256 



Among the fossil remains worthy of note collected at the foot of 

 ^Parliament Hill may be mentioned a large sponge referred by Mr. 

 Whiteaves to the genus Brachiospongia (Marsh.) This beautitul speci- 

 men was obtained by the writer above low water mark in a bed of lime- 

 stone six inches in thickness, and immediately overlying that containing 

 tracks or trails of marine animals, at one of the geological sub_ 

 excursions of the Club, Dr. Baptie being present. It is the tirst time 

 that the genus has been recognized as occurring in Canada. This 

 Ottawa specimen measures 10 inches or 24'5 centimetres in diameter, 

 and presents seven " brachia," or "arms" — so called. These lobes, more 

 pioperly speaking, are seen to radiate from a broad circular central 

 portion. There appear between these, in the intermediate spaces, lobes 

 slightly elevated above the gener.il level of the others ; whether these 

 are structural or not has not yet been ascertained. The specific refer- 

 ence is still doubtful as microscopic sections carefully ])repared by Mr. 

 Weston, of the Geological Survey, have not given definite structure. 

 In certain minor details our specimen differs from either of the thi-ee 

 species described by Profs. Owen and Mar.sh, fi-om the Cincinnati group 

 of Ohio, and whether they are all the same or different species, still re- 

 mains to be settled. 



Associated with it was discovered a series of tracks, probably 

 made l)y mollusca, resembling in miniature those described by Billings 

 as Scerichrutes, fiom the Cambro-Silurian deposits of Anticosti. That 

 they are not referable to Billing's species, S. abruptus, is at once evi- 

 dent by comparing the specimens with the description. 



The Ottawa specimens are often tortuous in their courae, the marks 

 or pits are arranged in an alternating manner, and aV>out three-eighths 

 of an inch is the greatest width of these tracks, there being about 

 twelve steps or series of footprints in the space of twenty-four lines. 

 Ichnites like these are generally sui)posed to have been moUuscan in 

 origin. Amongst the other species of interest collected at the same 

 sub-excursion may be mentioned as of more esi)ecial interest, Ophileta 

 Otlawaensis (Billings), Strophomena ddtoidea (Conrad), Bucania hid- 

 orsata (Hal'), &c. Besides the above, the Trenton formation has also 

 yielded Amplexopora Canudentiis (Foord), Vholidops snUruncutiis (Hall), 

 lUd'Hits trottoiiensis (Emmons), a hfijriehui very difficult to distinguish 



