however are nol only of a different size, l>ut the proportion of their 

 dimi /ariable according to their state ol contraction. The bare medio-dorsal 



is very narrow, hardly visible, in other ones its diameter measures a 

 third o\ tl Ith <>t' the body, The number of the segments amounts to 



aruncle (PI. III. fig. i) is oblong and narrow, its breadth measuring about one 



its length; it extends over five segments and reaches the anterior part of the sixth 



front of the large dorsal eyes, situated in the anterior half of the caruncle, acylindrical 



with a short conical joint is inserted, stretching not far beyond them. The eyes on the 



ventral side of the caruncle are also exceedingly developed The oral orifice is bordered in 



■ : \ by a pair of pyriform palp-lobes, joining each other in the middle. Each parapodium 



I\', fig. i carries seven to eight branchial arbuscles, with a short, stout stem dichotom- 



lividing in several branches, that are elliptically dilated at the tips: this expanded extremity 



differs in structure from the remaining portion of the gill, and contains a group of thick-walled 



cells of a yellowish tint, highly refracting the light, that are probably of a glandular nature 



and mucus. 



The lateral dorsal cirrus, placed between the second anti third branchiae, is slender 

 and p: I deal beyond the tips of tin- gills, whereas the median one is much shorter. 



In front of the five median branchiae there is a single series of bifid bristles, somewhat Ion 

 than these; they havo a sh<>rt limb "f about a fourth of the length of the long one, that i> 

 furnished with a vitreous tip (PI. I\', lig. 2). Among them are some ringent setae of tin type 

 of /;". /,'/. ■ PI. VI, fig. 6); they have the short limb strongly enlarged and curved, whereas 

 the long one has its inferior grooved part bent over it, its plain, triangular, superior extremity 

 being directed upward. The neuropodium has a rounded triangular anterior lip and is 

 furnished with a slender. ventral cirrus ; as in other pclagic species its fascicle contains three 

 kinds of bristles, a : short ones, with a blunt extremity and a tubercle, not far from the tip, 

 a rudiment of the short limb (PI. IV, fig. 3^7); ó: longer ones, plainly bifurcated, with a 

 long, faintly curved limb, about four times as long as the short one (PI. IV, fig. $ó)\ c: slender, 

 elongated bristles, as Ion- as the ventral distance between the neuropodia ; they have the long 

 limb nearly straight, faintly serrated, about six times as long as the short one (PI. IV, fig. 3^). 

 The anal cirri have a semicircular shape. 



10. Euphrosyne longesetosa Horst. PI. V, figs. 1, 2, 3, 4; PI. VI, fig. 7. 

 II' 'K-t, loc. cit. p. 215. 



Stat. 310. 8° 30' Lat. S., iiq°7'.5 Long. E. Flores Sea. Depth -^ M. Sand with dead coral. 



I specimen. 

 St.it. 315. Anchoragc cast of Sailus Besar, Patcmostcr-islands. Depth up to 36 M. Coral and 



lithothamnion. 1 specimen. 



.\ small worm, measuring 10 mm. in length, and o mm. in breadth (the bristles included); 



with ten pairs of cirriform branchiae on each segment. The lateral dorsal cirrus, situated 



tween the second and third branchiae, somewhat longer than these. In front of the gills a 



transverse series of bifid bristles, some of which have an enormous length, being thrice as long 



M 



