Observations on the Aurora Borealis. 343 



piece of mechanism. The creature lives in the sand; in 

 which it burrows by means, principally, of its strong pro- 

 boscis, which, used as a wimble, opens up the way, the body 

 being held steady with the aid of the setigerous feet. It thus 

 buries itself witli almost incredible velocity : nor is it less 

 active in the water, should it accidentally be removed from its 

 furrow, and cast in the open sea ; swimming rapidly, with a 

 serpentine wriggling motion, and propelled, unquestionably, 

 by the lamellae which project from each side, like a double 

 bank of oars. 



From Nephtys HombergzY our species differs very much, in 

 the construction and form of the processes of the feet ; while, 

 in the shape and colour of the body, they seem very nearly to 

 agree. (Ann. des Sc. Nat., xxviii. p. 257. pi. 17. fig. 1 — 6.) 

 No other species has been yet accurately defined ; but ours 

 may be conjectured to be the Nereis clava of Leach : relative 

 to which, however, I have no means of deciding; and Blain- 

 ville has, it appears, introduced such an almost inextricable 

 confusion into the nomenclature of that species, that it might 

 be scarcely advisable to restore the name, should it prove 

 identical with the one now illustrated. 



Art. VI. Notices of 184 Observations on Aurora Borealis, made 

 during a Period of Thirteen Years, with the State of the Weather 

 immediately subsequent ; being contributive to the further Eluci- 

 dation of their Effects on the Atmosphere. By W. H. White, 

 Esq. 



The corroborative testimonies of my remarks on auroras 

 (p. 99.), by Mr. Conway and Mr. Gardener (p. 92— 97.), have 

 induced me to condense my observations during a period of 

 thirteen years, not only to show upon what grounds I made 

 the remarks just alluded to, but, if possible, to ascertain how 

 far the effects of aurora? may be depended upon, from the 

 intensity of their luminous manifestations, and whether any 

 material advantage to mariners can be pointed out. 



As I always carefully register, not only the commencement 

 of changeable weather, and other atmospheric phenomena 

 that come within the reach of my observation, but also the 

 variations, duration, &c, of whatever changes may occur ; so 

 I have given, as under, the average times, duration, &c, of the 

 several changes ; carefully classing the various auroras accord- 

 ing to the intensity of their luminous manifestations, dura- 

 tions, changes, &c. The result is as follows : — 



A a 4 



