Fossil Fish in Rocks of the Mansfield District. 9 



Ganoid fishes, some ten inches long and three inches broad, 

 with its heterocercal tail, and portion of the trunk clearly 

 defined, was exposed, also a portion of the anal fin ; and on 

 the stone being fully opened, it displayed in its scale- 

 markings the same rhomboidal character observed in the 

 large fish, with the osseous structure noticed in the smaller 

 one discovered a few days before. 



These were as finely sculptured, the form in some being 

 very distinct. The scaly trunk is well shown, some of the 

 scales in counterpart, with most of the head portions of the 

 pectoral, anal, and caudal fins and gill plates. Nothing was 

 observed of the internal skeleton of the trunk, and no traces 

 of ossified ribs were seen. The fins, where not removed, 

 have distinct rays. The specimen is in the hands of Professor 

 McCoy, for complete description, by whom it has been named 

 Cosmolepides sweeti (McCoy). The search was continued 

 till the highly-laminated shale (R), with its oval-shaped 

 lenticular masses on the under-side of varying thickness and 

 size, from a few inches to three or four feet were met with. 

 This bed was followed for some distance, when lenticular 

 stones were opened, having the same Jithological character as 

 that in which the first whole fish was found, and in such 

 masses we subsequently found most of the fish remains of 

 that bed. When it had been proved that this was the bed 

 from which the lenticular masses containing the fish had 

 come, the discovery of the other fossil-bearing beds soon 

 followed, so that now I am in a position to point out the 

 several beds in which the particular fossils were found. 



Several other trenches were opened up in the course of the 

 search, for similar purposes. 



We now come to observe the fossils found in situ at the 

 various beds. 



In the thirteen beds of rubbly shale, with an aggregate 

 thickness of one hundred and fifty-two feet, but few organic 

 remains were seen, except on the line of contact between 

 them and the adjoining beds. 



The first bed in ascending order containing many fossils 

 was F. From this bed were obtained several Ichthyodorii- 

 lites, a portion of large GyracanthusA^k^ spine, and a large 

 bone belonging to the head of a Ganoid fish, with other 

 large undetermined Ichthyic remains, now in the hands of 

 Professor McCoy. A few scales, some an inch and a half in 

 diameter, allied to Glyptolepis, and a tooth, about an inch 

 in length of a conical form, curved and hollow, with a few 



