ROTATORI2B, 337 



each end indented so as to form two pair of teeth. Mr. 

 Pritchard says : "In addition to the rotatory organs 

 for supplying it with food, 1 have observed it attached 

 to a stem of confervce, and abrading it with its teeth 

 fixed in the bulbous sesophagus, which, during the opera- 

 tion, oscillates quickly; the rotatory cilia at the same 

 time move rapidly, which makes it highly probable that 

 they perform some office connected with the organs of 

 respiration, as their motion seems altogether unnecessary 

 while the creature is feeding in this manner." Brachionus 

 Bakeri, " Baker's brachionus," (fig. 186, No. 4), is a curious 

 and beautifully-formed animal. At the points of a half- 

 circle are situated the rotatory organs and cilia, between 

 which rise some long spines, each side of the shell pro- 

 ceeding to a point in the lower part, while a square seems 

 taken out of its body, forming thus two spines ; from the 

 central part of the body projects a long tail. The eggs are 

 sometimes attached to these spines, and in other instances 

 in the ovisac, found in the interior of the animal. 



Notommata Aurita, the " Eared notommata." The ana- 

 tomy of this animal, a genus of JRotatoria, family Hyda- 

 tincea, has been most lucidly explained and illustrated by 

 Mr. P. H. Gosse, in the Microscopical Society's Transactions. 



Mr. Gosse states, that his specimens were found in a jar 

 of water obtained in the autumn from a pond near Wal- 

 thamstow, the jar having stood in his study- window 

 through the winter; and from a swarm in the succeeding 

 February he selected one the 70th of an inch in length 

 when extended, but its contractions and elongations 

 rendered its size variable. 



" Its form, viewed dorsally, is somewhat cylindrical, but 

 it frequently becomes pyriform by the repletion of the 

 abdominal viscera. Viewed laterally, the back is arched 

 gibbous posteriorly, with the head somewhat obliquely 

 truncate, the belly nearly straight. The posterior ex- 

 tremity is produced into a retractile foot, terminating in 

 two pointed toes ; this, both in function and structure, is 

 certainly analogous to a limb, and must not be mistaken 

 for the tail, which is a minute projection higher up the 

 body. When not swimming or rotating, the head assumes 

 a rounded outline, displaying through the transparent 



