FLOSCULARIA HOODII. 291 



of types were present when the bottom fauna first became estab- 

 lished. 



As we pass backwards towards the lower Cambrian, we find 

 closer and closer agreement with the zoological conception of the 

 character of primitive life on the bottom. While we cannot regard 

 the oldest fauna which has been discovered as the first which 

 existed on the bottom, we may feel confident that the first fauna of 

 the bottom resembled that of the lower Cambrian in its physical 

 conditions and in its most distinctive peculiarities ; the abundance 

 of types, and the slight amount of differentiation among the 

 representatives of these types ; and we must regard it as a decided 

 and unmistakable approximation to the beginning of the modern 

 fauna of the earth, as distinguished from the more ancient and 

 simple fauna of the open ocean. 



3flo0culana Iboo&ii. 



By John Hood, F.R.M.S., Dundee. PL XIV. 



THIS large and strange Eotatorian was found by me for the 

 first time in December, 1882, attached to Sphagnum^ in a 

 ditch on Tents Muir, Fifeshire. The large size of the 

 rotifer, and its possessing a corona unlike any other species of the 

 genus Floscularia^ together with its great cowl-shaped, dorsal lobe, 

 would make it sufficiently remarkable ; but in addition to the two 

 extraordinary finger-shaped processes, perched one on each side of 

 the summit of the dorsal lobe (PI. XIV., Figs, i and 2, d. p.), 

 there are two very significant organs possessed by no other species 

 of the genus. It has been, indeed, suggested to me that ibis 

 species should be removed from the genus Floscularia and placed 

 in a new genus by itself. But with the exception of the finger-like 

 processes, the other organs are identical with those of a true 

 Floscule, so I therefore think it should be retained in that genus. 



Dr. Hudson described this Eotatorian from living specimens, 

 which I sent him from Dundee on the 25th December, 1882. His 

 description, with two figures, were pubUshed in the Journal of the 

 Royal Microscopical Society^ II. Series, Vol. III., pp. 161 — 171, 



