BY W. M. BALE. 763 



the gonaugia are of a totally distinct type. Only one of the latter 

 was present, which was slightly distorted, so that its exact form 

 was rather doubtful, but it appeared to have two lateral wings 

 terminating upwards in angles at each side of the aperture. 



SERTULARELLA MICROGONA, von Lendenfeld. 

 (Plate XVI., fig. 8). 



Hydrocaulus simple, about 1 5 inch in height, composed of long, 

 slender internodes which are abbreviated above close to the 

 hydrothecaB, and are undulated somewhat spirally in their lower 

 portions. Hydrothecae barrel-shaped, rather slender, somewhat 

 contracted towards the aperture, with about three transverse 

 rugae ; adnate of their height or somewhat more, directed out- 

 wards and but slightly forwards ; aperture with four teeth and a 

 four-sided operculuni ; three internal compressed vertical teeth, 

 two of which are within the two upper emarginations of the 

 border, and the third opposite the inferior marginal tooth. 



Gonothecse 1 



Hab.PoYt Phillip. 



This species is a close ally of the S. tenella of Hincks, and is 

 very slender throughout. The portions of the intemodes below 

 the bydrothecsB are slightly waved, long, and tubular, often being 

 fully double the length of the hydrotheca. The internal teeth 

 are three in number, and are arranged precisely as in S. indivisa ; 

 but as S. microyoHa has four marginal teeth, the internal ones do 

 not alternate regularly with them, the lower one being opposite a 

 marginal tooth, while the others are between the three upper 

 marginal teeth. A close examination of specimens of S. polyzonias 

 from Port Phillip shows that a similar arrangement exists in that 

 species, though the internal teeth are so delicate and transparent 

 that they are easily overlooked. 



Dr. von Lendenfeld says that the gonangia of S. microgona, 

 are without rings, but his outline figure shows them transversely 

 wrinkled. 



