44:0 ON THE FAUNA AND BOTTOM-DEPOSITS NEAR THE 30-FM. LINE 



HydroM j)olype (one of the Titbulariidae), which seems to take advantage of tlie strong 

 gyratory current jiroduced l)y the mollusc for its own food- seeking ])uriiose." It is 

 jn-obalile tliat the reference is to the present species, tliougli in my specimens the hydroid 

 was always on the posterior end of the shell, 



Hydradinia echinata (Table VI., p. 529). Generally on Baccinum 



undatum shells occupied by Uiipagiirus Bernhardus, occasionally (haul 



93) on shell occupied by £. Prideauxii. The presence of Hydradinia 



appears to be rather more frequent on the fine sand than on the 



coarser grounds. 



DlSTRlBl'TiON. Geogj-ajyhical. Greenland, Iceland, North Sea, British coasts, 

 Normandy and Brittany, and North America (Agassiz). [Fide Hincks, No. 46, and 

 Hartlaub, No. 38.] 



Depth. Low-water to 90 fathoms. 



Habitat. On Buccinum undatum, Fiisus corneus, Turrifella communis, Nassa reticu- 

 lata, Littoj-ina, Natica, Trochus zizyphinus (Hincks). On Mytilus edulis and on stones 

 (Hartlaub). 



Eudcndrium rameum (Chart III.). Specimens of B. ramenm were 

 obtained only on the Bolt Head Shell Gravel, in hauls 106 and 107 

 (Ground XVll.). In 106 a fine colony was growing on an old 

 fragment of the leathery tube of Chaetopterus, and in 107 another 

 fine colony was found on a shell of Fedcn opercularis. 



Distribution. Geographical. West Greenland, Kara Sea, Norway, Baltic, North 

 Sea, British Seas, Mediterranean, and Kerguelen {Challenger). [Fide Hartlaub, No. 38.] 



Depth. 5-105 fathoms {Challenger, No. 3). 



Habitat. On shells, stones, etc. (Hincks, No. 46). 



Eudendrium ramosum (Chart III.). Generally growing on shells 

 or on other hydroids. The species is far more frequent and abundant 

 on sandy grounds than on the gravels. It was most numerous on 

 Grounds I., Ill, IV., VII., and XII. 



Dlstribution. Geographicad, Greenland, Norway, North Sea, British Seas, Mediter- 

 ranean (Hartlaub, No. 38). 



Depth. Low-water to 542 fathoms {Porcupine, Allnian, No. 4). 



Habitat. On shells and on Laminaria roots (Hincks, No. 46 ; Hartlaub, No. 38). 



Eudendrium capillare and E. sp. (Table VI., p. 529). The true 

 Eudcndrium capillare was met with on several grounds, generally 

 growing on other hydroids, sometimes on worm tubes or shells. A 

 small Eudendrium of a rather more robust character was also 

 frequently taken in similar situations, but there is some doubt as to 

 whether this is a distinct species. 



DiSTRiBTJTiON. Geographical. Norway, Baltic, North Sea, British coasts (Hartlaub, 

 No. 38). 



Depth. 4 to 30 fathoms (E. J. A.). 



Habitat. On Antennularia ramosa, Delesseria sangidnea, on Salicornaria farciminoides 

 (= Cellaria fisttdosa) {fide Hincks). 



Ptriyoninius repens (Table VI.). A good colony of this hydroid was 

 found growing on the claw of Eupagurus Bernhardus, in haul 104, 

 on the fine sand of Ground II. The species was not found on any 

 other ground. 



