Taxonomy and Morphology of the Ligulate Species 

 of the Genus Desmarestia* 



ViNNiE A. Pease 

 IJnivers'itii of Miv)icsota, Minneapolis 



Contents 



1. Introduction 313 



2. Taxonomy 314 



a. General 314 



h. Desmai-estia ligtdata (Lightfoot) Lamouroux .... 314 



Q. Desmarestia herhacea (Turner) Lamouroux . . . . 317 



d. Desmarestia latissima Setchell and Gardner in Litt. n. sp. . 319 



e. Desmarestia foliacea n. sp 322 



f. Key to species 325 



3. Morphology 326 



a. Historical 326 



b. Methods 331 



c. Desmarestia ligulata (Lightfoot) Lamouroux .... 332 



d. Desmarestia herhacea (Turner) Lamouroux 340 



e. Desmarestia latissima Setchell and Gardner in Litt. n. sp. . .341 



f. Desmarestia foliacea n. sp 342 



g. Conclusions 343 



4. Summary 344 



5. Bibliography 345 



1. iNTnODUCTION 



In a preliminary paper on the north Pacific coast species of Desmar- 

 estia, the writer (Pease, 1917) discussed briefly the principal characters 

 of the genus, and described five species which she had collected in the San 

 Juan Islands. The paper proposed two or three changes in classification, 

 eliminated one species, and inserted D. tahacoides Okamura, which had 

 previously been reported only from Japan. 



The present paper deals with the taxonomy and morphology of the 

 ligulate species of the genus. Reproducing material of these species has 

 not been collected in the San Juan Islands, and tlie writer is not yet ready 

 to discuss the functions of the various tissues. 



* A thesis submitted to the Faculty of the Graduate School of the Univer- 

 sity of Minnesota, in partial fulfillment of the requirements for the degree of 

 Doctor of Philosophy, 1910. 



(313) 



