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SMITHSONIAN MISCELLANEOUS COLLECTIONS 



[vol. 47 



number and arrangement of thecal plates as in Anomalocystites. 

 The arrangement of the plates on the anal side, however, is quite 

 different, there being 6 more or less complete columns in Anomal- 

 ocystites, whereas Placocystitcs has only 4 series. 



So far as known, Anomalocystites is restricted to the American 

 Lower Devonic. 



ANOMALOCYSTITES CORNUTUS Hall 



(Plate XL, figures 4, 5) 



Anomalocystites cornutus Hall, Nat. Hist. N. Y., Pal, in, 1859 [1861], 

 P- L33, pi. 7 A, figs. 5-7. — Woodward, Geol. Mag., dec. 11, vn, 1880, 

 p. 193, pi. 6, figs. 4, 5. 



Anomalocystis cornuta Haeckel, Die Amphorideen, etc., 1896, p. 41, pi. 2, 

 figs. 8, 9. 



Length of theca 12 mm. ; width 9 mm. ; depth about 3 mm. 

 Theca subovoid, with the anal side depressed convex and the 

 anterior side slightly concave. Lower half of theca with the plates 



sculptured by transverse wavy 

 lines and the upper half with 

 widely separated depressed pus- 

 tules. Plates arranged as in 

 figure 21. 



Arms small, tapering rap- 

 idly, sharply angulated medi- 

 ally on the adambulacral side, 

 about 6 to 7 mm. long, and 

 composed of about 20 pieces 

 in each column. Ambulacra 

 very wide and deep ; there ap- 

 pear to have been near the base 

 of the arms about 3 or 4 ambu- 

 lacralia to each arm-plate. 

 Column short, about 18 mm. long, and composed of about 64 nar- 

 row and 7 wide segments, each consisting of 2 pieces. The segments 

 on each side, alternate with those of the opposite, are thin walled, 

 imbricating, and with a great central cavity. 



Formation and locality. — Not rare in the Coeymans limestone of 

 the Lower Devonic of Litchfield township, Herkimer county, New 

 York. The writer found one small slab having at least three fair 

 specimens and possibly a dozen or more with the plates separated. 

 Another slab shows a theca with the entire column. 

 Cat. numbers 35,078, 35,079, U. S. N. M. 



Fig. 21. — Analysis of both sides of 

 Anomalocystites cornutus Hall. (a, a, 

 Plates to which the two free arms are 

 attached. The black spot indicates the 

 probable position of the anus.) 



