lO BAILEY : A MESSMATE OF LIMN^A STAGNALIS. 



anterior portion of the worm into the stomach posterior to the 

 constriction. At length tlie worm divided while still under 

 observation, and became t^\o worms, presenting the appearance 

 represented in Fig. i. Comparing the new worm with the 

 original, it was seen that the mouth of the former was yet 

 imperfect, time being required for the further development. 



FiGUKt 2. A group of tetaj from Chutogastey vcnnicnlaiis, enlarged. 



There were twelve clusters of bristles, or setae, arranged as 

 shown in Fig. i, on each worm ; and these setae were instruments 

 used as hooks for the purpose of hanging on to the body of the 

 mollusc. Being forked hooks (Fig. 2), they were well adapted 

 for this purpose. As I saw Chcetogastev, it was clinging to 

 Liinuira, and waving itself to and fro continually, as though 

 feeding or searching for food in the water. 



The contents of the stomach of one of these di\idcd speci- 

 mens furnish interesting data respecting the food of Cluelogastcr. 

 Most numerous was a quantity of oval bodies — transparent sacs 

 hlled with chlorophyll grains, doubtless unicellular plants. 

 There was a number of flat circular organisms, of a deep brown 

 colour, which might be diatoms with the endochrome not 

 destroyed. Several species of diatoms (Fig. i) were nicely 

 cleaned and very perfect, especially Naviciila and Cocconcnia. 



