358 POLYCH^TA OF THE FAMILIES SERPULID^ AND SABELLID^. 



EXPLANATION OF THE PLATE. 



Fig. 1. Serpula vermicularis L. Collar-set?e from a single specimen to show variation: la, with the 

 normal two processes at base of blade ; Ih, with four nearly equal processes. x 300. 



Fig. 2. Apomatus brownii n. sp. 2a, collar-seta ; 26, bladed sickle from thorax ; '2c, sickle-shaped seta 

 from abdomen ; '2d, thoracic uncinus ; 2e, abdominal uncinus. x 375. 



Fig. 3. Spirorbis antarcticus a. sp. 3a, tube with three small ones towards its centre, xl2; 3b, 

 operculum, x 48 ; 3c, collar-seta, x 375. 



Fig. 4. Spirurbis patagonicus CauUery and Mesnil. Collar-seta, x 375. 



Fig. 5. Spirorbis falMandicus n. sp. 5a, operculum of young specimen, x 36 ; 56, collar-seta, x 375 ; 

 be, seta of bladed sickle type, from third thoracic fascicle, x 375. 



Fig. 6. Eurato melanostigma (Schmarda). 6a and 66, thoracic setae, x 220 ; 6f, thoracic crotchet, 

 x220. 



Fig. 7. Potamis scotix n. sp. 7a, thoracic avicular crotchet, x 48 ; 76, head of same, x220; 7c, thoracic 

 pennoned seta, x 48 ; 7d, head of same, x220; 7e, abdominal avicular crotchet, x220; If, abdominal 

 lanceolate seta, x 150; 7g, superior thoracic seta, x 150; 7/i, inferior thoracic seta, x 150. 



