824 



NORTH AMERICAN INDEX FOSSILS. 



of Osage group, lower Mississippic 



of Mississippi Valley. 

 Burrow — a hole in the ground, rock or 



wood, etc., made by certain animals 



for shelter (see Fig. 1539). 

 Byssal — ^pertaining to the byssus. 



Byssal notch — in pelecypods, the 

 notch or opening for the emission 

 of the byssus. 

 Byssus — tough threads formed by the 



foot of certain pelecypods by which 



they attach themselves to rocks or 



other support. 



Calcarenite — a limestone composed of 

 small, sand-like calcareous fragments. 



Calcareous — formed of or containing 

 lime. 



Calciferous formation — old name for 

 Chazy limestone. 



Calcilutite — a very fine-grained lime- 

 stone formed of a lime-mud. 



Calcirudite — a limestone breccia or 

 conglomerate composed of calcareous 

 fragments. 



Calcite — calcium carbonate (CaCOs), 

 crystallizing in the hexagonal sys- 

 tem. In shells it is translucent. 



Calices — plural of calyx. 



Calicinal — pertaining to the calyx or 

 cup. 



Calicle — a small, cup-like cavity. 



Calicular — resembling a cup. 



Callosity — a hardened spot or area. 



Callovian — division of the middle Ju- 

 rassic. 



Callus — in gastropods, the thickened 

 part of the inner lip, which usually 

 covers portions of the preceding volu- 

 tions, thus more or less completely 

 concealing the umbilicus. 



Caloosahatchie — lower Pliocenic of 

 Florida. 



Calvert formation — middle Miocenic of 

 Maryland. 



Calyx — a cup. In corals, the cup lim- 

 ited below by the upper edges of the 

 septa. In crinoids, cystoids and blas- 

 toids, the body exclusive of the arms 

 and stem. 



Cambric — the lowest of the Paleozoic 

 systems. 



Cambridge limestone — Conemaugh for- 

 mation, upper Carbonic. 



Camera — air-chambers of a cephalopod 

 shell, separated from one another by 

 septa. 



Camerate — chambered. 



Camillus shale — subdivision of the Sa- 

 lina of New York. 



Canal — in some gastropods, the ante- 

 rior edge of the aperture is drawn 

 out into a canal, the anterior canal, 

 as in Fusus; in some there is likewise 

 present an anal canal at the posterior 

 margin of the aperture, as in Apor- 

 rhais. 



Axial canal — the tubular passage 

 through the center of the stem of 

 crinoids (see II., 488). 



Canaliculate — channeled ; having a 

 canal. 



Cancellated — marked by lines crossing 

 one another forming a lattice-like 

 pattern. 



Caney shale — upper Mississippic of Ok- 

 lahoma, etc. 



Canyon — upper Carbonic of Texas. 



Capitan limestone — upper Permic of 

 Oklahoma, etc. 



Carapace — the hard shell or shield cov- 

 ering the back of Crustacea, etc. In 

 trilobites its three transverse divi- 

 sions are named cephalon, thorax and 

 pygidium (see Fig. 1542). 



Cardiac — pertaining to the heart or to 

 the region of the heart. 



Cardiff shale — middle Devonic, New 

 York. 



Cardinal — pertaining to the hinge. 

 Cardinal angle — in bivalve shells, the 

 angle formed at each of the ex- 

 tremities of the hinge between the 

 hinge and the forward extension 

 • of the shell. 



Cardinal area — in many brachiopods, 

 the flattened area on each valve 

 between the beak and the hinge 

 line, and extending to the cardinal 

 angles (see Fig. 218). 



