422 White : Tylostomaceae of North America 



dehiscence are very different in the various genera, some having a 

 definite apical mouth, the peridium withering and collapsing as 

 the spores escape ; others rupture irregularly from above down- 

 wards, more as in the Sclerodermataceae. Battarrca has a regular 

 line of dehiscence where the upper portion of the somewhat hem- 

 ispheric peridium breaks away, leaving the lower portion at the 

 summit of the long stem. 



In the peridial characters, Tylostoma is closely allied to the 

 Lycoperdaceae. The relation of this family to the Phallaceae 

 is one of analogy mainly, shown in the elongation of the stem 

 which forces the spore-bearing parts to a higher position for the 

 better scattering of the spores. 



In his latest treatment of the family, Fischer* recognizes 

 four genera : Tylostoma with forty species, widely distributed ; 

 Qiicletia with a single species from France, failing to note that it 

 had also been reported from America ; Battarrea with eight spe- 

 cies ; and Sphaericeps with one species from Angola. The genus 

 Chlaviydopjis, described by Spegazzinif from Argentina, after 

 Fischer's first draft was prepared, was later too summarily assigned 

 as a synonym of TylostomaX for the differences are so marked that 

 it would be unfortunate to include these two diverse types under 

 one genus. 



Within the past year several specimens of a Oilamydopus have 

 been found at Mesilla Park, New Mexico, and it was the original 

 purpose of this paper simply to describe and figure these. It soon 

 became necessary to study the members of the allied genus 

 Tylostoma, of which extensive suites of specimens were found in the 

 Ellis collection, mainly from the western half of the country, rep- 

 resenting some species hitherto undescribed, so that it was finally 

 concluded to prepare a revision of the entire family as represented 

 in North America. Finally some specimens collected by Mr. E. 

 Bethel, of Denver, Colorado, and sent by him to Mr. Ellis, proved 

 to belong to an undescribed genus. This large amount of ma- 

 terial, mostly forming a part of the Ellis collection at the New 

 York Botanical Garden has made the preparation of this paper 



*Engler& Prantl, Die nat. Pilanzenfam. i'**: 342. I900. 

 I An. Mus. Nac. Buenos Aires, 6 : //. 4. f. 2, 3- 189. 1899. 

 X Engler & Prantl, Die nat. Pflanzen'^am. i'** : 357. 1900. 



