Stylonuroides (Stylonurus?) limbatus nov. Page 295 1 Specimen showing the visual surface, but no border. Natural size 2 Large carapace showing the eye nodes and visual surfaces and marginal border. Type of species. Natural size 3 Smaller carapace well exhibiting the concentric striation of the border and showing traces of ornamentation. Natural size 4 Small, broader carapace, referred with doubt to this species. × 2 5 Long carapace, apparently somewhat laterally compressed, showing triangular scales along posterior margin; probably belonging to a different species. Natural size Horizon and locality. Lower Siluric: Schenectady shale. Originals of figures 1–4 from Dettbarn quarry, Schenectady, that of figure 5 from Duanesburg, Schenectady co.

Stylonurus, disjecta membra 6 Fragment of abdomen, showing tergites with an elevated medio-transversal region bearing broad, flat nodes; possibly belonging to Stylonurus limbatus. Natural size 7 Patch of integument with slender spines, possibly belonging to a Stylonurus. × 5 8 Patch of integument with closely arranged mucros, possibly belonging to the carapace figure 5. × 5 9 Articulation with parts of two slender segments suggesting the walking leg of a Stylonurus. Natural size 10 Fragment of a leg with peculiar ornamentation consisting of a lattice work of sharply raised straight lines. × 5 Horizon and locality. Lower Siluric: Schenectady shale, figures 6, 7, 8, 10 from Dettbarn quarry, figure 9 from Aqueduct, near Schenectady

Hughmilleria magna nov. Page 341 11 Small carapace, well retaining the probable original form and the lateral eyes. Type of species. Also showing traces of ocelli. Natural size 12 Carapace of very young (neanic) individual, showing the larger size of lateral eyes. × 2 13 Specimen retaining besides carapace portion of abdomen and swimming leg. The carapace shows faintly two lateral eyes well within the margin. The segments of the swimming leg are indistinct save the last two. Natural size 14 Small carapace which apparently has suffered but very little distortion and shows the intramarginal position of the larger lateral eyes. Natural size