1907.] FnoM THE cape vepde islands. [61] 



sharp spine lying almost parallel to the continuation of the 

 branch. Tlie spiny appearance of the bi-anch-bearing processes 

 of the stem when denuded of their branches is also noteworthy 

 (c/. Allman, 1888, p. 72). 



Locality. Porto Pi-aya, Cape Yerde Islands : piles of pier ; 

 12th Augu,st, 1904. 



Other localities: — Of}\ Bermuda, 30 fathoms {^Challenger'); 

 Cape Verde Islands, 25 metres {Versluys); on floating gulf-weed 

 (^Albatross ') ; X.W. of Cape Blanc (Soudan), in 55 to 60 metres 

 (BiUard, 1900). 



In the colonies examined, the gonophores were all male and in 

 an advanced stage of development. Their structures i-esemble 

 those of Sertularia pamila as described hj Nutting (1904, pp. 26 

 et seq.), but in most, owing perhaps to the advanced stage of the 

 gonophore, the blastostyle is compai-atively small, and in no case 

 could be observeil to terminate in a thickened plug or " Decken- 

 platte." On the other hand, delicate strands of ectoderm stretched 

 from the outer coat of the gonophore to the gonaugial wall, to 

 which they were attached, thus mooring the gonophore within 

 the gonangium. Nutting, who also has found similar " guber- 

 nacula" in a male gonangium but aiising from a sperm-bearing 

 blastostyle instead of from a tiue gonophore, suggests that they 

 mav connect the ectoderm of the bla.stostyle, or in this case of the 

 gonophore, with a delicate ectodermal laj'er which in some cases 

 lines the inside of the gonangial walls (Nutting, 1904, p. 29). 

 In these specimens I have been unable to detect the presence of 

 an ectodermic gonangial layer such as Nutting describes. He 

 also suggests that they may possess the nutritive function 

 atti-ibuted by Wcismann (1883) to the gubernacula of "Sertalaria 

 pwnilu." 



Sertularia l.evimargin'ata, sp. n. (Plate XXVI. figs. 5 k 6.) 



Several minute colonics, less than 3 mm. in height, spring from 

 a creeping hydrorhizal tube which ramifies over a polyzoon- 

 encru.sted frond. The stems are unfascicled and unbranched and 

 are divided into distinct internodes, about 0-3 mm. long, which 

 become much constricted in the neighbourhood of the nodes. 

 The portion of the stem proximal to the fii-st distinct node, which 

 slopes at a high angle from buck to front, is athecate, but each 

 internode bears two opposite liydrothecai towards its distal end. 



The hydrotheciB rest upon a bvdging portion of the internode 

 and are somewhat ventricose, the bulging portions meeting on the 

 front of the stem, but lieing slightly sejaratcd, for O'Ol mm., 

 behind. For less than lialf their height they are adnate to the 

 stem, but the distal portion (about 0-28 mm. in length) bends 

 sharply outwaids, so that the apparent upper sides form an 

 almost straight horizontal line. The free portion becomes 

 gradually constricted and tube-like towards the margin, which is 

 smooth and is characterised b_v a shallow sinus on its upper edge 

 at the base of which is attached a disc-shaj ed adcauline operculum 



507 



