Retrospective Criticism, 473 



nites, on the contrary, the width and height, both of the 

 scapulae and costse, will be found to be nearly equal. The 

 relative position of the bones in the cyathocrinite and in my 



specimen is shown in 

 58 59 Jigs. 58. and 59. Here, 



VV Cuneiform arm-joint. ffij Cuneiform arm -joint. Ci. , X7 ;|1 U« r»hc£»T"irorl 



^Second arm-joint. 9 First arm-joint. l \ Wl [ l De OUServeU,. 



" First arm.jomt. ^jjf^ Scapula. that in my specimen 



costal. {.fig' 58.) the base 



Second costal. c \i 



First costal. ^-^ ^ or the second costal 



rests entirely upon the 

 surface of the first, and the base of the scapula covers the 

 whole superior surface of the second costal ; and this is their 

 position in the encrinite. In the cyathocrinite, however, the 

 scapula rests, by lateral planes, upon two costae, as represented 

 in Jg. 59. 



Having thus pointed out the resemblance between my 

 specimen and the encrinite, I am bound, in justice, to point 

 out also in what it differs. The outline of the Encrinites 

 moniliformis will be found in Jig. 56. a, showing the differ- 

 ence between it and my specimen in the form of the bones. 

 This difference arises from certain tubercular swellings or 

 projections of each of the costal bones and scapular plates of 

 the encrinite, which causes them to project over, and in some 

 measure conceal, its base. There are no such projections in 

 my specimen. Again, the encrinite differs from mine in 

 having "several thinner joints succeeding the first arm joint." 

 (Miller, p. 42.) Lastly, Mr. Woodward points out the form 

 of the vertebral column as differing, in my specimen, from 

 that of the encrinite. I much question if any great importance 

 ought to be attached to this : it certainly is not a sufficient 

 ground for constituting a specific difference. It will be ob- 

 served that Miller speaks of the vertebral joints as alternately 

 larger and smaller as they approach the pelvis : and for a 

 considerable distance from the pelvis, in my specimen, the 

 column is hid or destroyed. But if the reader will refer to 

 Miller's work, he will find Cyathocrinites planus figured 

 with the joints of the vertebral column of uniform size ; while 

 the column of C. tuberculatus is represented with the joints 

 alternately larger and smaller : so that Miller evidently did 

 not consider this of sufficient importance to found upon it a 

 specific difference. 



I think I have now fairly stated wherein my specimen 

 agrees with and differs from the Encrinites monilit6rmis ; and 

 I think I have clearly demonstrated that it cannot possibly 

 be referred to the genus Cyathocrinites. I think that its 

 analogy to the Encrinites moniliformis is so close, so much 



