CLASSIFICATION OF THE BRACHIOPODA. 



75 



forked cardinal process in De Blainville's ' Conchyliologie et Malacologie ;' but it is to 

 Professor King and M. Suess that science is indebted for the knowledge we now possess of 

 the calcified supports of the labial appendages. The first-named author published a restored 

 figure of a loop, which he describes as a single piece, having a tolerably close agreement 

 with that of certain Terehratulae, but M. Suess subsequently discovered that Professor 

 King's drawing, although correct, was incomplete, since a number of lamellae, sometimes 

 single, at other times bifurcated, branched off from the inner edge of the loop, as repre- 

 sented in the annexed woodcuts ■} and it still remains to be known with certainty whether 



Fig. 26. 



Fig. 27. 



Unrestored Figure. 



Profile {partly restored). 



3, Cardinal process ; l, loop; ds. dorsal septum; 

 vs, ventral septum. 



' Sketches of the diagrams here introduced were kindly forwarded by my Viennese friend, and are the 

 result of his continued researches on the genus : — 



Fig. (26) is an unrestored representation by M. Suess, of his best example, and exhibits the exact 

 extent of our knowledge on the shape and character of the internal skeleton or loop. 



Fig. (27) is a restored profile of both valves. M. Suess accompanies this diagram with a few observa- 

 tions which I have much pleasure in reproducing. " The profile view which has been added, although, 

 perhaps incomplete, is correct, and contains all I know on the subject. The great lateral expansions of 

 the loop (which may not exactly be termed crural plates, since the crura are fixed beneath them), have been 

 omitted, because they would cover the upper part of the loop, the rim following exactly the contour of the 

 shell, so that the cirri might surround the whole circumference of the shell, with the single exception of 

 the cardinal region. A comparison of the loop and its branches with the corresponding process of 

 the one-lobed Argiope (bearing one septum), has shown me much analogy between those forms : the flat, 

 broad, widely developed loop is hardly recurved in front, the deflected portion so considerable in most 

 Terebratidce is barely indicated in Stringoeephalus by a straightened frontal piece, similar to that in 



