234 The Genus Cejphalosiphon. 



season. A three and three-quarter inch object-glass, if good, 

 will show the five old satellites every clear night, unless any of 

 them happen to be before or behind the planet, or in its shadow. 

 The shadow of Titan, the largest statellite, was once seen cross- 

 ing the disc by Sir W. Herschelin 1789. Gruithtiisen also says 

 he saw it in 1833 with a four and a-quarter inch object-glass ; 

 which is no doubt possible, as it may have a diameter of 0""75; 

 but his assertion that he saw the two innermost and most 

 minute satellites at the same time, gives an imaginary character 

 to the recital. 



THE GENUS CEPHALOSIPHON. 



BY ANDKEW PRITCHAED. 



It may interest naturalists engaged in these studies to learn 

 the source from which I obtained the character of the genus 

 Cephalo siphon, referred to in a paper by Mr. Gosse, " On a 

 Eotifer new to Britain" {Intellectual Observer, p. 49). Allow 

 me to premise that in preparing the fourth edition of my work 

 on Infusoria, one part of my self-imposed task was the search 

 through foreign transactions and journals for new forms, having 

 determined to introduce every published genus and species. 

 This task became laborious, as no public library contains the 

 whole of the foreign works on this subject ; nay, even a com- 

 plete set of the proceedings of the Berlin Academy is not to 

 be found in any one of them. After making these searches, a 

 copy of my notes on the Rotifers was forwarded to Professor 

 "Williamson, who inserted the Cephalosijphon in his revise, for 

 it is not in his MS., nor in my edition of 1852. On looking 

 over my notes, I find that referred to was taken from the 

 Proceedings of the Berlin Academy for 1853, p. 193, in the 

 library of the College of Surgeons, and is as follows : — 



" Cephalo siphon (new genus, Ehrenberg), Horn-Rbschen. 

 Eamily, Flosculariorum ; organon rotatorium bilobum; ocelli 

 duo ; Vagina s. lorica singula ; Comicula duo frontalia siphonem 

 includentia. 



" C. Limnias, E. Vaginulis membranaceis annulatis, 1""6' 

 1"*5'. In ceratophyllo : Berolini." 



In conclusion, permit me to express the pleasure I feel that 

 the labour of collecting the characters of so many exotic forms 

 has not been thrown away; also for Mr. Slack's valuable re- 

 searches, by which we learn the rotatorial animalcules have a 

 wide range of geographical distribution. 



