304 The Crinoidea of the Loicer Niagara Limestone. 



takes place. Arm joints nodose, gradually decreasing in size near the distal 

 extremity, without further bifurcation some 28 joints can be counted in one 

 of the arms. Column round, joints unequal in width by reason of the differ- 

 ence in extent of the central elevations or rims ; between the wider ones there 

 are from one to three narrower. It increases somewhat in size after leaving 

 the calyx as far as observed, i. e., about 2 cm. 



Another specimen, preservinj? some of the arms and the ventral 

 tube, shows what seem to have been pinnules; but their exact 

 nature cannot be made out on account of the imperfection of the 

 specimen. The ventral tube is long and rather wide in its com- 

 pressed state, and is exposed up to about one-half of the height of 

 the arms above which point it is covered by them. Five rows of 

 plates can be seen on the posterior side ; the median of which are 

 smooth, hexagonal, and depressed below the level of the others ; 

 the two adjoining rows interlock with the median, and are of the 

 same height and about the same width, but are pentagonal and 

 alternate with the adjoining outer rows, having a straight suture 

 line between these rows. The plates of each of the adjoining rows 

 are of the same pentagonal character with their truncate sides pre- 

 senting at the straight longitudinal suture line, and have the suture 

 lines between the successive plates depressed, and at their termina- 

 tion opposite the middle of the opposite plate, there commences a 

 groove which extends half-way across the plate. This arrangement 

 gives a zigzag ornamentation on each side of the tube. 



From the Lower Niagara Limestone, Lockport, N. Y. 



I have been somewhat at a loss as to the exact generic relations 

 of this crinoid, on account of what seem to be pinnules, but these 

 may turn out to be lateral armlets. 



Glyptaster (Eucriims) lockportensis n. sp. PI. Ill, fig. 4. — 

 Calyx pentagonal below ; angles marked by moderately elevated radial 

 ridges, which arise from the underlying basals and meet in the first radials. 

 This ridge grows stronger and more sharply defined after its bifurcation with 

 the second and third series of radials. Surface ornamented by sharply defined 

 and prominent large granules and ridges, arranged in a radiating manner 

 on the larger plates. Under basals small, projecting but little beyond the 

 column. Basals large, pentagonal, posterior one heptagonal. Primary radials 

 3X5, secondary 2 X 10, and of the tertiary series three can be made out in 

 the only portion so far observed, i. e., the posterior side. In the posterior side 

 the anal area contains upwards of twenty plates, of which the first anal rests 

 upon the truncate top of the posterior basal ; it is the largest plate in the 

 area ; immediately above this are tliree somewhat smaller plates, and the suc- 

 ceeding rows of plates decrease regularly in size towards the top. 



