GLOSSARY 



15 



TERMINOLOGY 



Terms describing Paleozoic corals in more 

 or less common English usage have not been 

 assembled previously in any one publication. 

 Hill's (1935) compilation of British ter- 

 minology is the most authoritative list to 

 date, but it is far from complete. The com- 

 pilation presented here includes most of the 

 terms used since about 1900. Definitions 

 are worded as simply as possible. Words 

 describing fleshy parts and post-Paleozoic 

 corals are not included. 



There has never been an accepted Amer- 

 ican system of morphologic terms, probably 

 because corals have been less studied in 

 America than in Europe; moreover, an 

 "American terminology" is not needed. It 

 is necessary, however, to provide American 

 students with an adequate index of available 

 terms. Partial lists published by Americans 

 include those by Robinson (1917), Grabau 

 (1922, in a Chinese journal), Sanford 

 (1939), Twenhofel and Shrock (1937), 

 Moore (1933), Grabau and Shimer 

 (1909), Grove (1934), and Moore and 



Jeffords (1941), but some of these compila- 

 tions are only incidental and none was 

 intended to be complete. The following list 

 likewise is known to be incomplete, but it 

 does contain all terms in more or less cur- 

 rent usage. For those who wish more de- 

 tailed morphologic discussions, the reader is 

 referred to Hill (1935), Grabau (1922), 

 and Sanford (1939). 



Most of the terms included in the follow- 

 ing list are morphologic, but a few refer to 

 ontogenetic and evolutionary stages. Some 

 have had more than one meaning and some 

 are used as adjectives to modify different 

 nouns. Synonyms are italicized after the 

 definitions and homonyms are listed sepa- 

 rately and numbered. Previously published 

 definitions have been drawn upon freely 

 without acknowledgment. 



Each student has his own preference in 

 terminology within reasonable limits. In 

 the following glossary, some obsolete terms 

 are indicated and others which the writer 

 does not recommend are indicated by as- 

 terisks (*). 



Glossary 



Acanthine septa: Discontinuous septa consist- 

 ing of unfused trabeculae. 



Acceleration: Addition of more secondary sep- 

 ta in one pair of quadrants than in the other. 



Acrocolumella : Axial structure consisting of 

 distally elevated tabulae. 



Alar: Indicates lateral position or at alar sep- 

 ta; is determined primarily by abutting of 

 counter septa against an alar sextum. Ab- 

 breviated: A. 



Alar pseudofossula: Gap between alar septum 

 and next adjacent counter septum. Lateral 

 fossula. 



Amplexoid: Having septa withdrawn toward 

 periphery. 



Amplexoid septum: Retreats from axis, lies 

 upon upper surfaces of tabulae, and extends 

 progressively shorter distances axially as 

 distance from tabulae increases. Short sep- 

 tum in part. 



Anastomosing: Joining, as in reticulate col- 

 onies of Cladopora. Inosculation. 



Angulo-concentric dissepiments: Similar to 

 concentric dissepiments except in being an- 

 gular with apex directed peripherally. 



Annulation*: Encircling depression on epith- 

 eca. 



Apex*: Pointed end of coral. Apical end. 



Aphroid: Plocoid coralla separated by dissepi- 

 ments only. 



Apical end: Pointed end of coral. Apex. 



Asexual increase: Growth or spread of coral 

 or colony by sending out ofFsets. See Bud- 

 ding, Gemmation, Fission. 



Astraeform: Having polygonal corallites in 

 transverse section. 



Astraeoid: Closely packed plocoid corals with 

 indefinite boundaries between corallites. 



Atavo-tissue : Tissue common to parent and 

 offset corallites. 



Attenuated septum: Thin throughout length. 



Aulophylloid* : Tendency toward complex 

 axial structures. 



Aulos*: 1 Any axial structure. 



Aulos*: 2 See Inner wall. 



Axial area: That portion of thecarium lo- 

 cated axially from inner wall. 



Axial boss: Elevation in calyx corresponding 

 to an axial structure. Calicular boss. 



Axial complex: A columella or pseudocolum- 

 ella; unrestricted in usage, but inferring 

 pseudocolumella. 



Axial edge: Edge of septa nearest axis. 



Term not recommended. 



