284 PROCEEDINGS OF THE AMERICAN ACADEMY 



C. LINEARIS, Dougl. According to Professor Henderson, the sta- 

 mens are always three and the petals decidedly unequal. 



C. DiCHOTOMA, Nutt. in Torr. & Gray, Fl. The larger forms of 

 this little plant are not very obviously distinguishable from C. linearis. 

 The smallest and most depressed include Montia Howellii, "Watson, 

 Proc. Am. Acad, xviii. 191, which agrees not badly with some of 

 Nuttall's originals. 



MONTIA, Micheli. The Northern forms of M. fontana, from 

 Greenland and Newfoundland to Lower Canada and New Brunswick, 

 and from Arctic Alaska to British Columbia, all have the areolate- 

 tuberculate seeds with smoothed and somewhat shininjj surface of 

 31. rivulai'is, Gmelin, Fl. Bad., or M. Iamprospe7-ma, Cham. ; while 

 those of Oregon and California have the duller and rather sharply 

 muriculate seeds of M. minor, Gmelin. These differences do not 

 correspond with any clear difference in habit. The species is singu- 

 larly absent from the Atlantic United States. 



SPRAGUEA, Torr. Of a single species: for I can make nothing 

 more than a casual variation of S. paniculata, Kellogg. Mr. Watson 

 has indicated (in Proc. Am. Acad. xx. 35 G) the near approach which 

 one species of Calyptridium makes to this otherwise peculiar genus ; 

 and Professor Greene has consequently united the genera. I think 

 that Spraguea should still be retained upon the assigned characters. 



CALYPTRIDIUM, Nutt. The genus was so named upon a 

 partial misconception. The petals are not "united into a minute di- 

 aphanous conical corolla, slightly 3-toothed at the apex," as Nuttall 

 supposed. They are quite separate, expanded in anthesis, which is 

 ephemeral, then close over each other and over the pistil, are in this 

 state detached from their insertion, and carried up on the forming fruit, 

 just as in almost every plant of this family. Nuttall 's conjecture that 

 his plant might be the Talinum monanclrum, Ruiz & Pav., was wrong. 

 That is Fenzl's Monocosmin, of which it may here be remarked 

 that the utricular capsule is just that of Lewisia and of Calandri- 

 nia § Puchyrrhizea on a small scale. 



I distinguish four species of Calyptridiiim in two sections. The 

 section which approaches Spraguea is here put foremost. 



* Petals 4: stamens in the same species 1, 2, or 3 : capsule little if at 

 all surpassing the fructiferous calyx : seeds acute-margined. 

 C. QUADRIPETALUM, Watson, Proc. Am. Acad. xx. 356. A span 

 high : leaves oblong-spatulate (larger 2 inches long, including tapering 



