Publications

Graptolites have been isolated from lower Viola limestone (mid Mohawkian) by dissolving a block of it in acid. Fragments of Leptograptus? show tthat the development is of dicellograptid type, and that th 12 has an initially upward direction of growth. Pipiograptus hesperus, n. gen., n. sp., has sicula, initial bud, and proximal part of first three thecae with continuous periderm, remainder of scandent, biserial rhabdosome represented by a clathria. Thecae alternating, first and second hook-shaped, third and fourth with straight ventral walls, little overlap between them. Apertural spines, and spines on ventral and lateral walls, some forked. Development of non-septate diplograptid type. Pipiograptus, n. gen., is placed in the Diplograptidae. Phormograptus sooneri, n. gen., n. sp., has sicula and proximal portion of initial bud only with continuous periderm, remainder of scandent, biserial rhabdosome a reticula supported by a clathria; clathria includes virgella spine, apertural spines of sicula, median ventral lists of thecae, and cross-bars with virgula as central strand; reticula attached to tips of clathria. Thecal apertures introverted. Development of diplograptid type. Phormograptus, n. gen., is placed in the Retiolitidae. Associated with the graptolites are tiny, elongate sacs, here referred with question to the chitinozoan Rhabdocitina.