ALDINGA AND THE KIYER-MTJERAT CLIFFS, SOUTH AUSTRALIA. 309 



divisions, while in the fossil the dorsal sulci are not very marked, 

 and there are but few pores in each quadrangular division ; again 

 they are more numerous in the Charlotte-Bay example. The dif- 

 ference between this and C. guineensis and C. stellata consists in 

 the lamina not extending up to the distal border ; but this is a vari- 

 able character, and probably all three should be united under one 

 name. 



Log. Living : Madeira and Canaries ; Princess-Charlotte Bay 

 (sent by Mr. Brazier) ; Florida, common, 10-44 fathm. (Sm.). 

 Fossil : Miocene — Austria and Hungary. Pliocene, Crag — Hills of 

 Pisa, Castelarquato, Asti, Mt. Mario, Ehode Island ; Tortonian 

 and Saharian of Reggio (Calabria) (Seg.) ; Aldinga. 



73. Sele:n-aria maculata, Busk. 



Selenaria macttZato, Busk, Cat. Mar. Polyz. p. 101, pi. cxvii. ; 

 Waters, Quart. Journ. Geol, Soc. vol. xxxix. p. 440, pt. xii. figs. 7, 

 9, and 12. 



A specimen from the Eiver-Murray Cliffs is about 6 millim. in 

 diameter, and is exactly similar to specimens from Muddy Creek 

 and Bird Eock. The dorsal surface is divided by radiating ridges, 

 between which, there are single or double rows of large pores. 

 Another specimen from Aldinga (sent over as Lunulites rutella) has 

 smaller zocecia and very few vibracular chambers, and on the dorsal 

 surface there are, instead of the large pores, long erect tubes, which 

 may serve for attachment. 



Besides the species named there is a small cylindrical fragment 

 of what I believe is Lejpralia (Onchojpora) immersa, Haswell ; but 

 with so small a piece, imperfectly preserved, I cannot feel sure of 

 the determination. The collection also contains a Membranipora 

 from the Eiver-Murray Cliffs which belongs to the M.-simiifera 

 group, and another with oval opesia and a small avicularium above 

 the opening, which might be M. levata. Hincks. 



Upon reexamining the Mt.-Gambier collection I find that a 

 specimen which I thought was Retepora rimata, W., is R. jacJc- 

 soniensis, Busk ('Challenger' Eeport, p. 125, pi. xxvii. fig. 4). 

 These two species are very closely aUied, bat the avicularia differ in 

 shape. A further study as to the range of variability of R. jacJc- 

 soniensis would be of great interest. 



EXPLANATION OF PLATE VII. 



Fig. 1. Membranipora rhyncTiota, Busk. The zooecia on the left have ovicells; 

 those on the right are without. 



2. Mono^porella sexangularis, G-oldf. From specimen fig. 13. 



3. Membranvpora aperta, Busk. 



4. Micropora patula, Waters. 



5. Membranipora par vicella, T. Woods. 



6. Microporella elevata, T. -Woods ; showing marginal avicularia. 



7. Microporella magna, T.- Woods. 



a. J. 0. S. No. 163. z 



