Gattij Marine Labvra(ory, St. Andrew/^. 89 



of hooks. As a rule tlic spines rarely extend beyond the 

 fourth foot. The guhir tuft is elosc to the base of the great 

 fang in sucli hooks, and the general outline of the neek, 

 shoulder, and the shaft (which is short) differs from the type. 

 In the sixth and seventh segments the bristles and liooks are 

 anterior, and there is no furrow between the seventh and the 

 eighth. In the following segments the bristles and hooks 

 are posterior, and they continue so to the fourth segment 

 from the end of the series. The last three are short seg- 

 ments, and they bear their bristles and hooks in the mid- 

 lateral region. !Most show a single ring between the last 

 bristled segment and the anal cup, but one shows two. The 

 bristles of the last segments consist of rather strong capillary 

 bristles, with distinct wings and tapered tips devoid of spikes, 

 and a few more slender forms with long, fine, hair-like tips 

 and oi)posite spikes. 



The typical hook differs from that of N. lumhricalis or 

 Arwidsson's var. burealis. The great fang makes a smaller 

 angle with the neck, and five teeth occur on the crown above 

 it. The backward inclination of the neek is as great as in 

 var. borealis, but the neck is longer and the shoulder beneath 

 it is, perhaps, better defined. The gular tuft is separated 

 from the great fang by an interval as great as in var. borealis. 

 The hooks form a single row in each ease, the rows being 

 short in the anterior segments, but at the seventh bristle- 

 tuft each lies in the centre of a long, elevated, glandular 

 mass on the ventral surface, those following gradually 

 becoming ventro-lateral in position and separated from each 

 other by a groove in the mid-ventral line. The hooks 

 project from the surface, and thus give most efficient 

 anchorage when in action. By the elevation of the pads 

 the hooks in projection form a curved ridge of golden points, 

 and in life this can always be accomplished by muscular 

 agency. When loosened in their surroundings they eutangle 

 dilieate forms like the Ampharetidie, and it is difficult to 

 remove these without rupture. 



In the large example of Nicomache lumbricalis procured 

 by the 'Valorous' Expedition in 1875 the neck of the hook 

 is shorter and more uniformly broad, the strise are confined 

 to the distal or basal region, the great fang makes a larger 

 angle with the neck, and only three teeth are usually visible 

 on the crown in lateral view and they are more erect. This 

 hook makes a close approach to Arwidsson's var. borealis. 

 The large Canadian .species, again, has a hook which shows a 

 much longer shaft, longer neck which widens distally at the 

 striated region ; tlie great fang has a similar (right) angle 



