750 OBSERVATIONS ON SOME AUSTRALIAN POLYCH^TA. 



pairs of large, rounded brown eyes, placed close together at the 

 sides of the head, the anterior very slightly larger than the 

 posterior. There seem to be eight peristomial tentacles — three 

 shorter than the dorsal cirri, the rest of about the same length. 

 There are thirty-six segments in the body, each, as a rule, about 

 three-and a-half times as broad as long. The parapodia are very 

 prominent, being, with the setae, nearly as long as the bi'eadth 

 of the body. They are deeply divided, the neuropodium being 

 more prominent than the notopodium, and terminating in a 

 slender pointed process : there is a stout acicukim, finely striated 

 transversely, in each division, and a large number of tapering 

 compound setse, the basal parts of which are finely striated 

 transversely, and the distal divisions bordered with fine cilia along 

 one margin, and slightly hooked at the apex. Thei'e is a short 

 central cirrus not so long as the parapodia. The dorsal cirri are 

 very long, three or four times as long as the body is broad ; they 

 are not jointed, but are supported on a short ringed peduncle. 



The eversible proboscis is lined with two or three transverse 

 rows of club-shaped papillae. There are no teeth. The gizzard is 

 long ; its walls are marked by narrow transverse lines, and are 

 composed of transversely and longitudinally arranged non- 

 striated muscle-fibres. 



One specimeia of the species was obtained with the dredge in 

 Port Jackson. 



It would appear to be more nearly related to Psamathe than to 

 any other described form ; pi'obably, however, ought to be regarded 

 as the type of a distinct genus. 



IV. SIPHONOSTOMA. 



SiPHONOSTOMA AFFINE. N. sp. 



(Plate LIV., figs, l-fx) 



The body is about an inch in length, and a tenth of an inch in 

 greatest breadth : it is broadest in front, becoming narrower 



