1901. CoivK- — Observations on Oldhamia and Histioderma. 85 



it may be remarked, thought that the object might prove to 

 be Dictyonema ; but Walcott, who has examined a poorly pre- 

 served specimen, agrees that it is an Oldhamia, though of 

 doubtful species. At the same time, he is inclined to reject 

 Hall's Oldhamia fruticosa. 



Walcott then describes a new species, Oldhamia {Murchiso- 

 nites) occidens, an ally of O. antiqua, from beds of Upper 

 Cambrian or L,ower Ordovician age. The locality of these is 

 not clear to the outsider, as they occur in the " Troy Sheet" of 

 the Survey, and there are some ten towns called Troy, not 

 to speak of villages, in the United States. Nor can we 

 quite overlook the extraordinary references to previous 

 authors that disfigure Mr. Walcott's paper. Not only is Dr. 

 J. R. Kinahan called " Kinnehan" and "Kinnahan" at pleasure 

 but it is stated that "Prof. Brady"- discussed Oldhamia in 

 1865, and proposed the new genus Murchisonites. The 

 reference given is to the " Geological Magazine, 1865, p. 6." 

 Brad)*, however, is represented in that volume only by an 

 ahstract on p. 223, in which Oldhamia is not mentioned. H. R. 

 Goppert, 1 as Prof. Sollas knows, was the real author of the 

 proposal to rename O. antiqua as Murchisonites Forbesi ; this 

 proposal was combated by Salter, to whom Walcott actually 

 refers, without noting his full discussion of the subject. 

 After this, we may pass over minor slips that occur in this 

 series of references, which seem to have been got together by 

 someone other than the author of the paper. If Mr. Walcott's 

 Oldhamia occidens is to stand as a species, some forms from 

 Bray will have to be included in it, such as one figured by 

 Mr. W. H. Baily in 1865. 



So far as I am aware, Sollas 3 was the first, in 1893, to observe 

 that Oldhamia was " strikingly similar to the radiate branching 

 markings which may sometimes be seen on muddy flats 

 extending from the mouth of the tubes of burrowing worms." 

 In proportion as the view of the sertularian or algal affinities 

 of Oldhamia declines in favour, I think we must seek more 



1 Acad. Caes. Leop. Nova acta, Bd. xxvii., i860, p. 441. 



3 " Cambrian Rocks of the British Islands." Geol. Mag., 1S65, p. 394, 

 fig 4c 



3 " Geology of Dublin and its neighbourhood." Proc. Geol. Assoc, vol. 

 xiii., 1893-5, p. 94. 



