222 PROF. W. A. HASWELL : 



attached larvse) distinguishing this species from the last, apart from the 

 differences in tentacles and set?e. 



E. heterosetosa occurs in Port Jackson much more sparingly than E. fusti- 

 fera. 



Grubea pusilloides, n. sp. (Plate 17. figs. 27,28.) 



This small Syllid, not much over 2 mm. in length in the case of the largest 

 specimens, is not uncommon in certain situations between tide-marks in Port 

 Jackson. It is nearly allied to G. pusilla (Dujardin) ; but, unless the 

 published accounts err in certain important particulars, it is quite distinct 

 from that species, which has been found hitherto only in the Mediterranean 

 and in the English Channel. 



In describing G. pusilla Dujardin fell into the error of regarding it as 

 hermaphrodite, the rod-like bodies developed in glands in the dorsal cirri 

 being supposed by him to be spermatozoa. This misconception was corrected 

 by (Jlaparede (3. p. 44 : 4. p. 89) who pointed out tlut true nature of these 

 bodies. More recently Baron de St. Joseph (31. p. 79) has observed males 

 with natatory setse and spermatozoa and females with embryos on the ventral 

 side. 



The most interesting point about the Australian species is that, whereas its 

 very near relative was originally supposed (erroneously) to be hermaphrodite, 

 and proved when critically examined to have the sexes separate like the vast 

 majority of the Polychajta, the new form actually has the sexes united. 



The details of this condition will be given in the general part of this paper. 

 A complete specimen of Grubea pusilloides is about 2 mm. long and contains 

 some 25 to 33 segments. The palpi, united dorsally at their bases, are 

 separated distally by a cleft which may be widened to a distinct gap : they 

 are approximately equal in length to the prostomium. The prostomial 

 tentacles are dilated at the bases, narrow distally, tipped with non-motile 

 cilia: they project a little distance beyond the ends of the palpi, the median 

 tentacle being slightly longer than the others. There are two pairs of small 

 eyes, the anterior pair the larger. The peristomial tentacles are similar in 

 character to the prostomial, the upper of the two on each side being some- 

 what longer than the lower. 



The parapodia (see text-fig. 2, p. 235 ; PI. 17. fig. 28) are simple, pointed, 

 their length about a third of the breadth of the body. Of the seta', in all 

 but the first few segments the one situated most dorsally is simple, almost 

 straight, gently curved towards the end , with a row of very minute fine 

 teeth along its concave border *. All the rest are compound, with long and 

 slender terminal appendages. 



The dorsal cirri are, like the seta?, very similar to those of G. pusilla. 



* The seta in G. pusilla corresponding' to this is described nearly as above by De St. 

 Joseph, and the figure he gives agrees well with the corresponding seta in G. pusilloides. 

 But he erroneously refers to it as ventral instead of dorsal. 



