104 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 16 



Genus THECOPSAMMIA Pourtales 



Thecopsammia Pourtales (1868), Bull. Mus. Comp. ZooL, vol. 1, no. 7, 

 p. 138. 

 Genotype : Thecopsa?nmia socialis Pourtales. 



Thecopsammia pourtalesi Durham and Barnard, new species 



Plate 16, fig. 68 



Corallites pseudocolonial in appearance, forming a rudely sub- 

 phaceloid aggregate; individual corallites moderately small, usually 10- 

 15 mm long, occasionally up to 20 mm in length, some individuals only 

 about 5 mm; corallites scolecoid to ceratoid, highly epithecate, epitheca 

 developed up to within a short distance of the top of the calice; thecal 

 wall highly porous ; calice moderately deep, depth of fossa 2-3 mm, 

 varying from circular to slightly oval in cross-section, calice diameter 

 usually about 5 mm ; septa thin, in 4 cycles, interspaces 4 times as wide as 

 thickness of first cycle septa, traces of fifth cycle septa represented by 

 faint trabeculae projecting in septal interspaces; septa arranged in 

 Pourtales plan, which is readily seen when the columella is small, but 

 when the columella is large the Pourtales plan may be obscured ; septa 

 slightly exsert, those of first cycle most prominently so; upper edges of 

 septa sharply rounded, and then descending steeply into calicular fossa; 

 inner edges of septa slightly and crudely serrate; septal faces with a 

 moderate number of prominent granules ; all cycles of septa are perfor- 

 ate, but the third cycle is more perforate than the first and second ; costae 

 ill-defined, corresponding to septa, rudely spinose; columella varying 

 from one-fourth to one-half the diameter of the calice, not protruding 

 above bottom of fossa, consisting of a number of interlacing trabeculae. 



Remarks: This species may be distinguished from Balanophyllia 

 galapagensis Vaughan, which individual corallites of it resemble, by the 

 prominent columella of that species, by the much more perforate wall, 

 and the deeper calicular fossa of the present species. 



The new species is distinguished from Thecopsammia fistula (Al- 

 cock), by the more elongate calice and taller corallum of the latter, and 

 from T. socialis Pourtales by the more turbinate corallum, 5 cycles of 

 septa, and the more compact columella of Pourtales' species. 



Dimensions of holotype: Height 6 mm (immersed by surrounding 

 corallites), calice 5 by 6 mm, depth of calice 2 mm. 



Holotype: AHF no. 25, with 4 paratypes. 



