. Carnegie Institution of Washington publication. ^E. I79 the latter two peripherals are slightly wider proportionally than are those of T. bauri. As regards the thickness no definite statements can be made about either species, but both appear to resemble the corresponding peripherals of Lytoloma. The carapace of T. bauri has a length of about 530 mm.; its greatest width, when restored to what is regarded as its original form, is about 400 mm. The species was therefore of consid- erable size and the form was relatively narrow. In front the outline is concave along the nuchal; whil
. Carnegie Institution of Washington publication. ^E. I79 the latter two peripherals are slightly wider proportionally than are those of T. bauri. As regards the thickness no definite statements can be made about either species, but both appear to resemble the corresponding peripherals of Lytoloma. The carapace of T. bauri has a length of about 530 mm.; its greatest width, when restored to what is regarded as its original form, is about 400 mm. The species was therefore of consid- erable size and the form was relatively narrow. In front the outline is concave along the nuchal; while the rear is rounded. There are no excavations over the anterior limbs, such as are seen in the modern Cheloniidae. This carapace is composed of 8 pairs of costals, a nuchal, 9 neurals, apparently 3 suprapy- gals, a pygal, and 11 pairs of peripherals. The first, second, and tenth peripherals had no connection with the costals. The others received each the extremity of a rib in a pit. In all, except the third and the eleventh, this pit is nearest the hinder end of the peripheral. There are large costo-peripheral fontanels, which extended from the peripherals half-way to the neurals. Besides these vacuities, there is a small one on each side at the common meeting- place of the nuchal, the first costal, and the first neural. Similar vacuities are found in a few of the Trionvchidae. The accompanying table shows the dimensions of the neurals, taken from Wieland's description of the species. The forms may be determined from fig. 229. Neural. Length. Width. 1 38 38 2 44 37 3 44 40 4 46 44 5 34 45 6 5° 40 7 40 38 8 25 35 9 >5 35. Fig. 230.—Toxochelys bauri. Shell presenting left side. Xj. /, fontanels behind the nuchal; s, s, 5, series of ossicles surmounting certain of the neural bones. Reproduced from figure by Wieland. It seems evident that an extra neural was intercalated in the series. This is shown by the fact that, as the series runs, most of them are crowded somewhat out
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