266 NEW YORK STATE MUSEUM 



cuneate — wedge-shaped 



cuneiform — wedge-shaped 



cyathophylloid — in form like Cyathophyllum; one of the Tetracoralla 



cyst — a closed cavity 



cystoid — most primitive class of Pelmatozoa or stemmed echinoderms 



delthyrium — triangular fissure under the beak of the pedicle valve of the 



brachiopoda 

 deltidium — single covering plate of the delthyrium (also called pedicle plate) 

 deltidial plates — two plates which close the delthyrium in the higher 



brachiopoda (Telotremata) 

 dendroid — branching after the manner of a tree 

 dental plates — internal plates below the teeth in pedicle valve of the 



brachiopoda 

 denticles — small teeth, or tooth-like ridges 

 denticulate — toothed 



denticulation — set of denticles or small teeth 

 depressed — on a level with, or below the general surface 

 dextral (right handed) — the normal method of coiling in the gastropoda 

 diaphragm — transverse partitioning plate 

 dicyclic — with two cycles of basals; applied to crinoids 

 diductor muscles — opening muscles of the brachiopoda 

 discinoid — resembling Discina 

 discoid — disk-like 

 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 

 distichals — second series of arm plates or brachials of crinoids, situated 



above the axillary costals 

 divaricators — opening muscles of brachiopoda; also called diductors 

 dorsal — pertaining to the back 

 doublure — infolded margin of a trilobite 



ear — anterior cardinal expansion of the pelecypod shell, usually smaller and 



more distinctly defined than the posterior expansion or wing 

 echinate — spinous 



endoderm — inner cellular body layer 

 emarginate- — with a notched margin 

 endoderm — inner cellular body layer 



endothecal — within the theca; intrathecal; used for corals 

 epicontinental — encroaching on the continent 

 epidermal — pertaining to the skin 



epitheca — outer calcareous covering of a corallum or bryozoan 

 equilateral — with similar sides 

 equivalve — with similar valves 

 escharoides — like Eschara (a bryozoan) 



