1896.] NEW YORK ACADEMY OF SCIENCES. 73 



Mr. J. H. McGregor read a paper entitled "An Embryo of 

 Gryptohranchus.^'' 



The embryo described is about 1(5 mm. long, and is the first 

 to be recorded of this species. 



Prominent among its external features are the excessive amount 

 of 3^olk, the marked ventral flexure in the cervical region and 

 the very early and almost simultaneous appearance of the two 

 pairs of limbs. The dorsal surface is pigmented, the pigment 

 cells being arranged in transverse bands, one band over each 

 metamere of the body. Lateral line sense-organs can be distin- 

 guished. Among the most striking internal characters may be 

 mentioned the dorso-ventral flattening of the notochord, and the 

 late appearance of entoderm and alimentarj^ organs generally, 

 due doubtless to the great mass of 3^olk. The auditory vesicle 

 has an endolymphatic duct ending blindly immediately under 

 the skin on the top of the head. Along the sides of the body 

 a system of organs occurs which are probably homologous with 

 the embryonic sense-organs described by Beard in the sharks. 



Dr. J. L. Wortman spoke of the Ganodonta, a new and primi- 

 tive suborder of the Edentata from the Eocene of North Amer- 

 ica. One section or family of the suborder, viz : the Stylin- 

 odontidse, is composed of Hemiganus, Fsittacotherium, Ecto- 

 ganus and Stylinodon, and forms a closely connected and con- 

 secutive phylum reaching from the base of the Puerco to the 

 Bridger formation and leading directl}" to the Gravigrada or 

 ground sloths. A second famil}', viz : the Conoryctidse, com- 

 posed of Conoryctes and Onychodectes, may be regarded as an- 

 cestral to the Armadillos. The character and origin of the 

 Edentate fauna of South America was discussed at length and 

 the conclusion reached that its original home was in North 

 America. It was further held that there was a migration to the 

 southward before the close of the Eocene, and that there must 

 have then been an early land connection between the two con- 

 tinents. 



G. L. Bristol, 



Secretary. 



