Gatty Marine Laboratory, St. Andrews. 21 
Hooks appear in the ventral divisions of fifteenth to 
sixteenth foot. At the twentieth foot the branchia retains a 
similar shape and is still large, with the dorsal lamella on 
its outer edge. The bristles are similar to those in front. 
Ventrally the lamella has much increased in depth, and is 
separated only by a short gap from the dorsal, where its 
breadth is greatest, for it diminishes ventrally. From its 
lower edge fully half its border is occupied by hooks, which 
are closely arranged inferiorly, but have more space 
superiorly. The shaft of the hook dilates from the base 
upward to the bold forward curvature, when it slightly 
diminishes to the neck, from which the proportionally large 
main fang comes off at a little more than a right angle. A 
single spike (in lateral view) occurs on the crown. Distinct 
wings guard the tip of the hook, which is thus in reality 
hooded. The lamella of the feet are most prominent in the 
posterior part of the body, and thus differ from those of 
N. longirostris, and the latter lives in clean sand, whereas 
N. tridentata frequents Laminarian roots (Southern). 
In the ‘ Annals and Magazine of Natural History,’ ser. 8, 
vol. iii., February 1909*, a form from the ‘ Porcupine’ 
Hxpedition of 1869 was alluded to under the title of Sculeco- 
lepis (1). This has now been definitely termed S. /amellata, 
with the following characters :— 
Head with an even transverse margin in front, a short 
blunt tentacle at each angle, and from the centre a short 
elevated region proceeds backwards to end in a small pro- 
cess which is pointed posteriorly like an adherent tentacle. 
Minute eyes seem to be present on each side of the latter, 
but the condition of the specimen renders accurate deter- 
mination uncertain. The whole region is short, and the 
proboscis is thrust out as a short cylinder with a crenate 
margin. Body fragmentary, flattened, slightly and abruptly 
tapered anteriorly, and with a median band ventrally. The 
segments are narrow and numerous. The first foot carries 
a subulate branchia and a large lanceolate lamella projecting 
freely upward nearly as far as the branchia. The latter 
remains subulate at the fiftieth foot. Dorsal bristles of the 
first foot slender, long, and finely tapered, and the ventral 
are also long and slender. Behind the tenth foot the bristles 
are similar and of a dull golden colour. The ventral bristles 
form two groups, viz., upper finely tapered forms and a lower 
series of shorter broader bristles overlapping the former, 
* P.176, 
