306 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



0. F. Muller in 1773 classed it under Lumbricus as 

 L, tubifex, but bis description is very imperfect, and 

 is largely corrected by D'Udekem. Lamarck (1816) 

 separated Lumbricus tubifex and L. lineatus of Muller' s 

 Lumbricus and formed a new genus, Tubifex : tbe first 

 he called Tubifex rivulorum, tbe second Tubifex 

 marinus. Owing to apparent similarities in tbe structure 

 of these worms and that of the Naiads, Lamarck united 

 them in a class Hespides. In 1842 Hoffmeister recalled 

 the attention of naturalists to the old " genus Lombric" 

 of Muller, which he divided into three new genera, 

 Lumbricus, Enchytraeus and Ssenurus, and he placed 

 Tubifex rivulorum in his new genus Ssenurus. It 

 differed from the " genus Lombric " by the absence of a 

 gizzard and by the fact that the setae are of unequal 

 length. His observations on Tubifex rivulorum are very 

 incomplete and inaccurate .- 



Grube in 1851 classed Tubifex among the Naiads 

 under the name given to it by Hoffmeister — (Scenurus 

 variegatus), and he assigned to it the following 

 characters: " Ohne Kiemen, Borsten Bundelchen zwei- 

 zelich, obere Borsten haar und hakenformig, selten 

 obere und untere hakenformig, Blut lebhast roth oder 

 roth gelb." 



Budge (1850-51) has provided us with descriptions of 

 the genital and respiratory organs. These descriptions 

 are more accurate than those of Hoffmeister,'but still very 

 incomplete. 



D'Udekem in 1855 published an account of the 

 anatomy of the worm, dealing with all the systems in 

 order, but studying them only in the living animal and in 

 preparations made by teasing out parts of the body and 

 then subjecting them to examination. His observations 

 are certainly more detailed and accurate than those of 



