A FOSSIL MARINE D1AT0MACE0US DEPOSIT. G9 



0. Bothii, Gran. (I.e., PL 100, Figs. 20, 22).— Scarce and 

 smaller than the type. 



G. angulatus, Grev. ("T.M.S.," Vol. xii., p. 9, PI. 2, Fig. 11). 

 --Corresponding closely with Greville's description and figure, 

 •0025" to '003" in diain., usually with eight, but occasionally 

 with 10, and even 12 small marginal processes. Very common. 



C. Kutzingii, A. Sch. (Gran., " F. J. L.," p. 32, PL D, Fig. 

 18).— Diam. -0025'/ to -003". Scarce. 



G. curvatulus, Grun. (I.e., pp. 30, 31). — A small variety present, 

 but scarce. 



C. eccentricus, Ehr. (A. Sch., "Atl.," PL 58, Figs. 48,49). 

 — Not scarce, small. 



G. minor, Ehr. (I.e., PL 58, Fig. 39). — We class as this a 

 small form about '001" diam., with cellules arranged somewhat 

 as in G. eccentricus. Wot unfrequent in the lighter part. 



G. concavus, Greg., nee. Ehr. (" G. D. C.," p. 28, PL 2, Fig. 47). 

 — This form appears to us to be identical with recent specimens 

 of Gregory's species from the Orkney Islands. Diam. to *0075". 

 Cellules punctate, six in "001". This appears to be the same 

 as Greville's C. pulchellus (" T. M. S.," Vol. xiv, p. 3, PL 1, 

 Fig. 7), found in the Barbadoes deposit. W. Smith's Melosira, 

 cribrosa ("Ann. Wat. Hist.," Jan., 1857, p. 13, PL 2, Fig. 15), 

 may possibly be a smaller form of the same. Frequent. 



G. elegans, Grev. (" T.M. S.," Vol. xiv, p. 3, PL 1, Fig. 6).— 

 Type form, very rare. 



G. elegans, Grev. var. spinifera, Gr. and St. — Valve with central 

 conical elevation rising from a circular depression. Centre 

 filled with crowded fine granules, from which to the margin 

 radiate lines of larger granules, the spaces between which at 

 the outside are filled up by short lines, leaving distinct subulate 

 clear spaces between the marginal and central portions. On 

 the margin, which is striate, are from 20 to 30 small pro- 

 cesses. Frequent. Diam., to "0035". This form is akin to 

 Cestodiscus. (PL V., Fig. 9.) 



G. nitidus, Greg. (" G. D. C," p. 27, PL 2, Fig. 45).— Scarce. 



G. scintillans, Grev. (" Q.J.M.S.," Vol. xi, p. 230, PL 9, Fig. 

 6). — Rare. 



G. griseus, Grev., var. Galcpagensis, Grun. ("Van. Heurck 

 Syn.," PL 128, Fig. 7, and PL 132, Fig. 1).— Diam. about '0075". 

 Scarce. A smaller form, which seems to be typical, occurs rarely. 



