[From the Quakterly Journm, of the GRorooiCAi. Society /o 



November 1870. J 



NOTES 



ON SOME SPECIMENS OF 



LOWER SILURIAN TRILOBITES. 



E. BILL TNG 8, Esq., F.G.S. 



I'AL/KONTOLOGIST OF THE 6E0L0OICAI. PIJRVK . vy CANADA 



(Platbs XXXI. As» XXXII.) 



1. Asfjphus platycephalus, with sonie of the le<js preserved. 



Tnra specimen was collected in the Trenton Limestone, at the city 

 of Ottawa, about ten years ago. When disedvered it wa.s Kirig Hat 

 njion a thin slab of liniestone, and well preserved, witli the ex- 

 ception of the eyes, which seem to have been ll)rc(;d inwards by 

 pressure from above. It was also diviih^d into two pieces by a 

 tisstiie Avhich extended diftjj;<mally across, from the first segment 

 of the thorax on tin* left side \o the fifth seg7nent on the riglit. 



It remained in the Museum for several years without attracting 

 ])arti<ular attention, until one day, observing that the part in front 

 of the tissiire wat* somewhat loosely attached, I removed it, and was 

 surprised at finding, on the underside, not oidy the hypostoma in 

 place, but also what appeared to be some of the legs of the animal. 

 As the ])art behind the fissxire was men; firmly attached to the 

 stone, I had it cut across just behind the eighth segment by the 

 lapidary of the Survey. The remainder of the thorax was then 

 easily split off. The pygidium came otf with difficulty and in two 

 pieces. All the pieces were Ihen fiustened together; and we thus 

 obtained two specimens, one of which show.s the underside of the 

 Trilobite, tiiul (he other its impression on the stone. 



Un the underside (Tl. XXX I. fig. I) m broad shallow groove extends 



« 



