248 R. M. Brydone — Chalk Polyzoa. 



1906. " Prom the Ice Age to the Present " : Scottish Geogr. Mag., vol. xxii, 



pp. 397-407. 

 "On the so-called 'Postglacial Formations' of Scotland": Journ. 

 Geol. Chicago, vol. xiv, pp. 668-82. 



1907. .''Old Scottish Volcanoes": Scottish Geogr. Mag., vol. xxiii, 



pp. 449-63. 

 " Late Quaternary Formations of Scotland" : Zeitschr. fiir Gletscher- 

 kunde, Bd. i, pp. 21-30, fig. 



1908. Structural and Field Geology for Students, etc. 2nd ed., pp. 443, 



56 pis., 8vo, Edinburgh and London. 



1909. Earth ScuJpture, or the Origin of Land-forms. 2nd ed., Bvo, London. 

 " Calabrian Earthquakes": Scottish Geogr. Mag., vol. xxv, pp. 113- 



26, figs. 



1911, "The Architecture and Origin of the Alps": ibid., vol. xxvii, 



pp. 393-417,. figs. 



1912. Structural and Field Geology for Students, etc. 3rd ed., pp. 452, 



69 pis., 8vo, Edinburgh. 



" The ' Deeps ' of the Pacific Ocean and their Origin " : Scottish Geogr. 

 Ma,g., vol. xxviii, pp. 113-26, map. 



Memoirs of the Geological Survey of Scotland (partly contributed to by 

 J. Geikie). Sheet Memoirs : 1869, Sheet 7 (Ayrshire, South- 

 Western District), Sheet 14 (Ayrshire, Southern District), Sheet 24 

 (Peeblesshire) ; 1872, Sheet 22 (Ayrshire, North part) ; 1873, 

 Sheet 23 (Lanarkshire, Central Districts) ; 1879, Sheet 31 (Stirling- 

 shire).' 



II. — Notes on new ok imperfectly known Chalk Polyzoa. 

 By E. M. Brydone, F.G.S. 



(Continued from the May Numher, p. 199.) 

 (PLATE VIII.) 



AVICULARIA of what I have called the Zestieuri-tjpe are not 

 confined to Memhranipora. There are at least two species 

 provided with them which come nearer to SemiescJiara. 



Semieschaea labiatdla, sp. nov. (PI. VIII, Figs. 1-4.) 

 ' Zoarium always adherent. 



Zooecia subpyriforra, with separate side walls which are broad and 

 pass gradually down into the front wall ; apertures large and sub- 

 triangular, with the apex flattened owing to the development of 

 a slight internal front wall, fairly straight sides with a tendency 

 to bulge inwards tovyards the top and a lower lip always more or less 

 convex with an upturned tip Mdiicb catches the light and is very 

 useful for rapid recognition ; these convexities are most marked in 

 the later forms and may be so pronounced as to make the aperture 

 definitely trifoliate (Fig. 4). 



Ocecia abundant, narrow helmet-shaped swellings of the foot of the 

 succeeding zooecium. 



Avicularia abundant and typical ; aperture broadly elliptical, but 

 with a distinct tendency to assimilate itself in general outline to the 

 zooecial aperture (especially in the lower lip, which may be strongly 

 convex), the lower section nearly or quite equal in size to the upper; 

 the infold. of the side Avail sudden, with a concave edge; avicularia 

 of a modified form looking as if a small zooecium had been set into the 

 aperture of a normal avicularium occur very sparingly (Fig. 2). 



