2 20 Bulletin American Museum of Natural History. [Vol. X, 



figured. It now appears that the anterior dorsal vertebra (Fig. 2, p. 73, of 

 Cope's article), characterized like the cervicals, by the absence of the median 

 spine, was correctly determined by Cope. In this vertebra the hyposphen is 

 less accented than in the vertebra figured upon the following page (Fig. 5, p. 

 75), in which the hyposphen is sharply defined, and there is also a median dorsal 

 spine. (5) The fifth notice was by Marsh,' in which the name Atlantosaurus 



Fig. 7. Sacra of Cetiosauria. 



A, Apatosaurus ajax. Three coalesced sacrals. After Marsh, 1807, Plate xvii. 



B, Atlantosaurus nionta7ius. Three coalesced sacrals and portion of a fourth. After 

 Marsh, 1897, Plate xvii. 



C, Brontosaurus excelstts. Five coalesced sacrals. After Marsh, 1897, Plate x.xiii. All 

 figures approximately nV natural size. 



was proposed to replace Titanosaiirits. (6) In the same paper the new genus 

 Apatosauriis ajax, was distinguished by the opisthocoelous cervicals with hollow 

 centra ; anterior dorsals with similar characters ; posterior lumbars with flat 

 articular faces ; sacral vertebra; more solid ; anterior caudals biconcave ; chev- 

 rons not united above. (7) In the same paper the species A. grandis is 

 described with the following measurements : 



Length of femur 1050 mm. 



Transverse diameter of proximal end 340 mm. 



(8) The eighth notice by Cope was based upon characters of the posterior dorsal 

 vertebrae. The vertebra (Fig. 13, p. 80) with a very prominent dorsal spine, re- 



• Notice of new Dinosaurian Reptiles from the Jurassic Formation. Am. Jour. Sc, 

 Dec, 1877, P- 5I4' 



