J10R0SAURID.E. 



181 



2IOBOSA UBIDJE. 



MOKOSATJRTJS. 



The genus Morosaurus, the type of the family, was described by the 

 writer in 1878, in the American Journal of Science, which contains 

 most of the original descriptions of Sauropoda found in this country. 



THE SKULL. 



The head in this genus was very small. The posterior part of the skull 

 resembled that in Diplodocus, but the front was much more massive. 

 The lower jaw was especially powerful, as shown by the dentary bone 

 figured in PI. XXX, fig. 3. This figure also shows the size and posi- 

 tion of the teeth, one of which is figured in PI. XXXI, figs. 1 and 2. 



31 



32 



YiG. 31 — Anterior dorsal vertebra of Morosaurus grandis; front view. 



Fig. 32. — The same vertebra; side view. 



Tig. 33. — Traosverse section through centrum of same. 



All the figures are one-eighth, natural size. 6, ball ; c, cup ; rf, diapopbysis j /, cavity in centrum ; 

 m metapophysis ; n, neural canal ; ns, neural suture ; z, nnteiior zygapophysis ; z\ posterior zyga- 

 popbysis. 



The brain was very small. Its form and position in the skull are 

 shown in fig. 2 of PI.. XXX. At the back of the skull there are two 

 peculiar bones, called by the writer the postoccipital bones, which are 

 shown in PI. XXX, fig. 1. 



THE VEKTEBR/E. 



The neck was elongated, and except the atlas all the cervical verte- 

 br;e have deep cavities in the sides of the centra, similar to those in 

 birds of flight. They are also strongly opisthocodous. The atlas and 



