GLOSSARY. 



831 



Endocyclic — see regular. 



Endoderm — the inner cellular body 

 layer. 



Endopodite — see II., 387. 



Endosiphocone — see Fig. 1239. 



Endosipholining — see II., 20 



Endosipho sheaths — see II., 20 ; also Fig. 

 1239. 



Endosiphotube — see Fig. 1239. 



Endosiphuncle — in some cephalopods, 

 the small hollow axis at the center of 

 the siphuncle. It is surrounded by 

 thin calcareous cones filling the space 

 to the siphonal funnels (see II., 20). 



Endothecal — within the theca ; intra- 

 thecal. Used of corals. 



Englishtown sands {Columbus sands) — 

 Matawan (middle Cretacic) of Atlan- 

 tic coast. 



Ephebic — mature (see Oiitogeny). 



Epicranium — see II., 419. 



Epidermal — pertaining to the skin. 



Epidermis — for use in shells, see pe- 

 riostracum. 



Epimerum — see II., 420. 



Episternum — see II., 420. 



Epitheca — the concentrically wrinkled 

 calcareous crust often surrounding 

 the base of an individual coral (I., 

 47) ; in hydrocorallines and bryozoans 

 (I., 107), surrounding the base of a 

 colony. 



Epizygal — for use in crinoids, see 11. , 

 490. 



Equilateral — with equal sides. In bi- 

 valve shells, referring to the equality 

 of the two halves of a valve on each 

 side of a line passing from beak to 

 center of base. 



Equivalve — with the two valves of equal 

 size. 



Erian series — middle Devonic, general 

 term. 



Escutcheon — in pelecypods, the de- 

 pression behind the beak. 



Esopus shale — lower Devonic of New 

 York, Pennsylvania, etc. 



Etchegoin formation — upper Miocenic 

 of California. 



Etcheminian — a term for the lower 

 Cambric of the Atlantic province. 



Eureka shale (black) — Kinderhook of 

 Arkansas. 



Evolute — applied to loosely coiled shells 

 where the later whorls do not hide 

 the earlier. 



Excentric — not centrally placed ; eccen- 

 tric. 



Exfoliate — to remove small portions 

 from the surface. 



Exhalent — in sponges, applied to canals 

 with an outflowing current, either di- 

 rectly to the upper surface or indi- 

 rectly through a large general cavity, 

 the paragaster (see Fig. 21). 



Exocyclic — see irregular. 



Exopodite — see 11. , 387. 



Exothecal — outside of the theca. 



Explanate — spread out in a flat sur- 

 face. 



Extra — a prefix meaning beyond, out- 

 side, in addition to. 



Extrathecal — in corals, referring to the 

 portion outside of the theca. 



Extraverted — turned outward. In 

 brachiopods, applied to the spiral 

 brachidia when turned base to base 

 (see Fig. 467, c). 



Eye — in trilobites, see compound eye, 

 holochroal, schizochroal, ocellus, fa- 

 cet. 



Fabiform — bean-shaped. 



Facet — a little face ; a small, usually 

 plane, circumscribed surface. In the 

 compound eyes of most Crustacea and 

 insects, the external surface of a 

 single ocellus. 



Facetted — having facets or numerous 

 faces, as the eye of an insect, etc. 



Facial sutures — sutures in the cepha- 

 lon of trilobites which separate the 

 free cheeks from the fixed (see Fig. 

 1569, 1573). 



Fades — the general habit of a species 

 or group of species with reference to 

 its adaptation to its environment, as 

 littoral facies. 



