A FOSSIL MARINE PIATOMACEOUS DEPOSIT. 73 



N. sandriana, Grim. (A. Sell., "Atl.," PI. 70, Fig. 49).— 

 Rare. 



N. definita, n. sp., Gr. and St. — Valve large, ovato-lanceolate, 

 with obtuse rounded ends. Strias subradial, about 40 in 

 '001", occupying a space rather exceeding one-quarter of the 

 width of the valve, and having a very distinctly defined clear 

 space on each side of the median line. Central and end 

 nodules dilated transversely. Varies in length and breadth. 

 Typical specimen '0077" long, '0022" broad. Not very scarce. 

 (PI. VI, Fig. 11.) 



Ampliiprora rugosa, Pet. (" Diat. de l'lsle Campbell," p. 29, 

 PI. 5, Fig. 17). — One specimen pretty closely agreeing with 

 Petit's figure has been brought to our notice by W. J. Gray, 

 Esq, M.D. 



A ? ? cornuta, Chase (" Notes on New and Rare Diat," p. 2, 

 PI. 1, Fig. 6). — This form, which is certainly not an Amphi- 

 prora, occurs not infrequently. 



FRAGILARIEJ1. 



Dimeregramma fulvum (Greg.), Ralfs. (Denticula, " G. D. C," 

 p. 24, PI. 2, Fig. 38).— Frequent. 



Plagiogramma (constrictum var. ?) nancoorense, Grun. ("Nov.," 

 p. 94, PI. la, Fig. 8). — One worn specimen discovered by Herr 

 Weissflog. 



P. neo-gradense, Pantocsek (" Diat. Hungary," PI. 8, Figs. 63 

 and 71). — Rare. 



P. tesselatum, Grev. (" Q. J. M. S," Vol. vii, p. 208, PI. 10, 

 Fig. 7). — Narrower than the type. Rare. 



Stictodesmis australis, Grev. (" Ed. Trans. Bot. Soc," Vol. 

 vii, p. 535, PI. 13, f. 1-4). — Rare. 



Nitzschie^;. 



Nitzschia grundleri, Grun. (Cleve, " West Ind. Diat," p. 14, 

 PI. 4, Fig. 24).— Rare. 



2V7 antiqua, n. sp, Gr. and St. — One perfect valve and several 

 broken specimens have occurred hitherto. The ends suggest 

 Synedra, but in general appearance and in the character of the 

 striation, it resembles Nitzschia ; in which we place it with hesi- 

 tation. Keel narrow w r ith obscure puncta, surface of valve 

 covered with irregularly arranged dots, which take the form of 

 short parallel lines about 19 in '001" close to the ventral margin. 



