TARMANIAN IlYHUiiZOA — ItliKKiS. 295 



the fasciclcMl strucfiwe btMiisr cont iinicd io witliin IT) cm. of 

 tlie distal extremity. The iascicled poi-ticn of Ixiili I lie stem 

 and bi-aiiehes is composed of a series of tiihes \vi(li vciv iliick 

 bi'Owii-C()h)iii'ed walls, those towards the interior possessing- 

 much tliicker walls than those on the extei'ior of the colony. 

 In cross section the tubes aie compi'essed and almost cicsccntic 

 in outline. 



(hniOKdnic. — Tlie colonies are mature; the o-onan^i;! Ijciny 

 borne in i-ows along the fi'ont of the pinna\ to which they are 

 attached b\- a short stalk wliicli springs from the side of each 

 gona.nginm about 0"17 mm. from its lower end. '^J'hey ai'e 

 obovate bodies with seven or eight distinct transveise annula- 

 tions. The aperture is large with an elevated nnirgin ; the 

 neck being armed with several cui'ved, spine-like teeth, which 

 pi'oject inward and sliglitly upward toward the centre of the 

 aperture. 



Stem, diameter of cladate tube ... ... 0"54 mm. 



Pinna, length ... ... ... ... up to 48 mm. 



Pinna, diameter (including hydi'otheca^) ... O^T-O^SO mm. 



Hydrotheca, length ... ... ... 0'61-0"64 mm. 



Hydrotlieca, greatest diameter ... ... 012-0-15 mm. 



Gonangium, lengtli ... ... ... 1'41-153 mm. 



Gonangium, greatest diameter ... ... 0*68-0'75 mm. 



Dislribufioii. — Hitherto I'ecorded only from I'ort Molle, 

 Queensland (Bale) ; Station 54, within Jervis Bay, New 

 South Wales, 10-11 fathoms (Ritchie). 



Genus Sertularia, Liinnvnx. 



SeRTL'LARIA OPERCDLATA, Llllllil'ii.S. 



Sertnhd-'in niiercuhda, Linnaeus, Systema Naturae, 1758, p. 808. 

 /-/., Hincks, Brit. Hydroid Zoophytes, 1868, p. 26S, pi. 

 liv. /'/., Bale, Cat. Austr. Hydroid Zoopliytes, 1884, p. 

 67, pi. vi., fig. 1, j)l. xix., fig. 3. Id., Nutting, Amei'ican 

 Hydroids, pt. ii., — Sertiilai'ida^, 1904, p. 54, ])1. ii., figs. 

 3-5. hi, Bartlett, Geelong Natuiulist Vict., iii., 4, 1907, 

 p. 60. hi, Wai-ren, Anji. Natal Govt. Mas., i., 3, 1908, 

 p. 305. 



