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APPENDIX. 



ENCHYTRiEUS (page 63). 



This little worm is found lying rolled up in a loose spiral manner. 

 It cannot live except in moist places. When placed on the hand it 

 writhes painfully, and soon dies. "In humidiusculis commode 

 repit, in siccas valde sese torquet, ac defectu humidi brevi intabescendo 

 perit." — Mailer. 



Enchytrseus vermicularis (page 63). 



This worm is unspotted. There is, on many specimens, a milk- 

 white spot near the fore part of the body, but it seems rather to in- 

 dicate the position of the stomach than to be a clitellus. A much- 

 convoluted intestine runs through the entire length of the body, and 

 it is divided into rings by strictures corresponding to those in the 

 skin. This intestine is not red. The sides, when highly magnified, 

 appear thickened rather than crenulate. 



Saenuris tubifex (page 64). 



Body filiform or very slightly tapered towards the posterior end, 

 smooth, pellucid, annulose, with a vessel of a fine red colour and a 

 dusky intestine running tortuously from one end to the other, each 

 making a twist in every ring : hence the worm appears red in the 

 water, for the immersed half is a pale straw-yellow. Mouth inferior, 

 subterminal, the apex somewhat pointed. Rings each with four 

 small fascicles of bristles, four in every fascicle ; they are simple, 

 setaceous, entirely retractile, and one on the ventral aspect longer 

 than the others. Anus terminal, truncate. — When highly magnified 

 the margins are seen to be finely crenulated ; and when the worm is 

 killed by sudden immersion in spirits, the rings of the anterior half 

 become separated by such a deep stricture that it may be described 

 as moniliform or beaded. The series of bristles on two sides are 

 obvious, but to perceive the four it is necessary to compress the body 

 between plates of glass. Length nearly 1 inch ; as thick as good 

 sewing-thread. 



This little worm lives in a short cylindrical tube formed in the soft 

 mud at the bottom of its pools. It frequents especially little pools 

 at the side of rivulets. It is gregarious, and during the summer 

 attracts notice by the vivid red of its moving groups ; for, having the 

 .anterior half immersed, it stretches up the posterior, and waves it to 

 and fro with a sort of circular serpentine movement that reminds one 

 of a perpetual motion. The worm is very watchful and alert. When 

 any one approaches unwarily, or the water is disturbed, the whole 

 community instantly disappear, sinking in the tubes ; nor do they 

 reappear until after a considerable interval of quietness. The tubes 

 dissolve on a very slight agitation, and cannot be taken up entire. 

 The worm itself is the favourite food of the Hydra. 



It lives, says Hoffmeister, buried in the mud with the posterior 



