2 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 17 



All collection numbers cited with the prefix "D," are those of the 

 author. The dates of collection are as follows: 16-1094, January- Feb- 

 ruary 1946; 1095-1655, April 1946; 1646-1989, May 1946; 2756-3145, 

 October 1946; 3146-3581, November 1946; 3582-3764, December 

 1946; 3765-3940, January-February 1947; 5143-5312, September 1948; 

 6462-7278, 7795-7810, March 1949; 8124-8917, December 1949-Jan- 

 uary 1950; 9044-9554, April-May 1950; 9624-10095, April 1951; 

 10269-10596, August-November 1951. 



Representative examples of all collections cited are in the Herbarium 

 of the Allan Hancock Foundation (HAHF) unless otherwise indicated. 



Distribution records are given from north to south for the sake of 

 consistency, the Gulf of California following Pacific Baja California. 



In some of the older species the citation of literature and synonymy 

 is not intended to be exhaustive. In each case, however, the sources for 

 the original description and the transfer to the currently accepted genus 

 are given together with the significant references to the plant in the 

 literature of Pacific North American algae. An original illustration is 

 given, or an existing one cited, for each species. 



The descriptions of the species are for the most part drawn up from, 

 and intended to represent, the plants as they occur in the Mexican flora. 

 On this account, there may be instances in which the description does 

 not represent satisfactorily a variant of a given species from another part 

 of its range. 



As a number of specimens have been contributed by others, and as 

 new material continues to come in, acknowledgement for these will in 

 most cases be postponed until completion of the systematic parts of this 

 series. 



A comprehensive key to the genera and species of Mexican Rhodo- 

 phyta will accompany the concluding part on this group in a later 

 volume. 



Translations of Latin diagnoses were prepared by Dr. Robert B. 

 Cross. 



November 20, 1951 



