A CONSIDERATION OF CERTAIN GENERA 203 



Scirpus Carices Retz. {Scirpus compressus Pers., not Moench). 



13. — TiPHOGETON Ehrh., 1. c. 

 The type is designated as Isnardia palustris L., and since it is 

 also the type of Isnardia, Tiphogeton becomes a synonym of 

 Isnardia. 



14. — Hydrophila Ehrh., 1. c. 



The type is designated as Tillaea aquatica L. The same species 



is made the type of Tilleastrum'Britton (Bull. N. Y. Bot. Gard. 



3:1- 1903) 



H. aquatica (L.) Tillaea aquatica L., Tillaea sim- 



plex Nutt., Bulliarda aquatica DC, Tilleastrum aquatica 

 Britton. 



H. Drummondii (T. & G.) Tillaea DrumondiiT. & G., Tillea- 



strum Drumondii Britton. 



H. Vaillantii (Willd.) Tillaea Vaillantii Willd., Tillea- 



strum Vaillaniii Britton. 



15. — Praticola Ehrh., 1. c. 

 The type is designated as Thalicirum simplex L., native of 

 Europe. The name is not valid unless quite extensive segregation 

 of the genus Thalictrum, as now constituted, should be made. 



16. — LiMNAS Ehrh., 1. c. 



The type is designated as Ophrys paludosa L. This has been 

 placed in the genus Sturmia Reichb. (1828), which is invalidated 

 by Sturmia Hoppe (1799) and Sturmia Gaertn. (1805). 



The writer has previously pointed out (Torr. Club Bu^l. 32: 378. 

 1905) that the type of Orphys L., is Orphys ovata L., and that 

 Listera is a generic synonym. The type of Malaxis Sw. (1788) is 

 M. spicata, congeneric with our native species now known as M. 

 monophylla (L.) Sw., and M. unifolia Michx. Ophrys paludosa L., 

 was also included by Swartz in Malaxis, and has been reported 

 from Otter Tail County, Minn, and is common in Europe, so that 

 Limnas Ehrh., must be regarded as a synonymous generic name of 

 Malaxis. M. paludosa however, differs in certain important 

 characters from our native species, and if seperated from Malaxis, 

 the generic name Limnas would be available for it. 



21. — Mariscus Ehrh., 1. c. 

 The type is designated as Schoenus mariscus L. This name dating 



