. Bulletin - United States National Museum. Science. Figure 78.—^Dorsal view of skull, USNM 10677, of Parietobalaena palmeri Kellogg. For abbreviations, see figure 79. Between the intertemporal region contributed by the parietals and the posterior ends of the rostral bones, the frontal bones (USNM 10677; fig. 78) are exposed for an interval of less than 15 mm. Each frontal slopes gradually downward from the midline behind the nasals to the orbital rim of the supraorbital process of the frontal. The transverse ridge or crest is low and indistinctly developed on the suprao
. Bulletin - United States National Museum. Science. Figure 78.—^Dorsal view of skull, USNM 10677, of Parietobalaena palmeri Kellogg. For abbreviations, see figure 79. Between the intertemporal region contributed by the parietals and the posterior ends of the rostral bones, the frontal bones (USNM 10677; fig. 78) are exposed for an interval of less than 15 mm. Each frontal slopes gradually downward from the midline behind the nasals to the orbital rim of the supraorbital process of the frontal. The transverse ridge or crest is low and indistinctly developed on the supraorbital processes of all the skulls. Whether or not the rounded preorbital angle of the supraorbital process pro- jected outward beyond the lateral extensions of the postero- external end of the maxillary cannot be determined since this region is missing on all the skulls. The stout postorbital projection of the supraorbital process is extended backward to the anterior end of the zygomatic process. The opposite parietals meet on the midline of the cranium to constitute a sharp-edged ridge; they are also overlapped above and behind by the lateral borders of the supraoccipital shield. The thin anterior border of each parietal overlaps the interorbital basal portion of the corresponding frontal. On each side the posteroventral portion of the braincase is constituted by the squamosal. Behind its contact with the pterygoid, the squamosal follows the curvature of the. 10668, of antorbital Figure 79.—Dorsal view of skull (type), USNM Parietobalaena palmeri Kellogg. Abbrs.: ant. n., notch; Bo., basioccipital; Bs., basisphenoid; c, occipital condyle; , exoccipital; , foramen magnum; , maxUlary foramen or incisure; , foramen ovale; Fr., frontal; , hamular process of pterygoid; , jugular notch or incisure; 1. pr., lateral or descending protuberance of basiocipital; Max., maxilla; , channel for external auditory meatus; Na., nasal; , optic ca
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