Arthroacantha, Williams. 275 



me that these authors are dohig Prof. Williams an injustice 

 in endeavouring to foist upon him the authorship of a species 

 to which he lajs no claim, and which he has not taken steps 

 to establish. 



When Prof. Hall properly describes (and publishes) the 

 typical specimen which bears his MS. name of P. puncto- 

 hrachiatuSj it will then be seen if it is identical with Hijstri- 

 crinus Carpenteri ; and in this latter eventuality his MS. name 

 must lapse. 



Notwithstanding the scanty imperfect notice of the MS. P. 

 jyunclobracht'atus given by Williams, and the absence of any 

 published figure, Messrs. Wachsmuth and Springer profess to 

 be able to recognize with confidence specimens of it from the 

 Hamilton group of the Province of Ontario ; but they are 

 unable to determine their identity with my Hystricrinus Car- 

 penteri^ though this latter form has been minutely described 

 and figured ! Still further, these authors recognize the spines 

 of P. punctohrachiatus, though none were present in the 

 typical specimens of this form ; and yet they cannot tell if 

 they are similar to those of //. Carpenteri^ although these 

 latter have been carefully figured to scale ! 



Further comment on the remarkable insight and the peculiar 

 views of Messrs. Wachsmuth and Springer respecting zoolo- 

 gical nomenclature is needless. I venture to believe that it 

 has been sufficiently shown that both the generic terms /^s- 

 iricrinus 2a\dL the species H. Carpenteri have been formed in 

 accordance with the rules of the British Association ; and I 

 therefore append the following summary as an emendation 

 of that given by the above-named authors : — 



Hystricrinus, Hinde (=Arthroacantha, Williams, 

 previously occupied). 

 1885, Ann. & Mag. Nat. Hist. ser. 5, vol. xv. p. 158. 

 1883. Hystricrinus (Arthroacantha) ithacensisj Williams, 

 sp. Type of the genus. Proc. Amer. Phil. Soc. 

 April, p. 85, with plate. — Upper Devonian, Che- 

 mung group. Ithaca, New York. 

 1885. Hystricrinus Carpejiteri, Hinde, Ann. & Mag. Nat. 

 Hist. ser. 5, vol. xv. p. 162, with plate and wood- 

 cut. — Middle Devonian, Hamilton group. Arkona, 

 Ontario, Canada. 



(Besides the above, Prof. Williams mentions a specimen to 

 which Prof. Hall has given the MS. \\2a1\Q, Plati/crinus 2^unctO' 

 brachiatus. The form has not yet been described and pub- 

 lished, and cannot therefore at present be included in the 

 genus. According to Williams, the type-specimen is from 

 the Hamilton group, but no locality is given.) 



