1910.] FEOM MERGUI ARCHIPELAGO. 823 



the teeth in general. The margin of the mesial sarcotheca is 

 .slightly sinuated. 



The attachment of the hydroclades to stem and branches is 

 weak, for, whenever an attempt is made to clear the specimen 

 of flesh, by immersion in a solution of sodium hydrate, the liydro- 

 clades invariably fall off. 



The soft parts of the specimens from Station 9 are woll jiro- 

 served, as the preservation of Plumularians in geneial collections 

 goes. The tentacles are about sixteen in number. The whole of 

 the inside of the hydrotheca, practically to the margin, is lined 

 with a thin layer of ectoderm, with which the hydi-anth is in 

 connection by means of exceedingly numerous strands which, 

 proceeding from its ectodermal layer, give the appearance of 

 filling the space between hydrotheca and hydi-anth with a delicate 

 open meshwork. An opening leads from the hydrotheca cavity 

 to that of the mesial sarcotheca, immediately proximal to the 

 point where the sarcotheca joins the hydrotheca, and tlirough 

 this passes a strand of coenosarc, connecting sarcostyle and 

 hydranth. 



A hydrotheca was observed, abnormal in lacking a mesial 

 sarcotheca. 



Localities. Specimens from Stt. 9, 18, 19, 25 bore phylactocarps. 

 St. 9, between Bentinck Island and Courts Island, 12 to 26 

 fathoms, sand and shells; one colony. St. 18, west and south- 

 west of Paye Island, 10 to 21 fathoms, sand, shells and rock ; 

 a large colony. St. 19, Paye Island and Pink Island, 7 to 9 

 fathoms, rock and sand ; fragment. St. 25, Gregory Group and 

 Crichton Island, 4 to 14 fathoms, stones and broken shells, and 

 rock ; three colonies. Moskos Islands, 3 to 26 fathoms, rock 

 and sand, or rock and mud ; fragment. 



Lytocaepus PHCENiCEUS Busk, 1852. 



The hydrothecse of these specimens approach most closely those 

 of Bale's fig. 2, pi. xv., 1884, although the chitinous septa and 

 walls are not so strongly developed in my specimens, and the 

 small lobe at the back of the hydrotheca is not produced into a 

 tooth. There are two sarcotheca at the base of each liydroclade 

 — one proximal, the other lateral— and, in addition, a sarcostyle 

 issues through a mere perforation with raised lips, on the anterior 

 of the stem-process on which the hydroclade is borne. 



Localities. Stt. 15 and 16, Ravenshaw Island, Sir John Mal- 

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

 or rock and mud ; three colonies. St. 32, south-west of Domel 

 Island, 26 to 29 fathoms, sand and mud ; one colony. St. 35, 

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

 20 fathoms, rock and sand ; one colony. Moskos Islands, 3 to 

 26 fathoms, rock and sand, or rock and mud ; one colony. 



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