8 ST. PAUL’S ROCKS. (cuar. 1. 
this cuttle-fish, which, though concealed in a hole, thus often led 
me to its discovery. That it possesses the power of ejecting 
water there is no doubt, and it appeared to me that it could cer- 
tainly take good aim by directing the tube or siphon on the under 
side of its body. From the difficulty which these animals have 
in carrying their heads, they cannot crawl with ease when placed 
on the ground. I observed that one which I kept in the cabin 
was slightly phosphorescent in the dark. 
Sr. Paux’s Rocxs.—In crossing the Atlantic we hove-to, 
during the morning of February 16th, close to the island of St. 
‘Paul’s. This cluster of rocks is situated in 0° 58’ north latitude, 
and 29° 15! west longitude. It is 540 miles distant from the 
coast of America, and 350 from the island of Fernando Noronha. 
The highest point is only fifty feet above the level of the sea, and 
the entire circumference is under three-quarters of a mile. This 
small point rises abruptly out of the depths of the ocean. Its 
mineralogical constitution is not simple; in some parts the rock 
is of a cherty, in others of a felspathic nature, including thin 
veins of serpentine. It is a remarkable fact, that all the many 
small islands, lying far from any continent, in the Pacific, Indian, 
and Atlantic Oceans, with the exception of the Seychelles and 
this little point of rock, are, I believe, composed either of coral 
or of erupted matter. The volcanic nature of these oceanic 
islands is evidently an extension of that law, and the effect of 
those same causes, whether chemical or mechanical, from which 
it results that a vast majority of the volcanoes now in action 
stand either near sea-coasts or as islands in the midst of the sea. 
The rocks of St. Paul appear from a distance of a brilliantly 
white colour. This is partly owing to the dung of a vast multi- 
tude of seafowl, and partly to a coating of a hard glossy sub- 
stance with a pearly lustre, which is intimately united to the sur- 
face of the rocks. This, when examined with a lens, is found to 
consist of numerous exceedingly thin layers, its total thickness 
being about the tenth of an inch. It contains much animal 
_matter, and its origin, no doubt, is due to the action of the rain 
or spray on the birds’ dung. Below some small masses of guano 
at Ascension, and on the Abrolhos Islets, I found certain stalac- 
titic branching bodies, formed apparently in the same manner as 
