382 BOTANY OF SOCOTRA. 



9. ARTHOTHELIUM. 



Arthothclium, Mass. Hie. 54 ; Th. Fries, Heterol. 97 ; Stitzb. Beitr. 152. 

 Arthonia, Auct. pr. p. 



The generally rare species of this genus are for the smaller part dispersed 

 in hot and temperate regions, and are not so numerous as the species of 

 Arthonia. 



1. A. leucocarpum, Miill. Arg. in Proc. Roy. Soc. Edin. xi. (1882), 468. 



Thallus albus, effusus, crassiusculus, rugulosus, nonnibil farinulentus; gonidia oblongata, concate- 

 nata ; apotbecia hemisphoerica, subregularia, interdum geminatim coufluentia, immarginata, 

 £-1 mm. lata, tota extus intusque alba, ulbo-farinosa, demum ascis carneolis bine hide 

 emergentibus Stigmatidii more puncticulata ; lamina undique pallida ; parapbyses creber- 

 rime reticulatim ramosoe et tenuissimae ; asci pauci tantum cylindrico-obovoidei, 8-spori 

 sporse hyalinae, eire. 75 /j. longae, 18 /x latae, 8-loculares, loculi ipsi semel v. bis cruciatim 

 parenchymatice divisi, balo amplus, demum creberrime hyphemoideo-vestitus. 



Nulli nisi A. scriblitcllo (Arthonice scriblitcllce, Nyl. in Prod. Nov. Granat. p. 102) proxime 

 affinis est, a quo ex diagnosi loc. eit. data differt forte leviter tballo crassiore ruguloso, 

 effuso et praesertim forma apotbeciorum ambituque multo angustiore sporarum. Extus 

 baud male simul at Arthoniam Rampeanam, Miill. Arg. (L.B. n. 280). 



Soeotra. Corticola ad ramos crassiores. B.C.S. nn. 1465, 1467. 

 Distrib. Endemic. 



2. A. emersum, Mull. Arg. in Proc. Roy. Soc. Edin. xi. (1882), 468. 



Tballus albus, effusus, tenuissimus, bevis, subfarinulentus ; apotbecia £-§ mm. longa, emerso- 

 sessilia, orbicularia v. saepius dimidio et paullo ultra lougiora quam lata, depresso-convexa, 

 atra, nuda, opaca ; epitbecium olivaceo-nigricans v. tenuissime sectum olivaceum, lamina 

 olivaceo-subobscura, hypothecium cum lamina concolor ; asci oblongato-obovoidei, 8-spori ; 

 sporae hyalinae, 15-17 /x longa3, 7-9 /x lata?, ovoideo-fusiformes, sequaliter 6-loculares, loculi 

 nonnulli longitrorsum semel divisi. 



Arthothelio intervenicnti, sc. Arthonice intervenienti, Nyl. in Prodr. Nov. Gran. p. 104, accedit, 

 sed apotbecia magis emerso-sessilia, crassiora, et sporse minores minusque intus divisoe. 



Soeotra. Ad truncos. B.C.S. n. 1381. 

 Distrib. Endemic. 



10. ENTEROGRAPHA. 



Enterorjrapha, Fee Meth. 17 (1824) ; Tb. Fries, Heterol. 95 ; Stitzb. 153. 

 Stigmatidium, Mey. Flecht. 328 (1825); Nyl. Essai. 188. 



A small genus, widely dispersed, with very small and rare but easily over- 

 looked plants. Our species are of the smallest known lichens, and are all new, 

 and as yet endemic. 



Sclerophyton elegans Escbw. Bras. p. 203, a cl. Nyl. Stigmatidio adscriptum (in ej. Syn. Lich., 

 Nov. Caledon. p. 58, et Lich. Husnot. p. 18), ab Enterographa (Stigmatidio) ob peritbeciuin 



