The Fossil Fishes of the English Chalk (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1902 Excerpt: ...it affords is partly confirmed, partly supplemented by two other fragments evidently of the same species in the British Museum. The cranium is shown to be very narrow and elongated, and its constituent bones are remarkably stout. Its roof in the parietal and frontal regions rises into a sharp median longitudinal ridge, and the occipital border is also raised. The parietal bones (pa.), as usual, meet in the middle line, but the shape of the suture between these and the frontals is uncertain. The squamosal bone on each side (PI. IX, fig. 2, sq.) is traversed by a deep longitudinal slime-canal and extends in a slender pointed extremity nearly as far forwards as the anterior end of the frontals. The alisphenoidal ossification (as.) is seen below. There is a sharp post-orbital prominence (fig. 1, sp.), evidently formed by the cartilage-postfrontal or sphenotic. The precise shape of the ethmoidal rostral region (fig. 1, eth.) is not shown in either of the known specimens; but its total length seems to be about half that of the whole cranium. A displaced stout bar of bone on the right side of the type specimen above the maxilla is probably the parasphenoid (pas.). The mandibular suspensorium is well displayed on each side of the type specimen. The upper articulation of the expanded hyomandibular (hm.) extends as far forwards as the sphenotic; and the articular end of the quadrate (qu.), for the support of the mandible, is directly beneath the same element. The pterygoid arcade (PI. IX, fig. 3, pt.) is very delicate and toothless, and quite short, as usual in eels. The maxilla (fig. 1, mx.) is especially stout; and this element is displaced both on the left side of the type specimen (fig. 1 a, mx.) and in B. M. no. P. 4510 a (fig. 2, mx.) so as to expose its oral f...