GLOSSARY 



21 



Tertiary septa: Late-formed generally short 

 septa inserted between neighboring prin- 

 cipal septa. Minor septa, in part. 



Thamnastraeoid: Closely packed phaceloid 

 corals without boundaries between coral- 

 lites and with septa of adjacent corallites 

 confluent. 



Theca: External sheath of corallites; com- 

 monly of unrestricted significance. 



Thecarium : Portion of corallite encircled by 

 theca. Endotheca. 



Trabeculae: 1 Microscopic longitudinal spic- 

 ular elements forming septa. 



Trabeculae*: 2 Irregularly formed skeletal 

 tissue characteristic of Cleistopora appear- 

 ing reticulate in section. 



Transverse striation: Fine encircling stria- 

 tions on epitheca. 



Trochoid: Conical corals with apical angle of 

 about 40°. 



Varice : Encircling irregularity on wall coarser 

 than growth-line ; may be expansion or con- 

 striction. Bourrelet in part. 



Vertical skeletal element. Structure formed 

 by invagination of polyp in more or less 

 vertical plane. 



Vesicular*: Having dissepiments. 



Wall*: Outer sheath. Theca, Epitheca, Outer 

 wall. 



Yard-arm carinae: Carinae opposed in posi- 

 tion on the two sides of a septum. 



Zaphrentoid stage: With axially coalesced 

 pinnate septa, very large cardinal fossula, 

 complete tabulae ; possibly common to all 

 rugose corals. 



Zooid*: Individual coral within compound 

 corallum. Corallite. 



Term not recommended. 



