1926] Bahcock-Lesley : Cliromosomes and Taxonomic Relationships 331 



Our analysis of relationships among these twenty-one species, as 

 based on comparative morphology, is summarized in table 2. This 

 analysis is presented only in a tentative way, as an aid in the study of 

 cytological evidence and a step toward the classification of the entire 

 genus. 



The correspondence of the new taxonomic grouping with chromo- 

 some number and size is shown in table 3. 



Since the foregoing was written, the chromosomes have been 

 examined in the following additional species of Crepis. The classifica- 

 tion into sections is according to the tentative new arrangement shown 

 in tables 2 and 3. 



IV. Nemauchenes 



C. amplexifolia (Godr.) Willk N= 4 size medium 



VI. Eucrepis 



C. lyrata Fvoel N= 6 size medium 



C. 7nollis (Jacq.) Asch N= 6 size medium 



C.pygmaeah N= 6 size medium 



C. chondrilloides Jacq N= 4 size large 



C.Blavii Asch N= 4 size large 



C. ciliata C Koch N = 20 size medium 



VII. Youngia 



C . fuscipappa {Thw .) Benth N= 8 size medium 



IX. Omalocline 



C. Hooker iana Ball N= 4 size medium 



X. Soyeria 



C. conyzaefolia (Gouan) Dalla Torre N= 4 size large 



C. tingitana Salz. ex Ball N= 5 size medium 



C. paludosa (L) Much N= 6 size large 



With reference to the six species classified under Eucrepis, the first 

 group of three lyrata, mollis, and p\jgmaea, must be grouped with 

 montana on the basis of morphology, and they have similar chromo- 

 somes. The next two, chandriUokles and Blavii, represent a subdivision 

 of Eucrepis not previously studied and are very distinct from other 

 members of Eucrepis, Lastly ciliata is certainly in Eucrepis, and its 

 chromosomes indicate relationship to biennis, to which species there is 

 considerable resemblance in the rosettes of our immature plants. 

 Evidently Eucrepis is too heterogeneous a group to be retained as a 

 section, and in the taxonomic revision of the genus which is now in 

 preparation it will become a subgenus containing several sections. 



