100 AUSTRALIAN SYLLIDAE, EUSYLI.IDAK AND At'TOI-YTIDAE, 



palpi are broad at the l)ase, fused with oue another lor a shoi't distance, 

 longer thau the prostomium, usuaUy directed downwards, hollowed out lielow 

 and internally. The eyes are rather small, those of the anterior pair larger 

 and wider apart than those of the posterior. The three prostomial tentacles are 

 feubequal, a little longer than the palpi, indistinctly segmented or entirely unseg- 

 mented. The peristomial tentacles which are also indistinctly ringed, are subei|iial, 

 the dorsal a little longer than the ventral, shorter than the prostomial. 



The parapodia are relatively short. Each bears 15 to 20 compound setae. 

 These (Plate xi., figs. 29-31) are all of the same essential character, with bideatate 

 falces, but the most dorsally situated (fig. 29) have the falces long and slender, 

 a gradual transition taking place towards the most ventral setae which have the 

 falces short and comparatively broad. In a few of the most posterior segments 

 tliere are also simple setae — one dorsal to the comi^ound setae of each jjarapodium. 

 slender and hair-like, the other ventral, very short, terminating like the compound 

 setae but without the articulation. There are 5 to 7 or more pointed acicula in 

 each parapodium, one sharply bent forwards at the end. The dorsal cirri are 

 alternately longer and shorter, about equal in length to the breadth of the body, 

 not very distinctly segmented, smooth and unsegmented at the base, indistinctly 

 segmented towards the apex. 



In the original description I stated that in this species male stolons are given 

 off from a female stock. In my more recent notes I can find no confirmation of 

 this. Female stolons are very rare, but they occur. In the case of the female, 

 as in that of the male, stolon, sexual elements similar to those in the stolon occur 

 also, as in other species of Syllis, in the posterior region of the stock. It may 

 be that in certain circumstances, or at certain seasons, the formation of a female 

 stolon may so rapidly follow that of a male that the posterior region of the stock 

 contains well formed ova before the male zooid becomes detached. But I have 

 been unable to find any such case among recently examined specimens, which all 

 show evidence of normal schizogamy without hermaphroditism.* 



S. eoruscans is far from being a typical Syllis. Structurally, in fact, it is 

 closely connected with various species of Eusyllis, and it might quite well be 

 described as a Eusyllis which i-eproduces with schizogamy. Apart from the super- 

 ficial features of connection between the palpi at theu- bases and imperfect seg- 

 mentation of the tentacles and dorsal cirri, S. eoruscans is Eusyllis-M^n in having 

 the rim of the cuticle of the pharynx ocea-sionally divided in an iiTegular way into 

 a number of lobes, which can hardly be termed teeth. t Moreover the arrangement 

 of the radial muscles of the wall of the pro vent riculus corresponds completely 

 with that which characterises Eusyllis, and differs from that which occurs gener- 

 ally, if not universally, in typical sjiecies of Syllis. 



Sub-geniis Haplosyllis Langerhans. 



Syli.is (Haplosyllis) spoxgicola Grube. 



Syllis sponyicola, Grube, (18), p. 104, PI. 4, fig. 4. 

 Syllis djiboutiensis, Gravier, (Ki), p. 147, PI. 9, fig. 3, lOOO. 

 Syllis djiboutiensis, Augener, (1), p. 213. 

 (For additional synonymy see Mcintosh, (39), p. 197.) 



'Sec F. A. Potts (47). ' ' 



tDo Saint-Joseph (48) states :— "Chez beauccup de liiisylli.':, et cola indiifi'reinnieut 



dans chaque esp^ce, lo bord de la trompe, au lieu d'i-tro donti'h' nVst ijiic cli'cliiijuctr et 



s'^loigne peu du bord uni et quelquefois aussi an jieu di'chiquetc' de la tronipo dos 



Pionosyllis. ' ' 



