CLADONIACEAE. 475 



and whitish, and the delicately colored, waxy, discoid apothecia are so 

 small as easily to escape notice. The apothecia resemble those of Bilimbia 

 Brittoniana, but the thallus is entirely different. 



Gyalecta Farlowi Tuck, is another of the endemic species found on 

 the calcareous rocks. Like the preceding species it is easily overlooked, 

 the minute apothecia being almost immersed in the white thallus. 



Family 3. LECIDEACEAE. 



In this family, a knowledge of the spore-characters is necessary in 

 order to distinguish even the few species found in Bermuda. Those here 

 described all grow on bark.* The most distinctive of these is the endemic 

 Bilimbia Brittoniana Riddle, which has a minutely powdery, straw-colored 

 thallus, made up entirely of fine granules, among which are hidden the 

 minute, thick-margined, flesh-colored apothecia. The species is named 

 in honor of Dr. and Mrs. Britton, the original specimens having been col- 

 lected by Mrs. Britton, along the north shore, where it was growing on 

 Juniperus. 



The remaining three species resemble each other closely in external 

 appearance, all having a thin thallus and convex apothecia, which vary 

 from flesh-colored or pallid-brown to dark brown. They can readily be 

 distinguished by their spores, since Biatora fuscorubescens (Nyl.) Riddle 

 has one-celled spores; Bilimbia sphaeroides vacillans (Nyl.) Riddle has 

 short, spindle-shaped spores with four cells; and Bacidia fuscorubella 

 (Hoffm.) Th. Fr. has long, needle-like spores with eight or more cells. 



Family 4. CLADONIACEAE. 



Conditions in Bermuda are not favorable for the plants of this 

 family. Few species have been found, and the specimens of these are not 

 altogether typical. There are only two common species. Cladonia 

 mitrula Tuck, is a small species, growing on the ground, and always well- 

 fruited, the brown apothecia being borne on slender, simple or sparingly 

 branched stalks, less than one centimeter high. C. fimbriata (L.) Fr. is a 

 polymorphic species represented in Bermuda by at least three varieties, 

 in all of which the ends of the podetia are typically cup-shaped. C. fim- 

 briata simplex (Weis.) Flot. has short podetia, rarely branched, and with 

 regular cups. The other two varieties, nemoxyna (Ach.) Coem. and bor- 

 bonica (Del.) Wainio, are taller and variously branched, with cups -more 

 irregular or even absent on some of the podetia ; they can be distinguished 

 by the fact that the podetia of the latter variety are much more granulose 

 than is the case in the former. In addition to these two common species, 

 C. rangiformis pungens (Ach.) Wainio, with copiously branched podetia, 

 was collected by the Challenger Expedition, but does not seem to have 

 been found since, and C. pityrea (Flke.) Fr., a nondescript species, has 

 been found growing with C. mitrula, from which it may be distinguished 

 by the scurfy-granulate surface of the podetia, as well as by the occasional 

 occurrence of reduced cups. 



* Any resident of Bermuda who could make careful collections of the rock- 

 lichens would probably find additional species of Lecideaceae. In the Journal of the 

 Linnean Society of London, volume 14 (1875). Stirton described three such species, 

 but they were based on such fragmentary specimens that they can not be accepted 

 until more is known of them. 



