172 QUARTERLY CHRONICLE. 



The action of the whole apparatus is explained as follows by 

 Professor Claparede : — The superior range of cilia, when in 

 action, produces currents tangential to the vibratile organ 

 and perpendicular to its plane. These currents are closed, 

 and appear to be nearly of an elliptical form ; particles in- 

 volved in them pass repeatedly over the same course, and if 

 they are thus brought in contact with the extremities of the 

 inferior cilia, which reach a little above the base of the 

 superior range, they pass into the channel above mentioned, 

 and are pushed along in it towards the mouth. The author 

 remarks that the apparent movement of the inferior cilia is 

 from the mouth ; but this is illusory, and due to the circum- 

 stance that the slow elevation of each cilium preparatory to 

 its stroke produces a greater effect upon the eye than the 

 more rapid stroke itself. This double row of cilia in Melicerta 

 and Lacinularia has been observed and described in this 

 country by Huxley and Williamson, and in Germany by 

 Leydig, but its existence seems to have escaped the notice 

 of subsequent observers. Professor Huxley has also observed 

 this second row of cilia in Philodina, a genus belonging to 

 the Rotatoria Zygotrocha. M. Claparede here describes and 

 figures it in Rotifer inflatus (Duj.), in which the inferior cilia 

 are borne upon a crest which is oblique relatively to the 

 plane of the vibratile wheel ; in all other respects the arrange- 

 ment and action of these inferior cilia are the »ame as in 

 Melicerta. The same characters have been observed in 

 Rotifer vulgaris (Ehr.). M. Claparede appends to this 

 paper a note confirming Mr. Gosse's account of the mode 

 in which Melicerta ringens builds up its tube, and remarks 

 that this does not appear to have attracted attention on the 

 Continent. 



" Teeth of Fossil Fishes from the Coal-measures, North- 

 umberland." — Professor Owen has published a pap^-, illus- 

 trated by very beautiful figures in fifteen plates, in the 

 * Proceedings of the Odontological Society.' He describes 

 various new genera and species on these characters. Mr. 

 Albany Hancock and Mr. Thomas Atthey, however, publish 

 papers in the ' Annals and Magazine of Natural History,' in 

 which they point out what they consider to be serious errors 

 in Professor Owen's paper, and refuse to admit some of his 

 genera, they being founded on fragments only of the teeth of 

 other genera. 



" Dentition of the Mole." — Mr. C. Spence Bate has also 

 sent us a copy of his paper on this subject, published by the 

 Odontological Society. Mr. Bate's researches on the develop- 

 ment of the teeth are highly interesting, and clearly prove 



