124 



CRYPTOGAMIA. 



Thallus growing in dense masses ; very slender and fragile ; dividing 

 at the base irregularly into a few elongated, subsimple, terete branches, 

 which are often fastigiate-branched at the summit, and are clothed with 

 a delicate tomentum ; glaucous-white. Phyllocladia minute, rounded, 

 becoming powdery, loosely scattered, but rather more numerous above; 

 Cephalodia obscure ; apothecia wanting. Nearest to S. nanwn, but a 

 larger and more branched lichen. It is quite distinct from S. nanodes, 

 Tuckerm. (Suppl. Enum. Lich. N. Amer.), nor have I seen anything like 

 it in North America; but it is possibly identical with S. albicans, Th. 

 Fries (1. c. p. 36), from Peru. The figures exhibit, 1. the habit of 

 our specimen, and 2, a portion slightly magnified. 



6. S I P H U L A, Fr. 



1. Siphula Pickeringii, Sp. Nov. (Tab. 2. fig. 4). 



S. thallo ccesjriticio fragili glabro subdichotomo-mmoso e glauco albicante; 

 ramis erectiusculis tereti-compressis dernum sulcatis ; apotheciis laterali- 

 bus. 



Hab. Mountains behind Honolulu, Oahu, Sandwich Islands; grow- 

 ing on the earth, among mosses. 



Caespitose ; the very fragile fronds dividing irregularly near the base 

 into more or less dichotomous, erectish, smooth, terete-compressed, at 

 length pitted and furrowed branches ; the abortive apothecia (exhi- 

 bited in Fig. 2) appearing to be lateral. Both the habit and the struc- 

 ture appear to connect this lichen with Siphula, and it is undoubtedly 

 an undescribed species, but the specimen is too imperfect for farther 

 elucidation. Siphula pteruloides, Nyl., from Peru, of which a brief 

 diagnosis has just appeared (Oct. 1859) in the "Lichenes Exotici" of 

 Dr. Nylander, also from infertile specimens, should be compared with 

 the Oahu Lichen, which considerably resembles Pterida subulata of 

 Moug. & Nestl. Crypt. Vog. n. 995, cited by the former author, as 

 expressing the habit of his species.— Our first figure represents the 

 largest specimen, and the second a slightly magnified branch, with abor- 

 tive apothecia. 



