128 Field Columbian Museum — Geology, Vol. II. 



the lower border of the anterior cup; parapophyses [i. e., exapophyses] are 

 less produced. The lower surface of the centrum is flattened and quad- 

 rate in form. The parapophysis, diapophysis and rudimental rib coalesce 

 around the vertebrarterial canal; an oblique ridge is continued from the 

 anterior zygapophysis downward and outward upcn the pleurapophvsis 

 and behind the zygapophysis. Above these developments the neural arch 

 contracts from before backward to an extent of five lines, compared with 

 a total vertebral breadth anteriorly of one inch, eight lines; it then rapidly 

 expands, rising vertically at its fore part, and developing at its back 

 part the posterior zygapophysis, the articular facets of which look more 

 directly outward than in the long cervical vertebrae; the superincumbent 

 tubercle is more distinct from the facet; the posterior zygapophyses are 

 also much more approximated than in those vertebrae." 



It would seem evident from this description, which applies in the main 

 to the corresponding vertebra of the Kansas forms, that the eighth post- 

 cranial vertebra is really a cervical. Certainly we can hardly put a 

 vertebra with rudimentary ribs at the beginning of the dorsal series! 

 Owen afterwards ascribed eight vertebrae to the neck, or seven, counting 

 the united axis and atlas as one. Quenstedt, also, in 1855, gave the num- 

 ber as eight. O. Fraas (Paleontographica, 1878, p. 166) found eight 

 vertebrae in the neck of Pterodactylus suevicus, but mistook the third for 

 the axis, thus counting only seven. 



In my earliest paper* on Nyctosaurus I said: "The centra of twelve 

 vertebrae are preserved from the region back of the neck. Three of these 

 are evidently anterior thoracic, judging from their structure and the posi- 

 tion in which they lie. The shortest of them, to which was attached a 

 very large rib, and which was lying in front of the scapula, may represent 

 the first thoracic vertebra." This specimen I have figured in PI. XLIII, 

 Fig. 7, of the present paper. The specimen is fortunately preserved with 

 little or no distortion, though a part of the spine is wanting. As seen 

 from the front (the view figured), the transverse, shallowly concave cup is 

 straight or gently concave on its upper margin, and convex below. Aris- 

 ing from the front end of the centrum there is, on each side, a very stout 

 parapophysis, with which the head of the rib referred to was in apposi- 

 tion. On the anterior side of this process, and continuous, or nearly so, 

 with the outer side of the cup, there is an oval, convex articular surface 

 for union with the exapophysis. Above this process, separated by a 

 notch, there is a long, flattened diapophysis, for articulation with the 

 well-developed tubercle of the rib. The anterior zygapophyses are much 

 more approximated than in the long cervical verterbrae. Their articular 



* Kansas University Quarterly, vol. i, p. o. 



