104 AUSTRALIAN- SYLLIDAE, EUSYLLIDAE AXD AVTOLTTIDAE, 



fak-es become shorter, and the secontlary tooth comes to preponderate over the 

 tenninal. In the parapodia of the most posterior region there are two sets of 

 simple setae, one of the fli'st set on the dorsal side of each bundle of compound 

 setae, and one of the second set on the ventral side. The dorsal simple setae are 

 slender liairs like the capillary swimming setae; the ventral resemble the sliortest 

 and most ventral of the compound setae except in the absence of the articulation. 

 In scxiuiUy mature specimens the seg-meuts containing the ripe genital products, 

 and usually a few in front of them, have notopodial Ijundles of capillary setae; 

 but these are very sliort, much shorter than the compound setae. 



The dorsal eii-ri are alternately longer and shorter; the longer are in general 

 about as long as the breadth of the body or a little longer; all are verj- slender 

 i'nd indistinctly segmented. The ventral cirri are short, rarely extending as far 

 as the ends of the parapodia, and usually falling far short of it. in shape they 

 are elongated compressed cones, the terminal portion comparatively slender. 

 These ventral cirri are mobile to a quite unusual degree, the slender tip moving 

 about freely. The anal cirri are entirely unsegmented. 



When the proboscis is retracted, the ring of phar^-ngeal papillae lies in the 

 fifth segment. In the eighth seg-mcnt lies the single dorsal tooth, which is thus 

 well behind its usual position, though it is still in front of the middle of the 

 pharynx. The pharynx extends back as far as the thirteenth segment; the pio- 

 ventrieulus lies in the fourteenth to the twentieth. The latter has about twenty- 

 five rows of muscle-columns. 



There is no trace of schizogamy. Mature males have the segments full of 

 sperms from about the twentieth segment backwards, except in a limited regit n 

 at the posterior end. The females, when mature, have numerous small ova in 

 each of the segments from about the twenty-third to about tlie fifty-fifth. Gesta- 

 tion apparently does not occur. 



The nephridia are very conspicuous in most specimens owing to their walls 

 containing much black pigiuent. 



In spite of the fact that the union between tiie palpi is absent, and in 

 spite of the presence of the limited degree of segmentation in the tentacles and 

 dorsal cirri, this species seems to find its nearest allies in the members of the genus 

 Piotiosi/llis. The position of the tooth, though it is not further back than in 

 certain species of Si/Uif', such as S. prolifera, seems to separate it from the other 

 described species of Pimiosiilli^ ■ Apparently it comes nearest to P. u-eissmanni 

 Langerhans [(3G). ji. 24G, fig. 11] and P. ireissmainioides of Augeuer [(1), p. 

 223. text-fig. 30] . 



P. melaenoncphra is not rare among the roots of oar-weeds (Eklonia radiatii) 

 in Tort .Tackson. It is very alert and active and very fragile, so that complete 

 s|)(Mimens are not easily obtained. 



PioxosTi.iJS DIVARICATA Keferstcin. (Plate xiii.. figs. 2 and 3). 



SijUift divaricalri. Kefersteiu. (30). ]> . 111. 



Si/llis nnrmamiica, Claparede, (4), ]>. 40, Taf. xiii.. fig. 24. 



PinnosyUis dh-aricrita. Langerhans, (SO. p. .54.5. 



Piotwsiillis ? diriiriraln. ^fclntosh, (38). p. llU. PI. lix., fig. 12; PI. Ix., fig. 

 7; PI. Ixxix., fig. 17. 



Tlu' only specimen of this species which T have obtained is about 8 mm. in 

 lengtli in tlic preserved condition and less than 1 mm. in greatest breadth. It 

 '\a.s almost colourless in I'roiit when alive, but for black pigment in the proto- 



