. The Cyathaspididae; a family of Silurian and Devonian jawless vertebrates. Cyathaspididae. pop '"""^J! mrp Fig. 117. Vernonaspis vaningeni, anterior part of dorsal shield; New York State Museum 9625 (X 4). A, rostral view; B, dorsal view. mrp, median rostral process; pop, preorbital process. and figured specimens which he referred to Cyathaspis wardelli. The characters by which Bryant distinguished these two species are at- tributable either to distortion in preservation or to misinterpretation of their structure. V. vaningeni was considered to have a narrower shield, but the
. The Cyathaspididae; a family of Silurian and Devonian jawless vertebrates. Cyathaspididae. pop '"""^J! mrp Fig. 117. Vernonaspis vaningeni, anterior part of dorsal shield; New York State Museum 9625 (X 4). A, rostral view; B, dorsal view. mrp, median rostral process; pop, preorbital process. and figured specimens which he referred to Cyathaspis wardelli. The characters by which Bryant distinguished these two species are at- tributable either to distortion in preservation or to misinterpretation of their structure. V. vaningeni was considered to have a narrower shield, but the type (fig. 116) is incomplete and is missing nearly all of the left side posteriorly; if restored it would have a moderately broad shield comparable to that of specimens referred to C. wardelli. Besides, the type of vaningeni is compressed laterally while most of the specimens that Bryant referred to wardelli are compressed dorso- ventrally. The differences he mentions in proportion, arching, and depression of the snout may all be attributed to differences in pres- ervation. Therefore, two of the specimens referred by Bryant to Cyathaspis wardelli (Princeton 12920-1) are here referred to Ver- nonaspis vaningeni, while another (Princeton 12922) belongs to V. bryanti. Kiaer (1932) and Beerbower and Hait (1959) have pre- viously expressed the belief that Bryant's two species were really identical. This species has the characteristics of Vernonaspis as defined above, and is clearly different from Cyathaspis and Archegonaspis. It is about the size of V. leonardi but has coarser ridges. It is smaller than V. allenae, with which it agrees in coarseness of ridges. The ridge pattern is similar in general to that described above in V. allenae but is variable in detail. The central ridges of the rostral epitegum may be longitudinal, fanned, denticulate (in the type), or irregular (New York State Mus. 11470, 9625, fig. 117). The rostral margin is denticulate in Princeton 12919. A pineal ma
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