NAIDES. 69 



II. NAIDINA. 



Naidina, Ehrenberg in Lam. An. s. Vert. 2de edit. iii. 611. 

 SoMATOTOMA, Ann. des Sc. nat. vii. 101 (1847) & 189. 



Fam. III. NAIDES. 



Nais, Mull. Zool. Dan. Prod, xxviii. ; Verm. i. ii. 20. 



Naides, Cuv. Tthgn. Anim. iii. 211. Duges in Ann. des Sc. nat. xv. 

 319. Williams' Rep. Brit. Assoc. 1851, 218. Oersted in Kroyer, 

 Naturh. TidssJc. 1843, 131. Ray Soc. Rep. 1845, 282. 



Vers hispides. Lam. An. s. Vert. iii. 221. 



Nais, Blainville in Diet, des Sc. nat. Ivii. 497- 



Naidea (— ), Grube, Fam. Annel. 101. 



Obs. The Naides are small pellucid ^dvacious worms distinguished 

 from the aquatic Lumbricidae by the flatness of the segments, fur- 

 nished with comparatively long setaceous bristles ; by having the 

 front segment conformed into the likeness of a head ; and by the 

 two or three following segments being without bristles. In these 

 respects the Naides approximate some of the errant Annelides, and 

 differ so much from Scoloces that it has been proposed to segregate 

 them as aa order in their class, to be named Somatotoma. They 

 are all strictly lacustrine, living amidst subaquatic plants, or, half- 

 parasitical, vdthin the shell of fluviate mollusca. They creep about 

 actively, and can even swim. The bristles consist of spinets forked 

 at the apex, and of setaceous bristles, always collected in small fas- 

 cicles. The family is zoophagous ; probably oviparous, but they 

 multiply easily by spontaneous division. 



6. PROTO, Oken, 1815. 



Proto, Oersted in Kroyer Naturh. TidssJc. 1843, 133. 

 Dero, Grube, Fam. Annel. 105. 



Char. Body furnished at the posterior extremity with from six to 

 ten digitiform appendages : no eyes. 



1. P. digitata. Length 5'". 



Nais digitata, Miill. Verm. i. ii. 22. Wurm. 90. tab. 5. f. 1-4. Turt. 

 Gmel. iv. 91; Brit. Faun. 137. Stew. Elem. i. 391. Bosc, Vers, 

 i. 239. Penn. Brit. Zool. iv. 98. Blainv. Diet, des Sc. nat. Ivii. 

 498, Atlas, pi. fig. 1. 



Proto digitata. Oersted in lib. cit. 133. 



Dero digitata, Grube, Fam. Annel. 105. 



Hab. In the sandy bed of rivulets. 



Obs. The evidence on which this species has been introduced into 

 the British Fauna is unsatisfactory. 



