300 ERNEST WARE EN. 



be possible to arrive at any decision as to whether or not the 

 Pacific hydroid should be regarded as the same as the Natal 

 hydroid. In the meantime it has been considered advisable 

 to give a new name to the present hydroid, and tumid a has 

 been chosen on account of the swollen condition of the 

 hydrotheca. 



(14) Sertularella campanulata sp. n. (PI. XLVII, figs. 



21 and 22.) 



This minute but remarkable hydroid occurs creeping on 

 sea- weeds, often in company with Pasythea quadriden- 

 tata. It has been found at Scottburgh and Park Rynie, but 

 is not particularly common. The habit of growth is more like 

 that of a Campanularian than a Sertularian, and the species is 

 clearly allied to Sertularella sol it aria Nutting, from the 

 Bahamas, and Calamphora parvula Allman, Bass Strait, 

 Australia. 



Trophosome. — Hydrorhiza consists of a creeping, some- 

 what flattened stolon branching sparingly or forming a loose 

 reticulum. 



Diameter O'OGl mm. On the surface attached to the sea- 

 weed the perisarc is very thin, while on the outer surface it 

 has a moderate thickness, 8*2^ (PL XLVII, fig. 22, R.). 



Hydro caulus. — Short stems, with 2-5 spiral turns, arise 

 from the hydrorhiza and carry a terminal hydrotheca (fig. 

 22, H.) . The stems appear always to arise at an angle of about 

 45° with the hydrorhiza, and they sometimes come off sloping 

 alternately to the right and left sides of the hydrorhiza. 



The diameter of the hydrocaulus (which is practically the 

 peduncle of the hydrotheca) is 0"083 mm. and the average 

 length 0'16 mm. The thickness of the perisarc is about 8'7fji. 



Hydrotheca. — Barrel-shaped, set terminally on hydro- 

 caulus, provided with 5-7 well-marked transverse ruga' ; the 

 proximal portion is sometimes smooth. The mouth is 

 quadrangular and expanding, and has 4 pointed teeth, which 

 appear to be arranged in a definite manner with respect to 



