392 Transactions of the Society. 



and longitudes ]41°-143^ E., in from fourteen to thirty-seven 

 fathoms.* 



The next instance of the occurrence of Heteropora is interesting, 

 as being found under somewhat parallel circumstances. 



In the Australian seas there is a Cellepora, probably common, 

 as I have seen it in several collections. It grows round the stalks 

 of seaweeds, &c., and is raised into ridges irregularly encircling the 

 zooarium (Fig. 8), with zooecia on each face of the ridge, so that 

 it may be said to have in part a biserial growth, and this is known 

 in Mesenteripora, Reticulipora, Eschara, Flustra, Biflustra, &c. 



I have not been able yetf to identify it with any described 

 species, and in my own collection distinguish it as G. repleta (thus 

 in part retaining the meaning of the generic name Plethopora). 



It is not, however, with this we have now to deal, but with a 

 Bryozoon (Fig. 9) of quite similar mode of growth, found in a small 

 boxful of the Celleporae, just mentioned, which my sister picked 

 up on the Semaphore near Adelaide ; however, as soon as it is put 

 under the Microscope, it is seen to be a Cyclostomatous Bryozoon, 

 and I do not at present see any reason for placing it in any other 

 genus than Heteropora. 



The zooecial apertures (Fig. 10) are more irregularly placed 

 than in the last species, in which the region of the aperture was 

 only slightly raised ; but here it is elevated in a tubular form, and 

 the walls of the cancelli are also elevated. The perforations of the 

 cancelli covers are larger, with the white rim round each hole very 

 distinct. Where this film is removed (Fig. 11) there are spinous 

 protuberances round the aperture. 



This is apparently the PlethojJora cervicornis d'Orb., 'Pal. 

 Fr.,' pi. 799, figs. 4, 5, found in the Senonien, and which is placed 

 by him among the Cyclostomatous forms, but until I discovered 

 this recent one I had always supposed the figure represented a 

 worn specimen of Cellepora, similar to the one already mentioned. 



Heteropora cervicornis d'Orb. 



Plethopora cervicornis d'Orb., 'Pal. Fr.,' vol. v. p. 1045, pi. 799, 

 figs. 4, 5. 



Zooarium incrusting stalk of seaweed, raised into irregular 

 ridges. Zooecial aperture crateriform ; cancelli, mostly one series 

 round the zooecium, covers perforated with few large holes. 



* There are from the same locality stems of varying sizes, some not more than 

 half the diameter figured, but whether they are all the same species I cannot say 

 with certainty. If the material liad been my own, I should have chipped frag- 

 ments otr all and made detail examination, but this could hardly be allowed in a 

 national collection, and I have to thank the Museum authorities for allowing me 

 to make sections of a broken fragment. 



t I take this opportunity of saying I hope shortly to carefully study the 

 Australian recent and tertiary Bryozoa, and shall be glad of any assistance that 

 Jiaturalists can give me. 



