REVIEWS, 
21 
the prehensile antennas are freed from their cases ; the two eyes stand further apart; 
the three posterior pairs of legs have been developed, nnd a small abdomen has be¬ 
come distinctly separated from the thorax. When the due time for the act of 
the metamorphosis has arrived, the pupal carapace splits along the dorsal edge and 
is cast off, together with the acoustic sacks, the basil segments of the two antennas, 
and the great, black, compound eyes, hanging to the UU-like apodemes. The ex- 
uvias usually continue for a time united to the cemented antenna, but are finally 
washed away.” 
We need hardly say that the above extracts are only a tithe of the 
account given by the author, which extends over many pages, and that 
in several species slight modifications occur. We have a long account of 
the structure of the shell and of the anatomy of the various parts of the 
body of the Cirripede. In speaking of their nervous system, we have 
some interesting remarks on them sensitiveness, which we subjoin— 
“ I found the following three species—viz., Balanus balanoides , B. crenatus , 
and Chthamalus stellatus —very sensitive to shadows—that is, to an object like my 
hand, passing even quickly, and at the distance of about a foot between them and 
the source of light. They were indifferent to a gradual change from bright to ob¬ 
scure light; but instantly perceived and drew in their cirri, when my hand was 
passed between the basin in which they were kept and the window, even when this 
was tried rather late on a dusky evening, and, likewise, when my hand was passed 
between them and a single candle. I took, of course, the precaution of passing my 
hand in other directions, but this never produced any effect. These species are 
moderately sensible to any vibration in the vessel in which they were kept, but they 
were indifferent to noises made in the air, or in the water. I found it impossible 
to touch, under water, an individual shell ever so lightly with a needle without all 
the immediately surrounding individuals, when several adhered together, perceiving 
it and retracting their cirri; it made no difference whether the one touched had 
withdrawn its cirri and was motionless. From this fact, and from seeing that a simi¬ 
lar, but slighter effect was produced by touching the rock on which the specimens 
adhered, I infer that the perception by the others of the one being touched, is com¬ 
municated by vibration. When an individual was touched under water, not by a 
needle but by a pointed camel-hair brush, it generally withdrew its cirri; but the 
neighbouring specimens took no notice ; when touched by a single hair of the brush 
no notice was taken, unless the skin of the orifice leading into the sack was so 
touched.” 
With respect to the geographical range of this sub-class, the results 
arrived at have no very peculiar interest, owing to the species not being 
sufficiently distinct, and, what is still more adverse, the genera, with unim¬ 
portant exceptions, range over the world. Sessile Cirripedes are found in 
every sea, from lat. 74° 18' north, to Cape Horn. Mr. Darwin divides 
the globe into four provinces and one sub-province. First, the North 
Atlantic Province, to lat. 30° north, contains 31 species, of which 22 are 
confined to the province; if the West Indies be included, the numbers 
will be 42 and 28. Second, sub-province of South Africa, total number 
of species, 11 ; peculiar to the province, 5. Third, second province, west 
coast of North and South America, total number of species, 22; peculiar, 
15. Fourth, third province, East Indian Archipelago, total number, 37 ; 
peculiar, 24. Fifth, fourth province, Australia, total number, 30; 
