NORTH AMERICAN PLESIOSAURS 



731 



below, separating this anterior projection, which goes forward to 

 meet the premaxilla, from the true parietal. 



The supraoccipitals are shaped nearly as T. oshorni, though they 

 may meet for a short distance above. 



Twenty-three cervicals in a continuous series are present, their 

 processes for the most part lost. As this is the first absolutely positive 



Fig. 12. — T. anonymum. A, left humerus; B, left femur, No. 11 29 Yale Museum. 



determination of the number of cervical vertebrae in this genus, I 

 give careful outline figures of the series (fig. 11). The centrum of 

 the third vertebra measures 23™"^ in length, 32 in height, and 40 in 

 width. The tenth vertebra has for its corresponding measurements 

 32, 34, 42; the twentieth, 32, 40, 58. The zygapophyses are heavy 

 and large, placed nearly at right angles with each other, and are 

 nearly plane. The twenty-fourth has the diapophyses wholly on the 



