HOLLAND: THE OSTEOLOGY OF DIPLODOCUS MARSH 257 
agency of carnivorous animals or by the action of currents of water. That con- 
siderable shifting of this sort took place is shown by referring to the diagram of 
Quarry ““C” (Memoirs Carnegie Museum, Vol. I., Plate I.) where it will be seen 
that the ischia had been shifted forward and were found lying in a position anterior 
even to that of the sternal plates. 
The Supposed Clavicle.— In connection with specimen No. 84 (Carnegie Museum 
Catalogue of Vertebrate Fossils), there was found.a bone, which was described by 
Mr. Hatcher on p. 41 of his Memoir upon Diplodocus. He expressed himself as 
strongly inclined to the opinion that it was a clavicle. In the Memoirs of the Car- 
negie Museum, Volume II., p. 74, he described a second specimen of a similar bone 
found in connection with skeleton No. 662 and gave figures. Mr. Hatcher adhered 
to the opinion that this bone might very well have functioned as a clavicle, though 
he also suggests that the bone may be regarded as an os penis. At the time that the 
restoration of the skeleton of Diplodocus was being set up I had with me a repro- 
duction of the second specimen which belongs to skeleton No. 662, and Mr. Barlow, 
the skilful preparator in the Paleontological Laboratory of the British Museum, 
Fic. 25. Photograph of the two sternal plates and the supposed clavicles as provisionally and temporarily placed 
by the author in the pectoral region of the restored skeleton at the British Museum, May, 1905. The so-called clav- 
icles have since been taken down and laid aside. 
