nCHINdliERMATA. 
62 ^ 
of the Eimbulacral system had just made their appearaiide. Thd 
larv0e of these starfishes are sufficiently distinct in aspect, so 
that the author is confident he has avoided such erroVs aS might 
have accrued from confusion of species ; moreover the spawn- 
ing-season of A. berylinus is very short, and takes place at least 
three w^eeks later than that of A. pallidus. 
The larva'of A. pallidus a well-marked Brachiolaria, having, 
in addition to the ordinary vibratile fringes and bands with their 
long tentaculiform processes, three small heavy appendages, 
surmounted by short warts. These brachiolar appendages are 
supplied with tubular extensions from the ambulacral system. 
Of tlie two rudiments of this system which appear while as yet 
the larva is destitute of appendages, one, invariably the left, gives 
rise to a prolongation opening externally as the water-pore. At 
a later period the two rudiments extend to the extremity 
of the digestive cavity, and towards one another, beyond the 
mouth, where they unite, forming a Y-shaped tube.^^ " On these 
water-tubes is developed the starfish — one of the water-tubes 
(the one with the water-pore) developing the actinal [oral] side 
and the tentacles, the other developing the spines and the ab- 
actinal area. These opposite parts of the starfish sire open pen- 
tagonal spiral surfaces, not in the same plane, but making nearly 
a right angle with one another. The water- pore becomes the 
madreporic body. The open pentagons do not close till after the 
starfish has absorbed the whole of the larva. The complicated 
system of arms and the whole of the Brachiolaria is absorbed 
by the starfish, which is not separated from the larval stock, as 
seems to be the case in Bipinnaria according to Muller’s state- 
ments.” 
The arms of the star-fish are broad and short in the young. 
The suckers are pointed, and arranged only in two rows* The 
disk is developed only later. The odd terminal tentacle has an 
eye at its base, and never developes a disk. The abactinal surface 
is very arched. The spines are arranged in regular rows, and 
the plates remind us of the arrangement of plates of Crinoids. 
The anus opens near the edge of the disk on the lower side. The 
madreporic body also is situated on the edge.” 
The above account is intended to appear in full, with many 
plates, in the fifth volume of the Contributions to the Natural 
History of the United States,’ of Prof. Agassiz.” 
Sars has met with a new Brachiolaria^ the similarity of which 
to Bipinnaria^ both in structure and mode of development, is 
particularly striking. At the same time he points out the dis- 
tinctions between the two forms, his statements on this subject 
essentially according with those of A. Agassiz. 
Sars has also observed that the characteristic appendages of 
Brachiolaria act as organs of attachment. He compares thenj 
