Mekkiam. I 



Triassic Ichthyopterygia . 



both coracoid and scapula. The whole form is most closely 

 approximated, although not exactly duplicated, in the pubis of 

 perrini, and inasmuch as the vertebrae with which they were 

 associated are quite distant from the region of the shoulder 

 girdle, they probably correspond to that element. 



Fig. 1. Fig. 2. 



Fig. 1. — Cross-section of proximal end of left (?) pubis. S. pacificus. 

 Fig. 2.— Cross -section of proximal end of right coracoid. S. alexandrw. 



The only other specimen showing vertebra? from this portion 

 of the dorsal region is the skeleton of perrini. From this it differs 

 very considerably in length of centrum and thickness of neural 

 spine. The centra are much shorter than in perrini , and some- 

 what longer than in all of the other known species. At the 

 present time we cannot determine definitely the relations of 

 pacificus to the better known species, and it is not impossible 

 that when other parts of the skeleton of those forms are known 

 it will be found that some one of them should be included in 

 pacificus. 



Measurements : 

 Vertebrae 



Height of first centrum in cross-section* 68 mm. 



Width 70 



Length of fourth centrum 36 



Height of second upper arch 67 



Width " " » 35 



Thickness of spine of sixth upper arch 14 



Pubis 



Greatest length 130 



Width of proximal end 95 



Thickness 46 



*The original measurement of height was made on an imperfectly exposed 

 vertebra and measured only to the neural groove. 



