THE BREATHING AND FEEDING MECHANISM OF 



THE LAMPREYS. II. 



( Concluded. ) 

 JEAN DAWSON. 



CONTENTS. 



II. FOOD AND MECHANISM OF FEEDING 91 



A. Mode of Attachment 91 



B. Mode of Feeding of Attached Lampreys 94 



C. Character of Food 94 



III. MECHANISM OF RESPIRATION 96 



A. When the Lamprey is Attached 96 



B. When the Animal is not Attached 99 



C. Detachment and Regurgitation IOI 



D. Velar Jaws 105 



IV. SUMMARY 1 06 



V. REFERENCES in 



II. FOOD AND MECHANISM OF FEEDING. 



A. Mode of Attachment. If a living Lampctra wilderi or an 

 Ichthyomyzon concolor (Kirtland) be placed in a glass dish its 

 mode of attachment to the sides of the dish may be observed. 

 The animal, when swimming freely, brings the sides of the oral 

 funnel together so that it forms a vertical wedge-shaped cut- 

 water which offers less resistance to the water than the open funnel. 

 When it is about to attach itself, the closed funnel quickly opens 

 against the glass and, with a single rapid backward and forward 

 stroke of the tongue, the animal becomes firmly attached. The 

 tongue in moving forward resumes its normal position in contact 

 with the surface of attachment and is not seen to move again dur- 

 ing the time of attachment, unless one attempts to pull the animal 

 away in which case the tongue is seen to move as in the case of 



91 



