374 OONXHIBUTIONS TO CANADIAN PALEONTOLOGY. 



minute tubercle. All the interbrachials, except the first, appear to be 

 nearly or quite smooth. 



Basals three, hexagonal, rather more than twice as broad as high, 

 slight)}' concave at their lower margin, which is thickened and projects 

 outward in such a ^vay as to form a narrow elevated rim. Radials and 

 costals as high as broad, the radials and first costals hexagonal, the 

 second costals heptagonal, but with an angular notch in the upper 

 margin, between the two surfaces which articulate with the bases of each 

 pair of primary distichals. Distichals 2 x 10 : primary distiohals rectan- 

 gular and higher than wide, secondary distichals pentagonal : palmars 

 rectangular, nearly square : arms biserial and apparently eight in each ray. 

 "Interbrachials" 1, 3, 5 (though the plates in this genus which Wachs- 

 muth and Springer call the first interbrachials seem to the writer to be 

 true interradials), the first large and heptagonal, the others hexagonal, 

 decreasing slowly in size upward and succee led by a row of about seven 

 smaller plates. Characters of the tegmen unknown. 



Column long, slender, in some cases apparently adherent to foreign 

 bodies Vjy a small, thin, laterally expanded base of attachment : its seg- 

 ments cylindrical or slightly swollen in the middle externally, circular in 

 section, uniform in breadth and distinctly crenulated on both of their 

 articulating faces. 



Good fragments of the arms and pinnules of this crinoid are not rare 

 at Bartlett's Mills, but the only specimens with the dorsal cup preserved 

 that the writer has seen are two collected at that locality by Mr. Kearney, 

 one in 1895, and the other in 1896. The one collected in 1895, which 

 has been kindly lent by Mr. ^Schuchert, belongs to the United States 

 National Museum, and is No. 26,470 of its Catalogue of Invertebrate 

 Fossils, and the one collected in 1896, which is figured on Plate 48, is 

 now in the Museum of the Survey. Both of them have the whole of one 

 side of the dorsal cup buried in the matrix. The specimen figured shows, 

 on one side, two rays and a considerable portion of their arms and 

 pinnules in sit/u, with the interradial or " interbrachial " plates between 

 them, and a detached portion of the column ; — and on, the other, a beauti- 

 fully preserved aggregation of arms and pinnules, with another small 

 piece of the column. la a specimen fromThedford, which consists of the 

 two posterior segments of the column only, and which seems to be 

 referable to this species, the terminal segment is attached to a flattened 

 branching polyzoon by a thin lateral expansion. 



An apparently well marked species, characterized by its small dorsal 

 cup, slender column, and, more especially, by its very feeble and almost 

 obsolete surface markings. 



