POLYCII^TA OF PLYMOUTH. 613 



Marenzeller was right in separating this form from the P. scolo- 

 'pendrina Savigny of Johnston and other authors. In P. crassipalpa 

 the body is much more slender and the dorsum is more strongly 

 pigmented, the dark brown colour being arranged in a characteristic 

 pattern. The posterior part of the ventral surface is also strongly 

 pigmented. The elytra are small, to quote Savigny " separated by 

 an interval equal to their breadth, the two rows thus leaving all 

 the middle of the back uncovered ; but the elytra of each row 

 mutually overlap a little " (Syst. des Annelides, p. 25). This character 

 and the complete absence of tubercles on the uncovered, posterior 

 paii3 of the dorsum give the species a quite characteristic appearance 

 to the naked eye or under a low power lens. The bristles of the 

 dorsal bundle in the typical foot are few, two or three only in one 

 specimen examined by me, six in Marenzeller's specimens, and 

 spinous rows are little developed on them. The ventral bristles as 

 well as other details of the worm are well described by Marenzeller. 

 The latter author, however, in my opinion, attaches undue import- 

 ance in distinguishing the species of this genus to the relative lengths 

 of the median tentacle, palps and tentacular cirri, especially as these 

 have apparently been noted both by himself and by other authors 

 only on preserved specimens. The palps especially seem to be 

 subject to considerable and very variable degrees of contraction 

 under the influence of preservatives. In a well preserved specimen 

 which shows little sign of contraction I find the median tentacle 

 just a little longer than the palps, and the dorsal tentacular cirri about 

 the same length as the median tentacle. The palps taper gradually 

 to a point and are not shaped as in Marenzeller's figure, which seems 

 to have been drawn from a specimen in which they were much 

 contracted. 



Although I have not much doubt that Savigny's description 

 applies to the present species it is impossible to be quite certain 

 on the point, and it therefore seems better to use P. scolopendrina 

 for the other form, which has been known under that name for half 

 a century, and to call the present one P. crassijoalpa, the name 



under which it was first clearly described by Marenzeller. 



* 



Lepidasthenia ARGUS Hodgsou : Journ. M.B.A., vol. 6, 1900, p. 250. 



Salcombe. Found in the tubes of Arnphitrite Edwardsi, on the 

 shore between Salcombe town and Sandhill Point (under Marine 

 Hotel) (t.v.h.). 



The species has since been taken on many occasions in the same 

 locality and under the same conditions as originally described by 

 Hodgson. It has never been found elsewhere. 



AcHOLOE ASTERicoLA (Dellc Chiajc) : Mcintosh, Mon. Brit. Ann. I. 2, 

 1900, p. 397. 

 In the ambulacral groove of Astropecten irregularis : common 



(t.v.h., R.A.T., E.J.A.). 



