OF ANIMALCULES. 181 



very pellucid, and open at both ends, the upper extremity 

 having sharp indentations on one side, and being wavy 

 on the other : the body is affixed to the centre of the 

 shell, being free at both ends to contract or extend itself 

 at pleasure. According to Dr. Ehrenberg, it has a single 

 eye, and is an example of the Gasterodela form of the 

 digestive organs. The young are produced from eggs 

 while attached to the parent, in the manner shewn at the 

 figure 296. Some specimens have four or five eggs, 

 and others are without any : as soon as the embryo is 

 matured, the parent brer.ks the shell by means of its tail, 

 when the young animalcule thrusts out its head and body, 

 and immediately commences whirling. When of suffi- 

 cient age to defend itself, the parent detaches it from 

 itself, and swims away. (See figures 295 and 299.) 



432. Brachionus Baker i. — Mr. Baker's loricated- 

 wheel animalcule is exhibited at figures 292 and 29.3 : 

 the form of the shell is different from that of the preced- 

 ing, having, besides some very long spines at its anterior 

 extremity, its posterior terminated by a single long one 

 on either side of \t, as shewn in the figures. The eggs 

 are sometimes disposed on these long posterior spines ; 

 at others, they are attached to the tail. The largest spe- 

 cimen I have seen measured l-30th of an inch in length. 



433. Brachionus patulus. The wide-mouthed Bra- 

 chionus is shewn at figures 300 and 301 : it is about half 

 the size of the preceding one ; very transparent, like 

 crvstal, and has the anterior indentations of the shell 



