PLATE XXXVI— Continued. 



TURRILEPAS (?) NeWBERRYI. 

 Page 219. 



Fig. 16. Two valves of this species in an uncompressed condition, natural size. The upper and more per- 

 fect specimen has a rounded dorsum, the unrepresented side being of the same character as 

 that which is shown. There also appears to lie evidence of a cleft extending from the apex to 

 the anterior margin, as in Spathiocaris. Plates of this character are distinctly different from 

 the others here represented under the term Turrilepas. 



Cleveland shal^ (Chemung group). Birmingham, Erit county, Ohio. 



Pig. 17. A large plate, natural size, showing the concentric surface markings, and a broad postero-lateral 

 depression. This plate has the same outline as one side of the plates lepresented in the last 

 figure ; it is, however, impossible to determine from the specimen whether or not the plate was 

 folded along the dorsal line. 



Cleveland shale (Chemung group). Sheffield, Erie county, Ohio. 



Fig. IS. A smaller plate, natural size, showing a different form and more closely crowded growth-lines. 



Cleveland shale (Chemung group). Sheffield, Erie county, Ohio. 

 Fig. 19. A small plate having an outline similar to that represented in figure 17. 



Cleveland shale (Chemung group). Sheffield, Eric county, Ohio, 

 The illustrations of this species have been drawn from the type specimens. 



Strobilepis SPINIGERA. 

 Page 212. 



Fig. 20. A nearly entire capitulum, in which the parts retain somewhat of their proper arrangement. The 

 conical terminal plate is overlapped at its edges by three vertical ranges of plates, those of the 

 left range lying in juxtaposition, while those of the right range have been considerably dis- 

 placed. Of the axial range of smaller plates, three are shown in place, and a fourth plate of this 

 range lies beneath the edge of the fourth plate of the left range. The range of spines has been 

 pushed from its normal position around to the right, and the lower members of the row have been 

 displaced. These spines were probably symmetrical in position with the axial row of plates. 

 The specimen is enlarged to one and a half diameters. 



Pig, 21. The last three spines of the undetached portion of the row, enlarged to two diameters. These 

 spines are numerically the ninth, tenth and eleventh ; the first two, like all those preceding 

 them, bear a deep ami conspicuous groove for nearly their entire length, while the eleventh and 

 all those following, appear to have been inverted, showing a convex surface with a sharp axial 

 carina, the lateral slopes being more or less incurved. 



Fig. 22. An enlargement of a portion of the surface of one of the plates, showing their punctate structure, 

 the quincunx arrangement, the oblique direction of the punctae, and. tfye concentric lines pro- 

 duced by the excavation of the shell about the aperture of each puncta. 

 Hamilton group. Menteth's Point, Canandaigua Lake. 



Pro tobalan us Hamiltonensis. 



Page 209. 

 Fig. 23. The type specimen enlarged to fifteen diameters. This has been somewhat broken over the pos- 

 terior portion, but shows the composition of the capitulum, its twelve discrete plates, consisting 

 of the carina, rostrum and live pairs of latcralia, the radiating ridges upon the surface of these 

 plates and the smooth radial areas. On the right side the peripheral portion of the shell has 

 been somewhat flattened. 



Hamilton group. In the Marcclhis shales at Avon, Livingston county. 



PaLjEOCREUSIA Devonica. 



Page 2f0. 

 Fig. 24. A view of the type specimen, natural size, showing the capitulum, the remainder of the shell being 



imbedded in' a colony of Favosites 1/emisphericus. 

 Fig, 25. A constructive representation of the profile of this specimen, showing the long, tubular basis sur- 

 rounded by cell tubes, and the elevation of the capitulum. 

 Fig. 2i'>. The same view of the specimen as that presented in figure 2-1, enlarged to two diameters. The 



alum has 1. i encroached upon by the walls of the cell tubes, which have apparently ex- 



tended as far as tie- aperture, and subsequently been broken away. The surface of the plate 

 shows faint radiating stria', and a single furrow concentric with the margin. The aperture 

 appears somewhal too large on account of the slight imperfection of its anterior margin. 

 Corniferous limestone. LeRoy, Genessee county. 



