SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 8 1 



GRIMM I ACE AE 



COSCINODON ARSENEI Ther., sp. nov. 



(Fig. 2) 



Queretaro : Jurica, upon stones (iiooi). 



Autoicus, pusillus, sat compactus. Caulis brevis, simplex, 3-5 mm. 

 altus. Folia sicca imbricata, bumida erecto-patula, obovata, breviter 

 acuminata, longe pilifera, 1.5 mm. longa, i mm. lata, marginibus 

 planis, integerrimis, costa valida, basi 80 /x, in pilum longum, hyalinum, 

 integrum excedente, cellulis basilaribus quadratis, parce chlorophyl- 



FiG. 2. — Coscinodon Arsenci Ther. i, leaf ; 2, median cells ; 3, marginal cells ; 

 4, basal areolation ; 5, capsule with calyptra ; 6, operculum ; 7, cross-section of 

 calyptra; 8, teeth of peristome. 



losis, sequentibus breviter rectangularibus vel hexagonis, laevibus, 

 parietibus tenuibus, majusculis, 15-30 jx longis, 12-15 /^ latis. Pedi- 

 cellus erectus, circa i mm. longus ; capsula subimmersa, minuta, ovata, 

 sicca laevis ; operculum conico-rostratum ; annulus latus ; peristomii 

 dentes irregulares, nunc simplices, parum lacunosi, nunc fere ad basin 

 fissi, papillosi, 0.35-0.40 mm. lati ; sporae 12-15 /* crassae ; calyptra 

 mitraeformis, valde plicata, profunde laciniata, fere totam capsulam 

 obtegens. 



Close to C. Wrightii Sull., but very distinct ; differing from it by 

 the larger, entire leaves, thin-walled cells, the capsule borne upon a 

 longer pedicel and consequently almost exserted, and, finally and 

 chiefly, by the narrow, slightly lacunose teeth of the peristome. 



