176 proceedings: biological society 



Barton W. Evermann reported that a wireless message had just been 

 received from Agent Lembkey at the Pribilof Islands in which it was 

 stated that the reindeer herds on St. Paul and St. George had increased 

 during the past year from 37 to 65 animals and that all are in excellent 

 condition. 



The regular program consisted of two communications: 



Notes on the biology of the common termites of the eastern United States: 

 Thomas E. Snyder. This paper was illustrated by many lantern slides 

 and was discussed by E. A. Schwarz. 



The biting powers of ants: W. L. McAtee. The speaker's personal 

 observations as well as instances gathered from many sources 

 were cited to show the powers of these small animals. Messrs. E. A. 

 Schwarz, A. C. Weed, A. D. Hopkins and the author of the paper took 

 part in the discussion which followed. 



The 507th regular meeting was held February 8, \Aath President Nel- 

 son in the chair and 57 persons present. 



Prof. Burt G. Wilder gave an illustrated lecture on The brain as a 

 guide to the affinities of vertebrates, basing his remarks primarily on the 

 brain of the shark Pentanchus recently described by Smith andRad- 

 cliffe as the type of a new family. The speaker showed by means of 

 diagrams the evolution of the selachian brain from the most primitive 

 form found in Chlamydoselachus thru the other Notidani to the typical 

 sharks; and announced his conclusion, from the evidence afforded by 

 the brain, that Pentanchus is not a Notidanid. He did not venture, how- 

 ever, to say just what the systematic position of this shark may be until 

 the vertebrae and intestines have been studied, although it is certainly 

 not related to the Scylliorhinidse, to which Regan {Science, July 19, 

 1912) assigns it on the theory that the single dorsal fin is an abnormality. 



In the discussion which followed, H. M. Smith said that in assigning 

 Pentanchus to the order of ancient sharks, partly on account of the single 

 dorsal fin, he and Mr. Radcliffe had been aware of characters in which 

 this shark differs from typical Diplospondyli, but that no other course 

 seemed expedient at the time the preliminary description was published. 

 The vertebrae, while not diplospondylous but modified cyclospondy- 

 lous, are of a very primitive type, being only half the size of those in a 

 scylliorhinid shark of the same length, with an extremely small centrum 

 and a very large neural canal. 



Theodore Gill discussed the subject at length, and agreed with Prof. 

 Wilder in attaching great taxonomic importance to the brains in sharks 

 and rays. He had concurred in the assignment of Pentanchus to the 

 Notadini, and now regarded it as the type of a peculiar family whose 

 affinities remain to be determined. 



D. E. Lantz, Recording Secretary. 



