THE \Mi:i l.\< I; \. ",1 



and not by Mr. Rofe; for he takes it to be a Buture, meaning that the lancet-plate 



was composed of two pieces." It is quite true thai Mr. Rofe imagined the lancet- 

 plate to be composed of two pieces, but he only referred to the canal as a Lozenge- 

 shaped opening; and be certainly never imagined this to be a suture. His observa- 

 tions were no doubt incomplete; but in this respect they were not incorrect, as would 



be inferred from Ilambach's account of them. 



Hambach only described the canal within the lancet-plate in the t\ pica! Pentremites ; 

 but it was soon figured in Granatocrinns Hfbrwoodi by Wachsmuth and Springer 1 . A 

 few months later we confirmed these discoveries 2 , and extended them to Schizoblastua, 

 Phcenbschisma, Orophocrirms, and Codaster (PI. XII. figs. 9, 15, 17 ; PI. XVII. figs. 1, 

 4-8, 12, 13 ; PI. XVIII. figs. 1, 3, 4, G) ; and we stated at the same time that in all 

 these genera we had been able to demonstrate the existence of an oral ring uniting 

 the five lancet-canals. Hambach 3 has since given a general confirmation to our 

 results (but without mentioning them) in the following terms: — " Further investiga- 

 tions prove that these canals are only the radiating rays of a pentagonal ring 

 surrounding the central orifice. In other words, the base portion of the deltoid piece 

 is likewise perforated transversely about midways, also the little process on the interior 

 base portion of the lancet piece, from where this canal runs downwards to the apex 

 of the ambulacral field." 



The first portion of the last sentence appears to us to contain a grave error. A 

 perforation " about midways " in the deltoid piece must be interradial in its position ; 

 whereas a similar opening on the little process beneath the central end of the lancet- 

 piece (PI. XII. fig. 14) is exactly radial, and would be separated from the interradial 

 openings in the deltoids at its sides by angles of 36°. Nevertheless Hambach describes 

 the two openings as corresponding in position, so that the canal within the lancet- 

 piece passes through the opening " about midways " in the deltoid and joins the oral 

 ring. There is, however, an opening just beneath the process under the central end 

 of the lancet-plate which is undoubtedly that to which Hambach refers ; but instead 

 of perforating a deltoid, it interrupts the suture between two deltoids, and is there- 

 fore precisely radial in position. It was figured in l'i nf re mites by Wachsmuth and 

 Springer 4 , who described it as equivalent to the openings at the base of the arms in 

 Palaeocrinoids. But they were unaware that there is a canal within the lancet-plate 

 of this genus, as was afterwards discovered by Hambach ; for they imagined the 

 under lancet-plate to be perforated. This opening was subsequently seen by ourselves 

 in Granatocrinns, Pentremites, and Orojihocrinus (PI. X. fig. 15 ; PI. XII. fig. 13 ; 

 PI. XV. fig. 4), and its relations were described in 1882 5 . Hambach, however, 



1 ltevision of the Palaeocrinoidea, Part II. pi. six. Gg. i ; . 

 - Ann. & Mag. Xat. Ili-t. L882, vol. Is. pp. 217 219. 



3 Trans. St. Louis Acad. Sci. 1884, vol. iv. no. 3, p 



4 Revision of the Palaeoerinoidea, Part I. pi. iii. fig. 4. 



5 Ann. & Mag. Xat. Hist. 18S2, vol. ix. p. 218. 



