106 . DINOCEKATA. 



In the right kinar of Dinoceras mirahUe (number 1230), the distal face 

 for articulation with the scaphoid makes less than a right angle with the 

 face for the magnum, instead of an obtuse angle, as in most other 

 specimens. 



The lunar bone in Tinoceras presents no articular face for the 

 trapezoid, and is much produced posteriorly, thus distinguishing it from 

 the lunar in the genus Linocenis. Its main features are shown in the 

 woodcuts, 115 and 116, above. 



The more important measurements of the lunar bone in four 

 individuals of the IJinocerata are as follows : 



Measurements of Right Lunar. {Dinocerus mirabile, No. 1230.) 



m. 



Length of longitudinal axis of lunar, .050 



Antero-posterior diameter of proximal end, .n.5 9 



Transverse diameter of proximal end, .056 



Antero-posterior diameter of distal end, .... . .075 



Transverse diameter of distal end, .... ... .046 



Measurements of Left Lunar. {Tinoceras inr/ens, No. 1503.) 



m. 



Length of longitudinal axis of lunar, . __ .051 



Antero-posterior diameter of proximal end, .061 



Transverse diameter of proximal end, __ .053 



Antero-posterior diameter of distal end, _. 083 



Transverse diameter of distal end, .047 



In this sj^ecimen, the distal face for the fecaphoid is quite large, and 

 encroaches on the face for the magnum. 



Measurements of Rigid Lunar. [Tinoceras ingens^'Ko. 1504.) 



m. 



Length of longitudinal axis of lunar, .054 



Antero-posterior diameter of proximal end, .062 



Transverse diameter of proximal end, .. .065 



A'ltero-posterior diameter of distal end, 088 



Transverse diameter of distal end, .050 



Mei/sureme?its of I^ift Lunar. [Tinoceras ingens. No. 1246.) 



rn. 

 Length of longitudinal axis of lunar, . _ .061 



Antero-posterior diameter of proximal end, _ .ooii 



Transverse diameter of proximal end, ,. . .o60 



Antero-posterior diameter of distal end, _ .092 



Transverse diameter of distal end, ■ .. .05:! 



