456 ON THE FAUNA AND BOTTOM-DEPOSITS NEAR THE 30-FM. LINE 



Plumularia pinnata. This species is very generally distributed, but 

 less frequently met with on the fine sand grounds than on the gravels 

 to the westward of the Eddystone. It is usually attached on these 

 gravels to Chaetoi^terns tubes or to other hydroids. It was met with 

 occasionally only on the Bolt Head Shell Gravel (XVII.) and on the 



Prawle Stony Ground (XVIII.). 



Distribution. Geographical. Nonvay, Baltic, Kattegat (common), North Sea (rare at 

 Heligoland), British Seas (Hartlaub, No. 38 ; Levinsen, No 66 ; Hincks, No. 46), Medi- 

 terranean (?) (Carus, No. 14). 



Depth. To 50 fathoms (Schnlze, No 105, Pommerania). 



Habitat. On shells, stones, sea-weeds, etc. (Hincks). Tiiis species seems to be less 

 restricted by the nature of the material to which it readily fixes than some other hydroids. 



Plumularia setacea. Less common on the Eddystone Grounds than 

 P. pinnata. Especially scarce on fine sand grounds. Generally growing 

 on other hydroids or on polychaete tubes. Taken several times on 

 the Prawle Stony Ground (XA^IIL). 



Distribution. Geographical. Mediterranean, French Coast, British Seas. More 

 plentiful at Heligoland than P. pinnata {fide Hartlaub, No. 38). 



Depth. Littoral to 106 fathoms. 



Habitat. On weed, zoophytes, rock, etc. (Hincks). On Ciena intestincolis (Sars, fide 

 Hincks, No. 46), on Laminaria (Van. Ben. fide Hincks ; Hartlaub), on Halichondria 

 panicca (Bourne, No. 12). 



Plumularia Catharina (Chart IV.). This is the most abundant 

 species of Plumvlaria on the Eddystone Grounds, and it is present 

 both on the fine sand grounds and on the gravels. On the fine sand 

 grounds it is generally growing on other hydroids. On the gravels to 

 the west of the Eddystone it is often very abundant on Chactopterns 

 tubes, generally in the form of the green variety described by Hincks, 

 in which the erect stem is wanting. In this form it is quite a char- 

 acteristic feature of the grounds where ChadopUrus abounds. In haul 

 90 (Ground V.), which is a fine sand ground, one colony only of this 

 variety was taken, and it was growing on a piece of old leather. This 

 is significant in view of the two facts that there were plenty of Pectcn 

 shells on this ground, to which one would at first sight have supposed 

 that the species could attach itself, and that the species is abundant on 

 other grounds in the immediate neighbourhood, fixed to the leathery 

 tube of Chaetopterus. 



Amongst the hydroids to which the ordinary form of the species has 

 been found attached I have noted Hydrallmania falcata and Halecium 

 halecinum. The species was never taken on the J>olt or Prawle 

 Grounds. 



Distribution. Geographical. British Coasts (Hincks, No. 46), Heligoland (Leuckart), 

 between Cuba and Florida (Allnian, No. 2), North Sea (Schulze, No. 105). 



Depth. To 50 fathoms (Schulze). 



Habitat. On shells, corallines, and especially the tests of Ascidians from deep water, 

 shells of Pinna; stemless variety on Sertula,rella Gayi (Hincks). Tlie Pommerania 

 generally dredged the species on sandy ground. 



