Dr. W. Nylander on new British Lichens. 103 



ferences : it has the same figure as in 0, capensis, but is some- 

 what thickened only at the lower margin, whilst the upper part, 

 near the suture with the maxillary bone, is deeply excavated, 

 80 that the suture is even more elevated than the bones be- 

 neath it. 



The fossa temporalis resembles that of O. capensis in form, 

 and is much more elongated than in 0. gladiator; it is acute in 

 front and rounded behind. It is 10 inches long, 4 inches broad 

 in the middle ; the lower margin is of a sigmoid form, and has 

 a stronger protuberance over the region of the ear than in O. 

 capensis ; but the hinder part of the occiput, corresponding with 

 the mastoid process of higher animals, is not so strong as it 

 seems to be in O. capensis, and is somewhat shorter. 



The tympanic bones are wanting, and the articular cavity for 

 the lower jaw is strongly excavated, with a prominent lower 

 margin. 



The number of teeth is twelve in each jaw ; each of them is 

 situated in a large socket, the first sockets being somewhat 

 smaller than the following ones. In front of the first socket, in , 

 the intermaxillary bone, there is a small and not very deep 

 groove, in which there has probably been a small tooth, now 

 wanting. The total number of teeth would then have been 

 thirteen in the upper jaw. 



Each tooth is of a conical form and somewhat curved, with 

 the apex backward, and the anterior margin more perpendicular 

 than the somewhat inclined posterior margin. The upper half 

 of the crown is whitish, the lower half brown ; on the former 

 there is a thin layer of enamel, which is wanting on the lower 

 brown portion. 



Buenos Ayres, Your sincere Friend, 



May 5, 1866. H. BuRMEISTER. 



XVII. — NotulcB Lichenologicee. No. VIII. 

 By the Rev. W. A. Leighton, B.A., F.L.S. 



NEW BRITISH LICHENS. 



The following additions to our British Lichens are made by 

 Dr. W. Nylander in the ' Flora' for February 1866, p. 85. 



1. Lecidea chlorotiza, Nyl. 



Thallus cinereo-virescens, tenuis, subleprosus, efi'usus ; apothecia 

 carneo-flavida, convexiuscula vel convexa (latit. 0"4-0*6 mil- 

 lim.), immarginata (solum juvenilia margine obtuso), intus 

 incoloria; sporae 8°®, incolores, oblongse vel oblongo-fusi- 

 formes, l-septatae, longit. 0009-0012 millim., crass. 0002- 



