38i Bulletin 5 in 



\^Foot note, page i4j^. 

 ta of Sowerby, in the undulated line of the edges of the valves; but it is a 

 much moi-e depressed shell, and of a much less rounded form. 



In the young state, the undulation of the edge is not very distinct, but 

 this character increases with age, so that in the young state, it appears 

 like a totally different species from the adult. 



2. In the same rock are very numerous arquated spines, like ribs of 

 ^sh, some of them i 1-2 inches long. 



3. A fragment of a Terebratula or Productus, imbedded, with very 

 long spines, which may possibly be the same with the above. 



4. A specimen being a mass of comminuted fragments- of shells, 

 amongst which are only recognizable a few segments of the column of the 

 Encrinus, and minute turretted univalves of five whirls which resemble 

 Turritella, and are about one-twentieth of an inch long. 



5. Millepora cylindrica. Say. Branched, cylindric; pores very regular, 

 alternate, oval, placed nearer to each other than the length of their own 

 transverse diameters, and resembling those of an Alveolite. 



Diameter, about one-tenth of an inch. 



6. Segments of the column of Encrinus of authors, of a pentagonal 

 form. 



7. Ossiculfe of the body of a crinoid animal of the analogous species to 

 No. 21. 



8. Fragment of a Perna? 



9. A mass of argillaceous sandstone, containing spines of a Linnaean 

 Echinus, belonging probably to the genus Cidarites of Lamarck. Of 

 these spines some are elongate-conic, others slightly fusiform, obtuse and 

 slightly dilated near the tip, both are armed with short asperities through- 

 out their length. They resemble in some degree those of the Cidarites pis- 

 tillaris of Lamarck, but they are smaller, less fusiform, and the asperities 

 are not .so prominent. 



In the same mass are fragments of Encrinus, and fragments of Re- 

 tepore. 



10. Retepore, much resembling the Milleporites flustriforniis of Mar- 

 tin, Petrif. Derbi. pi. 43, fig. i and 2., but the alveoles in our specimens 

 are rather smaller. 



11. MSW^f^oxdL cylindrica. Say. Of the diameter of half an inch. 



12. Productus snbserratus. Say. Shell transvere, convex valve semi- 

 circular, destitute of asperities or striae, longitudinally indented in the 

 middle; line of the hinge rectilinear, half as long again as the length of 

 the shell, with three or four spines or serratures on each side towards the 

 angle ; umbo not prominent, the beak hardly prominent beyond the 

 line of the hinge. Length, more than three-tenths ; breadth, more than 

 one half an inch. A large specimen was four-fifths of an inch wide. 



If we except the beak, the outline of this shell as respects the hinge 

 margin and the sides, considerably resembles that of P. spi)iiilosus of Sow- 

 erby, but the base is far more obtusely rounded, and it is a shorter shell 

 comparatively with its width. The serratures are very often broken oif. 



\_Foot note, page /^S] . 

 The curvature of the sides, does not in the slightest degree project be- 

 yond the angles of the hinge line. 



13. An imperfect cast, very like the Terebratula subundata of Sower- 

 by, and of equal magnitude. 



[Long's Expedition to the Rocky Mountains, Vol. I, 1823]. 



