ORGANIC DEPENDENCE AND DISEASE 
87 
the Silurian as Vioa prisca and which was made by us to 
include not only tubes of that type, that is, straight sub- 
clavate fillings, but also very much smaller, much more 
intricate, arborescent or vagrant tubules. It is evident to 
ns now that only the latter can be assigned to the sponges 
and that hence our name Clionolitlies, devised to suggest 
relationship to sponges, is applicable only to this division. 
It is proposed to retain the name for that group, even 
though this may not be in precise accord with proper no- 
71 
Fig. 71. Etching of a tube cluster of Clionolitlies radicans in the shell substance 
of the brachiopod Leptostropliia magnified. From an enlarged photograph, x 61. 
Grande Greve limestone (Lower Devonian). 
Fig. 72. The same in a shell of Atrypa reticularis from the Chemung sandstone 
(Upper Devonian). 
