216 Frederick Chapman.- 



Occurrence. — This species was found in the Silurian (Yerin- 

 gian) of Cave Hill, Lilydale, by the writer in 1902. 



Alveolites regularis, sp. nov. 



Description. — Corallum compact, forming comparatively large 

 masses, occasionally as low divergent branches. One specimen 

 measures over 9cm. in expanse. Corallites polygonal or sub- 

 triangular to rounded, averaging .5mm. in diameter, with a strong 

 projecting tooth, and very minute spiny septa. Walls of corallites 

 moderately thick, divided by horizontal tabulae fairly regularly 

 spaced, about 10 in 5mm. Pores rare, large, situated in the 

 angles of corallites. 



Affinities. — This form also sfiows certain characters common 

 to A. sub orbicularis, but is distinguished by the regularity of the 

 corallites. . It also approaches A. vallorum, Meek 9 , a Devonian 

 species of Canada, especially in the fine and delicate spiniferous 

 septa. 



Occurrence. — Silurian (Yeringian), Cave Hill, Lilydale. Type 

 presented to the Museum by F. Chapman. Also found at Cooper's 

 Creek, Thomson River, Gippsland ; presented by the late Rev. A. 

 W. Cresswell, M.A. 



Genus Pleurodictyum, Goldfuss. 

 Pleurodictyum megastomum, Dun. 



Pleurodictyum megastoma, McCoy, 1867, Intercolonial Exhi- 

 bition Essays, 1866. On the recent Zoology and Palaeontology of 

 Victoria, p. 23 footnote (nomen nudum), also Ann. and Mag. 

 Nat. Hist., 1867, ser. 3, vol. xx, p. 201. 



Pleurodictyum problematicum, Goldfuss, Foerste, 1888, Notes 

 on Palaeozoic Fossils. Bull. Sci. Lob. Denison Univ. vol iii., 

 p. 132, pi. xiii., fig. 22. 



Pleurodictyum sp. indet., R. Etheridge jnr. 1896, Descr. Tas- 

 manian Silurian Fossils, from Rep. of Secy, for Mines, p. 31, 



P i. i„ % »; 



Pleurodictyum megastomum, Dun, (McCoy MS.), 1898, Proc. 

 Roy. Soc. Vict., vol. x. (N.S.), pt. ii., p. 83, pi. iii., figs. 1, 2. 



P. megastomum, Dun, Chapman, 1903, ibid., vol. xv. (N.S.), 

 pt. ii., p. 105, pi. xvi., figs. 2-5. Idem, 1914, Australasian Fossils, 

 p. 114 and fig. 69E. 



9. Trans. Chicago Acad. Sci., vol. I., 1868, p. 86, pi. XL, figs. 9, 9a. 





