Dr. J. R. KiNAHAN on the Genus Oldhamia. 549 



Edward Forbes, Palteontologist to the Geological Survey, in which the fol- 

 lowing sentences occur: — 



" These bodies (i. e. certain plant-Uke impressions) present the appearance 

 in most specimens of a central filiform axis, with fasciculi of short radiating 

 branches proceeding from its sides at regular intervals, or of branches of such 

 filiform rays without an axis. A close examination of them shows, that each 

 branch is formed of a series of articulations marking the j^ositions of minute 

 cells. The entire body presents a striking resemblance to the arrangement of 

 parts in certain Zoophytes, as in Sertularia cupressina, but also consistent vnth 

 those exhibited in many Bryozoa (Polyzoa), as in Gemellaria and Cellaria, an 

 alliance more in accordance with the minute structure. I propose the name Old- 

 hamia for these remarkable fossils in honour of their discoverer, who has in 

 them made us acquainted with what in all probability is a group of Ascidian 

 Zoophytes, or rather compound tunicated Mollusca, in stratified rocks of a very 

 early date." — vol. iv. p. 20. 



I omit the rest of the abstract, as not bearing on the subject, and have itali- 

 cized those parts of this description to which I wish particularly to refer. 



Two species of the genus thus published were subsequently distinguished 

 by Professor Forbes (but without description, that I can find), under the names 

 of Old. antiqua, and Old. radiata, and are to be found commonly in museums, 

 and also in catalogues of fossils under these names. 



We now proceed to the subject of the afiinities of the group, omitting for 

 the present a detailed description of its characters. 



Probable Affinities of Groups. 



Professor Forbes, as will be seen from the extract given above, while 

 suggesting the possibility of either of two distinct alliances for these fossils, 

 obviously leans more strongly to that which supposes them to have been 

 Polyzoan molluscoids ; and, if I venture to dissent from an opinion put for- 

 ward by one deservedly of so much authority as an accurate and philosophi- 

 cal observer, it is solely because I have had more numerous and better 

 opportunities of studying these fossils than fell to his lot — having for the 

 past two years been making frequent, often nearly daily, examinations of the 

 rocks at Bray in which the fossils occur. I should state, also, that I had 

 VOL. xxiii. 4 c 



