OF ANIMALCULES. 177 



eyes, and a bifid tail. It is very graceful in its move- 

 ments. Found among confervse. 



418. Brachionus patella, M. and E. The deep-dish 

 Animalcule is exhibited at figures 272 and 273 ; its shell 

 is very convex, and indented at both extremities. The 

 head and trunk are marked by a contraction or neck, 

 and the tail, which is jointed, terminates with two bristles : 

 by these it can attach itself to any substance, and move its 

 small rotatory organs in any direction. Length, 1-lOOth 

 of an inch. 



419. Brachionus patina {Pterodina,lEi.) Theround 

 shallow-dish Animalcule is furnished with two distinct 

 rotatory organs ; hence it is placed in the family Zygo- 

 trocha : two eyes have been recognized. The shell, 

 which is very pellucid, and of a circular form, with a 

 slight indentation in front, is attached to the creature by 

 the middle of its concave surface. Its body is of a bright 

 crystal-like appearance, and the two conical rotatory 

 organs at the mouth can be withdrawn at pleasure. The 

 bulbous oesophagus, alimentary canal, &c. may be very 

 distinctly recognized. Dr. E. states that the tail is 

 forked. In the specimen from which I made the sketch, 

 figure 284, it appeared to me simple. Figure 285 is an 

 under view, magnified. Size, l-50th of an inch. Found 

 in summer among confervas. 



420. Brachionus bractea {Squamella hractea, E. — 

 S, linulina, Bory.) This creature has a polytrochal rota- 

 tory organ, with very delicate cilia, four eyes, and a bifid 

 tail, above which are two spines. When the head is con- 



