218 WORMS. INFUSORIA. 80. 81. 



and Innate denticulate alternate ramifications growing 

 smaller towards the bottom. 



Sowerby Brit. Mifcell i./>. 51. tab. 25. 



Stem long, reddish-grey, ending at top in a bony substance, witll 

 very short ramifications. 



80. HYDRA. Polype. 



751. H.viridis. Green, with about 10 arms shorter 

 than the hody. 



Adams. and Kanm. Microfc. p. 364, tab. 21. f. 5. 



In ftagnant waters and slow ftreams, generaJly on the under sur- 

 face of aquatic plants, appearing like a tranfparent green jelly 

 when contracted.; when expanded it is a linear body, fixed at one 

 end, and furrounded at the other by 8-10 tentacula or arms pla- 

 ced in a circle round the mouth, and gradually producing its young 

 from the sides, which at first feem small protuberances, increasing 

 in length, till they afsumc the form of the parent, and then drop- 

 ping off. Like all its tribe, it has the power of reproducing parts 

 which have been deftroyed ; and if cut or divided in any direction, 

 each feparate part will become a perfect polype. 



752. H. grisea. Yellowish-grey, with about 7 arms 

 longer than the body. 



Adams and Ktznm. Microfc. p. 364. tab. i\.f. 6. 



In rivulets and ftagnant waters, tapering towards the bafe, with 

 fometimes 12 arms or tentacula. 



153. H./wsca. Grey-brown, with about 8 arms, many 

 times as long as the body. 



Adams and Kanm. Microfc. p. 363. tab. 21. /. 7. 8. 



In fresh waters, a little tapering to the bafe, with very fine feta- 

 ccous and long tentacula or arms. 



ORDER V. INFUSORIA. 

 81. BRACHIONUS, 



754. Br. urceolaris. Univalve, bell-shaped, with the shell 

 many-toothed at top, and rounded at the base : tail 

 long, cloven at the end. 



Adams Microfc. p. 568. /. 22. /. 36-38- '- 27-/- 5 6 - 57- 

 Vorticella urceolaris. Donovan Br. Ins. t. \-j.f. 1.2. 



In stagnant waters, appearing to the naked eye as a fmall white 

 fpeck : rotatory organ double, which can be protruded or con- 

 cealed at pleafure. 



755. Br. stnatus. Univalve, with an oval striate s 



" 6-toothed at top and -entire at the base; without 

 tail. 



4Jams Microfc. p. 36"4' tab. 27 .Jig. 04- 65. 



In fait water, tranfparent, crystalline, truncate on the f< 

 and rounded behind: shell varying in form, with 12 longitudi- 



tfSfjI^Bi- 1 . $ Tripus. Bivalve, with the shell unarmed at 

 ' the top and 3-horned at the base? tail double. 



Adams Microfc. p. 566. tab. 27. f. 59. 



In waters which have been kept fome time, very tranfparent and 

 ntarly triangular, with a double rotatory organ. 



