. Annals of the New York Academy of Sciences. Science. HAHN, DICTYONEMA-FAUNA OF NAVY ISLAND, X. B. 143. long, .5 mm. wide) with terminal expansion to an adhesive bulb (of .8 mm. in width). Branches 10 to 13 in 10 mm. width, . mm. wide, closely arranged, sub-parallel, sometimes slightly flexuose. Sicula of one specimen 7 mm. long, determinable as being a very thin tube about 1 mm. in length, with a minute basal disk .3 mm. in width. Within the first 5 mm. of the length of the dendrome, a very frequent branching, sometimes of monopodial aspect, with a common angle of 50-60° takes place. Bra
. Annals of the New York Academy of Sciences. Science. HAHN, DICTYONEMA-FAUNA OF NAVY ISLAND, X. B. 143. long, .5 mm. wide) with terminal expansion to an adhesive bulb (of .8 mm. in width). Branches 10 to 13 in 10 mm. width, . mm. wide, closely arranged, sub-parallel, sometimes slightly flexuose. Sicula of one specimen 7 mm. long, determinable as being a very thin tube about 1 mm. in length, with a minute basal disk .3 mm. in width. Within the first 5 mm. of the length of the dendrome, a very frequent branching, sometimes of monopodial aspect, with a common angle of 50-60° takes place. Branches of the third and fourth order are usual, those of the sixth still observable. The interspaces be- tween the branches vary from .3 mm. to 1 mm. in width. Most of the specimens are dorsally de- pressed and therefore, as commonly found in sandy shales, they do not exhibit the theca?. Only a few branches, laterally compressed, show 19 to 21 thecse in 10 mm. of length of the branch, as sharp spinelike prolongations, quite similar to those of Dictyonema flabelliforme (cf. Ruedemann (1), p. 601, fig. 26). Very seldom one or the other of these apertural processes reaches the neighboring branch, joining it like a dissepiment. The periderm seems to be composed of two layers, of which the greenish external one adheres to one side of a split slab, while the black interior layer remains on the other side, distinguished by a wrinkled sur- face. Aside from this no striation is visible. Fig. 1.—Callograptits grabaui sp. nov. (3/1) Stratigraphic Position and Mode of Occurrence: The type specimen was sent to the Columbia Collection by Victor Ziegler, who obtained the fossil from Center County, Pa., "2000 feet from the bottom of the lime- stone series which are referred by Collie to the ; 17 The animal mass is profusely scattered on the sandy surface of the thin- bedded, impure limestone. The close relationship of this species to Callograptus salteri Hall and G. com
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectscience, bookyear1877
