NORTH AMERICAN INDEX FOSSILS. 



CoproUte — the fossil excrement of ani- 

 mals. 

 Corallian — division of upper Jurassic 



(Sequanian). 

 Corallite — an individual from a com- 

 pound corallum. 

 Corallum — the hard structure secreted 

 by the coral polyp. 



Compound corallum — jnade up of cor- 

 allites, either separate or closely 

 joined by their walls (as in Favo- 

 sites). 

 Composite corallum — compound cor- 

 allum with ccenenchyma or extra- 

 thecal calcareous tissue connecting 

 the corallites as in Galaxia and 

 many other recent forms. 

 Corneous — horny. 



Corona — crown. In echinoids, all of 

 the test except the plates at or near 

 the center of the dorsal surface (see 

 II., 572). 

 Coronal — crown-like. 

 Coronate — somewhat crown-shaped ; ap- 

 plied to those gastropods which bear 

 a crown-like row of spines upon the 

 upper angle of their whorls. 

 Costa (plural costce) — rib or ridge. In 

 corals, extrathecal extension of a 

 septum (see I., 47). In insects, one 

 of the wing veins (see Fig. 1724). 

 Costals — in crinoids, the first brachial 

 or arm plates, lying between the ra- 

 dials and the first bifurcation of the 

 arms (see Figs. 1804, 1907). 

 Axillary costals — in crinoids, see Fig. 

 1907, Co. 

 Cotype — see type. 

 Council Grove formation — lower Per- 



mic of Kansas. 

 Counter — opposite. 



Counter quadrant — the quadrant 

 bounding the counter septum of a 

 tetracorallum. 

 Counter septum — the front, primary 

 septum of a tetracorallum, opposite 

 the cardinal septum ; the secondary 

 septa are parallel with it (see Fig. 

 75). 



Coxa — in insects, the basal segment of 

 the leg (see II., 420). 



Coxopodite — see II., 388. 



Cranidium — in trilobites, all of the 

 cephalon except the free cheeks (see 

 Fig. 1559, a). 



Crenulate — with margin cut into round- 

 ed notches. 



Crescentic — shaped like a new moon. 



Crest — for use in ammonoids, see II., 

 23. 



Crinoidal limestone — see Ames lime- 

 stone. 



Croatan beds — middle Fliocenic of 

 North Carolina. 



Cross-veins — for arrangement in in- 

 sects' wings and their nomenclature, 

 see II., 422, 423. 



Crown — all of a crinoid except the stem. 



Cruciform — cross-shaped. 



Crura — in brachiopods, the two short 

 curved processes attached to the 

 hinge plate of the brachial valve. To 

 these are united the brachidia when 

 these are present (in Figs. 2204 and 

 383, the crura extend from the hinge 

 plate to the sharp, inward tooth-like 

 projection). 



Cruralium — the name applied to the two 

 crura when united. 



Ctenidia — the plume-like gills of mol- 

 lusks. 



Cubitus — in insects, one of the wing 

 veins (see Fig. 1724). 



Cumberland limestone — lower Cambric 

 to lower Ordovicic of Pennsylvania. 



Cuneate — wedge-shaped. 



Cuneiform — wedge-shaped. 



Cuyahoga limestone — division of Wa- 

 verly group. 



Cyathophylloid — in form like Cyatho- 

 phyllum, one of the Tetracoralla. 



Cyclodont dentition — in pelecypods, see 

 I., 361. 



Cypress sandstone — upper Mississippic 



and Mississippi Valley. 

 Cyrtoceracones — Nautiloid cephalopod 

 shells which are merely bent without 

 making a complete revolution. 

 Cyst — a closed sac or bladder. 



