235 



tin, an alloy of iron and nickel, phosphoric acid, and a trace of 

 chlorine. 



These ingredients being determined, the plan for a quantitative 

 analysis was laid out, and was duly executed by the usual and ap- 

 proved methods. The following are the results of this analysis, per 

 centum : 



Silica, with traces of tin 40.000 



Magnesia 26.600 



Per-oxide of ii-on 27.700 



Metalhc iron 3.500 



Metallic nickel 0.800 



Alumina 0.400 



Chlorine 0.049 



Phosphoric acid not weighed. 



"99^ 



Being unwilling to destroy more of this very valuable specimen, I 

 did not quantitatively determine the phosphoric acid, the presence of 

 which was distinctly shown by the molybdate of ammonia test. 



Specimens of the meteoric stones which were seen to fall in Noble- 

 boro', Maine, and in Weston, Connecticut, were exhibited, and com- 

 pared with the Dhurmsalla stone, which they closely resemble. In- 

 deed, the Weston meteorite can hardly be distinguished from them. 



A mass of meteoric iron from Clayborn Co., Alabama, in which Dr. 

 Jackson first discovered chlorine, was also shown. 



On motion of Dr. Jackson, the thanks of the Society were 

 voted to his Excellency the Governor General of India, for 

 this valuable specimen ; it was also voted that a copy of Dr. 

 Jackson's report be sent to him. 



Ox THE Homologies of Echixoderms. By L. Agassiz. 

 Since the pubUcation of the memoirs of Gray, and of Mliller and 

 Troschel, hardly anything has been done with reference to Starfishes. 

 The simultaneous appearance of the results of their researches has 

 spread through our nomenclature the names of many genera under sev- 

 eral names, and a revision of the whole order is greatly needed. The 

 many Starfishes in the collections of the Museum of Comparative 

 Zoology, at Cambridge, have enabled me to reexamine the whole 

 subject, and I propose, in a series of communications to this Society, 

 to present the results at which I have arrived. Neither Gray nor 

 Miiller and Troschel have adopted a terminology founded upon 

 homoloo-y, and their nomenclature has so little relation to that used 

 in describino- the other members of the class, as, for instance, Echini 



