l'I,ATK IV K— Continued. 

 LiNGULA LAMELLATA, Hall. 



l"i}r. 10. View from the pedicle-valve of an intcnial cast, retiiiiiing llie iiuiiivssioii of the lateral and central 



muscular scars ami of the jiallial sinuses. Tlie luati-ix i.s tilled with minute ovoid bodies (ova). 



which appear to lie distributed wherevei- the siuu.ses and llieir branches have extended. About 



the anterior and lateral luargius of the valve the matrix is the opacjue mud of the .sediment ; 



elsewhere the spaces between the ova are transluceut. X -i- 

 I'ig-. II. The opposite side of the .same .specimen ; also showing- the muscidar, vascular and sejilal impres- 



sion.s. The intermixture of the opacxuc matrix on this side is somewhat greater than on the 



other, obliteratinjj the ova to some extent. X 3. 

 Fif,'. 12. A thin section of a portion of this specimen, which shows the ovoid bodies to be opacpie and 



homo^-enous. X 12 

 Kijr. i:!. An enlargement of the surface of the cast ; showing the appearance of the ova when magnified 12 



diameters. The \-ertical ridges are (•asf.s of radiating furrows on the interior of the valve. 

 Niagara group. Near Hamilton., Ontario. 



LINGULOPS, Hall. 



rage IS. 

 LlNGULOPS GrANTI, Sp. IIOV. 



Fig. 14. The inferior of a brachial valve. X t>. 



Fig. IT). The interior of a pedicle-valve. The muscular area is here developed into a well-iletiupd plat- 

 form, while in the other species of the genus, L. WhitfieUli and L. Norwoodi, it still retains its 

 linguloid character. X 6. 



Niagara group. Hamilton, Ontario. 



CONOTEETA, Walcott. 



Page 104. 

 CONOTRETA RuSTI, Wtllcolt. 



Fig. U). Anterior view of a pedicle-valve. The apical and anterior regions retain a. portion of the shell, 



but elsewhere the shell is removed, showing the impressions of the internal radiating mu,scu!a,r 



ridges. X 4. 

 Fig. 17. An intei-nal cast of a smaller j)edicle-valve ; sliowing the iilipression of the strong apical callosity, 



and the radiating ridges. X 8. 

 Fig. 18. An apical view of the .same valve ; showing the subtriangular posterior slo]ie, and its obscui'ely 



defined median furi-ow. X 9- 

 Fig. 10. Cardinal view of a very young individual, in which the po.stei-ior slope is vei-y faint. X 12. 



Trenton liiiKwtone. Trenton Fall.t, N. Y. 

 Fig. 2(1. Cartiinal view of another very small example, retaining the shell. 

 Fig. 21. Profile of same. X 25 



Hudson River group. Cooinyton, Kij. 



OBOLUS, EicHWAij). 



Page SO. 



Obolus [?] PULGHEU, Matlliew. 



Fig. 22. The e.\terior of a vaKe, I'etaiuing the shell and showing the character of its ornamentation. X ii. 

 St. .lohn group. Cato7i'.i Island, New Brun.'iwick. 



DISCINA, Lamakck. 



P.ige 120. 

 DbSCINA 8TUIATA, Sclllllliaclll'f. 

 Fig. 23. The interior of a pedicle-valve. 

 Fit' 21. The exterior of a similar valve. Mu(-h enlarged. 

 Recent. Cape Palmas. 

 (After n.wiDso.v. Trans. Linnean Soc, Ser. 2, Zool., vol. i\-, pi. 2:", tigs. 24, 25. 18S9.) 



