SERTULARELLA GAYI. 237 



single sporosac ; and the eggs at a certain stage of their 

 development are discharged from it into an external mar- 

 supium, in Avhich they are matured into free, ciliated 

 embryos (planufa) . Ellis, with his accustomed accuracy, 

 has figured it in this condition, surmounted by the delicate 

 sac crowded with the ripening ova. 



The male and female capsules differ considerably in size, 

 the former being the smaller and of a whitish colour, whilst 

 the female are coloured yellow by the contents. 



Hab. On shells, seaweeds, &c. ; generally distributed 

 round our coasts. 



[Massachusetts, robust var. ; Greenland, do. (Sars) : 

 Iceland, do. (T. H.) : Newfoundland (Landsborough) : 

 Straits of Belle Isle, between tide-marks, common, in 

 deeper water very stout and large (A. S. Packard, j mi.): 

 Grand Manan, Bay of Fundy (Stimpson) : Madeira; 

 South Africa; Falkland Islands (Busk) : Red Sea (T. H.): 

 La Charente inferieure (Beltremieux): Lussin Piccolo, 

 Adriatic (Grube): Mediterranean (Cavolini).] 



2. S. GAYI, Lamouroux. 



SKRTTLARTA GAYI, Lamx. Expos. Mth. 12, tab. Ixvi. figs. 8, 9 ; HincJcs, Cat. 



Devon and Corn. Zooph., Ann. N. H. (3rd ser.) viii. 2r>2; 



Alder, Cat. North. Zooph., SuppL, in Trans. Tynes. F. C- 



v. 23(i. 



ERICOIDES, var., Pall. Elench. 128. 

 LA SEUTULAIRE DE GAY, Blainv. Man. d'Actinol. 481. 

 SERTULARIA POLYZONIAS, var. /3, Johnst. B. Z. Gl, pi. x. fig. 2. 



Plate XLVI. fig. 2. 



SHOOTS erect, composite, pinnate; BRANCHES alternate, 

 approximate, obliquely jointed, of various lengths, giving 

 off ramules here and there ; HYDROTHECTE urceolate, dis- 

 tant, one to each internode, frequently wrinkled, swollen 

 below, narrower and divergent above, with a 4-toothed 

 aperture ; GONOTHEC^: elongate, ovate, tapering towards 



