54 AUSTRALASIAN ANTARCTIC EXPEDITION. 



The eyes are brown ; the median tentacle springs from the dorsal surface in front 

 of the level of the eyes ; it is more slender than the anterior tentacles, and about as long 

 as the length of the prostomium. The two pairs of anterior tentacles have the usual 

 position and shape, and are shorter than the median. 



The first segment is distinct dorsally, behind the prostomium, and is of the same 

 width. It bears on each side one comparatively short tentacular cirrus, which has 

 the same form as the tentacles, but is stouter. The second segment carries two 

 tentacular cirri on each side, the dorsal of which is sub-cylindrical and long, while the 

 ventral is shorter, wide and distinctly foliaceous, produced into a short filamentous 

 point. . It is longer than the normal dorsal cirrus, to which, however, it bears a 

 resemblance. 



The third segment bears a long sub-cylindrical dorsal tentacular cirrus, longer 

 than that of the preceding segment ; below it is the chaetigerous lobe and a small 

 foliaceous ventral cirrus. 



These long tentacular cirri are not, in reality, circular in section, but more or 

 less compressed. The longest of them reaches to the 15th segment ; it is 2-25 mm. 

 in length. It may be noticed that these anterior segments are shorter than those that 

 follow, the increase in length being gradual. 



The parapods (fig. 50) are short, with the anterior lip longer than the posterior. 

 The foliaceous dorsal cirrus is broad, as wide as its length, with an asymmetrically 

 situated apex ; the cirrophore is close to the body wall. The ventral cirrus is oval, 

 not pointed, about as long as the chaetigerous lobe. 



The chsetse (fig. 51). The shaft is a great deal wider than the appendix, and of 

 a much higher degree of refringency, so that at the junction between the two there is a 

 very marked transition when viewed under the microscope. The articular cup is 

 strongly " heterogomph " and, as usual in the family, is very narrow ; one lip is very 

 short, the other is produced into a long curved claw-like structure, both are smooth, 

 and present no striations. The appendix is relatively short ; its proximal end is 

 narrow, but soon acquires its full breadth, and then rather rapidly dwindles, to be 

 prolonged into a very fine distal portion. It is very thin even in the lower portion, 

 and is obliquely striated along its whole length ; and its concave edge is faintly but 

 distinctly denticulate. 



The pharynx was exposed by dissection ; the buccal region extends through 

 25 segments, and the pharynx occupies nine more, i.e., its hinder end reaches to the 42nd. 

 At its entrance are 16 small conical papillae. The buccal cavity is lined uniformly 

 with closely set, round-topped, nearly cylindrical papillae, slightly narrower at the base 

 than at the apex, and about 3 times as high as broad (fig. 52). They are practically 

 of uniform size and shape throughout. In the everted condition the pharynx, there- 

 fore, would be said to be covered with these papillae. 



