LAONOME KROYEBI. 245 



convex prow, and an oblique, tapered base (corresponding to the shaft). Moreover, a series 

 of short, modified bristles occur with them, the tips being short, bent at an angle and with 

 broad wings, the whole resembling a beak. The curved shafts dilate from the base to the 

 neck, where a slight constriction occurs ; then it bends forward and tapers to the short 

 tip. In some views slight grooves appear on the enlarged basal part of the tip, so that 

 thej at first sight resemble the long hooks of Terebellides and other forms. The posterior 

 hooks (Plate CXXVIII, fig. 1 c) are smaller, their necks longer, and the bases more 

 oblique. 



Tube. — Some are in tubes of tough secretion with a few fine sand-grains attached, 

 after the manner of the Canadian examples of P. Torelli. 



Amongst the masses of the foregoing Sabella B.C. from Berehaven are a few 

 characterised by the striking madder-brown pigment-spots on the branchige, and without 

 the general arrangement of the pigment characteristic of the former Sabellid B.C. 

 Yet in the disposition of the cephalic collar the two forms appear to be identical. It is 

 true some of them show seven anterior segments with bristles, but others have the normal 

 number, and some which apparently have lost the cephalic plate and other parts have 

 fewer. Injury or abnormality also would explain the occurrence of the median ventral 

 furrow from the first scute backward. The anterior hooks and their accompanying 

 bristles and the posterior hooks are identical. 



Genus CLXIII. — Laonomb, Malmgren, 1865. 



Cephalic region with the collar slightly developed, and a wide dorsal fissure which 

 increases from behind forward, the margins being slightly reflexed, whilst the edges of 

 the ventral fissure are carried a little further forward and the one overlapping the other. 

 Branchiae forming a semicircle on each side, not elongated; filaments with slender 

 tapering free extremities, and bearing ocular spots. Tentacles comparatively short, broad 

 at the base, tapered to a blunt point. Body elongated, little tapered anteriorly, more so 

 posteriorly, rounded, with the anus terminal. Ventral scutes broad in front, forming a 

 narrow belt posteriorly divided by a median groove. Dorsal groove turns to the left and 

 joins it. Setigerous lobes from the second segment, bearing long, tapering winged 

 bristles and paddle-shaped forms, posteriorly bristles with broad wings and finely tapered 

 tips. Hooks commence at the second segment, are avicular throughout, but the basal 

 region posteriorly shows only a rudiment in the anterior bristles, and is absent in the 

 posterior. Tube of secretion and mud. This genus extends to the Antarctic Seas. 



1. Laonome Kroyeri, Malmgren, 1865. Plate CXXIX, figs. 3 — 3 e — branchia, bristles 



and hooks. 



Specific Characters. — Cephalic region with a short collar widely split dorsally, the 

 sides of the ventral hiatus overlapping in spirit. Branchiae (fourteen to sixteen) of 

 moderate length, the chordoid axis with narrow segments toward the base ; pinnse of 

 moderate length, the tips delicately filiform. Tentacles short, bluntly tapered. Body 

 narrow and long, somewhat rounded ; ventral scutes broad in front, continued posteriorly 



