1890.] XEW YORK ACADEMY OF SCIENCES. 133 



fences of the paired fins. Among the fish-remains sent to me 

 for examination by Mr. Gurley, are several spines which have 

 much the character of those described by Mr. St. John under 

 the name of Physonemus altonensis, but which, as I have else- 

 where shown, are certainly pectoral spines, since I have speci- 

 mens in which the pectoral fin is still inserted in the posterior 

 cleft. With these spines (which do not belong to the genus 

 Physonemus, since they are not and never were tubercled) I 

 have others, shorter, broader, and more robust, having the same 

 anatomical characters and being, like the first, unsymmetrical, 

 that is, having one of the edges which border the posterior cleft 

 much broader than the other. These I have supposed to be the 

 spines of the ventral fins. Also in the collection of Mr. Gurley 

 is a short, broad spine with the surface markings of Or acanthus, 

 and having, what is rarely found, the posterior margins entire. 

 These are of unequal breadth, and, as in the pectoral spines of 

 Stethacanthus altonensis, the posterior opening reaches nearly 

 to the summit. I can come to no other conclusion than that 

 this spine is the defence of either the pectoral or ventral fin of 

 Oracanthus. 



March 17, 1890. 



Stated Meeting. 



The President, Dr. Newberry, in the chair. 



About one hundred and fifty persons present. 



The minutes of March 10th were read and approved. 



Mr. John Tatlock was nominated as Resident Member. 



The sixth lecture of the Public Course was then delivered, 

 entitled 



NEBULJi AND THE NEBULAR HYPOTHESIS. 

 BY PROF. CHARLES F, YOUNG, OF PRINCETON, N. J. 



The lecture was fully illustrated by interesting lantern slides. 

 At the conclusion of the lecture a vote of thanks was unanimously 

 given to Prof. Young for his entertaining and instructive lec- 

 ture. 



