358 dh. baird on several genera oe etjnicea. 



tinationa or teeth rather numerous, all on the same plane and 

 equal in size; they vary in number, there being sometimes as 

 many as ten in one fascicle. No compound setae. Aciculse or 

 spines two to each foot on the middle or lower part of the body 

 only, straight and very sharp-pointed. These spines are not round 

 like those in the Eunicidse, but are flat and more like simple seta), 

 taking the place of aciculse. Uncini or booklets generally two in 

 number, a little shorter than the aciculse, more cylindrical, and 

 forcipate or bidentate at the apex. 



Sp. 2. Hyalinceoia biltneata, Baird. 



Animal slender and narrow, gradually diminishing in size 

 towards the tail, convex dorsally, and marked with two longitu- 

 dinal reddish-coloured lines, which run throughout the whole 

 length, one on each side. A small dark-red spot occurs between 

 each foot. The organs attached to the head, autennules, tenta- 

 cle, antennse, and palpi, are very similar to those of tubicola ; and 

 the feet are furnished with only the same kinds of setse as in 

 that species. The simple setse, however, are linear-lanceolate, not 

 limbate or broadly lanceolate in the upper third as in tubicola. 

 Dorsal and ventral cirri occur on the two upper thirds of the 

 body. 



These setso and cirri vary considerably according to their situa- 

 tion. In tho anterior pairs of feet tliere are no uncini or booklets ; 

 but instead of them are two setse very like the compound setse of 

 JEunice, only the falciform appendage (which is bidentate near tho 

 apex) is as it were soldered to the shaft and not moveable. To- 

 wards the middle of the body these compound-looking seta^ dis- 

 appear, and their place is taken by two regular forcipate uncini, 

 as in tuhicola. The shaft, however, is much curved, and it is by 

 far the stoutest of all the setse of the feet. On the lower portion 

 of the body the simple setse are of two kinds — one, three or four in 

 number, being straight, stout, and very sharp-pointed, more like 

 sharp-pointed aciculse than setse (are they aciculse ?), the others 

 of the usual form, linear-lanceolate, about half the size of the 

 others. 



The cirri appear to be three in number on the segments of the 

 upper third of the body. One of these is longer than the two 

 others, and may be considered the branchial filament. About the 

 middle third of the body this branchial filament disappears, only 

 the two cirri being present. On the lower third of the body one 



