NOTES AND LITEEATUEE 



North American Early Tertiary Bryozoa. By Ferdinand 

 Canu and Ray S. Bassler. Smitlisonian Institution. United 

 States National Museum. Bulletin 106. 1920, 879 pages, 

 279 text figures and 162 plates. 



Students of both fossil and recent bryozoa will greet with 

 interest and pleasure this monumental work long anticipated 

 and recently issued, for while treating primarily of fossil 

 bryozoa this monograph contains much of interest to students 

 of living forms. This work appears in two volumes, one con- 

 taining the text and text figures, the other consisting of photo- 

 graphic plates alone. A cursory inspection reveals the fact 

 that these volumes possess the excellence of copious illustration, 

 a most satisfactory virtue in the eye of those who will use them. 

 The text figures are abundant, the number as stated above (279) 

 by no means giving a true idea of the actual number, since each 

 figure consists of from two to ten or more illustrations, repre- 

 senting portions or organs of tlie species under discussion, and 

 often besides figures of nearly related species for comparison. 

 From this point of view the number given should be multiplied 

 many times, and by actual count the first fifteen text figures 

 contain more than one hundred separate drawings or prepara- 

 tions. These are all either original with the authors or are 

 taken from the illustrations of other bryozoologists. Each pho- 

 tographic plate likewise contains from twelve to twenty-five 

 separate photographs. These are distinguished by a remarkable 

 clearness and definiteness of outline, even of minute details, 

 revealing an unusually skilful management of light and shade 

 and producing an excellent and expert piece of work which will 

 not fail to call forth the gratitude as well as the admiration of 

 their fellow workers. 



Over 700 species belonging chiefly to the two orders, Cyclosto- 

 mata and Cheilostomata, are treated in this monograph. In the 

 seventy or more pages of introduction the authors present many 

 topics of interest involving new points of view which will doubt- 

 less stimulate further research. Of these topics but three will 

 be touched upon. 



1. It is gratifying to find clear definition and illustration of 



