Vihratile Tags or Flame Cell in Rotifera. 135 



of flagella and to have the protoplasmic cap expanded into a 

 vesicle. They appeared less flattened. Other cells such as Figs. 

 10 and II possessed lesser vesicles in the cap and flagella in 

 conjunction. 



The whole of the figures were drawn from a magnification of 

 about 1000 dia. using a Leitz yV^^ semi-apochroniatic oil immer- 

 sion lens, and a Watson ife Son's parachromatic condenser. Rigid 

 adherence to the conditions necessary to produce a "critical 

 image " was found necessary, and all observations were made in 

 a flame image, daylight being unequal to bringing out the finer 

 details. 



I h<ave to express my thanks to Professor Spencer for procuring 

 me the literature, and to Mr. W. Stickland for assistance in 

 reading the German and French Papers. 



EXPLANATION OF FIGURES. 



Euchlanis dilatata. 



Fig. 1. — Flat view of tag 

 ,, 2. — Edge view of tag. Dimensions, length -013 mm.; 



breadth -007 mm. 

 ,, 3. — Optical section of tag seen end on {a) striated surfaces. 

 ,, 4. — Portion of lateral canal. 



Brachioniis pa/a. 



„ 5. — Flat view of tag. 



,, 6. — Edge view of tag. Length -012 mm. 



Hydatina senta. 



,, 7. — Flat view of tag. 



,, 8. — Edge view of tag. Length -014 mm.; breadth -01 mm. 



Asplandmopus juyrmeleo. 



,, 9. — Portion of lateral canals with tags attached in edge 

 view (fl), (/;), (<:), and flat view {d). Length of 

 tag -009 mm.; breadth -004. 



„ 10. — Flat view of tag with vesicle in cap and flagellum. 



