RECORDS 



447 



Summary of Papers. 



J. H. MacGregor gave a brief preliminary report on the de- 

 velopment of the skull in Ceratodus, the Australian lung-fish. 

 The research is made conjointly with Professor Bashford Dean. 



Only the early stages of the chondrocranium have as yet 

 been studied ; but it is noteworthy that these early stages show 

 even closer resemblance to the amphibian skull than does the 

 adult. The suspensorium is ante-stylic from the first, and the 

 union of quadrate to cranium by ascending and otic processes 

 is exactly as in urodele amphibia. The hyomandibular appears 

 later than the body of the hyoid arch, and has no connection 

 with the jaw. The trabulse are widely separated, leaving a 

 large ventral fontanelle, also an amphibian character. The 

 palatopterygoid bar is almost entirely suppressed. The one 

 character which is entirely fish-like is the otic capsule. 



Dr. Sumner's paper brought out the following points : 



I. The generally accepted account of gastrulation in the Tele- 

 osts, as proposed first by Gotte, was shown to be incomplete, 

 in so far as it failed to give a true account of the hypo-blast. 



II. A view of Kupfer's vesicle was maintained, closely 

 similar to that proposed by the great morphologist, after whom 

 this structure has been named. 



III. The present author has arrived, on purely morphological 

 grounds, at a view of concrescence identical with that proposed 

 by Kopsch on the basis of the latest experimental work. 



Dr. Huntington's paper dealt specifically with the retro- 

 clavicular group of supernumerary muscles, for the purpose of 

 determining their mutual relationship and common derivation. 

 The new muscle, here described for the first time, completes a 

 series of retroclavicular aberrant muscles which represent dif- 

 ferent stages in migration and recession of the typical mam- 

 malian-sterno-chondro-scapularis. The members of this group 

 appear, therefore, as myo-typical reversions representing per- 

 sistent portions of this muscular plane, with secondary skeletal 

 attachments, depending upon the degree of recession. 



Francis E. Lloyd, 



Secretary. 



