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PROCEEDINGS OF THE AMERICAN ACADEMY. 



recte divergentia, duo summa propinqua. Nuculae 4 mm. longae 

 2.5-3 mm. latae basin versus angustatae, quam in speciebus affinibus 

 latius coriaceo-alatae, apice saepius auriculatae. — Guatemala :. San 

 Lucas, Department of Zacatepequez, alt. 1700 m., J. Donnell Smith, no. 

 2188 (type, in hb. Gray) ; Antigua, Department of Zacatepequez, Keller- 

 man, no. 4966 ; San Miguel Uspantan, Department of Quiche", alt. 1800 

 m., Heyde et Lux, no. 2923. It was from the type of this species, in 

 the main, that Professor Fernald drew up the description of Alnus 

 acuminata in his Synopsis of the Mexican and Central American 

 Species of Alnus. There the peculiar ashy-brown color of the bark 

 and strobiles is mentioned, a character afterward emphasized as of 

 diagnostic worth in his characterization of Alnus Pringlei Fern. The 

 color is peculiar to the type specimen and seems to be due to a thin 

 deposit of clay, perhaps wind-borne dust. Professor Thaxter has kindly 

 examined the specimen for fungi, with negative results. 



Alnus Pringlei Fern. The range of this species probably extends 

 northward to Durango. At least the following specimens in the 

 National Herbarium are nearer to A. Pringlei than to any other 

 species : Terreria, Jalisco, 31. E. Jones, no. 439 a; San Ramon, Durango, 

 21 April-18 May, 1906, Palmer, no. 207. 



Alnus rhombifolia Nutt. The accrediting of this species to 

 Mexico in the Pflanzenreich is based upon an error in determination. 

 The number cited as A. rhombifolia is A. glabrata Fern. 



