NATURAL SCIENCES OF PHILADELPHIA. 249 



Ilab. Mexico. (Coll. Entom. Society.) 



A very beautiful species, closely allied to the Xenarchus of Hewitson, but 

 from which its differences, as indicated in the diagnosis, are invariably per- 

 sistent. 



July 3d. 

 The President, Dr. Hays, in the Chair. 



Twenty-nine members present. 



The Chairman made some remarks on Trichina spiralis, and exhibited 

 a portion of human flesh infected with the parasite taken from one of 

 five persons who recently died of Trichiniasis in Iowa. 



July 10th. 

 ^Mr. Cassin, Vice President, in the Chair. 

 Thirteen members present. 



July Villi. 

 The President, Dr. Hays, in the Chair. 

 Nine members present. 



July lith. 

 Mr. Vaux, Vice-President, in the Chair. 

 Fifteen members present. 



Prof. Cope remarked that he had made a few observations on some of the 

 extinct vertebrates of the Mesozoic Red Sandstone, during: an examination 

 of the specimens preserved in the collection of Charles M. Wheatley, A. M., 

 at Phcenixville, Pa. 



Rtiytidodon carolinensis (Emmons, usually misspelled Rutiodoii) appears 

 to be, so far as extant remains are conclusive, a species of Belodon, Von Meyer, 

 allied to B. plieningeri. One confirmation, the identity of dentition of 

 the Wiirtembergian and Pennsylvanian species, had been pointed out to him by 

 C. M. Wheatley. The posterior teeth are lenticular in section, nearly broad as 

 high, crenate on both eiges ; the anterior cylindrical, slender and coarsely 

 fluted ; the first represent Eurydorus serridens, Leidy, Pr. A. N. S., Pnila., 1859, 

 110, and the latter Rhytidodon Emmons.* 



Clep>isauru3 pennnsylvanicus Lea, whose affinities have never been 

 indicated, apparently belongs to the same great type as the preceding : while 

 its teeth are without pulp-cavity, as pointed out by Leidy, those of the fangs of 

 Belodon are very small. 



He was also enabled to announce the discovery of the first undoubted Laby- 

 rinthod;m of these beds. The species, which is of considerable size, is repre- 

 sented by portions of two crania and numerous teeth. It is apparently nearest 

 Mastodonsaurus (Labyrinthodon) diagnosticus Von Meyer, in the propor- 

 tions of the cranial segments and sculpture. 



The larges # t fragment is eight inches long and eight and one-half wide, and is 



* Prof. Owen (Palaeontology) states that Cladyodon Ow. was apflied to the same genus as, and 

 is older than the name Belodon. 



1866.] 



