394 



THE GEOLOGIST. 



found some small spines that are smooth and slightly arched ; they appear 

 to belong to two species. Among the scales are, of course, those of Me- 

 galichthys Hibberti. They occur either isolated or in patches. Sometimes 

 they are associated with the enamelled plates that cover the head of this 

 fish, including the maxillary bones showing the teeth. Isolated scales of 

 great size, belonging to a large Holoptychius, are not uncommon, as well 

 as others that seem to belong to a smaller species of the same genus. 

 There are also numerous small ganoid scales, in some cases with sculp- 

 tured surfaces and serrated margins ; some of them belong to a species of 

 Platysomus, and others to Palseoniscus or Amblypterus, or possibly Eu- 

 rynotus. 



In some parts of the " blackstone " large quantities of small thorny 

 tubercles are met with, which have evidently formed part of the dermal 

 armature of a Placoidean, and from the way in which they are associated 

 with the spines of Gyracanthus tuherculosus, they not unlikely belong to 

 that fish. 



A great number of maxillary bones, most of them with teeth, are among 

 the fossils found at Newsham. Some of them, as we have already men- 

 tioned, belong to Megalichthys ; others, as large in size, have been re- 

 ferred to Holoptychius and Bliizodus. All these maxillaries are armed 

 with sharp-pointed, conical teeth, which are not easily distinguishable 

 from each other when found detached. A fragment of another large 

 maxillary, with the external surface irregularly and deeply pitted, and 

 with large lancet-shaped teeth, has been found. Numerous smaller jaws, 

 varying from 2 inches to \ an inch in length, occur, and among them dif- 

 ferences are to be observed, both in the character and arrangement of the 

 teeth, that appear to indicate the presence of several distinct forms. One 

 of these differs so strikingly from the others in its cylindrical, bluntly- 

 pointed teeth, as to suggest the probability of it belonging to a reptile 

 rather than a fish. Besides detached teeth of the maxillaries noticed in 

 the preceding paragraph, the authors have also met with teeth belonging 

 to Placoideans. Among these are two species of Ctenoptychius, which 

 we doubtfully refer to C. pectinatus and C. denticulatus. Diplodus gib- 

 bosus also is not a rare form ; and in one instance these teeth have been 

 found connected with the bony plates to which they were affixed. Some 

 very beautiful palatal teeth of Ctenodus and Ceratodus have also occurred, 

 as well as others that seem to belong to Psammodus. Of more common 

 occurrence than any of the foregoing fossils are various detached bones . 

 Many of these are evidently cephalic bones, and such as belong to the 

 thoracic arch. Vertebrae, too, are not uncommon, some of them being large 

 and apparently referable to a fish the size of Gyracanthus tuberculatum, to 

 which they probably belong. There is also repeatedly found in conjunc- 

 tion with the latter spine a large triangular bone, which appears to have 

 been originally articulated. 



Having now mentioned the various fragmentary remains of fish that we 

 have found in the Newsham blackstone, we may add that the only fossils 

 of the same class which have occurred in that deposit in a more perfect 

 condition is a nearly complete example of a Platysomus. and another of 

 a fish which we identify with Cacclacanthus. Both examples are small, 

 the former being 3 inches long and the latter 4| inches. Associated with 

 these remains are large quantities of coprolitic matter ; also large irregular 

 masses of a substance showing a roe-like structure, that may possibly re- 

 present spawn or ova of some kind. The vegetable fossils that occur in 

 the same bed are Lepidodendron elegans, h. Sternberg) t 1, Lepidostrobus sp., 

 Calamitus nodosus, Buthrodcndron punetatuin, Sternbergia approximata, 

 Megaphyton sp, 



