BT V^^ A. HASWELL. 105 



plasmic cores of the radial muscle-fibres of the proventriculus; but throughout 

 the greater part of its leng-th it was strongly coloured with dark browu, almost 

 black, pigment, not collected into transverse lines, but distributed over the dorsal 

 surface and the parapodia, with a tendency to the formation, in places, of irregu- 

 lar longitudinal lines. There are 43 segments, but some have been lost. To- 

 wards the middle, where the body is broadest, the length of the segments is about 

 one-fourth of the breadth. 



The prostomium is a little broader than long, and bears lour rather large 

 eyes, the twiy of each side in close contact. The tentacles and dorsal cirri are 

 entirely devoid of segmentation. The median tentacle is about three to four 

 times the length of the prostomium, the lateral scarcely twice that length. The 

 palpi diverge widely from one another, and their basal junction is of very slight 

 extent. The dorsal peristomial tentacle is longer than the median prostoniial, 

 about five times the length of the prostomium. 



The dorsal cirri are longer than the breadth of the segments in front ; shorter 

 behind. The parapodia are simple and undivided, much shorter than the breadth 

 of the segments. 



The setae (Plate xiii., figs. 2 and 3) usually about 12 in each parapodium, 

 are very long and slender, and are all of one type, though decreasing as usual in 

 the length of the fals from the dorsal towards the ventral side. The falx ter- 

 minates in two teeth situated close together, the secondary tooth rather more pro- 

 nounced than the terminal, and strongly hooked. No simple setae are present, 

 but this may be due to the loss of the posterior segments. The acicula, two or 

 three in number, are simple and straight and sharp-pointed or blunt. The ven- 

 tral ein-i are shorter than the parapodia, long, conical, but with a suddenly nar- 

 rowing terminal part. 



The phar^Tix extends to the tenth segment : its median tooth, which is blunt, 

 lies just Ijehind its anterior margin in the 5th segment . The proventriculus ex- 

 tends to the 15th segment, and has about 30 rows of muscle-columns. 



Though there are one or two points (such as the absence of frontal eyes) in 

 which the single specimen does not agree with the description of the European 

 species, the correspondence on the whole is very close. 



Genus Odoktosyllis Claparcde. 



Odontosyllis detecta Augener. 



Odontosyllis detecta Augener (1), p. 236, Taf. iii., fig. 33 and text-tig. 34. 



I have obtained five specimens which seem to be referable to this species — • 

 three mature males and two mature females. Since Augener had only a single 

 incomplete specimen before him, I am able to supplement his account with sundry 

 additional particulars. 



The largest specimens are about 6 mm. in lengtli and contain 35 to 40 

 segments. There is no definite colouration apart from the colours of the int,rnal 

 organs. Vibratile cilia are widely distributed on the surface — on the palpi, on 

 the prostomium, on the peristomium, on the borders of the segments, and on the 

 parapodia. Non-motile (sensory) cilia are also abundant, and are sjiecially elon- 

 gated on the inner borders of the palpi. 



In the males the enonnous eyes occupy a large part of the dorsal portion 

 of the prostomium, and posteriorly those of opposite sides are only separated by 

 a very narrow interval ; in one specimen they bulge out beyond the normal limits 



