78 TURBELLARIA. 



eye-specks, and assume the form of the parent 

 animal. An interesting discovery has been made 

 by Professor Agassiz, that the animals which, under 

 the names of Kolpoda and Paramcecium, had been 

 described as genera of Infusoria, are really the 

 larvse of Planarice; and probably other Infusorial 

 forms may ultimately prove to be the earlier stages 



of TURBELLARIA. 



Localities. — A large number of the genera are 

 confined to fresh waters. Such as are marine are 

 mostly found between tide-marks, crawling about 

 sea-weeds, or clinging to the under-surfaces of 

 stones. The Cestoidea often hide themselves in 

 narrow crevices and hollows of rocks ; and a very 

 productive mode of searching for these, as well as 

 many others of that extensive Class that the Shet- 

 land fishermen so expressively term " pushen," is 

 to break up the flat friable ledges of sandstone or 

 conglomerate, between which the sea has worked 

 innumerable cracks, sand-layers and caverns ; which 

 are found well peopled with strange and uncouth 

 creatures. The curious genus Seiyentaria, the giant 

 of the tribe, was obtained by Mr. Goodsir from 

 deep water. 



Authorities. — I have used for the arrangement 

 of the Class, Oersted's " Plattwurmer," an admir- 

 able little monograph ; and for the British species 

 I am chiefly indebted to Dr. Johnston's " Index to 

 the British Annelides," to Mr. Thompson's papers 

 in the " Annals of Nat. Hist.," and my own per- 

 sonal observations. 



TURBELLARIA. 



Bilateral animals, of soft fleshy substance, covered 

 with vibrating cilia, with the body more or less 



