118 Huene and Lull — Triassic Reptile Hallqpus. 



near the good dorsal rib, the other (left) metatarsal III and, 

 near the ischia, the left fourth metatarsal with fragments of 

 phalanges.. Metatarsal II and III are straight, while meta- 

 tarsal IV is a little curved near the proximal extremity. The 

 second one is the broadest and the third the longest. Metatar- 

 sal IV is probably only little shorter than metatarsal II. 

 Yery short, but broad at the 'proximal end, is metatarsal V. 

 All of the metatarsals are hollow. 



Length of metatarsal II 41 mm 



Length of metatarsal III . 48 



Length of left metatarsal IV (preserved portion) 30 

 (incomplete at proximal end) 



Length of metatai'sal V 15 



Breadth of proximal end of metatai'sal V 6 



One of the phalanges of the left fourth digit seems to be 7 mm 

 long and about 2 mm broad. The other remains of phalanges 

 are too fragmentary to be measured. 



In addition to the described bones and impressions there are 

 still a few impressions which we are not yet able to determine. 



Conclusions. 

 Marsh placed Hallopus among the theropodous Dinosauria. 

 The pelvic bones, as Marsh determined them, are quite differ- 

 ent from all Theropoda and other Dinosaurs. Following our 

 interpretation of the ischium and pubis, the pelvis is more dino- 

 saurian. The long and slender spina anterior ilai is im- 

 possible for a theropodous dinosaur, and resembles nearly that 

 of the Orthopoda. But there are some other facts which would 

 be veiw striking even for the Orthopoda : the pubis, the calca- 

 neum, the extreme thickness of the astralagus, the form of the 

 scapula, also the surprisingly high ilium, are different from 

 those of the Orthopoda. We find Hallopus more naturally 

 placed with Scleromorphus,* Ornithosuchus, Erpetosuchus and 

 Aetosaurus. These systematic and phylogenetic views we shall 

 present in detail in our forthcoming memoir. 



Bibliography . 



Marsh, 1877, this Journal, xiv, p. 255. 

 " 1881, " " xxi, p. 422-423. 



" 1882, " " xxiii, p. 85, 86.f 



" 1890, " " xxxix, p.. 415-417, 1 fig. J 



" 1895, The Dinosaurs of North America, p. 153-155, 

 1 hV. p. 233, 240, 241, pi. vi.§ 



AVilliston, 1905, Jour, of G-eol., xiii, p. 338-341. § 



* The senior author has been able to study all these type specimens and 

 has found some new evidence. 



f As distinct order, doubtful if dinosaurian or not. 



% As theropod. 



§As Triassic, recognized for the first time. 



