Benham. — The Sipunculids of New Zealand. 175 



immediately above the mouth, with the concavity directed 

 dorsally. In this dorsal gap are 4 black eye-spots ; and oc- 

 cupying the intra- tentacular area is a somewhat rectangular 

 disc, slightly lobed right and left to form 2 small rounded 

 projections, which are only visible on extreme extension. As 

 in some other species, such as P. varlans, there is a post-oral 

 collar, but it is very small in the present species. 



Immediately below the mouth there are several circles of 

 closely set booklets, each circle having the appearance of a 

 brown narrow ring. The number of these rings varies a 

 good deal : Hutton gives 12 as the number, but in some 

 i count 16 or 18, while in others, when mounted for micro- 

 scopical examination, there are as many as 20 — -to which 

 must be added some 5 or more very closely set rings at the 

 oral end of the series, which are not recognisable except 

 under a high-magnifying lens. Tlie individual booklets are 

 much curved, as shown in the figure. 



Colour. — The colour is highly variable ; it is generally pale 

 to dark brown, gradually becoming darker at each end. In 

 some of the very pale specimens there are large blotches of 

 very dark pigment, irregular in size and arrangement ; but 

 the ground-colour is always very pale — indeed, it appears 

 white in preserved material — and the brown colour is due 

 to pigment in the dermal papillae which cover the body. 



These papillae are largest and most densely packed at 

 either end, slightly larger — at any rate, in some individuals— 

 at the anterior than at the posterior end, but along the entire 

 ventral surface they are small ; and both dorsally and laterally 

 in the middle region of the body they are also quite small. 

 These smaller papillse have less pigment in them than the 

 larger, so that this middle region is of a paler tint, for the 

 papillae are here more widely separated from one another, 

 and allow a greater amount of ground-colour to come into 

 view. The papillae are of the usual circular form. 



The anus is, generally, quite inconspicuous, but in some 

 specimens it forms a slight prominence ; and occasionally it 

 appears as a paler spot in the dark-brown surroundings. 



The colour of the introvert is usually paler than that of 

 the body — sometimes, indeed, it is almost white — and in these 

 cases it is often marked with dark-brown blotches, which are 

 larger near the oral extremity. But the colour at the 

 proximal region graduates into that of the body, and except 

 in this portion, where the papillae graduate into those of the 

 anterior end of the body, the papillae are quite minute and 

 invisible without a lens. 



Dimensions. — There is a considerable range in the size of 

 the body of my specimens — from 20 mm. to 40 mm. — though 

 an average specimen is about 30 mm. to 35 mm. The " type " 



