Gaitij Marine Ldboratory ^ St. Andreios. 5-33 



ought to have, according to some, a marked effect on the 

 plenitude of the fishes. Yet there can be little doubt that 

 such trifling changes have no more influence on Nature's 

 ways than the removal of many of the right whales had on 

 the pelagic fauna on which they fed in the arctic seas. 

 Greater reason for concern would exist if the swarms of 

 sea-birds were to die from inanition, if the slaughter of 

 thousands of sea-birds improved the fishes of an area, or if 

 their increase were marked by a diminution of the sea- 

 fishes. 



3. On the British Euuicidfe. 



There is much to be said in favour of the view of Elders, 

 who groups, in the second part of his ' Borstenwiirmer ' ^, 

 the Onuphididse, the Lumbriconereidse, and the Stauro- 

 cephalidpe under the Eunicidae. Of the three, the latter is 

 the most widely divergent, since it has bifid feet and other 

 features in general structure and in the form of the bristles 

 Avhich call for special note. Each of the groups just men- 

 tioned constitutes a distinct division, yet they have many 

 features in common, and fall fairly under Ehlers's two great 

 sections of the Eunicea Lahidoynatha and E. Prionognatha. 

 The former contains those forms in which the pieces com- 

 posing the upper dental apparatus are heterogeneous; the 

 maxillae and the great dental plates have in front a series of 

 smaller pieces. The feet are simple, though the presence of 

 slender spines which pass into the dorsal cirrus indicates that 

 even here the bifid foot is foreshadowed. The bristles are of 

 three kinds, viz., simple bristles with a tapering wiuged tip 

 accompanied by shorter brush-shaped forms superiorly, and, 

 in most species, compound bristles inferiorly, the latter having 

 the terminal piece bifid at the tip and guarded by wdngs, 

 and, moreover, posteriorly, a powerful hook or two project 

 inferiorly. In the Onuphids, however, a modification of 

 this type occurs. 



As Ehlers has pointed out, this group (E. Labidognatha) 

 may readily be divided into two subdivisions : the first, 

 including the Onuphididee, Eunicidge, and other allied forms, 

 is characterized by the presence of an azygos piece below 

 the great dental plate on the left, whilst the head bears 

 tentacles. The second division has its dental apparatus 

 symmetrical and the head is devoid of tentacles : the 

 Lumbriconereidje and Ninoe fall under this section. 



The Eunicea Prionognatha, forming the second great 



* 1868. 



