PLA TE 1. 



[The figures of Plates i, ii, iii and iv, with two exceptions, are taken from Decade li, of Figures and Descriptions 

 of Canadian Organic Remains, and are illustrations of both Canadian and New York species.] 



Graftolitmus CLINTONENSIS, HaIjL. 



(Palaeontology of New' York, Vol. ii, page 39.) 

 Figures 1, 3 and 4 are enlarged to six diameters, and Jig. 3 to nine diameters. 



Fig. 1. A fragment from near the base of the stipe, where the cellules are less developed than 

 those of fig. 2, and of a different form from those of the other specimen figured- 

 The cellules are partially filled with mineral matter and have an angular form. 



" 2. A lateral view of a part of a mature stipe, showing the form of the cellules, and the 

 recurved extremities, causing the apertures to open downwards. The specimen is 

 filled with mineral matter. 



" 3. A front view of a part of the same stipe, showing the lateral extent of the cell-bases and 

 the expansion at the aperture. 



" 4. A dorsal view of the same, showing a groove which indicates the place of the solid axis. 



DiCTYONEMA GRACILIS, HaLL. 



" 5. Ahranchol Didyonema gracilis, showing the serrated margin indicating cell-apertures 

 (enlarged six diameters). 



DiFLOGRAPTUS WSITFIELDI, HaLL. 



Figures (3-10 are of ^latural sizej fig. 11 is enlarged to two diameters. 



Fig. 6. A celluliferous stipe, with a few partially developed reproductive sacs in the upper part. 

 " 7. A stipe where the sacs are more fully developed. 

 " 8. A stipe with numerous reproductive sacs, some of which have apparently become dehiscent, 



and exhibit numerous extremely slender fibres. In connection with one of these 



sacs there are two minute germs, one of them lying beneath the sac, and the other 



just beyond its outer margin and barely separated from its fibres. See fig. 11. 

 " 9. A stipe with a few of the sacs remaining, and the bases of some others which have 



apparently been broken ofi". One of these sacs appears to be attached to the axis 



above the cellules, and lying beneath the axis. 

 " 10. A stipe from which the reproductive sacs have been removed (by maceration), showing 



only the marginal fibres by which they were attached to the axis in their extension 



beyond the cellules. 

 '• 11. An enlargement of a single sac, from fig. 8, showing the position of the two germs. 



GERMS OF GBAPTOLITES. 



The figures {except 15) are Germs of Graptolites, enlarged to six diameters. 



Fig. 12. A germ of a biserrate form, before the cellules have assumed distinctive shape. The axis 

 is extended, and the common envelope spreads on both sides in the lower part ; the 

 coenosarc embracing the lateral processes, which are seen at the base of most of the 

 diprionidian forms, and extending along one side of the axis above. 



" 13. A form similar to fig. 12, a little further advanced, where the lower cellules have begun 

 to assume their proper form. 



" 14. Another form of germ resembling G. ciliatus ; the ciliated processes are visible beyond 

 the limits of the sac, but the cellules appear not to have assumed definite form. 



" 15. A young individual of O. ciliatus (natural size). 



" 16. A discoid germ. This may be the central disc of a compound form of a Graptolite. 



" 17. A germ showing the common body extended on the two sides of the axis, but without 

 any visible or apparent cellules. 



" 18. A germ where the common body or sac is much expanded on the two sides of the axis, 

 and the central portion is apparently becoming more solid. 



" 19. A germ where the solid axis is on one side; the species probably belongs to the 

 monoprionidian type. , 



