Embryology &c. of Yoldia liinatula, Say. 



275 



In this way foraminifers, ostracods, and even small lamelli- 

 branchs and gastropods, are passed along the groove, between 

 the palps, and finally into the mouth. 



Thus we find that Mitsukuri's surmise (5), based on finding 

 sand in the grooves of the palp-appendages of preserved 

 specimens, was right. The palp-appendages are food-col- 

 lectors. 



Experiments were tried to determine if possible the part 

 taken by the gills in collecting food. No definite results 

 were reached, but in no case was Kellogg's observation (2) 

 that the gills are extremely active food-collectors confirmed. 



Considering the remarkable activity of the palps in col- 

 lecting food, such activity for the gills seems rather unneces- 

 sary, and it would also seem that the pumping action of the 

 gills, presently to be described, would seriously interfere with 

 their performing such a function. 



Fig. 6. 



Diagrammatic transverse section of an adult animal, taken just in front 

 of the posterior adductor muscle. /, foot ; g, gills ; gs, gill 

 suspensory membrane ; m, mantle ; s, shell. 



It is well known that each pair of gills is suspended from 

 the body-wall by a membrane, but little or no attention has 

 been given the fact that this membrane is muscular. As the 

 gills are composed of wide plates, they are sufficiently broad 

 to span the spaces between the foot and the mantle-lobes 

 (fig. 6), and behind the foot unitedly to span the entire 



