490 THE ANNELIDA POLYCHAETA. 



lobes in pennata being comparatively small. A characteristic difference is 

 presented by the large dorsal thoracic paleae. These in the present species are 

 shorter and broader and do not expand at all distally as they do in pennata, etc. 

 In structure this species is very similar to /. johnstoni (Mcintosh). The 

 dark brown pigment of the head is more extensive, covering the entire operculum 

 and the branchiae, and the entire surface elsewhere excepting caudally. It 

 differs also in the conspicuous dark marks above the neuropodia of the abdomen. 

 In size it is very much larger, the maximum diameter across the thorax being 

 7.5 mm. as against 4.5 mm., while the width across the opercular lobes is 11 mm. 

 The outer paleae are very much alike, as are also the inner ones, excepting that 

 these have a curvature distally seemingly absent in johnstoni; but in both cases 

 they are decidedly more numerous. The thoracic paleae are very similar. 

 The papillae below the outer series of paleae are twice as numerous, — eighteen 

 to twenty instead of seven to nine. 



Tetreres Caullery. 



Bull. Soc. zool. France, 1913, 38, p. 198. 



Tetreres nesiotes, sp. nov.^ 

 Plate 75, fig. 1-7. 



The body is a uniform yellow, excepting the operculum and immediately 

 adjacent surface, which is a dark violet-brown. The inner opercular paleae are 

 dark-colored throughout their length. The outer paleae are dark at tips, but 

 elsewhere are pale yellow and transparent. 



Behind the thoracic somites, the last four of which bear the rows of stout 

 notopodial paleae, there are forty-eight to fifty abdominal somites in front of 

 the narrowed caudal division of fecal tube which, in the type-specimens, is 

 broken off near its anterior end. Exclusive of the fecal tube, the type is 32 mm. 

 long, with a maximum width across abdomen of 5.8 mm. The width across 

 the operculum is 5 -|- mm. 



The prostomium fully concealed by the peristomium. 



The mouth is a rather large, somewhat diamond-shaped, the opening imme-- 

 diatcly bounded on all sides by a thin, plate-fold which apparently represents 

 the inner edges of the palpi, which are more or less completely fused dorsally 

 with the peristomium. 



\i'riaiwTr)s, islandor. 



