8 DR. P. H. CARPEKTEB ON CEETAIK POIISTTS 



for 12, whicli is nowhere noticed in Eorbes's description of the 

 cup, while he states that 13 is on the posteal side ; and so far as I 

 can judge from the specimens which I have seen, this is certainly 

 the case. 



In Hall's figures of Apiocystis elegans * the plate bearing the 

 lower half of the left-hand rhomb is marked 12, and, I believe, 

 correctly so ; but I cannot agree with his interpretation of the 

 higher plates of the cup. Hesting on basals 7 and 8, and notched, 

 like them, by the anal opening, is a plate which Hall describes as 

 sometimes simple and sometimes divided into three t. He refers 

 to it as belonging to the third series, and rightly so, I think ; but 

 the simple plate is marked 17 in one of his figures, and in the 

 other its three parts are called 17, 18, and 19 respectively, which 

 would seem to imply that it belongs to the fourth or supra- 

 ovarian series. It appears to me, however, that this plate, 

 whether simple or compound, is plate 13 of the centrolateral 

 series, or, as I should call it, radial D. It touches on the left 

 the rhombiferous plate 12, and altogether corresponds to plate 13 

 in Torbes's figures of EcMnoencrinus, more especially JE. armatus, 

 var. (PL I. fig. 3). In like manner the rhombiferous plate on 

 the right, which is marked 13 in Hall's figures, is radial C, plate 

 14 of Forbes's nomenclature, and I would alter the numbering of 

 the remaining plates as follows : — 



* • Palasontology of New York,' vol. ii. pi. li. figs. 5, 6. 

 t Ibid, p. 242. 



