240 FREDERICK W. SARDESON 



PREVIOUSLY DESCRIBED FORMS 



A few primitive Crinoidal bases have been heretofore described. 

 James Hall noticed specimens from Trenton Falls in the Trenton 

 limestone.^ A drawing after Hall's figure 2a, is reproduced here in 

 Fig. I. p. 243. His description of this and others merely states that 

 they are "bases of attachment" "of the columns of some (uncertain) 

 species of Crinoidea." Again James Hall described^ specimens as 

 occurring in the Niagara limestone, which may perhaps be well 

 considered in this connection. One, represented by his Fig. 11, is 

 described as "a fragment of a root with few radicles, .... showing 

 a hexagonal canal," and the other. Fig. 10, is described as "a frag- 

 ment of a root with numerous radicles." Those Figs. 11 and 10 are 

 here represented by Figs. 2 and 3 respectively, by which their general 

 character can be seen. Bather^ calls attention to others which James 

 Hall had described, in Pal. N. Y., Vol. Ill, 1859, as Aspidocrinus, 

 and of which Hall distinguishes three species, all from the Lower 

 Helderberg, describing them on pp. 122-23, ^^^ giving figures of 

 them, Plate V, Figs. 13-20. Hall appears much in doubt about their 

 structure and relations. Neither his descriptions nor his figures are 

 in any respect satisfactory. The fossils may, I think, rather be 

 columnals, than bases. 



From the Trenton limestone at Ottawa, Canada, Billings reports'* 

 certain specimens which should be noted. One specimen, represented 

 in Fig. i^, Plate V, loc. cit., he says is "the base of the column" of 

 cleiocrinus regius Bill. This specimen is not further described nor 

 details of the root's structure shown. One may, however, infer that 

 it is similar to that of the fragmental columns upon which he bases the 

 species, C. grandis Bill.,s and of which he says, "The radix or base 

 of attachment of the column consists of a number of large roots 

 which appear to be composed of small polygonal plates." The 

 figure of this one shows no more than the meager description gives, 



1 Pal. N. Y., Vol. I, p. 86, PL XXIX, Fig. 2 a, b, 1847. 



2 Pal. N. Y., Vol. II, p. 231, PI. -VLV, Figs. 10, 11. 



3 Loc. cit. 



4 Canadian Organic Remains, Decade 4, 1859. 

 s Loc. cit., p. 54, PL V, Fig. 2a. 



