HATCHER : DIPLODOCUS (mARSH) 7 



from the palate, as shown in Fig. 1. Above this, for a large part of their length, the 

 ascending processes of the maxillaries underlap the ascending processes of the pre- 

 maxillaries and join each other on the median line. 



"The orbits are situated posteriorly in the skull, being nearly over the articula- 

 tions in the lower jaw. They are of medium size, nearly circular in outline, their 

 plane looking outward and slightly backward. No indications of the sclerotic plates 

 have been found either in •Diplodocus or in the other genera of Sauropoda. 



"The supratemporal fossa is small, oval in outline, and directed upward and out- 

 ward. The lateral temporal fossa is elongated, and oblique in position, bounded, 

 both above and below, by rather slender temporal bars. 



"The prefrontal and lachrymal bones are both small; the suture connect- 

 ing them and also that uniting the latter with the jugal, cannot be determined 

 with certainty. 



"The postfrontals are triradiate bones. The longest and most slender branch is 

 that descending downward and forward for connection with the jugal; the shortest 

 is the triangular projection directed backward and fitting into a groove of the squa- 

 mosal; the anterior branch, which is thickened and rugose, forms part of the orbital 

 border above. 



"The squamosal lies upon the upper border of the paroccipital process. The 

 lower portion is thin and closely fitted over the head of the quadrate bone. 



"The quadrate is elongate and slender, with its lower end projecting very much 

 forward. In front it has a thin plate extending inward and overlapping the pos- 

 terior end of the pterygoid. 



"The quaclratojugal is an elongate bone, firmly attached posteriorly to the quad- 

 rate by its expanded portion. In front of the quadrate it forms for a short distance 

 a slender bar, which is the lower temporal arcade. 



"The palate is very high and roof-like, and composed chiefly of the pterygoids, 

 as shown in Fig. 1. The basipterygoid processes are elongate, much more so than in 

 the other genera of Sauropoda. 



"The pterygoids have a shallow cavity for the reception of these processes, but 

 no distinct impression for a columella. Immediately in front of this cavity the 

 pterygoids begin to expand, and soon form a broad, flat plate, which stands nearly 

 vertical. Its upper border is thin, nearly straight, and extends far forward. The 

 anterior end is acute and unites along its inferior border with the vomer. A little 

 in front of the middle a process extends downward and outward, for union with the 

 transverse bone. In front of this process, uniting with it and with the transverse 

 bone, is the palatine. 



