1910.] FROM METIGUI ARCIJIPELAGO. 815 



Dimensions : — 



Hydrotliecn , length 0-7-1 • 1 2 mm. 



,, diameter 0-10-0-14 mm. 



Length of flaps of operculum 0-1 1-0"13 mm. 



Localities. St. 1, east of Tavoy Island and Port Owen, 4 to 12 

 fathoms, sand and broken shells, and mud ; rare hydrothecse on 

 Thi/roscyphus vitiensis. St. 3, French Bay, King Island, and 

 south end of Iron Island, 3 to 8 fathoms, mud and rock, or sand ; 

 very rare, on Thyroscyphtis vitiensis. 



Family LAFoiiiD^. 



Lafoea serrata Clarke, 1 879. 



A widely distributed, but moderately rare species. Repeated 

 regeneration of tlie hydranth had furnished one liydrotheca (from 

 St. 22) with the exceptionally large number of eleven successive 

 margins. 



Localities. St. 1, east of Tavoy Island and Port Owen, 4 to 12 

 fathoms, sand and broken shells, and mud ; fairly common, on 

 Idia pristis. St. 9, between Bentinck Island and Courts Island, 

 12 to 26 fathoms, sand and shell; very rare, on Thyroscyphus 

 tritiensis. Stt. 15 and 16, Ravenshaw Island, Sir John Malcolm 

 Island, and Alligator Rock, 5 to 18 fathoms, rock and sand, or 

 rock and mud ; rare, on Idia pristis. St. 22, Hastings Harbour, 

 shore to 20 fathoms, rock and sand ; fairly common, on Thyro- 

 scyphus vitiensis and Idia pristis. St. 23, Five Islands, 8 to 12 

 fathoms, rock and sand, and mud ; rare, on Eadendrium attenua- 

 tum'i St. 25, Gregory Group and Crichton Island, 4 to 14 

 fathoms, stones and broken shells, and rock ; rare, on Idia pristis. 

 St. 35, between Warden Island, Howe Island, and Lyall Island, 

 15 to 20 fathoms, rock and sand ; rare, on Idia pristis. 



LAFoiiA VENUSTA Allman (?), 1877. (Plate LXXVI. figs. 5 & 6.) 



Various Hydroids have associated with them a small foi-m 

 which I refer, with a query, to this species. 



The trophosome consists of a creeping hydrorhiza from which 

 spring small cylindrical hydrotheca?, set on stout but variable 

 stalks, and zoned by numerous, well-defined, and regular corru- 

 gations. These decrease in distinctness towards the base of the 

 hydrotheca. The margin of the hydrotheca is everted, and the 

 stalk bears no regular rings. A marked and distinctive character 

 exists in the colour of the perisarc which possesses a brownish - 

 smoke tint, slightly variable in density. An exceedingly delicate 

 membrane forms the floor of the hydi'otheca. 



The hydranth is cylindrical and minute, furnished with a 

 hemispherical hypostome, surrounded by tentacles varying in 

 number from nine to eleven. The tentacles and body of the 

 hytlranth have a gi^anular appearance owing to the presence 

 of scattered nematoey.sts, which do not seem, even in the tentacles, 



53* 



