Polychaeta.\ SUBANTARCTIC ISLANDS OF NEW ZEALAND. 243 



(Marriner) are smaller and contracted ; while those in weaker spirit (Benham), 

 being softer, are longer and broader. The former are from 20 mm. to 35 mm. in 

 length, the latter reach 42 mm. The diameter is 2 mm., and the number of seg- 

 ments is from 70 mm. to 80 mm. This agrees pretty well with the dimensions of 

 L. quadraticeps given by Quatrefages (loc. cit.). 



The colour in spirit is dead-white, without any markings, though the dark- 

 brown chaetae projecting from the parapodia are particularly conspicuous. 



The following account is founded on an examination of one of Marriner's well- 

 preserved specimens : — 



The dorsal surface of the body is much arched, the ventral nearly flat ; the 

 parapodia spring from the angle formed by the junction of the two surfaces, and 

 project laterally in a somewhat downward direction. They are about the same 

 size throug out the worm, but diminish slightly towards the binder end. 



The breadth of the segments is about four times their length, and the para- 

 podium is about one-eighth of this breadth when the body is viewed in a flattened 

 state ; but as seen in section only one-third, for the base is overlapped by a fold of 

 the body-roof. 



The prostomium is almost quadrate in outline (Plate IX, fig. 2) ; the anterior 

 margin is nearly straight ; the two sides slope outwards and backwards, so that 

 the posterior margin is about twice the width of the anterior.* The two eyes of 

 each side are close together, and the area on which they lie is extended outwards ; 

 the eyes are without lenses ; the anterior is the larger, and placed somewhat 

 more laterally than the posterior. The upper face of the prostomium is traversed 

 by a broad, shallow, longitudinal groove. 



The tentacles are very small, no longer than the terminal joint of the palp, 

 conical in form, and widely separated, springing from the rounded corners of the 

 prostomium. On the other hand, the palps are of great size, adherent to the sides 

 of the prostomium, except the terminal portion, and under a low-power dissecting- 

 lens their outline is readily mistaken for that of the prostomium itself, so that the 

 quadrate appearance of the head is increased. So close are they on the ventral 

 surface that they touch one another in median line. (Plate IX, fig. 3.) 



The peristomium is not longer than the first chaetigerous segment ; it is, indeed, 

 somewhat shorter in these well-preserved specimens. It carries the 4 pairs of peri- 

 stomial cirri characteristic of the family. These are quite short; the uppermost 

 and longest extends slightly further outwards than the anterior feet. 



The pygidium is much narrower than the preceding segment, is funnel-shaped, 

 and bears 2 short conical cirri. (Plate IX fig .5.) 



The parapodia are rounded and simple, without the ligules and prominent lips 

 so characteristic of the Nereids. The base of the parapodium is hidden, when 

 viewed from above, by the lateral margin of the dorsal surface of the body, which 

 overhangs it like the eaves of a house. (Plate IX, figs. 2-8.) 



The dorsal cirrus, which is shorter on the anterior feet than on those of the 

 mid and hind body, is conical, and borne by a cylindrical peduncle. In the greater 

 part of the body the dorsal cirri are longer than the chaetigerous lobe, but in the 



* In one soft individual the prostomium is almost triangular, as the anterior end is roundly pointed. 



