1910.] 



PROM MERGUI ARCHIPELAGO. 



189 



Thyone sacellus Selenka. 



Stolus sacella Selenka, 1867 (6). 

 Thyone rigida Semper, 1868 (7). 

 Stereoderma murrayi Bell, 1883 (11). 

 Thyone sacellus Bell, 1884 (12). 

 Stereoderma murrayi Lam pert, 1885 (13). 

 Thyone sacellus Lampert, 1885 (13); Bell, 1886 (14). 

 Thyone sacella Thee], 1886 (15). 



Thyone sacellus Sluiter, 1887 (18) ; Ludwig, 1891 (19) ; 

 Sluiter, 1901 (20); Pearson, 1903 (21). 



Text-fiff. 20. 



mJiMM 



Tin/one sacellus. 



A. Spicule. X 450. 



B. Calcareous ring. X 8. 



r. = radial, i.r. = inter-radial. 



One specimen from Station XXV. Gregory Group. 

 Length 33 mm. ; breadth 8 mm. 



