General Index 



169 



Septa, of Arenicolix, 61, 62, 7;"); of B. 

 vincenti, 152. 



Septal pouches, of Arcnicoht, 62; ab- 

 sent i]i A. pusilla and assimilis, 

 62, and in Ji. viiirnifi, 152. 



Serpuleae (Savign,\), lo, 19. 



Setipodes (Blainville), 14, 15. 



Size, of ^1. marina, 97, loveiii, 105, 

 cristata, 108, 109, glacialis, 114, 

 ptisiUa, 121, as.si»iilis, 130, ecaii- 

 data, 135, 136, hranchialis, 145, 

 7i. vincenti, 148. 



Spermatozoa of Are.nicola, 72. 



Statoc^'sts, of Arcnicola, 67-70 ; varia- 

 tion in size of, 70 ; external aper- 

 tures of in marina, assimilis, gla- 

 cialis, 39 ; of post-larval marina, 

 78, cristata, 79, assimilis var. 

 affinis, 80, rcandata, 81, //ra//- 

 chialis, 82. 



Statocysts, absent in ^-1. _/>/<«///«, 67, 

 and in i?. vincenti, 153. 



Statoliths of Arcnicola, 67-70 ; differ- 

 ence in nature of, 69. See also 

 statocysts. 



Sternaspidae, contrasted with Areni- 

 colidae, 160. 



Sub-rostral process of crotchet, 48, 50. 



Swimming, of A. marina, 97; of A. 

 ecaudata, 135. 



Tail, of caudate species of Arenicola, 



87, 38; of A. cristata, 109, 110. 

 Tail segments, site of production of, 38. 



Tclethusa, Telethusae, Telethuses 

 (Savignv), = Arenicolidae, 13-16, 

 2J, 25, 20, 27, 159. 



Tube, presence of as character of group 

 of worms, 11 ; enveloping post- 

 larval A. marina, 11, 78, cristata, 

 79, assimilis var. affi,nis, 80. 



Tubicoles (Cuvier), 12, 16, 23. 



Type specimens, remarks on, of .1. 

 loveiii, 105, glacialis, 113, 114, 

 imsilla, 117-119. 



Variations, in nature of statoliths, 67- 

 69 ; in size of statocysts, 70 ; in 

 number of gills, of A. cristata, 



109, pnsilla, 122, assimilis, 130, 

 ecaudata, 136, hranchialis, 145; 

 in number of nephridia of cristata, 



110, assimilis var. affinis, 131. 

 ecaudata, 136 ; in number of 

 oesophageal ginniXii oi pusilla, 122, 

 assimilis, 131 ; in number of seg- 

 ments of ecaudata, 136, hranchi- 

 alis, 145 ; in caudal processes of 

 cristata, 109, 110. 



Ventral groove of Arenicola, 38. 

 Ventral nerve-cord of Arenicola, 66. 

 Vermes, 2-9 ; distinguished fi-om " In- 



secta," 9. 

 vincenti {Brancliiomaldane), 147-159. 



Willis, 4. 

 Willughby, 5, 91. 

 WottoD, 2. 



