NOTES AND ADDENDA. 1"1 



striae, and less numerous serrations. Dorsal scales pointed posteriorly. 

 Anal tin somewhat remote from caudal and opposite dorsal. 



The next species, and perhaps the last, may belong to the genus Elonichthya 

 of Giebel. They are much larger than the preceding. 



P. (Elonichthys) Brownii, Jackson, is deep in form, with large dorsal and 

 anal, the latter reaching almost to base of caudal. Scales of body broad and 

 with numerous fine horizontal striato-punctate furrows, which turn abruptly 

 upwards at the anterior side of each scale. A nearly perfect specimen, 

 collected by Mr Ells, is 10 inches long and 3£ inches wide, the breadth at 

 the dorsal fin being about equal to that at the shoulder, andsuddenly dimi- 

 nishing to the tail. The crystalline lens of the eye is preserved in this 

 specimen in calcite, and shows its structure, which is on the same plan with 

 that of our modern ganoid Arnia ocellicauda. It is the firstinstance known 

 to me of the preservation of the structure of the eye of a Pakeozoic fish. 



P. Jacksonii, s. N. — A species figured, but not described, by Jackson, is 

 represented by several fragments in my collection, and by a cast obtained 

 from Mr Matthews of St John. It is the largest of these fishes, reaching a 

 length of 15 inches. It may be distinguished from the last by its more 

 slender form, its small anal fin, more remote from the caudal, and by the 

 character of the scales, which are marked with numerous horizontal striae, 

 and have in the broader ones a few deep and strong serrations posteriorly. 



The whole of these fishes have been preserved entire ; their bodies being 

 perfectly flattened, and thrown into attitudes which imply that they were 

 embedded when living or immediately after death. The material in which 

 they are contained is shown, by its microscopical and chemical characters, 

 to have been a vegetable muck or mud, and the fish were either over- 

 whelmed by it in the manner of a bursting bog, or were stifled by the non- 

 oxygenated water mixed with this mud, and suddenly killed and embedded 

 in the accumulating sediment. That they occur in this perfect state, and 

 in a limited thickness of the deposit, may imply that at certain times they 

 were overwhelmed by the irruption of the fetid organic mud into the water 

 in which they lived. The bed is low down in the Lower Carboniferous 

 series, being the equivalent of the Horton series of Nova Scotia; so that 

 these fishes are among the oldest that we know in the Carboniferous 

 system ; but we know, from the Horton beds, that many far larger and pre- 

 daceous ganoids were their contemporaries. No remains of these have, 

 however, as yet been found in the Albert or Beliveau beds, which were 

 probably deposited in limited fresh-water basins, perhaps not ordinarily 

 accessible to the larger fishes. 



Sir Philip Egerton* and Dr Traquairf have both remarked on the 

 similarity of these fishes to those found in the Lower Carboniferous of 

 Scotland, and Dr Newberry has described very similar species from the 

 Carboniferous of Illinois and Ohio.J 



3. New Spirorbi*. 

 Spirorbis arietina, referred to at page 35 above, is figured in the Report 

 of the Canada Geological Survey for 1866-69, p. 14. It is spiral, sinistral ; 



* Journal of Geological Society, 1853. 



f Report on Illinois, vol. ii. ; Palaeontology of Ohio, vol. i. 



X Journal of Geological Society, 1877. 



