844 The American Naturalist. [October, 
Railway levels from tide water at Vera Cruz to datum 
in Chalchicomula ` 8313.571 feet. 
Spirit levels from Chalchicomula to Station A. 4696.188 feet. 
Triangulation from Station A. 5302.267 feet. 
Elevation via Station A. 18,312.026 feet. 
Spirit levels from Chalchicomula to Station B. 4720.569 feet. 
Triangulation from Station B. 5282.146 feet. 
Elevation via Station B. 18316.687 feet. 
Mean elevation 18314.357 feet. 
It was a source of great satisfaction to Dr. Kaska and myself to 
find our results, obtained by different methods, so closely confirmatory 
aud not widely different from the results obtained by Prof. Heilprin 
and myself with aneroid barometers. From the above results it seems 
safe to consider Mount Orizaba or Citlaltepetl as being about 18,300 
feet high. 
Popocatepetl (Smoking Mountain) about 100 miles west of Citlalte- 
petl is thought by many to be higher than the Star Mountain ; but 
one who has ascended both peaks would certainly consider Citlaltepetl 
the higher elevation. Prof. Heilprin’s observations made Popocate- 
petl about 700 feet lower than the Star Mountain, and my barometer 
indicated about the same ‘difference, so that the honor of being the 
culminating point of North America clearly lies between the Star 
Mountain of Mexico and Mount St. Elias of Alaska.—J. T. SCOVELL, 
Terre Haute, Indiana. 
Seeley on the Sauropterygia.—In the Proceedings of the 
Royal Society of Great Britain, Vol. li, p. 119, Prof. H. G. Seeley, F. 
R. S., gives a synopsis of the characters of the genera and families of 
the Sauropterygia which are found in the beds of the Jurassic and 
Cretaceous systems. He points out the fundamental character of the- 
difference between the structure of the shoulder girdle in the Elasmo- 
sauride and Plesiosauridz first insisted on by Cope, and regards the 
differences between the paradiapophyses of those families as of family 
significance instead of generic, as held originally by Cope. The pre- 
vious paper of Prof. Seeley on the structure of the shoulder girdle of 
the European genera threw great light on the systematic of this order 
of reptiles, and the present paper increases that knowledge and 
establishes the taxonomy on a firm basis. He places the long necked 
and short necked genera in different families, a proceeding which may 
require revision, although of the generic value of such groups there 
