POLYCH^TA BENHAM. C,:> 



Family NEREIDS. 

 Genus NEREIS Cuvier. 

 NEREIS LOXECHINI Kinberg. 

 Nicon loxechini, Kinberg (1865), No. 2, p. 178. 

 Nereis loxechini, Ehlers (1908), p. 73. 

 Nereis loxechini, Ehlers (1913), p. 497. 



(Plate 8, figs. 67-75.) 



This is evidently a rare worm, and the only species of Nereis ( other than 2V. uncinata 

 Ehlers) recorded from the Antarctic region. Up till 1908 it had not been met with 

 since Kinberg's record of it at Magellan Strait. In that year Ehlers published a brief 

 description of a small individual obtained from St. Paul's Island; the only one 

 collected by the expedition. In his later memoir he records a larger specimen, 

 measuring 77 mm. by 6 mm. across the body, and containing 86 segments, from 

 Kaiser Wilhelm II Land. It was noted as being " red-brown in colour " when alive. 

 He, however, added no new facts about the species. 



As no figures have been published (unless they are contained in Theel's new 

 edition of Kinberg's work, which I ha,ve not been able to consult), it seems desirable to 

 add another and more detailed illustrated account of the species. 



Three specimens were gathered by the " Aurora," in depths from 157 to 325 

 fathoms; all are more or less imperfect. The most nearly complete individual has a 

 length of 60 mm. and a breadth of 6 mm. over the parapods, and 5 mm. over the body. 

 anteriorly; thence it tapers, so that at about the middle of the body these measure- 

 ments are 4 and 3 mm. respectively. 



This worm consists of 132 segments, and only lacks a few of the hindmost. Another 

 fragment represents a larger individual; it consists of the head and 45 segments, and 

 measures 40 mm., with a breadth of 5 mm. over the body, and 7 mm. across the feet. 



The third specimen is rather soft; it is 26 mm. by 3 mm. over the body, and 

 4 mm. over the feet. The hinder end of the fragment, whose segments I did not count, 

 is 1 -25 mm. across the body. 



The dorsal surface is brown, more deeply tinted over the middle area, with a pale 

 line across the anterior margin of each segment; the lateral areas are almost white ; the 

 parapods are brown, with two glandular masses of greyish-brown at their bases. The 

 tips of the ligules are similarly tinted. 



The prostomium (fig. 67) is broader than long; the posterior oculiferous region 

 is rather abruptly marked off from the narrower tentacular region in the well preserved 

 specimen, but not so much in the less well preserved (fig. 68). The eyes are large, each 

 with a well developed lens; the posterior eye is oval rather than circular, with the long 



8389-21 



