The second or =axis= and following five cervical vertebrae, though showing distinct differences, resemble one another considerably, each having a fairly elongated centrum with a keel-like =hypapophysis=, each having also a neural arch with prominent articulating surfaces, the anterior of which, or =prezygapophyses=, look upwards and inwards, while the posterior ones, the =postzygapophyses=, look downwards and outwards. They however, as was previously mentioned, differ very remarkably in the character of the articulating surfaces of the centra. Thus the second and third vertebrae are convex in front and concave behind, the fourth is biconvex, the fifth is concave in front and convex behind. The sixth is concave in front and attached to the seventh by a flat surface behind, the seventh has a flat anterior face and two slightly convex facets behind. The vertebrae all have short blunt transverse processes and the second has a prominent =neural spine=. The =eighth cervical vertebra= is curiously modified, the centrum is very short, has a rather prominent hypapophysis, and is convex behind, while in front it articulates with the preceding centrum by two concave surfaces. The neural arch is deeply notched in front and bears two upwardly-directed prezygapophyses, while behind it is very massive and is drawn out far beyond the centrum, bearing a pair of flat postzygapophyses. The top of the neural arch almost or quite meets a blunt outgrowth from the nuchal plate. THE THORACIC VERTEBRAE. These are ten in number and are all firmly united with the ribs and elements forming the carapace. The first thoracic vertebra differs from the others, the centrum is short and has a concave anterior surface articulating with the centrum of the last cervical vertebra, and a pair of prezygapophyses borne on long outgrowths. The neural spine arises only from the anterior half of the centrum, and is not fused to the carapace. Arising laterally from the anterior part of the centrum are a small pair of ribs each of which is connected with a process arising from the rib of the succeeding vertebra. The next seven thoracic vertebrae are all very similar, each has a long cylindrical centrum, expanded at the ends, and firmly united to the preceding and succeeding vertebrae. The neural arches are flattened and expanded dorsally, and are united to one another and to the overlying neural plates; each arises only from the anterior half of its respective centrum, and overlaps the centrum of the vertebra in front of it. Between the base of the neural arch and its successor is a small foramen for the exit of the spinal nerve. There are no transverse processes or zygapophyses.