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SILURIC AND DEVONIC CYSTIDEA 



21 5 



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Basal pectinirhomb largest, with about 40 dichopores, while the 2 

 upper (Hies each have about 35. 



The conspicuous valvular pyramid of the anus is composed of 6 

 triangular plates surrounded by a circle of about iS very small pieces. 



All these parts are 

 deeply set between 

 plates 7, 8, and 13. 



I [ydropore smal 1, 

 placed just below the 

 c< mspicuous madrepor- 

 ite. Both are situated 

 on plate 21, making the 

 abutment on one side 

 f< >r 2 ambulacra. 



Column unknown. 

 In the cystid layer, 

 however, occur the 

 fused leech-shaped pieces of the column, so characteristic of Lepo- 

 crinites. They are smaller than in L. gebhardii and, as they occur 

 in the same zone as the theca of L. manlius, it is probable that these 

 pieces belong to the latter species. 



Compared with L. gebhardii of the Coeymans, L. manlius is con- 

 siderably smaller, in form more pyriform than subquadrate, has con- 

 siderably longer ambulacra, and the plate ornamentation is far more 

 decided. 



Formation and locality. — The only specimen was found by Mr. 

 Gordon at the Keyser quarries in the lower portion of the Manlius. 

 The species takes its name from the Manlius formation, the horizon 

 just beneath the Coeymans in which L. gebhardii occurs. 

 Cat. numbers 35,062, 35,073, 35,074, U. S. N. M. 



Fig. 23. — Analysis of Lepocrinites manlius n. sp. 



LEPOCRINITES GEBHARDII Conrad 



Lepocrinites gebhardii Conrad, Fourth Ann. Rep. N. Y. Geol. Surv., 1840, 

 p. 207. — Vanuxem, Nat. Hist. N. Y., Geol., in. 1842, p. 117, text-fig. 

 4. — Mather, ibidem, 1, 1843, p. 346, text-fig. 4. — Hall, ibidem, iv, 

 1843, tab. ill. 27, fig. 4. — Owen, Amer. Jour. Sci. (2), 1846, p. 49, 

 fig. 4 (fig. only). — Lincklaen, Fourteenth Rep. N. Y. State Cab. 

 Nat. Hist., 1861, p. 58, pi. 9, fig. 11. 



Lepadocrinus gebhardi Hall, Nat. Hist. N. Y., Pal., in, 1859 [1861], p. 

 127, pi. 7, figs. 1-20. — Haeckel, Die Amphorideen und Cystoideen, 

 Beitr. Morph. u. Phyl. d. Echinodermen, Leipzig, 1896, p. 135. 



Apiocystites gebhardii Jaekel, Stammesgeschichte der Pelmatozoen, 1, 

 Berlin, 1899, p. 282, fig. 59 on p. 280. 

 The writer has seen a number of specimens of this species belong- 

 ine to Yale University Museum and to the U. S. National Museum, 



