Dr. Storer exhibited a Fish, of the genus Alotella, to 

 which he had given the name caudacuta. He remarked, 



"This genus has been unknown to ihe waters of North Amer- 

 ica until 1 received the specimen which I now exhibit. Two 

 specimens were cast upon the beach at Long Point, Province- 

 town, in November kist. Capt. Atwood brought me one of them, 

 which I determined a new species, and have called caudacuta. 

 In some respects it agrees with F3iYne\Vs M. cimh^ia, or foiir- 

 hearded RockliJig, but differs in several important particulars. 

 The form of the tail furnishes the specific name." 



Mr. Ay res presented specimens of two species of Fish 

 Aphrododerus Sayaniis, which Dr. Dekay says he has 

 never seen, although this specimen was taken within a short 

 distance of Dr. D.'s house ; and Leucisciis nasutus, from 

 Hampden county, Mass. The individual presented was 

 the one from which iMr. Ayres constituted the species. 



Dr. Gould made some remarks upon the importance of 

 depositing in public cabinets, whenever they could be pro- 

 cured, the identical specimens from which species had been 

 described, and also of authentic specimens labelled by de- 

 scribers themselves, and of so designating them that the fact 

 should appear. He hoped the practice would prevail among 

 naturalists. 



Mr. J. D. Whitney exhibited and described Jacksonite, a 

 new mineral from the Lake Superior region. 



The analysis of the ignited mineral gave 



99.91 



The oxygen of the silica, alumina and lime being as 3 : IJ- : 1^ 

 or 6 : 3 : 2, the formula will be 



Ca^ Si + Al Si 

 This, it will be perceived, is the formula which is given by 



