94 AUSIRALIAN SYLLIDAE, EUSyl-MDAK AND ACTOLYTIDAE. 



Of tiie tlorsal cirri there is an alteniation oJ' longer and sliortcr. tin- longer 

 in the anteiior region more than twice as long as the breadtli of the body, and 

 composed of about forty segments. Tlie ventral cirri are short, not extending 

 as far as the ends of the parapodia. The anal cirri are similar to the larger 

 dorsal; between them is a well-dexclopcd, narrow median process. 



The pharynx, -which is brownisii or reddish, extends as far as the 9th seg- 

 ment. An important feature is that the tooth is situated some little distance be- 

 hind tlie anterior mai'gin of the pharynx (Plate x., fig. 3) . The proventriculus 

 is rather variable, lying in the lOth to 14th or 15th or 9th to 14th or 10th to 18th 

 segments — five to eight segments. Brown pigment runs in the raphes and the 

 annular bands of non-striated muscles, of wliich there arc about 35. The vcntri- 

 culus, light Ijrown or red in colour, has the usual T-shaped caeca, tlie anterior branch 

 the larger. The intestine is deeply constricted, usually of a dark grciii colour, 

 or yellow or orange mixed with green, or orange throughout. 



In ripe females, the ovaries, purple in colour, are developed from about the 

 30tli to the 40th segments, l)ackwards — the stohm, of about "20 to 25 segments, 

 beginning about the 40th or 50th. In the nuile, the ripe stolon is of a bright 

 red, pink or scarlet colour, and consists of about 20 segments witli dilated nei>,hridia 

 packed with sperms in roiuidetl groups. 



T. pectinans occurs veiy abundantly between tide-marks in Port Jackson, 

 and is particularly numerous among the tulics ol' the common Sorpulid. Cideolaria 

 hystrlx. 



Relying on Langerhans's account (30, ]>. 5.'30, Taf. 31, fig. 3) of the species 

 wliich he identified with S. prolij'era Krohn, I was at first indmed to regard the 

 form above described as referable to that species. One of the chief reasons for 

 thi.i view was the exceptional position in both of the pharyngeal tooth. A care- 

 ful comparison showed, however, that such a determination could not be main- 

 tained. Langerhans refers to the compound setae in 5. prnlifera as "bidentate" 

 without any qualification. jMoreocer, .V. armutidi, wliich Langerhans regards as 

 identical, is described liy Claparede (5, p. 70) as having setae with bidentate 

 appendages; and the same holds good of .v. lussincnsis Grubo (20, p. 40). also 

 regarded by Langerhans as synonymous with the sai\ie species.* Mcintosh's 

 figures (39) of the coiniiound setae in ,s'. (Pioiios/iUis) prolifera also all represent 

 them as strongly bidentate. On the whole the evidence .seems to be in favour 

 of the conclusion that the Australian sjiecies is a hitherto undescribed s])ecies of 

 T/iposi/His, characterised by llic combination of two unusual characters — the back- 

 ward position of the tooth and the ]>i('sciic(' of unidcntate compound setae. 



Svi.i.is (Ti-posVLLis) TitcxcATA. n.s|i. (Plate x., Iig;. 7-14.) 



Tliis, like 7'. jiecHindis, is a slender eloiigafcd Si/lli^, wliicli. when alive and 

 fully extended, becomes a narrow thread. There are over a hundred segments 

 (110-120) in a I'ldl-grown siiecinien . The general colour is reddish Avithout 

 definite markings, darkened behind liy the intestine. The length is from 1 to 2 

 cm. The tentacles and dorsal cirri are full of twisted (vermionlate) unicellular 

 glands similar to those of S. rnrinidla. 



•Langerhans regards S.fiuvieiisis of Elders i»« also identical with .s'. firoliffnt : if 

 that view bo woll-finmilcil. Ehlers's figure (fi, Taf. ix.. fig. 4) of a coinpoiinil seta must he 

 incorrect . 



