FOURTH FIELD MEETING. 17 
shells, &c., caught a crab in the very act of putting off his coat. 
It is well known that all animals of the class to which the crab 
belongs, cast their shells once a-year, but there are few instances 
recorded of the operation having been actually seen taking place. 
The parties who saw the process, describe it as being very like 
what a person does when he is wriggling himself out of a coat 
that is a little too tight for him. Most of the party proceeded 
northward to Marsden, examining as they progressed, the pecu- 
liar geological features of the magnesian limestone, here worn 
into picturesque arches, lofty pillars, or by the never-ceasing 
action of the ocean, worn into deep and extensive caverns, there 
cut into towering cliffs, or sometimes crumbling away before 
the power of the waves, forming heaps of larger or smaller blocks 
at the base of the main mass of which they once formed a por- 
tion. After the party had explored this interesting locality as 
long as their time allowed, they turned their course southward 
and dined at the Roker Baths Hotel. After dinner, the follow- 
ing papers were read :— 
“On some of the habits of the horse leech, Hamopsis sangui- 
suga, with notices of some rare insects,” by Mr. Hardy. 
“ Notice of the occurrence of Limnoria terebrans, at the mouth 
of the Tyne,” by Mr. Albany Hancock. 
Mr. Hardy also exhibited some very remarkable viviparous 
heads of the common cocksfoot grass, Dactylis glomerata. . 
THE PRESIDENT’S NOTES ON THE FOURTH FIELD MEETING. 
The flight of the locust, which we saw and marked down, and 
again sprung as if it had been a lark, was strong, quick, and well 
sustained. The insect evidently had the power of proceeding a 
long way without any fresh impulse from the ground, and could 
turn in any direction. It was scarcely smaller as seen flying than 
the larger dragon flies. 
The day was cloudless, and the air delightful; an extraor- 
dinary host of that brilliant insect the scarlet admiral butterfly, 
Vanessa atalanta, were on the wing. ‘They were flying past us 
or resting on the autumnal flowers, which are peculiarly fragrant 
VOL. I. D 
