Habitat Invertebrate Groups 65 



racemosa) ; Schneck's oak (Quercus Schneckii), from Indi- 

 ana; Arizona sycamore (Platanus Wrightii), and Mexican 

 walnut (Juglans rupestris), from Arizona; broad-leaved maple 

 (Acer macrophyllum), from Oregon; Oregon ash (Fraxinus 

 oregonia), from Oregon and California. 



In addition to these sprays of deciduous trees, one valuable 

 prepared conifer spray, of Douglas spruce (Pseudotsuga taxi- 

 folia), from Colorado, was purchased from Mr. A. E. Butler. 



The reference collection has been enriched by gifts of West 

 Indian and South American woods as follows : Porto Rico, 82 

 pieces, representing 40 varieties; Cuba, 23 pieces; and Co- 

 lombia, 38 pieces. A series of 62 photographs illustrating 

 Sitka spruce lumbering methods in the northwestern United 

 States has been added to the educational files of the department. 



EXISTING INVERTEBRATES * 

 Henry Edward Crampton, Curator 



The activities of the department as a whole have been con- 

 tinued along normal lines, although the war has affected these 

 activities in certain respects. Members of the staff have been 

 engaged in national service during part of the year, but have 

 now returned to their full work. Many collaborators, for- 

 merly engaged in the study of special collections, have been 

 in service, and necessarily their reports have remained uncom- 

 pleted, and publication has been postponed. Finally, field- 

 work has been temporarily suspended, excepting in the in- 

 stances noted below. 



The Nahant Tide Pool Group was completed and installed 

 in the early part of the year. This group, described in detail 

 in last year's report, is a noteworthy exhibit in the 

 Danvm series of habitat groups in the Darwin Hall. 



During the year the Bryozoa Group has been car- 

 ried partially to completion. It will represent the natural history 

 of a bit of sea bottom, one and five-eighths inches in diameter, 

 magnified twenty-five diameters. The minute animals and 

 plants naturally associated with the Bryozoa will be shown 



* Under the Department of Invertebrate Zoology (see also pages 186 to 188). 



