CRINOID GENUS SCYPHOCRINUS 2)7 



in the former. And from these facts he concluded finally: " It therefore does 

 not appear that the two parts can belong to one animal." 



The material now at hand, while not furnishing any complete stem, gives 

 a thorough exposition of its characters, and enables me to remove the doubts 

 as to the identity of the two organisms caused by Schuchert's observations 

 above cited. 



As a matter of fact, the stem of Scyphocrinus — at least of the present 

 species — tapers gradually from the calyx until its diameter is reduced to 

 about one-half at the distal end; and it has, moreover, a form of axial canal 

 which is perfectly consistent with the differences in this respect observed 

 by Mr. Schuchert. The largest stems are about 10 (occasionally 12) mm. in 

 diameter next to the calyx. The longest portion that can be traced directly from 

 a calyx and measured is 16 inches (40 cm.), and at this distance it has diminished 

 in diameter to 8 mm. Beyond this the dimensions cannot be traced continu- 

 ously, but there are many equally long detached parts of stems belonging 

 farther down in which the same taper is observed. Concurrently with this 

 decrease in diameter there is a similarly gradual increase in length of the stem 

 ossicles, or columnals. Proximal to the calyx where the stem is 10 mm. thick 

 the columnals are very short — several specimens showing an average of 

 0.7 mm.; and at the distance of 40 cm., with diameter reduced to 8 mm., they 

 have lengthened to about I.i mm. A detached portion of stem about 45 cm. 

 long changes from 8 mm. in diameter with columnals 1 mm. long at the larger 

 end to 7 mm. diameter with columnals 1.2 mm. long at the smaller; this 

 indicates an intermediate position in the stem, where the taper is less than 

 above. Another of about the same length tapers from 7.5 mm. in diameter 

 with columnals 1 mm. long to 6.5 mm. diameter with columnals 1.6 mm. 

 long — representing a more distal section. Shorter portions of stems are found 

 with still less diameter, in some of which the columnals have increased to 2 mm. 

 in length for a diameter of 6 mm. If this were near the distal end of an 

 average mature specimen — as is possible for reasons appearing later — it would 

 indicate a length of about 3 feet, estimating from the decrease in diameter, 

 and somewhat more if calculated by the increase in length of columnals. Judg- 

 ing, however, from the appearance of the longest stem seen in this material, 

 which is attached to a very large calyx but not in condition for accurate 

 measurement, the total length in mature specimens must have been consider- 

 ably more than this. 



Together with these external characters must be considered that of the 

 axial canal ; it is very large, obtusely pentagonal in the upper part of the stem, 

 often appearing to occupy two-thirds of its diameter; and it diminishes more 

 or less (not always regularly) to a sharply stellate opening distally. This canal 

 may be described as composed of a series of circular, bi-concave chambers, or 



