— 62 — 



growth when conditions become more favorable. In some cases the dry plants 

 are so inconspicuous that it is almost impossible to detect th.m. In discussing 

 the hepatic flora of western California, Campbell^ calls attention to many inter- 

 esting peculiarities of xerophilous species, and his remarks would apply equally 

 well to the hepatic flora of Arizona. 



The state of Arizona is bounded by Mexico, California, Nevada, Utah, 

 and New Mexico, while its northeastern corner meets the southwestern corner 

 of Colorado. The Hepaticae of Nevada and Utah are almost unknown, so that 

 it is impossible to make profitable comparison between the hepatic floras of these 

 states and that of Arizona. The Hepaticae of California, however, are known 

 to us through the thorough and comprehensive work of Howe,' who recognizes 

 eighty-six species, inclusive of the Anthocerotes. For Colorado the writer^ has 

 listed forty-one species, while Standley^ has reported twelve species from New 

 Mexico. The Hepaticae of Mexico were long ago described by Gottsche," and 

 only scattered references to them have since been published. Perhaps four 

 hundred species would be a conservative estimate for the entire country. Of 

 the twenty-one species listed fiom Arizona, fifteen have been recorded from 

 California, nine fiom Colorado, five from New Mexico, and twelve from Mexico. 

 These figures would indicate a close relationship between the species of Arizona 

 and those of California and Mexico. The number of Arizona species known 

 from New Mexico is surprisingly small and would probably be increased by 

 careful exploration. A closer relationship between the species of these two 

 states is certainly to be expected. 



Sheffield Scientific School, Yale University. 



^Torreya 4: 81-86. 1904. 



'The Hepaticae and Anthocerotes of Cahfornia. Mem. Torrey Club 7: 1-208. pi. 88-122. 



1899. 



SpreUminary Ust of Colorado Hepaticae. Bryologist 18: 44-47- iQiS. 



'Hepaticae of New Mexico. Bryologist 18: 81-83. iQiS- Additional notes upon New 

 Mexican Hepaticae. Bryologist 19: 64, 65. 1916. 



"> De mexikanske Leverraasser. Kongel. Danske Vidensk. Selsk. Skr. V. Naturv. og Math. 

 Afd. 6: 97-380. pi. 1-20. 1863. 



