328 Iie2Jorts and Proceedings — 



and GtenoplijcMus. Fossil teeth of these genera occur scattered rather 

 sparingly through the mass ; they are very perfectly preserved, and 

 do not show any signs of attrition. They must, however, be the 

 result of the disintegration of older rocks, or the genera which tliey 

 represent existed to a much later period than is generally supposed. 

 The following new species were described: — CtenoptijcMus Ordii, 

 Nemacanthns Jilifer, Ag., varieties a and ^, Nemacantlms minor, Sphe- 

 nonchus obtusus, Hybodus Austinensis and piistuJosus, Petalodus ? 



2. " On some Fish-spines from the Coal-measures." By J. W. 

 Davis, Esq., F.S.A., F.G.S. 



The author described in this paper three species of a new genus 

 of fossil fish from the Carboniferous formation, two of the species 

 having been found in the Cannel Coal of the West Kiding of York- 

 shire, and the other in the Burghlea limestone, near Edinburgh. 

 Anodontacanthiis is a straight spine, offering many points of resem- 

 blance to some of the Pleuracanths ; it has a similarly close-grained 

 microscopical structure, the internal cavity opens terminally at the 

 base of the spine, and it was not deeply implanted in the flesh of 

 the fish. It, however, differs from all the Pleuracanths in being 

 ■quite free from external denticles ; its surface is plain or but slightly 

 striated, whilst that of Pleur acanthus always possesses a double row 

 of denticles, either ranged laterally along the exposed part of the 

 spine, or in some position between the lateral and posterior aspects 

 of the spine. It is possible that evidence may be discovered which 

 will render necessary the removal of these spines to the genus 

 Pleiiracanthiis ; but at present there is no evidence that such is 

 advisable. All the specimens of P/eMracar?//n«s-spine found associated 

 with teeth or shagreen have been armed with the double row of 

 denticles, and at present no evidence exists that spines without 

 denticles were associated with remains of this genus. It is, there- 

 fore, considered best to institute a new genus for the three species 

 with the name Anodontacanthiis, in allusion to its having no teeth or 

 denticles. 



3. " On some Specimens of Diastopora and Stomatopora from the 

 Wenlock Limestone." By Francis D. Longe, Esq., F.Gr.S. 



Mr. Longe showed and described some specimens of Bryozoa from, 

 the Wenlock Limestone of Dudley, which he compared with corre- 

 sponding forms from the Oolites and later periods, and pointed out 

 the close similarity of the Silurian with the later forms, in respect 

 of the shape and dimensions of the cells, as well as in the habit of 

 ccenoecic growth. 



Alluding to some other Palaeozoic forms, assigned to the Bryozoa 

 under the generic names of Berenicea and Ceramopora, he pointed 

 out the difference between the shape of the cells in these forms and 

 those which he had described, and expressed a doubt whether they 

 should be classed as Bryozoa at all. 



On the other hand, he referred to some specimens described by 

 Professor Nicholson (Ann. & Mag. Nat. Hist. vol. xv,, 1875) under 

 the names of Ahcto auloporoides, etc., as having the true Bryozoan 

 cell, and furnishing additional evidence of the existence in the 



