106 Proceedings of the Royal Society of Victoria. 



pinna a little above the base, almost crossing the cell and curving 

 towards the aperture ; margin with a median anterior tooth and 

 three on each side, the last pair often hidden behind the lateral 

 sarcothecse ; back entire, adnate ; front of hydrotheca with an 

 external longitudinal ridge, terminating in an elevated pointed 

 tooth over the anterior tooth of the margin (sometimes absent). 

 Hydrothecal internodes with two folds, one opposite the fold of 

 the hydrotheca, the other at the base of the lateral sarcotheca?. 

 Mesial sarcotheca about three-fourths the length of the hydro- 

 theca, adnate most of its length, slightly projecting, terminal 

 and lateral apertures distinct or united. Lateral sarcotheca; 

 divergent, adnate up to the hydrotheca-margin, free terminal 

 portion short, conical, directed forward, terminal and lateral 

 apertures united. Cauline sarcothecse stout, with open margin, 

 two on the stem at the base of each pinna. 



Gonangial pinna generally springing from the basal part of a 

 branch, and bearing only sarcothecse on about the first five inter- 

 nodes. Corbula large, closed, composed of about nine pairs of 

 broad leaflets, the junction-lin»s marked by thickenings, which 

 towards the front of the corbula generally rise into free promi- 

 nent expansions, and which are beset with short, conical, 

 canaliculate sarcotheca?, except at the base, where each gives off" 

 a stout process armed with a very broad sarcotheca and a longer 

 and narrower pointed one below it ; each leaflet abruptly narrowed 

 on the proximal side near the base, leaving a series of openings 

 along each side of the corbula. A large sarcotheca projecting 

 into the corbula from the basal part of each leaflet. 



Colour. — Ligh t-brown. 



Hab. — Rottnest Island, Western Australia. 



This handsome species was obtained by Mr. A. H. Courderot, 

 and by him given to Mr. A. J. Campbell, to whom I am indebted 

 for the opportunity of describing it. 



Halicornaria ascidioides, Bale. 

 (Plate v., fig. 1.) 



Gonothecse in two rows, springing from the bases of the 

 hydrocladia, somewhat pyriform, with the top flattened, and a 



