230 



PALEONTOLOGY OF NEW-YORK, 



Position and locality. This specimen was found at Lockport, in the lower part of the 



limestone. {Collection of Col. Jewett.) 



PLATES OF UNDETERMINED CRINOIDEA. 



PLATE XLIX A. Figs. 4, 5, 6, 7 and 8. 



Fig. 4. This specimen has much the form of a pelvic plate of the preceding species, hut the 

 hase is very narrow. It is very abruptly bent through the middle in a longitudinal 

 direction, and slightly depressed on the upper edge. 



Fig. 5 and 6. These plates are apparently of the Lecanocrinus macropetalus, or a closely allied 

 species, though they present characters on their interior surface indicative of a dif- 

 ferent origin. The surfaces are smooth, partly, perhaps, from long maceration ; but 

 the angles are still preserved, showing that they have suffered little abrasion. 

 The preceding specimens were found in the shale at Lockport. 



Fig. 7. A plate of an unknown crinoid, the exposed surface of which is finely granulated, and 

 the margins apparently thickened : there is also a slight ridge or elevation extending 

 through the plate in a longitudinal direction. This specimen was found at Marshall's 

 mill in Sweden, Monroe county. 



Fig. 8. Plate of an unknown crinoid, but probably of Dendrocrinus, found at Rochester, on the 

 weathered surface of the shale. 



These specimens, with others not figured, as well as the fragments of columns to be noticed, 

 sufficiently indicate that there are still other species of Crinoidea to be discovered in the shale 

 of this period. 



COLUMNS OF UNDETERMINED CRINOIDEA. 



PLATE XLIV. Figs. 3, 4, 5, C, 7, 8 and 9. 



Fig. 2 a, b. A fragment of a column, of the natural size, with section of the same. 



Fig. 3 c, d. Enlargements of the same. 



This fragment of a column resembles, to a considerable degree, the column of 

 Saccocrinus; but the joints are thicker, and the nodes stronger. The joints consist 

 of a single smooth one alternating with a somewhat thicker one, which is nodose : 

 the striae on the articulating surfaces are numerous, slender, and often bifurcating, 

 and reach to the small circular canal. If belonging to this genus, it is of a species 

 different from the one described. 



Fig. 4 a. A fragment coiled upon the surface of a piece of shale. 



Fig. 4 5. A small portion of the same enlarged. 



The coiled specimen fig. 4 a has characters somewhat similar to the preceding, 

 but there are two or three thin joints between the thicker nodose ones. The nodes 

 also are not quite as prominent as those on the other fragment. 



Fig. 5 a, b, A fragment of a column where the joints are thin, the edges of the wider ones 

 being slightly crenulated, having two or more thin joints between. The enlargement 

 fig. 5 b shows a point where there is an intermediate joint not so wide as the widest, 

 but wider than the intervening ones. 



