OF THE ' CHALLENGE* ' EXPEDITION. 153 



tage ; besides, it happens unfortunately that I am in possession 

 of not more than a half of the ' Challenger ' specimens sent to me, 

 as in this proportion only were the samples divisible ; and my 

 first duty was, of course, to send to Kew all the types. As a 

 counterpoise, to a small extent, I made microscopical preparations 

 of the characteristic crustaceous lichens ; and these, along with 

 some notes taken at the time of investigation, will serve my pur- 

 pose in a certain proportion of the cases on which I wish to 

 comment. 



Bocella patellata, Strn., and Ramalina tenuior, Strn., I consider 

 good species. 



Endocarpiscurn aterrimum, Strn. — Why Mr. Crombie should 

 object to the distinction " at err i mum " is beyond my comprehen- 

 sion, as in a dry state the squamules are black enough ; and this 

 is all that is implied in the term. The specific distinction has no 

 diagnostic value. I need scarcely say I hold to aterrimum, and I 

 am much mistaken if others do not asree with me. 



The genus Endocarpiscum, founded by Nylander, rests, I allow, 

 on very slender grounds apart from those of Heppia ; but as it 

 marks a peculiar habit, more especially when confined to the poly- 



aterrimum ) 



stand. 



Lecidea teichiodes, Strn.— I was fully aware that the character 

 of the thallus pointed to Dirina ; but iu view of the manifest 

 discrepancies involved in the smooth, innate, concave apothecia, I 

 felt myself constrained to yield. My microscopical preparation 

 shows spores determinately 3-septate, and rather longer at times 

 than I have indicated. 



I have not yet reached that transcendentalism in lichenology 

 which gives a predominance to the spermogonia in the determi- 

 nation of genera over the larger and more obvious characters 

 afforded by the apothecia. 



Lecidea epipasta, Strn.,=Z. epiplacodia, Cromb— I have a de- 

 cided objection, both structurally and grammatically, to Mr. 

 Crombie's amendment in the shape of epiplacodia (Placodium 

 being essentially a noun and used exclusively as such) ; besides, 

 if used as a noun, the accusative plural is scarcely correct. 

 Further, I think my pedantry will be pardoned if I remind him 

 that "efusa" is not the Latin equivalent of epipasta. (See Mr. 



Crombie's paper.) 



m2 - 



