842 L. A. BORRADAILE. 



14. Thuiaria attenuata (Hincks) subsp. (14, p. 247). 



Unlike that of Hincks' type, the hydrocaulus of this form is unbranched, consisting of 

 simple stems without pinnae arising from a branched, creeping hydrorhiza. In all other 

 respects it is exactly like the type. 



Schneider puts this species in Dynamena (= Sertularia), but it agrees better with his 

 definition of Thuiaria. 



Dredged in 25 fathoms in N, Male Atoll. 



15. Thuiaria maldivensis n. sp. (PI. LXIX. fig. 6.) 



Definition: A Thuiaria whose hydrocaulus is not pinnate, the stems, which may reach 

 a height of 1 cm. and have no hydrothecae on the lower part and no nodes except one just 

 below the hydrothecae, arising separately from a creeping hydrorhiza ; while the hydrothecae 

 are set at moderately wide intervals, opposite, and turned sharply outwards with a crease, a 

 short free part, and a point on each side of the opening. 



Dredged in Suvadiva Atoll in 31 fathoms. 



Genus Sertularia. 

 Sertularia has priority over Dynamena as a generic name for this group of species. 



16. Sertularia digitalis Busk (12, p. 393; 7, p. 101). 



I can find no difference between my specimens and the type of this species as defined 

 by Bale. As this author points out, there is a very great likeness between it and the 

 Besmoscyphus longitheca of Allman from the West Indian region (5, p. 24). 



Dredged in 20 fiithoms in N. Male Atoll. 



Genus Idia. 



17. Idia pristis Lamouroux (15, p. 200; 7, p. 113). 



The hydrothecae of my specimens are directed more sharply outwards than those of 

 AUman's and have a more pointed outline than Bale's. 



Dredged in Suvadiva and N. Male Atolls in 38 and 25 fathoms respectively. 



Family Plumularidae. Genus Aglaophenia. 



18. Aglaophenia phoenicea (Busk) subsp. (12, p. 398; 7, ji. 159). 



My specimens differ from Busk's, as figured by Bale, in the following ways : (1) the 

 middle nematotheca is rather shorter and stouter, (2) the side nematothecae are more upright, 

 (3) the sides of the hydrothecae are less deeply notched. 



Dredged in Male, Addu, S. Nilandu, and Mahlos Atolls in 20 — 30 fathoms. 



19. Aglaophenia sinuosa Bale subsp. (8, p. 790). 



The middle nematotheca in the Maldive specimens has a wide, swollen end, unlike that 

 figured by Bale. 



Dredged in Male, Suvadiva, and N. Male Atolls in 25 — 38 fathoms. 



