Geological Society. 311 



mesially in expanded ends, applied to what the author regarded as 

 the ventral surface of the azygos bar, where they approach each other 

 very closely. These two diverging bones are regarded by the author 

 as the clavicles. All the evidence tends to show that the parts are 

 in their normal relations, in which case the clavicles bear the same 

 relation to the interclavicle as in the pectoral arch of existing 

 Lacertilia. 



The azygos piece is a long flattened bar, widening posteriorly for 

 some distance from the attachment of the clavicles, and then nar- 

 rowing slightly to the posterior extremity. The lateral borders 

 from the clavicles to the widest part are smooth and gently arcuate 

 for the articulation of the epicoracoid ; behind this they are rough 

 and apparently non-articular. The author discussed the nature of 

 the azygos piece, which evidently includes the interclavicle; but 

 whether it comprises the costal sternum is questionable. There are 

 no indications of the connexion of ribs with its lateral borders, and 

 its figure is quite unlike that of the sternum in existing Lacertilia 

 and Crocodilia. Prom all its characters the author concluded that 

 the azygos piece represents only the interclavicle, and he suggested 

 that the costal sternum may have been cartilaginous, as in existing 

 Crocodiles. 



June 24, 1885.— Prof. T. G. Bonuey, D.Sc, LL.D., P.E.S., 



President, in the Chair. 



The following communications were read : — 



1. " Note on the Zoological Position of the genus Microchcerus, 

 Wood, and its apparent Identity with Hyopsodus, Leidy." By K. 

 Lydekker, Esq., B.A., P.G.S. 



In this paper the author discussed the characters of the genus 

 Microclicerus, Wood, from English Upper Eocene deposits, which 

 has hitherto been regarded as an Ungulate form, and showed that 

 it is really an Insectivore. He also indicated that the American 

 Eocene form Hyopsodus, Leidy, is almost certainly identical with 

 Microchoerus. 



2. " Observations on some imperfectly known Madreporaria from 

 the Cretaceous Formation of England." By R. P, Tomes, Esq., 

 F.G.S. 



This communication contained notes on several species of Cre- 

 taceous corals. The author considered that Smilotrochus insignis of 

 Duncan must be referred to the genus Oeratotrochus ; that S. granu- 

 latus, Duncan, was founded on immature specimens of Troehocyatlius 

 Wiltshirei, Duncan ; that Micrahacia Fittoni, Duncan, is a variety 

 of Cyclocyathus Fittoni ; that tlie genus Podoseris, Duncan, and pro- 

 bably Syzygopliyllum, Peuss, are the same as JRhizangia, M.-Edw. 

 and Haime, and consequently P. mamilliformis, Duncan, and P. 

 elongata, Duncan, are species of Rhizangia. He further stated that 

 Turhinoseris, Duncan, is identical with Leptojphyllia, Reuss, and 



