646 EEPOET— 1881. 



gritstone and emptied itself into the fissure, from whicli were deposited the sandy 

 and clayey matters which gradually filled it. The animals whose bones are found 

 in the fissure no doubt frequented the district through which the stream ran, and 

 their skeleton remains were washed into the fissure along with the rounded stones 

 and boulders found associated with them. It may perhaps be inferred, from the 

 fact that the fine blue clay is superimposed on all the other beds, that the organic 

 remains found in the fissure are preglacial or interglacial in age, because the dis- 

 trict drained by the stream is entirely composed of grit-rocks ; and it is only by the 

 agency of glaciers that the limestone forming the blue clays could be conveyed to 

 so high elevations, prior to its re-deposition in the fissure. 



17. On the Zoological position of the genus Petalorliynclius, Ag., a Fossil 

 Fish from the Mo'untain LimcstoiiK. By James "W. Davis, F.G.S., 

 F.L.8. 



The two species of refalodus,\iz.2mttacim(s,Ag.,ani sagittatus, Ag.,are included 

 in the new genus PetalorJnjnchus, as well as that of Choimrfoclus tnmcatus, Ag. The 

 characters and arrangement of the teeth, discovered since Professor Agassiz insti- 

 tuted these genera, sliow that they extended in circular rows of probably seven 

 teeth in each upper and lower jaw. In front of these are four or five vertical rows 

 of disused teeth, which appear to serve the purpose of strengthening and support- 

 ing the row in use. In manj^ respects they are similar to the genus Janassa, 

 Munster, and with it appear to occupy an intermediate position between the 

 genus Myliohates and Cestraciontes, approaching nearer to the characters possessed 

 by the rays than the sharks. 



18. Oil Diodontopsodus, Davis, a neiv genus of Fossil Fishes from the 

 Mountain Limestone, at Hichmond, in YorJcshire. Bij James W. Davis, 

 F.Q.S., F.L.8. 



A number of teeth have been found in the Yorkshire Limestone, which were 

 ascribed by Professor Agassiz to tlie genus Petalorhynchus. They differ most 

 materially from that genus. In Diodontopsodus the teeth are extremely like the 

 single teeth of the existing fish, Diodon, in which the two rami of each jaw have 

 coalesced to form a single, bony, enamel-tipped inciso-palatal tooth, whilst in 

 Petalorhynchus the teeth are strong, with a long and thick base, the crown being 

 thin, sharp, aud spatulate ; the teeth of Diodontopsodus liave no basal prolonga- 

 tion, are hollow, and appear to have been attached to a cartilaginous jaw. 



WHn.VESBAT, SEPTEMBER 7. 

 The following Reports aud Papers were read : — 

 1. Meport on the Farthquahe Phenomena of Japan. — See Rejiorts, p. 200. 



2. A Contribution to Seismology } By John Milne, F.G.S., and Thomas 



Gkat, B.Sc, F.B..8.F. 



This paper is divided into two parts. The first part treats for the most part of 

 mechanical contrivances designed by the authors for the purpose of earthquake 

 investigation. It was pointed out that many of the instruments formerly in use 

 for such purposes gave very indefinite results, and hence were at the most only 

 entitled to the name seismoscopes. 



' The substance of this paper has been published under the title 'Earthquake 

 Observations and Experiments in Japan,' in the Philusojihical Magazine for Novem- 

 ber, 1881. 



