1 88 NEW YORK STATE MUSEUM 



likewise most American species. I. divaricatus Hall is an Inocaulis 

 s. sir. but I. bell a Hall and Whitfield and I. anastomotica Ringue- 

 berg lack the projecting bundles of opening thecae and possess other distin- 

 guishing features which characterize them as members of a different genus 

 (Palaeodictyota). I. arbuscula Ulrich is a true Dictyonema with dis- 

 sepiments, and also some of Spencer's species of Inocaulis will have to be 

 placed elsewhere. 



As in many other Dendroidea the rhabdosome of Inocaulis was evi- 

 dently fastened to the bottom of the sea or to other objects. This is already 

 indicated by its association with other Dendroidea as at Hamilton, Ontario, 

 in our Rochester shale and directly demonstrated by the presence of a basal 

 expansion in a specimen of I . plumulosu s. 



Inocaulis plumulosus Hall 



■ Plate 2, figure 4 ; plate 7, figures 1, 2 



" -?" Hall. Geol. N. Y. 4th Dist. 1843. p. 11 6, fig. 1 



Inocaulis plumulosa Hall. Pal. N. Y. 1852. 2:176; pi. 40G, fig. 2a, 2b 

 Inocaulis plumulosa Hall. Can. Org. Rem. Dec. 2, 1865. p.18, fig. 26 

 Inocaulis p 1 u m ulosa Hall. N. Y. State Cab. Nat. Hist. 20th An. Rep't. 1867, 



p. 1 85, fig. 28 

 Inocaulis plumulosa Hall. Id. rev. ed. 1870. p. 193, fig. 183 

 Inocaulis plumulosa Spencer. Can. Nat. 1878. 8:458 

 Inocaulis plumulosa Spencer. Can. Nat. 1882. 10:166 

 Inocaulis plumulosus Spencer. Acad. Sci. St Louis. Trans. 1884. 4:564,584. 



5 8 5; pl. 5, fi g- 1 

 Inocaulis plumulosus Spencer. Mus. Univ. State Mo. Bui. 1884. 1:14, 34, 35 ; 



pl. s, fig. 1 

 Inocaulis plumulosus Miller. N. Am. Geol. & Pal. 1889. p. 193, 194, fig. 1S3 

 Inocaulis plumulosa Pocta. Syst. Sil. Boheme. 1894. v. 8, t. 1, p.197 

 Inoc a u 1 i s plumulosus Gurley. Jour. Geol. 1896. 4: 99, 309 



Hall has given the following diagnosis of this species : 



Stems flattened, dichotomous ; structure fibrous or plumulose, appar- 

 ently composed of imbricating elongated scales or fibers which spread 

 equally on all sides. 



This coral is not abundant, though small fragments are frequently seen 

 in the slab. It is very often replaced by iron pyrites, and where the surface 



