in the same beds and really closely associated or whether they are found only along certain partings as is indeed indicated by Peach and Horne who say that "A characteristic feature of this eurypterid bed is the abundance on the divisional planes of that enigmatical fossil Dictyocaris ramsayi, forming, indeed, large black patches about an inch and a half across." One fact at least is clear: The eurypterids occur in a very thin band and are found in abundance in one section only, while a few fragments are found in one or two other nearby localities. The eurypterids are confined within a few inches vertically, while laterally the remains have a very limited extent, disappearing within a few yards. The occurrence at Gutterford Burn is in bed A of Brown and Henderson which contains ten species. Two species have been recorded from bed H to the northwest in a section exposed by the Henshaw Burn, a tributary of the North Esk. Except for these two isolated occurrences no eurypterids are found in the other beds or even in the same beds as they are traced along the strike. The remains of sixteen species representing five genera appear suddenly in a band a few inches thick, without forerunners in the underlying beds and with not a single straggler in the immediately overlying beds.
The following species of merostomes have been obtained from Gutterford Burn according to the identifications made by Malcolm Laurie (Peach and Horne, 215, 132, 593, 594):
- Bembicosoma pomphicus Laurie
- Stylonurus (Drepanopterus) pentlandicus (Laurie) emend. Clarke and R.
- S. (Drepanopterus) bembicoides (Laurie) emend. Clarke and Ruedemann
- S. (Drepanopterus) lobatus (Laurie) emend. Clarke and Ruedemann
- Eurypterus conicus Laurie
- E. minor Laurie
- Eusarcus scoticus (Laurie) emend. Clarke and Ruedemann
- Eurypterus 3 sp. undet.
- Stylonurus elegans Laurie
- S. macrophthalmus Laurie
- S. ornatus Laurie
- Slimonia dubia Laurie
- Dictyocaris ramsayi Salt
- Palaeophonus loudonensis Laurie
