66 JOURNAL OF THE WASHINGTON ACADEMY OF SCIENCES VOL. 11, NO. 3 



to be harboring a number of chiggers. The pests were confined to the scaly 

 outer membrane. A photograph of the infected snake and microscopic 

 preparations of the skin showing the chiggers were exhibited. 



Dr. Shufeldt's paper was discussed by Dr. Bartsch, who had seen ticks 

 upon a black snake. Mr Wm. Palmer had noticed ticks on the Pine Liz- 

 ard. Mr. Goldman had found ticks common in the ears of snakes and lizards 

 in South America. Dr. Ewing, commenting upon the specimen and in an- 

 swer to questions raised, said that the chiggers were doubtless wholly ad- 

 ventitious upon the snake, and that the instance did not throw any light 

 upon the life history of the chigger, which was unknown, except in the case 

 of a disease-bearing species of Japan. The supposed immunity of individuals 

 to chiggers, their very unequal distribution, even in circumscribed areas, 

 and other problems connected with their life history and economic relations, 

 were discussed. Col. Thomas Carey emphasized the need for investigations 

 of this pest. 



Charles W. Gilmore : Remarks on some additions to the fossil vertebrate 

 exhibition in the National Museum. 



Dr. Gilmore discussed some of the difficulties involved in building up a 

 representative exhibition collection of fossil vertebrates. It was pointed 

 out that of 20,000 specimens in the National Museum, only 40 were articu- 

 lated skeletons, or of every 1000 specimens collected, only two might be ex- 

 pected to be perfect enough to be suitable for exhibition purposes. This 

 ratio was not considered a constant one for all collections, but it indicated 

 the comparative rarity of well-preserved fossil vertebrate specimens. 



It was shown that the articulation and mounting of fossil skeletons for 

 public exhibition is a comparatively recent phase in the development of 

 vertebrate paleontology in this country. Very few were thus exhibited prior 

 to 1900, and the first skeleton in the National Museum was set up in 1902. 



The great amount of time consumed in prepairng fossil skeletons for 

 exhibition was discussed. A skeleton of Dimetrodon required 533 working 

 days, and that of Stegosaiiriis 626 days, or more than two years' steady work 

 for one man. The style of mounts was briefly touched upon, and the de- 

 sirability of preserving articulated skeletons, especially of the reptiles, 

 in the positions in which they were found in the field, was emphasized. 



The National Museum was said to rank third on the list among American 

 museums having similar exhibits of extinct vertebrate life. 



Following this brief discussion Dr. Gilmore exhibited slides of the more 

 important accessions to the collection in recent years. The most striking of 

 these were: Stegosaunis, an armored dinosaur; Ceratosaurus, a flesh-eating 

 dinosaur; Dimetrodon, a giant spined reptile; Brontotherium, a large mammal 

 from Nebraska; Epigaellus, a horned rodent from Kansas; Stenomylus, a 

 small camel from Nebraska. The more striking characteristics of these 

 animals were pointed out and life restorations were shown, including two 

 modeled by the speaker and here exhibited for the first time. (Author's 

 abstract.) 



The paper was discussed by Drs. T. S. Palmer, Shufeldt, and BarTSCH. 



A. A. DooLiTTLE, Recording Secretary. 



