GRAPHIDACEAE. 473 



Order 2. CONIOCARPALES. 

 Family 1. CYPHELIACEAE. 



This order has a single, interesting representative in Bermuda, Pyrgil- 

 lus cubanus Nyl. This species has been known previously from the 

 original collection only, made in Cuba by Charles Wright over half a 

 century ago. The Bermuda specimens grew on the same palmetto trunk 

 on Devonshire Marsh, upon which was found the new Anthracothecium 

 tetraspermum. Pyrgillus cubanus has a dull, olive-brown thallus, with 

 raised, wart-like apothecia, the tops of which are minutely roughened, and 

 red with a darker center. The spores with two globose cells would at once 

 distinguish this species if examined microscopically. 



Order 3. GRAPHIC ALES. 

 Family 1. ARTHONIACEAE. 



This is a group of inconspicuous lichens, the crustose thallus being 

 very thin and the minute apothecia irregular in outline. All grow on bark. 

 Arthonia rubella (Fee) Nyl. has stellate apothecia, the divisions being 

 linear and wavy, and varying from flesh-color to reddish-brown. (Sclero- 

 phyton elegans Eschw., although not belonging to this family, has suffi- 

 cient resemblance to Arthonia rubella to mention it here ; it may be recog- 

 nized by its long, flexuous, branched apothecia, which have the fineness of a 

 hair.) Arthonia conferta (Fee) Nyl. is a fairly common species, being 

 found most often on the bark of Melia Azederach. It is less inconspicuous 

 than the preceding species, on account of the abundant and crowded, dark 

 brown apothecia, which are very irregular in outline but rarely stellate. A. 

 polymorpha Ach. may be distinguished from A. conferta by the fact that 

 the apothecia are wholly black. Arthothelium spectabile (Flot.) Massal. 

 resembles externally Arthonia polymorpha, although the apothecia being 

 covered with a whitish bloom are less prominent ; under the microscope this 

 species can be recognized at once by its spores, which are divided longi- 

 tudinally as well as transversely. 



Family 2. GRAPHIDACEAE. 



The species of this family, with a few exceptions, resemble each other 

 very closely, the distinctions among them being based on technical char- 

 acters, and their determination requiring expert knowledge. In the genus 

 Opegrapha the apothecia are more superficial than in any black-fruited 

 species of Graphis found in Bermuda. Two of the Bermuda species of 

 Opegrapha grow on rocks, and three on bark. The rock-inhabiting species 

 are 0. Chevallieri incarnata Riddle and 0. ophites Tuck. The former has 

 a moderately thick thallus, tinged with rose-color, or sometimes fading to 

 coftee-color, and the apothecia are under one millimeter in length ; the 

 latter, no visible thallus, and apothecia up to 2.5 millimeters in length. 

 The bark-inhabiting species require examination of the spores in order to 

 distinguish them. In 0. atra Pers. the spores are four-celled, in 0. vulgata 

 six-celled, and in 0. Bonplandi Fee, eight- to ten-celled. The first two have 

 a white or gray thallus; in 0. Bonplandi it may be whitish, but more 



