1883.] NATURAL SCIENCES OF PHILADELPHIA. 69 



March 6. 

 Mr. Geo. W. Tryon, Jr., in the chair. 

 Twenty-six persons present. 



Permian Fishes and Beptiles. — Prof. Cope exhibited some 

 specimens of fishes and reptiles from tlie Permian formation of 

 Texas. One of these was a new species of Crossopterygian fisli 

 which he named Ectosteorhachis ciceronius, which esliibited some 

 important characters of the posterior cranial region. He stated 

 that the base of the skull consists of ossified parachordals, and 

 these embrace the chordadorsalis posteriorly, and are continued 

 for a short distance posteriorly as a tube. Anteiiorly the chordal 

 groove is open. Trabecular not ossified. He considered the 

 cranial structure to be an excellent illustration of a permanent 

 embryonic type. 



The most interesting reptile was a new genus which occupies a 

 place between the Pelycosauria with molar teeth, and those with 

 raptorial teeth, but with more resemblance to the former, or Dia- 

 dectidse. The teeth are placed transversely in the jaws, but the 

 crowns terminate in an incurved apex, without ledge. He named 

 the genus Chilonyx, and referred it provisionally to tlie Bolo- 

 sauridse. The t3^pical species is the Bolo,sauriis rajndens ( Cope, 

 1878), an animal with a skull as large as that of a hog, and with 

 robust limbs. The surface of the skull is divided by grooves 

 into numerous swollen areas, and some of these are, on the lateral 

 occipital region, developed into tuberosities like the rudimental 

 horns of the Phrynosoma douglassi. 



Phenomena of Glaciation. — Professor Heilprin, referring to 

 his former communication on the phenomena of glaciation, stated 

 that if the principles laid down by him as to the limitation (in 

 height) of a polar ice-cap be correct, then the same principles must 

 likewise hold good for all portions of tlie earth's surface. In other 

 words, given an elevation of sufficient magnitude, then the upper 

 portion of the same, by virtue of its rising above the cloud-line, 

 must be either bare of snow or covered only with a comparatively^ 

 feeble thickness of the same. This view, which the speaker 

 believed was first enunciated by Humboldt, receives confirmation 

 from observations made on the Alps and on other high mountain 

 peaks. Thus, according to Tschudi, only a comparatively very 

 feeble thickness of snow falls on the Alpine summits above an 

 altitude of about 10,800 feet, the heavy precipitation being princi- 

 pally confined to a zone comprised between 7000 and 9000 feet. 

 The brothers Schlagintweit determined the cumulus line in the 



