Mebriam.J 



Triassic IcMhyopterygia . 



95 



Upper arch of cervical vertebra 



Height 60 



Width half way between summit and posterior 



zygapophyses 17 



Thickness half way between summit and posterior 



zygapophyses 15 



Upper arch of anterior dorsal 



Height 06 



Width half way between summit and posterior 



zygapophyses 25 



Thickness half way between summit and posterior 



zygapophyses 13 



Length of posterior zygapophysis 18.5 



Width of anterior zygapophysis 10 



Upper arch of middle dorsal 



Height 65 



Width half way between summit and posterior 



zygapophyses 32 



Thickness half way between summit and posterior 



zygapophyses 15 



Length of posterior zygapophysis 18.5 



Width of anterior zygapophysis 7 



The dorsal ribs of this species show the characteristic back- 

 ward twist of the rib-head and the flattening of the superior 

 surface of the shaft (PI. 9, tip;. 6) . The grooving of the shaft is 

 stronger on the posterior side. The rib-head is slightly bent so 

 that the posterior side is somewhat concave, also the upper part 

 of the proximal surface turns outward. Both of these characters 

 are much less pronounced than in alUspinus. 



The anterior arch (PI. 10) is characterized by extreme thick- 

 ness and relative naiTOwness of the coracoids (figs. 2 and 3). 

 The scapula (figs. 4 and 5) is relatively heavier than that 

 of alexandrce. The distal end of a clavicle present shows no 

 distinguishing characters. 



Following are the principal measurements compared with 

 those of alexandne : 



Coracoid 



Length 160 170 



Greatest width al70 205 



Width of proximal end allO 144 



Thickness of distal end 71 65 



Greatest thickness of proximal end 60 62 



Scapula 



Length 120 150 



Greatest thickness of proximal end 52 52 



a Approximate. 



