Horizon and locality: Linton, Ohio, Coal Measures.
The genus and species were established on a single, large, almost perfect interclavicle of peculiar form. It may or may not be distinct, but it can not be associated definitely with any known genus, so that it will be designated as Cope described it. It exhibits on its outer or lateral borders broad, smooth surfaces for the contact of the overlapping margins of the lateral plates. The form is subround, with a large excavation from the posterior margin on each side. The narrowed portion left in the middle behind has a convex outline. Some delicate radiating grooves occur on the exposed surface, but they are very shallow.
| Measurements of Type. | |
| mm. | |
| Length of interclavicle | 71.5 |
| Greatest width | 78 |
| Width of lateral concavity | 39 |
[CHAPTER XXII.]
THE MICROSAURIAN FAMILY ICHTHYCANTHIDÆ, FROM THE COAL MEASURES OF OHIO.
Family ICHTHYCANTHIDÆ new family.
This family is the most recently recognized group of the Linton fauna. Its members, of which there are two known species, are distinct from all other Coal Measures Amphibia in the possession of an osseous tarsus ([483], [484]), with its associated reptile-like limb bones. There are preserved fine scutellæ in a large patch near the vertebral column. The vertebral spines are broad and heavy, with the vertebral centra amphicœlous.