NOVEMBEB 15, 1907] 



SCIENCE 



679 



of physiology and a professor of pathology. 

 The maximum salai-y for these positions is 

 fixed at $5,000. 



ARCHEOLOGICAL WORE IN ARIZONA 



During the past season the Committee on 

 American Archeology of the Archeological In- 

 stitute of America offered properly qualified 

 students the privilege of joining the-field ex- 

 peditions of the Institute in Colorado, Utah 

 and New Mexico. A number of students 

 availed themselves of the opportunity to par- 

 ticipate in the practical work of exploration, 

 mapping and excavation of ruins in the San 

 Juan and Rio Grande basins. These expedi- 

 tions closed on October 1. 



Through the courtesy of the Secretary of 

 the Smithsonian Institution the committee is 

 authorized to announce that the government 

 excavations at Casa Grande, in the Gila 

 Valley, Arizona, will be resumed about No- 

 Tcmber 1, under the direction of Dr. J. Walter 

 Fewkes, to continue during the fall and 

 winter, and that students may arrange through 

 the Archeological Institute to participate in 

 the work at this site. As government institu- 

 tions are not permitted to accept volunteer 

 services. Dr. Fewkes is authorized to pay a 

 limited number of students (not to exceed ten) 

 for their services in connection with the work 

 a nominal salary of ten dollars per month, it 

 being understood that they provide for their 

 own traveling- expenses and subsistence. This' 

 nominal salary will about cover field sub- 

 sistence at Casa Grande. 



Students desiring to avail themselves of this 

 opportunity should correspond with the under- 

 signed as early as convenient. Applications 

 should be accompanied by the recommenda- 

 tion of the professor under whom the appli-' 

 cant has studied. Edgar L. Hewett, 



Director of American Archeology 



Abcheologioal Institute or Ameeica, 

 1333 F Street, Washington, D. C, 

 October 21, 1907 



BRITISH MUSEUM MODEL OF EURTPTERVS 



In the Upper Silurian rocks of the island 



of Oesel, in , the Baltic, are found the fossil 



remains of an arthropod called Eurypterus 



Fischeri. This animal is of interest as one 

 of an extinct group of arthropods that appear 

 to have been allied to the modern Limulus or 

 king-crab, as well as to the scorpions. These 

 particular fossils have a further interest in 

 that the chitinous substance of the outer coat 

 of the animal has been preserved unaltered in 

 chemical and physical composition. Thus 

 Professor G. Holm, of Stockholm, has been 

 able to dissolve the remains out from the 

 rock by means of acid, and to mount them on 

 glass slides in Canada balsam. On the pre- 

 parations thus obtained, he based an elaborate 

 description, published in the Memoirs of the 

 Academy of Science, St. Petersburg (Ser. 8, 

 Vol. VIII., No. 2, 1898). It can now be said 

 that the structure of this species is known 

 better than that of any other extinct 

 arthropod. Several of Professor Holm's prep- 

 arations preserved in the geological depart- 

 ment of the British Museum are quite marvel- 

 ous, and it is difficult to believe that one is 

 looking at a fossil at all, still more one dating 

 from the Silurian Epoch. 



The perfection of these specimens and the 

 interest of the animal suggested to members 

 of the staff of the British Museum (Natural 

 History) the advisability of preparing a com- 

 plete model of it, and such a model in colored 

 wax, of about twice the natural size, has now 

 been made under the direction of Dr. W. T. 

 Caiman and Dr. F. A. Bather by Mrs. Vernon 

 Blackman, whose beautiful models of plants, 

 of the parasite of malaria, and of the tsetse 

 fly are well known to all visitors to the 

 Natural JTistory Museum in the Cromwell 

 Road. 



The model was first placed on exhibition on 

 the occasion of the visit of foreign geologists 

 to the Centenary of the Geological Society of 

 London and evoked their enthusiastic admira- 

 tion. It measures 23 x 15 cm. The wax of 

 which it is made will stand any extremes of 

 temperature likely to be met with in a mu- 

 seum, and the colors are believed to be quite 

 permanent; they are based upon those of the 

 recent Limulus, and Sir Ray Lankester has 

 shown great interest in their selection. The 

 model which, it may be mentioned, has been 

 subjected to the careful scrutiny of Professor 



