452 MR. G. W. BUTLER ON THE SUBDIVISION OF [NoV. 19, 



A communication was read from the Rev. Thomas R. R. Stebbing 

 and Mr. David Robertson containing the descriptions of four new 

 British Amphipodous Crustaceans. These were named Sophrosyne 

 robertsoni, Syrrhoc fimbriata, Podoceropsis palmatus, and I'odocerus 

 cumhrensis. Of these, Sophrosyne robertsoni belonged to a genus 

 first ol)served at Kerguelen Island. 



This paper-will be printed entire in the Society's 'Transactions.' 



The following papers were read: — 



1. On the Subdivision of the Body-cavity in Lizards^ Croco- 

 clilesj and Birds. By Gerard W. Butler, B.A. 

 (Communicated by Prof. G. B. Howes, F.Z.S., F.L.S.) 



[Eeceived November 14, 1889.] 

 (Plates XL VI. -XL IX.) 



Contents. l^age 



I. Introductory 452 



II. On the Subclivision of the Body-cavity in the adult Fowl 453 



III. On the Development and Homclugies of the various Septa in the 



Body-cavity of the Chick 455 



(a) On the Development of the Air-sacs in relation to the parts of 



the Avian Diaphragm • 456 



(6) Certain previous opinions vrith regard to the Avian Diaphragm. 458 

 (c) On the Development of the Pulmohepatic Ligaments and 



Eeoesses 460 



{d) On the Homology of the Avian and Mammalian Diaphragms... 461 

 (e) On the Development of the two parts of the Pust-hepatic Septum 



of the Bird 463 



IV. On the Body-cavity of the Lacertilia and of the Teiidse in particular. 464 



(a) The Lacertilia generally 464 



(6) TheTeiidas 466 



V. On the Body-cavity of the Crocodilia 467 



VI. Conclusions 470 



VII. List of Memoirs and Papers referred to, and Postscript 471 



VIII. Explanation of the Plates 472 



I. Introductory. 



There are embodied in this and another communication on the 

 " Relations of the Fat-bodies of the Sauropsida " (see below, p. 602), 

 the results of some months' work, carried on in the Biological Labo- 

 ratory of the Normal School of Science and Roval School of Mines, 

 at the instigation of my teacher. Prof. G. B. Howes. To him my 

 best thanks are due for most of the material employed, and still 

 more for the time and trouble which he has always been ready to 

 devote to furnishing me with suggestions and advice. For lesser 

 gifts of specimens I have to acknowledge my indebtedness to Dr. A. 

 Giinther, F.R.S., to Mr. G. A. Boulenger, to Prof. Wiedersheim 

 of Freiburg, and to my fellow-student, Mr. E. W. L. Holt. Mr. 

 Boulenger has, moreover, on various occasions kindly furnished me 

 with welcome information. 



