REPORT OF NATIONAL, MUSEUM, 1923, 73 



particular groups on which they are working: Dr. Henry B. Bige- 

 low (Medusae, Ctenophora), Dr. K. H. Barnard (Isopods), Dr. L. 

 R. Gary (Alcyonarians), Dr. R. V. Chamberlin (Annelids and 

 Gcphyrea), Dr. Henri Coutiere (Crangonidae (Crustacea)), Dr. 

 Joseph A. Cushman (Foraminifera), Prof. Arthur Dendy 

 (Sponges), Prof. A. A. Doolittle (Fresh-water Entomostraca), 

 Prof. G. S. Dodds (Fresh- water Entomostraca), Prof. C. O. Es- 

 terly (Marine copepods), Dr. A. G. Huntsman (Ascidians), Frits 

 Johansen (Fresh-water Entomostraca), T. Kaburaki (Turbellaria), 

 Dr. C. D wight Marsh (Fresh- water copepods). Dr. Maynard M. 

 Metcalf (Salpa, Pyrosoma, Protozoa), Dr. J. Percy Moore 

 (Leeches), Dr. Charles C. Nutting (Hydroids), Dr. Raymond C. 

 Osburn (Bryozoa), Dr. Henry A. Pilsbry (Barnacles), Capt. F. A. 

 Potts (Rhizocephalids (Crustacea)), Prof. Frank Smith (Earth- 

 worms, Fresh-water sponges). Dr. W. M. Tattersall (Mysidacea 

 (Crustacea)), Dr. Aaron L. Treadwell (Annelids), Dr. Willard G. 

 Van Name (Ascidians), and Dr. C. B. Wilson (Parasitic, and free- 

 swimming marine copepods). 



The division of mollusks has not been greatly dependent on the 

 research of outsiders, although indebted to Dr. Frank Baker, Uni- 

 versity of Illinois, for identification of mollusks of the genus 

 Physa; Prof. T. D. A. Cockerell, University of Colorado, for deter- 

 mination of a collection of slugs; Dr. H. A. Pilsbry, Academy of 

 Natural Sciences, Philadelphia, Pa., of a naiad from Mexico, and to 

 Dr. Victor Sterki, New Philadelphia, Ohio, for identification of 

 some fresh-water mussels. Assistance is gratefully acknowledged to 

 tk» Navy Department for transportation of Doctor Bartsch during 

 his recent collecting trip to Cuba, Haiti, and Porto Rico. 



In the National Herbarium Dr. S. F. Blake, of the Department of 

 Agriculture, has rearranged the material of several critical gi'oups 

 and has determined large quantities of unidentified specimens, 

 chiefly in the composites. Dr. C. V. Piper also has given attention 

 to several groups of the family Fabaceae; and Ivar Tidestrom has 

 completed a flora of Utah and Nevada, which has been in course of 

 preparation for several years, and is now ready for publication. As 

 in previous years, correspondents whose cooperation has increased 

 the value of the material in the herbarium are those to whom speci- 

 mens have been transmitted for critical study. Special mention may 

 be made of several persons who have rendered assistance in the 

 determination of plants of special groups. Because of the fact that 

 there is in the herbarium no one who is engaged in study of the 

 lower cryptogams, it is necessary to send these to outside specialists 

 for identification. Among those who have cooperated in this con- 

 nection are Mrs. E. G. Britton, Dr. W. A. Murrill, Dr. M. A. Howe, 



