POLYCH.-ETA. BENHAM. 195 



PHYSALIDONOTUS TURRITUS X , sp. nov. 

 (Plate xxxix., figs. 33-35.) 



Four specimens of this small species, one of which measures 

 12 mm. in length by 6 mm. across the elytra. 



The characteristic marginal obconical papillae are relatively 

 large for the size of the worm ; they are shorter and wider 

 than those in the preceding species. 



There is a row of 3-4 large cylindrical papillae over the 

 areola ; each springs from a distinctly stellate base, and 

 terminates in a crown of rounded lobes, rather than spines. 

 The width of these papillae is less than half the height (PI. 

 xxxix., fig. 33). 



Along the posterior margin there is a row of very irregular 

 spinose papillae, and at the external margin a few large 

 papillae, some of which, towards the anterior edge, are nearly 

 cylindrical, others towards the posterior side are inverted 

 cones, with a very narrow base of attachment, widening out 

 terminally. All these bear blunt spines. 



The general surface of the elytron is covered by closely 

 arranged low stellate tubercles, small in the anterior region, 

 larger towards the areola, and still larger on the posterior 

 region, where they are also of more irregular form and size. 

 In colour they are varied, some being nearly black. 



On the covered portion the tubercles are very small and 

 rounded. 



The margin, as usual in the genus, is fringed with relatively 

 long " cilia," longer on the external than on the posterior 

 margin. 



The gills. On the anterior face there are two papulae 

 close together, about midway along the foot, and one shorter 

 one on the cushion. On the posterior face there is only one 

 papula, that a long one springing from the base of the cushion, 

 but in a cirriferous segment there is, in addition, a second 

 one close to the base of the cirrus (PI. xxxix., fig. 35). 



The prostomium is broader than long, widest at its middle, 

 where the anterior pair of eyes is situated, the other pair 

 lies immediately behind them (PI. xxxix., fig. 34). 



The tentacles are uniformly pale brown, the median more 

 than twice the length of the laterals. (In these measurements 

 the basal " tentaculophore " is not included). 



1. "Furnished with towers," so named from the castle-like form of 

 the large papillae on the elytra. 



