372 



Dissepiments — partitions; the intrathecal connecting plates 

 between the septa of the corals ; the connecting bars 

 between the branches of a Fenestelloid bryozoum. 



Distal — situated away from the center of the body. 



Distic lulls — the second series of arm-} dates or brachials of 

 Crinoids. situated above the axillary costals. 



Divaricators — the opening muscles of Brachiopoda; also 

 called diduetors. 



Dorsal — pertaining to the back. 



Doublure — the infolded margin of the cephalonof a Trilobite. 



Ear — the anterior cardinal expansion of the Pelecvpod shell. 

 It is usually smaller and more distinctly defined than the 

 posterior expansion or wing. 



Ectoderm — the outer cellular bodv layer. 



Emarginate — with a notched margin. 



Endoderm — the inner cellular body layer. 



Endothecal — within the theca : intrathecal; used for corals. 



Epitheca — the extrathecal sheath or covering, usually wrin- 

 kled, found in most Tetracoralla and manv Hexa- 

 coralla . 



Escutcheon — the depression behind the beak of the Pelecvpod 

 shell. 



Ex folia te — peeling off. 



Exothecal — same as extrathecal. 



Extrathecal — outside of the theca of corals. 



Extroverted — turned base to base; applied to spirals of 

 Brachiopods. 



Fast -it- ula te — clu stered . 



Fenestrule — the open spaces between the branches and dis- 

 sepiments of a Fenestella frond. 



Filiform — thread-like. 



Eimhr'ue — the spines or lateral prolongations of the pleurae 

 in Trilobites. 



Flabellate — fan-shaped. 



Fold— sun elevation on the surface of a shell (Brachiopoda). 



