480 ON THE FAUNA AND BOTTOM-DEPOSITS NEAll THE 30-FM. LINE 



the coarse gravel fauna in its purest form, and is still plentiful on the 

 gravel of the adjoining Ground XI. It was also taken in several hauls 

 on the Ophiothri.i- fragilis Ground (X.). On the coarse gravel and mud of 

 Ground XIII., south-west of the Eddy stone, the fauna of which resembles 

 in most of its features that of Ground IX., Ihjalinoecia was also abundant. 

 A few specimens were taken on the fine sand grounds adjoining the 

 coarse Eddystone Grounds (III., IV., VII., and VIII.). On the remain- 

 ing fine sand grounds and on the fine gravels and clean shell gravels 

 the species was entirely absent, nor was it taken on the Pravvle Stony 

 Ground. 



Hnhits. What are the habits of Hyalinoecia tuhicola in the natural 

 state I am unable to say. In confinement it does not burrow, but is 

 capable of somewhat rapid locomotion over the surface of a gravel 

 bottom. The movement is effected by protruding the head and anterior 

 portion of the body from the tube for a distance of about an inch 

 in specimens of the ordinary size, holding to the gravel by the 

 appendages of the most anterior segments and drawing the tube along, 

 the body being bent sharply at right angles at the point where it 

 emerges from the tube. The head is then thrown forward, attached 

 again to the gravel, and the previous movement repeated. 



Distribution. Geographical. North and West Norway, Kattegat, North Sea, British 

 Isles, Englisli Channel, west of France, Mediterranean, Madeira (/<?c Saint-Joseph, No. 102, 

 and Michaelsen, No. 79). Tlie Challenger obtained Hyalinoecia tuhicola at the Azores 

 (50-90 fathoms), and one small, dried specimen from the south of Japan (565 fathoms) is 

 also referred to this species (M'Intosh, No. 85). 



Bottom-deposit and Depth. In the Irish Sea the species is taken on pure mud at depths 

 of from 40 to 80 fathoms, where it constitutes one of the characteristic features of the 

 fauna (Herdnian, No. 40, Vol. VIII., p. 18 ; Vol. IX., p. 53). In the Skagcraek and 

 Kattegat it also occurs on deposits of pure mud (Levinsen, No. 66). Off the south-west 

 coast of Ireland, Haddon, on the other hand, found it on coarse sand (35-40 fathoms) and 

 on sand (110 fathoms) (Haddon, No. 34). The Challenger specimens off the Azores were 

 on volcanic mud (50-90 fathoms), and the one small specimen off the south of Japan was 

 on green mud (565 fathoms). Tlie Caudan found H. tuhicola abundant at 98 fathoms at 

 two stations on gravel and sand, and also at 137 fathoms at one station on nuid. 



From the above records, combined with my own from the Eddystone 

 Grounds, it would seem that Hijalinoccia tuhicola is equally at home on 

 pure mud and on gravels mixed with sand and mud. It is probable, 

 however, that further knowledge of its habits and distribution will show 

 that its real centre of distribution is on deposits of one only of these 

 kinds, and that those occurring in deposits of the other kind must 

 be regarded as outlying individuals, which have extended to grounds 

 where the conditions are still such that they can exist, though not such 

 as those to which they are most perfectly adapted. 



Lumhriconcreis. A large and a small species, which have not been 

 certidnly identified, were occasionally taken (see Table VI., p. 531). 



