. The Cyathaspididae; a family of Silurian and Devonian jawless vertebrates. Cyathaspididae. DENISON: THE CYATHASPIDIDAE 371 Occurrence.—Late Silurian, Vernon shale (Salina group), 2 miles southeast of Kenwood, Oneida County, New York (the lectotype). Late Silurian, High Falls formation, east side of Route 23, miles ( by road) south-southeast of Duttonville, Montague town- ship, Sussex County, New Jersey (CNHM, PF 840, 844, 846).. Fig. 115. Vernonaspis leonardi, photograph of rubber impression of anterior part of type dorsal shield (from Flower and Wayland-Smith, 1952); Museum of Compar
. The Cyathaspididae; a family of Silurian and Devonian jawless vertebrates. Cyathaspididae. DENISON: THE CYATHASPIDIDAE 371 Occurrence.—Late Silurian, Vernon shale (Salina group), 2 miles southeast of Kenwood, Oneida County, New York (the lectotype). Late Silurian, High Falls formation, east side of Route 23, miles ( by road) south-southeast of Duttonville, Montague town- ship, Sussex County, New Jersey (CNHM, PF 840, 844, 846).. Fig. 115. Vernonaspis leonardi, photograph of rubber impression of anterior part of type dorsal shield (from Flower and Wayland-Smith, 1952); Museum of Comparative Zoology 8872 (X 4). Also from High Falls formation, cut on Delaware Water Gap- Millbrook road, opposite Shawnee Island, Warren County, New Jersey (CNHM PF861). Diagnosis.—The length of the dorsal shield is 27-29 mm. The dentine ridges are very fine, 7}^-9 per mm. The shield is moderately narrow, with a width ratio of .54. Discussion.—This species is smaller than V. allenae and about the size of V. vaningeni, but has much finer dentine ridges than either. The gently convex crowns of the dentine ridges of the referred speci- mens are typical of Vernonaspis, but in the type they are flat, with a faint, narrow ridge centered on the crest; this peculiarity is believed to be the result of crushing. Flower and Wayland-Smith distin- guished V. leonardi from V. allenae by shape (but this is incomplete. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Denison, Robert H. (Robert Howland), 1911-1985; Chicago Natural History Museum. Chicago : Chicago Natural History Museum Press
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