372 



Dissepiments — partitions; the intrathecal connecting- plates 

 between the septa of the corals ; the connecting bars 

 between the branches of a Fenestelloid brvozoinn. 



Distal — situated away from the center of the body. 



Disticlials — the second series of arm-plates or brachials of 

 Crinoids, situated above the axillary costals. 



Divaricators — the opening muscles of Brachiopoda; also 

 called diductors. 



Dorsal — pertaining to the back. 



Doublure — the infolded margin of the cephalonof a Trilobite. 



Ear— the anterior cardinal expansion of the Pelecypod shell. 

 It is usually smaller and more distinctly defined than the 

 posterior expansion or wing. 



Ectoderm — the outer cellular body layer. 



Emariiinate — with a notched margin. 



Endoderm — the inner cellular body la^'er. 



Endothecal — within thetheca; intrathecal; used for corals. 



Epitheca — the extrathecal sheath or covering, usually wrin- 

 kled, found in most Tetracoralla and many Hexa- 

 coralla . 



Escutcheon — the depression behind the beak of the Pelecypod 

 shell. 



Exfoliate — peeling off. 



Exotbecal — same as extrathecal. 



Extrathecal — outside of the theca of corals. 



Extroverted — turned base to base; applied to spirals of 

 Brachiopods. 



Fascicula te — clustered. 



Fenestrule — the open spaces between the l)ranches and dis- 

 sepiments of a Fenestella frond. 



Filiform — threa d-like. 



Fimhriw — the spines or lateral prolongations of the pleunB 

 in Trilobites. 



Flabellate—ian-fihfi'ped. 



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



