878 



SCIENCE 



[N. S. Vol. XLI. No. 1067 



habit was useful in keeping the soil upturned and 

 "ploughed," but under artificial cultivation by 

 man this habit renders the animals a pest. 

 They are very destructive to root crops, clover, 

 alfalfa and grain. By cutting roots they often do 

 much damage to orchards, nurseries and vineyards. 

 They may be destroyed by trapping or on a large 

 scale by placing poisoned food in their burrows. 

 In a revision of the genus just submitted for pub- 

 lication as a number of the North American 

 Fauna a general discussion of the habits is given 

 as well as descriptions of species and subspecies, 

 and maps showing distribution. 



Mr. Bailey's communication was illustrated by 

 lantern slides from photographs of living animals 

 and of their work. 



Messrs. Cooke, Wilcox, Howard and others took 

 part in the discussion. 



The Sdlst meeting of the society was held in the 

 Assembly Hall of the Cosmos Club, Saturday, May 

 1, 1915, called to order by Vice-president Eose at 

 8 P.M., with twenty-six persons present. 



On recommendation of the council. Admiral G-. 

 W. Baird was elected to active membership. 



Under the heading of Brief Notes and Exhibi- 

 tion of Specimens, Dr. O. P. Hay made remarks 

 on the extinct ground sloths of America and 

 called attention to the existence of a specimen of 

 Nothrotherium from the North American Pleisto- 

 cene, in Baylor University, Texas. Mr. Wm. 

 Palmer announced that he had lately seen an ap- 

 parently wild specimen of the European skylark 

 in near-by Virginia. He also exhibited the jaws of 

 a ray, Bhinoptera honasus, collected at Chesapeake 

 Beach, Maryland. Mr. E. W. Nelson called atten- 

 tion to the newspaper notoriety attained by the 

 San Antonio (Texas) bat roost erected under the 

 misconception that bats were destructive to mos- 

 quitoes. He said there was no evidence that the 

 species of bats {Nyctinomus mexicanus) in these 

 roosts consumed mosquitoes, and that they foraged 

 so far from these roosts that there would be little 

 likelihood of their consuming insects in the vicin- 

 ity of San Antonio. 



The first communication of the regular program 

 was by C. W. GUmore, "Observations on New 

 Dinosauriaji Eeptiles. " 



The speaker discussed briefly some of the more 

 important discoveries of dinosaurian fossils made 

 in North America during the past two or three 

 years, referring especially to the explorations con- 

 ducted by the American Museum of Natural His- 

 tory and Canadian Geological Survey in the Ed- 



monton and Belly Eiver formations in the Prov- 

 ince of Alberta, Canada. He stated that the re- 

 cent finding of several specimens with which was 

 preserved impressions of considerable parts of the 

 epidermal covering, leads us to hope that the time 

 is not far distant when the external appearance of 

 these animals will be as well known as is the in- 

 ternal skeleton. 



Lantern slides of many of the more striking 

 specimens were shown, the speaker confining him- 

 self to brief explanatory remarks regarding their 

 systematic position and their more striking char- 

 acteristics. The following forms were discussed, 

 Saurolophus and Corthyosaurus of the Trachodont 

 dinosaurs; An^ylosauribS, an armored reptile; 

 Monoclonius, Ancliiceratops, Ceratops, Styraco- 

 saiirus and Braehyceratops, all of the Ceratopsia 

 or horned dinosaurs. In conclusion, life restora- 

 tions of Braehyceratops, Tliescelosaurus and Stego- 

 saurus modeled by the speaker were exhibited for 

 the first time. 



Mr. Gilmore's communication was discussed by 

 Messrs. O. P. Hay, Nelson and Lyon. 



The second eommunioation was by William 

 Palmer, "The Basic Pacts of Bird Coloration." 



The complex and varied coloration of birds was 

 explained as due to several causes, which were 

 grouped as pigmental, structural, chemical and a 

 mixture of two of these. The basic pigmentation 

 was considered as composed of blackish, reddish 

 and yellowish cells, the latter being much subdued 

 and principally diluting the others. This colora- 

 tion group was classed as physiological, in con- 

 tradistinction to all other tints, colors and glossi- 

 ness, which were considered as psychological re- 

 sults due to semi-consciousness, especially to eye- 

 'sight, food and certain phases of light. 



This arrangement was based on the experience 

 of the speaker on the forest slopes of Mt. Gede, in 

 western Java, where it was found that non-glossy, 

 dark and dingy colored birds were confined al- 

 most entirely to a habitat of damp, dense ground- 

 cover vegetation, while those clothed in more or 

 less brilliant colors were inhabitants of the inter- 

 mediate areas above the ground cover and below 

 the dense canopy of the branches of the tall forest 

 growth. 



In the tops of the forest trees a different type 

 of coloration was evident; glossy blacks, whites 

 and grays, were exclusively characteristic, or pre- 

 dominant. These types of coloration were con- 

 tinued down into the lowlands in the same order, 

 but with different species or genera, and with the 

 tree-top type spreading through the more open 



