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MISCELLANEOUS. 
On the Morphology and Affinities of the Brachiopoda. 
By H. Lacaze-Duruiers. 
Tew animals are so widely diffused in the strata of the surface of 
the globe as the Brachiopoda, and few consequently are so frequently 
in the hands of naturalists; nevertheless, although they are repre- 
sented by many species living in our seas, their zoological relations 
and their general plan of organization are by no means agreed upon. 
Placed in the first instance among the Acephala, side by side with 
the Lamellibranchiata, they now justly form a distinct division; but 
the relationships of this division are far from being the same in the 
eyes of all zoologists. Thus, to dwell only upon the last opinion, 
Messrs. Huxley and Hancock, two of the most eminent English 
naturalists, would place them among the Molluscoida, by the side of 
the Ascidia and Bryozoa or Polyzoa. 
This new mode of appreciating the affinities of this group led me 
to desire to study these creatures afresh ; and when the opportunity 
was afforded me of investigating the faunas of great depths im the 
Meditterranean, I hastened to resume observations commenced about 
1858 in the sea off Corsica. 
To determine the affinities of the Brachiopoda I seek in their 
nervous system for the criterion that must guide me. It is to the 
characteristic organ of animality that I apply myself, because, as has 
been so admirably shown by Cuvier, it furnishes the characters of 
highest value; and I .compare it on the one hand to that of the 
Lamellibranchiata, and on the other to that of the Bryozoa. 
In the Lamellibranchiate Acephalan the plan of organization is 
simple. The organs are repeated symmetrically on each side of the 
median line. Thus we find three double nervous centres—one near 
the mouth, another in the foot, the third between the base of the 
foot and the anus, near the branchize. Moreover certain organs 
have an existence, a peculiar symmetry, and very precise relations 
with these different centres. 
Upon the median line are the mouth, the foot, and the anus. At 
the base of the foot, between it and the anus, on each side, beyond 
the ganglia of the third or pallio-branchial group, open the two 
glandular bodies called the glands of Bojanus; lastly, to the right 
and left of the mouth there are two pairs of labial vela, which vary 
greatly in form in the different species. 
To compare this well-known plan, which it was necessary to refer 
to here, with that of the Brachiopods, we must first of all place the 
animals in a comparable position. Suppose, for example, that we 
have a Terebratula and an Anodonta to compare: the former must 
be placed with its ligament downwards, its apophysary valve to the 
left of the observer, and its perforated valve to his right; the second 
must have its hinge to the left and its mouth upwards. Most 
figures show the Brachiopoda in a position the reverse of that just 
indicated, which renders their comparison with the Acephala more 
difficult, 
