138 PROP. ALLMAN ON NEW HTDEOIDA TEOM 



These differences, however, obvious as they are, may possibly 

 be only of varietal value, and insufficient to justify a separation 

 of the present form from Synthecium elegans. 



Seettjlaima. 



Seettjlaria apeeta, n. sp. (PL XIII. figs. 1, 2.) 



Trophosome. — Stems slender, monosiplionic, much-branched, 

 with the ramification subdichotomous. Hydrothecse exactly 

 opposite, adnate for about half their height to the internode, and 

 then widely divergent ; aperture extending along the whole of the 

 posterior side of the free portion of the hydrothecse ; margin 

 deeply indented at the apocauline side, so as to present here two 

 long sharp teeth. 



Gonosome not known. 



Locality. Cape of Good Hope. 



This is a slender species, the colony attaining a height of about 

 one inch, and with the habit of Sertularia operculata, to which it 

 would seem to be nearly allied. It grew upon a seaweed along 

 with Aglaophenia chalarocarpa, see p. 150. 



Seetulaeia minima, lyA. W. Thompson*. (Pi. XIII. figs. 3, 4.) 



Trophosome. — Stem simple, monosiphonic, springing at short 

 intervals from a creeping network of tubular fibres, and carrying 

 usually from four to ten rather closely approximate pairs of 

 hydrothecse, which commence at some distance from the proximal 

 end and are continued to the distal. Hydrothecse deep, tubular, 

 adnate to the internode for nearly their whole height, and with 

 the apocauline edge of the aperture deeply cleft. 



Gonosome. — Gonangium springing from the stem just below 

 the proximal pair of hydrothecse, large, widely pyriform, destitute 

 of annulation, opening distally by an orifice raised on the summit 

 of a very short wide tube. 



Locality. Cape of Good Hope, where it occurs creeping over 

 the surface of a rooted species of Sargassum. 



This very minute species has been already described by Mr. 

 D' Arcy "W. Thompson from the Gulf of St. Vincent, and by Dr. 

 Coughtrey and Mr. Bale from New Zealand and Australia. It 

 attains a height of only one fourth of an inch, and is rendered 

 striking by the large size of its gonangia, which are always borne 

 singly just below the proximal pair of hydrothecse. The creeping 

 stolon from which the stems arise has the inner layers of its walls 

 * Ann. & Mag. Nat. Hist. ser. 5, vol. iii. p. 104 (Feb. 1879). 



