APHROPHYLLUM HALLEN^E AND LITHOSTROTION. 



59- 



variations, emphasised perhaps by the almost unwieldy 

 mass of material available for study* 



The growth-habit — whether fasciculate or massive, 

 correlated with the diameter attained by the mature coral- 

 lite and the corresponding complexity of structure, provide 

 the most satisfactory basis of specific separation. This 

 does not preclude the recognition of "species " distinguish- 

 able by other characters. 



A corallum is rarely indefinite in its growth-habit, 

 although there are semi-fasciculate and semi-massive forms 

 connecting the two conditions. Again, both in the fasci- 

 culate and massive varieties, the "species" are linked up 

 by forms intermediate in the size attained, but one does 

 not find adult corallites of two very distinct sizes associated 

 together in the same corallum. 



A very large number of "species" have been described t 

 but most of the specific names must be regarded as 

 synonyms. Many of the earlier-named species are insuffici- 

 ently described and inadequately illustrated, 



A thorough revision of the genus is needed involving a 

 careful re-examination of the type specimens by means of 

 thin sections. 



Pending this revision, and to serve present needs, I pro- 

 pose the following tentative classification for the British 

 representatives. 





Dimensions. 





Dimensions. 





Corallites 



Intrathecal 

 Area. 





Corallites 



Intrathecal 

 Area. 



> L. junceum 



2 mm. 



1 mm. 



L. m'coyanum 



2*5 mm. 



1 mm. 



(Fleming) 







Edwards&Haime 







L. irregular e 



5 ,, 



2o „ 



L. portlocki 



7 „ 



2-5 „ 



(Phil).) 







(Bronn) 







L. martini 



8 „ 



5 ., 



L. basaltiforme 



10 „ 



5 „ 



Edwards* Haime 







(Conybeare & 

 W. Phillips) 







'"L. afline 



13 „ 



10 „ 



?L. aranea 



larger 



forms. 



(Fleming) 







(M'Coy) 





1 



