PYREXULACEAE. 527 



On bark of Jacquinia keyensis, vicinity of The Bight, Cat Island (Britton and 

 Millspaugh, March 1-6, 1907, 58*0, type). 



The white epiphloeodal thallus and the shining globose perithecia will serve to 

 distinguish this from the few species of Microthelia having four-celled spores, such 

 as 11. thelena var. subtriseptata Wainio. 



6. CLATHR-OPORINA Muell. Arg. 



1. Clathroporina nuculastrum Muell. Arg. Flora 67: 618. 1884. 



On twigs, New Providence, at Maidenhead Coppice : Florida ; Madagascar. 



7. POLYBLASTIOPSIS Zahlbr. 



1. Polyblastiopsis lactea (Mass.) Zahlbr. in Engler and Prantl, Nat. Pflan- 

 zenfam. I 1 *: 65. 1903. 



Blastodesmia lactea Mass. apud Koerb. Parerg. Lich. 336. 1865. 



On bark, New Providence and The Bight, Cat Island : North America ; Europe. 



8. ANTHRACOTHECITJM Mass. 



Thallus from orange to yellow. 1. A. ochraceo-flavum. 



Thallus from white to olivaceous. 



Spores with two to four series of cells. 



Spores with two series of cells. 2. A. subglobosum. 



Spores with four series of cells. 3. A. corticatum. 



Spores with six to eight series of cells. 



Perithecia immersed except when old. 4. A. libricolum. 



Perithecium soon emergent and superficial. 5. A. americamim. 



1. Anthracothecium ochraceo-flavum (Xyl.) Muell. Arg. Linnaea 43: 44. 1880. 



Verrucaria ochraceo-flavum Xyl. Expos. Pyren. 50. 1858. 

 Verrucaria ochraceo-flavens Nyl. Act. Soc. Sci. Fenn. 7: 491. 1863. 



On bark of various species, Great Bahama, New Providence, Cave Cay, Exuma 

 Chain, Cat Island : widely distributed in tropical regions of both hemispheres. 



2. Anthracothecium subglobosum Riddle, sp. nov. 



Thallus epiphloeodes erustaceus uniformis effusus haud limitatus, sordide 

 aut virescenti-albidus, in crassitudine mediocris vel tenuis, rimosus rugulosus. 

 Gonidia chroolepoidea. Perithecia dispersa solitaria, primum immersa, verrueis 

 thallinis convexis, apice plus minusve nudato minute umbilicato, dein circa Vt 

 ad 1-& emergentia, globosa, 0.7-1.0 mm. diam., nigra integra. Paraphyses sim- 

 plices crassiuseulae. Asci cylindrices 8-spori. Sporae in ascis uniseriales, 

 fumosae aut fusco-atrae, globosae circa 12 n diam., aut subglobosae circa 

 12 X 10^, primum biloculares mox loculis altero ambobusve divisis rotundati-. 



On bark, New Providence (Brace. February 11, 1919, 1006',, type). 



The specific name refers not to the perithecia but to the peculiar spores. The 

 species is related to A. sinapispermum (Fee) Muell. Arg., but the latter species has 

 minute perithecia, 0.150.2 mm. in diameter, and oblong spores, 7-8 x 4-5 y. 



3. Anthracothecium corticatum Muell. Arg. Bull. Soc. Roy. Bot. Belg. 30 1 : 



96. 1891. 

 On bark, New Providence, at Waterloo Coppice: Costa Rica, Venezuela. 



4. Anthracothecium libricolum (Foe) Muell. Arg. Linnaea 43: 43. 1^80. 



Fyrenvla libricola Fee, Suppl. Essai Crypt. 82, pi. 41, f. SI. 1837, 



On bark of various species. Groat Bahama, New Providence, Great Exuina, Long 

 Island: widely distributed in tropical and subtropical regions of both hemispheres. 



This species is a common and variable one. All stages may be found from that 

 In which the perithecia are completely buried in the thallus and scarcely discernible 

 externally, to that in which the perithecia become half emergent, when they are con- 

 spicuous and appear relatively large. Superficially the two extremes look very 

 different. 



