2:56 



a broader or narrower Iransverse l)rancli. In a small, niosl ol'k'n Irianf^nlar open- 

 ing, situated proxinially to llie Iwo large spines, we lind generally hnl a single, 

 very sliorl, rndinienlary, solid spine, more rarely two. 



The lateral chambers. The sii])ra-seapular chamber has a number of scat- 

 tered pores, and in the proximal pari of the basal surface a rounded excision, 

 which is somewhat larger liiaii these. The infra-scapular chamber has a small, 

 round or oval opening proximally, and the small ])edal chamber an oval or long 

 frontal opening, which is niiicii larger. The mother-zoa'cium has no adzoo'cial, 

 infra-scaindar chandjcr. It is characteristic of this species Ihal the last of (he 

 zoa^cia completing a row sj)ringing from a daughlcr-zoo-cium has a lerminal, 

 coini)resse(l, narrow, rhond)ically rounded chaini)tT (I'l. XX, lig. (> !)). 



The ooecium. 'I'he gonozocrcium, which is but half as high as the covering 

 kenozoa'cinm, is sometimes Ijorne by a mother-zoa'cium, sometimes by an in- 

 serted single zoo;ciuni. It is provided with a rather broad but low frontal sinus, 

 which is bounded on either side by a very short somewhat bent spine, and lliiis 

 the single pair of spines do nol meet as in the other sj)ecies. The sternal area 

 is much reduced and has 5 very small fenestras situated immedialely on the 

 proximal side of the aperture. Along its frontal, central line the covering keno- 

 zooecium is provided with two rather large ])ores, which may be somelimes single, 

 sometimes more or less deeply divided by a tongue springing from I heir dislal 

 margin. The two groujis of jiores and spinous processes within the long, hderal 

 fenestra^ meet in a median, generally angularly bent j)ortion, which reaches the 

 proximal of the two median pores. The small, terminal kenozocccium is s(jme- 

 times developed as an aviculaiium and then communicates wilh two small 

 cavities. 



Form of colony. In the principal branches two l)izo(ecial inlernodi's succeed 

 each other (2, 2, 1, 2, 2, 1 ....). 



Of this species I have examined colonies from I'orl Phillip. 



Costicella hastata Jkisk. 



Calenicella liaslala Husk, Voyage of Rattlesnake, I, pag. .'{.');), Catalogue of Marine 



Polyzoa, Pari I, p. 7, PI. 11, ligs. ;{, 4. 



(I'l. XII, (l-s. I e, 1 (I, 1 f, I n, 1 J, 1']. X\, li.i^s. Sa, SI)). 



The sternal area, which may be about twice the length of the ai)erture, lias 



7 — 1) fenestra', disposed in a long curve, and as many hollow spines, of which 



each is provided wilh a |)ore in or towards the end. I-^acb of the spines in the 



lirsl pair has however olliii two, which llien corres])ond with a bifuri'ale cavity. 



The lateral chambers. The supra-scapular clKuuber, which may somelimes 



