIII. 1878, p. 460.—Gtjelry, Journ. Geo]., IV. 1896, pp. 101. 308. RMzograptus bulbosus Spencer. Trans. Acad. Sci. St. Louis, IV, 1884, p. 580, pi. 4, fig. 4; Bull. Mus. Univ. State Missouri, I, 1884, p. 30. pi. 4, fig. 4.—Miller, North Amer. Geol. and 1889, p. 202. text fig. 215. The original description is as follows: Frond cyathiform in growing state; numerous bifurcating branches overlie each other, or are united at points of contact to form a networl^, with fine, more or less irregular, rhomboidal in- terstices. The branches unite at base into .i slender axis which terminates in a bulbous root. The branches are usually less than one-fiftieth of an inch wide, and in some specimens short abrupt spinelike branchlets are given off. The texture is corneous. Only a few specimens have been obtained, except in fragments. Frond is about 2 inches high. It was first found by Colonel Grant in the Niagara limestones [near the base of the " chert bed " a
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