574 Aurora Borealis of Oct. 5. 1836. 



in the latter these muscular cords are united into a single 

 bundle, which has only one point of attachment. In Mytilus 

 the branchiae adhere through their whole length ; in Dreissena 

 the extremities are free, and float upon the posterior trans- 

 verse muscle. The differences in the shells are obvious ; 

 other points of comparison will be found in the memoir. 



[In the third Report of the British Association for the Ad- 

 vancement of Science, Mr. Charles Wilcox, Curator of the 

 Museum of the Portsmouth and Portsea Literary and Philo- 

 sophical Society, states that when His Majesty's ship Welles- 

 ley was docked at Portsmouth, in July, 1824, he discovered on 

 the lead of the cutwater, and under the keel, a great number 

 of ik/ytili, which, on examination, proved to belong to the 

 species named crena- 

 tus. The Wellesley 

 was launched at Bom- 

 bay about February, 



1815, and came into 

 this harbour in May, 



1816, where she re- 

 mained for upwards of 



eight years previously ^^^^^^^^^^^^ 74 



to her being taken into 

 dock. The same spe- 

 cies of Mytilus has, however, within the last twelve months, 

 been found by Mr. Wilcox among groups of Mytilus edulis, 

 on the fore part of the keel of several ships, on being taken 

 into dock, which proves their naturalisation in a climate ap- 

 parently uncongenial to their nature."] 



Art. V. A Jetv Observations on the Aurora Borealis visible at 

 Kensington on the Evening of Oct. 5. 1836. By John Morris, 

 Esq. 



The phenomena of Aurora Borealis were visible in our 

 neighbourhood this evening. I observed its commencement 

 when passing over Wormholt Scrubbs about 7 o'clock ; at 

 which time an arch of dull light was visible, extending from 

 n.e. to n.w., above the fog-bank of the horizon, with a few 

 streamers passing from it, those on the east side larger and 

 more defined than the rest. At 5 minutes past 7 the upper part 

 of the easterly streamers had changed to red; at 10 minutes, 

 the whole of the streamers more red, especially to the n.w. ; 

 at the same time the easterly ones became less distinct; at 15 

 minutes, the northerly streamers becoming more dull, those 

 of the n.w. more red, and two or three dark streaky clouds 



