20 uJ. W. Dawson—Footprints, etc., on Carboniferous Rocks. 
impressions of the type of Diplichnites are known to me only 
in the Carboniferous. Szrichnites of Billings, from the Anti- 
costi group,* has some points of resemblance to it, but is essen- 
tially distinct. My species may be named D. enigma. 
Rabdichnites Dawson. 
Under this name I would designate the straight or slightly 
curved marks usually striated or grooved longitudinally, and 
either single or in pairs, which abound on some Carboniferous 
beds, and also in much older formations. At Horton Bluff, in 
beds holding remains of fishes and numerous footprints of crus- 
taceans and reptiles, and scratches which were probably made 
by the fins of Rihas these marks abound. They were evidently 
furrows drawn by pointed objects trailed over the mud, and 
reproduced in relief on the under surfaces of the beds next 
deposited. Some have been produced by rounded points and 
are semi-cylindrical. Others are the work of chisel-shaped, 
pointed, notched or fimbriated organs, giving a variety of more 
or less close subordinate grooves or striz. In some cases they 
s into or are associated with punctures or impressions made 
perpendicularly like those last noticed, and this is especially the 
case with some of the smaller varieties. The whole of these 
different form found in the Primordial of Great Britain. He 
* Report on Silurian Fossils of Anticosti, 1866. 
