XXVIU 



INTRODUCTION. 



the points directed inwards, so that food can readily pass 

 into, but cannot return again from, the stomach. The 

 teeth on each side appear to correspond, so that they 

 probably play an important point in tearing and lacerating 

 the food as it passes into the stomach. Posterior to this 



Fig. 4. 



triturating apparatus there exists four leaf-like plates, 

 fringed with long and powerful cilia. These are attached 

 to the lateral walls in pairs, one anterior to the other; 

 immediately above the second or posterior pair, appa- 

 rently in a chamber of its own, is a gizzard-like apparatus. 

 We observed this most distinctly developed in Sulcator 

 and Talitrus, and we believe it to be present in all the 

 Amphipoda, and we take it to be the same appendage 

 which Bruzelius and Loven figure and describe as the 

 '^ mellanbalkan," which is situated within the "blind- 

 sacklikt organ/^ and not, as their figures * would lead one 

 to believe, on the floor of the stomach. 



• Ofversigt af K. Vetensk. Akad. Forhandl. 1859, pi. i., figs. 1, 3, 8. 



