170 MISSOURI BOTANICAL GARDEN. 
Thallo substellato-multifido decumbente coriaceo laevi nudo flavo- 
virescente (stramineo) laciniis discretis laxe intricatis repetito-di- 
chotomis marginibus recurvis (conniventibus) subtus fuscis (nigres- 
centibus) fibrillis nigris subpannosis; apotheciis. . ... . 
In his Genera Lichenum he mentions this same lichen, 
but concludes that it belongs to Parmelia molliuscula, Ach. 
In his synopsis of North American Lichens, I, p. 64, he 
still holds to this last determination and gives the follow- 
ing description: — 
Parmelia molliuscula, Ach.; Everniaeform, the narrowed lobes sub 
stellate, or loosely intricate, dichotomously more or less regularly di- 
vided, convex; beneath channeled, or the margins connivent, and 
densely, or now obsoletely fibrillose; apothecia unknown. 
Recently while looking over the lichens of the Engel- 
mann Herbarium at the Missouri Botanical Garden, a couple 
of fragments of this species were found bearing several 
apothecia. The specimens are from Upper Pole Creek in 
the Black Hills region, and were collected by Dr. H. 
Engelmann, August, 1856. 
A study of these specimens enables us to add to the fore- 
going descriptions: — Apothecia middling size; disk dark 
chestnut brown, becoming flattish; margin often at first 
entire, but soon becoming subcrenate. 
A careful study of numerous sections of the best de- 
veloped apothecia failed to show any mature spores in situ. 
Nearly all the asci contained shrunken masses of proto- 
plasm and many of them showed the beginning of spore 
differentiation. 
A few loose spores were found, however, that probably 
belong to this species. They were simple, colorless, ellip- 
soid, and measured 10 yp. long by 5 yw. in width. 
Plate 57 shows a sterile thallus above, and below, the 
fertile specimens referred to, x 2; a cross section through 
a medium sized apothecium near the revolute margin, x 10; 
and an ascus showing incipient spore formation, with a 
cluster of three paraphyses, x 650. 
T. A. WILLiAMs. 
