IV 



EXPLANATION OF THE 1'LATES. 



Fig. G. Two distal cervical?, with (?) parapophysis preserved ; a, from below ; b, the articular extremity, the (?) 

 parapophysis of the left side broken. 



Fig. 7. The connate atlas and axis. 



Fig. 8. The extremity of the muzzle, from above ; 8«, do. from the side, displaying the broken teeth ; 8b, the 

 symphysis, from below. 



Fig. 9. The alveolus and fang of a mandibular tooth. 



Fig. 10. Sacro-caudal vertebra of Elasmosaurus oriental!*, Cope, from near Swcdesboro, Gloucester Co., N. J., 

 inferior view ; 10a, from the side. Both one-third natural size. 



PLATE III. 



Four anterior dorsal vertebra; of Elasmosaurus plalyurus, Cope, of one-half the natural size, belonging to tho 

 individual figured on Plate II. Been from the right side. 



PLATE IV. 



Figs. l~'J. llolops obseurus, from Burlington Co, N. J., one individual. 



Fig. 1. Cervical, dorsal and isolated lumbar vertebra) a littlo more than three-fifths natural size. 



Fig. 2. Femur of same, one-half natural size. 



Fig. 3. Humerus of same, one-half natural size. 



Fig. 4. Vertebral column of a young llolops brenispinis, Cope, from Burlington Co., N. J., one-half natural size, 

 seen from below. 



Fig. 5. Anterior dorsal vertebra of adult llolops brevispinis, Cope, one-half natural size, from the side ; fig. 

 5a, same from the front. 



Fig. 0. Humerus of the same, one-half natural size. 



Fig. 7. Posterior-median dorsal of Holops caudatus, Cope, from Barnesboro, one-half natural size. 



Fig. 8-9. Vertebra) of llolops basitruncatus, Ow., one-half natural size (marked erroneously on the plato 

 Bottosauru* harlani). 



Fig. 8. Cervical vertebra of tho same, from below ; fig. 9, lumbar of tho same, anterior ; and 9a, inferior views. 



Fig. 10. Femur of llyposaurus rogersii, Ow., from the inside ; one-half natural size. 



Fig. 11. Humerus of the same individual as fig. 10. Both from Barnesboro, N. J., and in the cabinet of tho 

 State Geological survey at Kutger's College. 



PLATE V. 



Fig. 1. Anterior dorsal vertebra of Palmophis HUoralis, Cope, from the right side ; la, from the front ; 15, from 

 below. From specimens belonging to the Geological survey of N. Jersey. 



Fig. 2. Palmophis halidanus, Cope, anterior dorsal vertebra, from below : 2a, same from tho front ; both this 

 species and tho last, of natural size. The latter in Prof. Marsh's collection, Yalo College. 



Fig. 3. Dorsal vertebra of Glidasles iguanavui, one-half natural size, from the side ; tho neural spine is broken 

 away ; 3a, anterior view ; 3b, view from above ; 8c, from below. This vertebra is in Prof. Marsh's collection at Yalo 

 College, Conn. 



Fig. 4. Posterior lumbar vertebra, from Barnesboro, supposed by me formerly to belong to Mosasaurus depress-iis. 

 It is not probably that species, but more likely Liodon validus, but of this I cannot assure myself. 4a, from tho side ; 

 4b, from below. One-half natural size. 



