812 MR. J. RITCHIE ON HTDROIDS [Maj- 24, 



Harbour, shore to 20 fathoms, rock and sand. St. 23, Five 

 Islands, 8 to 12 fathoms, rock and .sand, and mud ; two colonies. 

 St. 25, between Warden Island, Howe Island, and Lyall Island, 

 1 5 to 20 fathoms, rock and sand ; many colonies. 



This species has already been recorded from the China Sea 

 (Jaderholm, 1896, p. 9), and from Bird Island, Algoa Bay, Cape 

 Colony (Warren, 1908, p. 344, as T. ceqiialis). 



Thtrosctphus vrriESSis Marktanner-Tumeretscher, 1890. 



A widely distributed species, occurring at eight of the fourteen 

 stations from which Hydroids were obtained. In this, as in 

 T. regidaris, the h3'dranth is attached to a row of minute chitinous 

 prominences on the inside of the lower portion of the hydrotheca. 

 These are an-anged as in the previous species, but they are moie 

 strongly developed, and are placed on a slightly raised portion 

 of the hydi'othecal wall. 



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

 fathoms, sand and broken shells, and mud ; common. St. 3, 

 French Bay, King Island, and south end of Iron Island, 3 to 8 

 fathoms, mud and rock, or sand ; common. St. 9, between 

 Bentinck Island and Courts Island, 12 to 26 fathoms, sand and 

 shells ; rare. St. 14, Bushby Island pearling-gi-ound, shore to 

 21 fathoms, sand and mud; rare. Stt. 15 and 16, Ravenshaw 

 Island, Su" John Malcolm Island, and Alligator Rock, 5 to 18 

 fathoms, rock and sand, or rock and mud; rare. St. 19, Pave 

 Island and Pink Island, 7 to 9 fathoms, rock and sand ; rare. 

 St. 25, Gregory Group .and Crichton Island, 4 to 14 fathoms, 

 stones and broken shells, and rock ; fairly common. St. 35, 

 between Warden Island, Howe Island, and Lyall Island, 15 to 

 20 fathoms, rock and sand ; lare. 



Family Campaxulinid^. 

 Opercclaeella lacerta Johnston, 1847. 



Identification depends upon trophosome characters alone, the 

 gonosome being absent. I can detect nothing, however, -which 

 could distinguish these specimens from Xorth Sea examples of 

 the above species. It occurs in its simplest form, a creeping 

 stolon, sending up here and there short ringed stalks, on each of 

 which is poised an exceedingly hyaline hydrotheca. 



Dimensions : — 



Hydrotheca, depth * 0-21 mm. 



diameter 0-08-0-O9 mm. 



Peduncle, diameter 0-04 mm. 



LocaliUj. jMoskos Islands, 3 to 26 fathoms, rock and sand, or 

 rock and mud ; rare, growing on a stem of Plumularia setacea. 



Although the range of the species is a wide one, for it has 

 been recorded from the North of Europe, from both sides of the 



* From top of operculum. 



[UJ 



