546 0. C. Harsh — Notes on Triassic Dinosauria. 



The remains of Thecodontosaurus are of special interest for 

 comparison, and a portion of the skull is given on Plate XVII, 

 figures 1 and 2, and the fore leg on Plate XYI, figure 5. 

 For these remains, the writer is indebted to the trustees of the 

 Bristol museum. The base of the skull shown on Plate XVII 

 differs in several important respects from that of Anchisau- 

 rus, particularly in its extended parasphenoid, and the very long 

 basipterygoid processes. The fore leg as a whole, especially 

 the fore foot, is much like that of Anchisaurus, but in the 

 latter, the coracoid is very small, and without a foramen. In 

 Thecodontosaurus, it is much larger, has a foramen, and is 

 coossified with the scapula. 



Plateosaurus (Zanclodon) includes reptilian forms much 

 larger than those described above. The pubis and ischia both 

 serve to distinguish this genus from the American and British 

 forms. The ischia have their distal ends expanded, as seen in 

 Plate XVII, while the pubes are broad, imperforate plates. 



The further discussion of these remains and of the other 

 Dinosaurs from the Triassic will be given elsewhere. 



New Haven, Conn., May 24, 1892. 



Explanation of Plates. 



Plate XV. 



Figure 1. — Skull of Anchisaurus colurus, Marsh; side view. One-half natural size. 



a, nasal opening; b, antorbital opening; bp, basipterygoid process; 



c, lower temporal fossa ; d, upper temporal fossa ; /, frontal : j, jugal ; 



n, nasal; o. orbit; oc, occipital condyle ; p, parietal; p', paroceipital 



process; pf, prefrontal ; pm, premaxillary ; ps, parasphenoid; q, 



quadrate ; so, supraoccipital. 

 Figure 2. — Bones of left fore leg of same individual ; outside view, c, coiacoid; h, 



humerus ; r, radius ; s, scapula ; u. ulua ; I. first digit ; V. fifth digit. 

 Figure 3. — Bones of left hind leg of same individual; outside view. Both 



figures are one-fourth natural size, a, astragalus ; c, calcaneum ; /, 



femur ; /'. fibula ; il, ilium ; is, ischium ; p. pubis ; t, tibia. 



Plate XVI. 



Figure 1. — Skull of Anchisaurus colurus ; top view. 



Figure 2. — Base of same skull ; back view. Both figures one-half natural size. 



Figure 3. —Left fore foot of Anchisaurus polyzelus, Hitchcock, sp. ; back view. 

 One-half natural size, c, central: r, radial; R, radius; U, ulna. 



Figure 4. — Right hind foot of Ammosaurus major, Marsh ; front view. One- 

 fourth natural size. F, fibula; T, tibia; t2, tS, tfc tarsal bones. 



Figure 5. — Bones of left fore leg of Thecodontosaurus platyodon, Riley and 

 Stutchbury ; outside view. One-fourth natural size. 



Plate XVII. 



Figure 1. — Base of skull of Thecodontosaurus platyodon ; seen from the left. 



Figure 2. — The same specimen ; back view. Both figures are one-half natural size. 



Figure 3. — Sacrum and ilia of Ammosaurus major; seen from below. One- 

 fourth natural size, ac, acetabulum ; is, face for ischium ; p>b, f ace f° r 

 pubis ; 1, 2, 3, sacral vertebras. 



Figure 4. — Pubis of Plateosaurus (Zanclodon) suevicus, von Meyer. One-sixth 

 natural size, a, front view ; b, back view ; s, symphysis. 



Figure 5. — Distal ends of ischia of same. One-sixth natural size, p, posterior. 



Figure 6. — Ischia of Anchisaurus polyzelus ; seen from above. One-half natural 

 size, a, distal ends ; il, face for ilium ; pb, face for pubis. 



