CLEISTOPORA 



57 



Family Cleistoporidae Easton, n. fam. 



Diagnosis. — Compound coralla, typically 

 flat, spreading or discoid; corallites poly- 

 gonal; calyces inverted, without prominent 

 calical structures; septa indistinct; tabulae 

 indistinct or merging with reticulate visceral 

 tissue ; tubular visceral spaces partitioned by 

 diaphragms; peritheca with or without 

 scales. 



Cleistopora Nicholson, 



genus. 



Type 

 1888. 



i^^m^ry^^.— Miller (1892, p. 616) sug- 

 gested that if Leptopora Winchell, 1863, 

 should stand alone, it would be referable to 

 the family Leptoporidae (for which a diag- 

 nosis was only incidentally given) and it 

 would obviously be the type genus of the fam- 

 ily. Leptopora Winchell, 1863, however, is a 

 junior homonym of Leptopora d'Orbigny, 

 1849, a Cretaceous bryozoan. Therefore a 

 new name is necessary for this family to 

 which Leptopora Winchell, 1863, Squameo- 

 phyllmn Smyth, 1933, EthTuoplax ( = 

 Stratiphyllum=Stratophyllum) Smyth, 

 1939, have been referred. 



The Cleistoporidae are closely related to 

 the Favositidae by reason of their compound 

 nature, tabulate corallites, and perforate 

 walls. 



Genus Cleistopora Nicholson, 1888. 

 emend. Easton 



Non Leptopora d'Orbigny, 1849, Mag. Zoology 

 Rev., no. 2, p. 504. 



Leptopora Winchell, 1863, Acad. Nat. Sci., Phila- 

 delphia Proc, p. 2. 



Cleistopora Nicholson, 1888, Geol. Mag., dec. 3, n. 



s., vol. 5, p. 150. 

 Leptopora, Robinson, 1917, Connecticut Acad. 



Arts Sci. Trans., vol. 21, p. 163. 

 Squameophyilum Smyth, 1933, Royal Irish Acad. 



Proc, vol. 41, sect. B, p. 171. 

 Stratophyllum Smyth, 1933, idem, p. 173. 

 Ethmoplax Symth, 1939, Nature, London, vol. 143, 



p. 859. 

 Non Stratiphyllum Scheffen, 1933, Norske vidensk- 



akad. Oslo Skrift., p. 35. 

 Stratiphyllum Lang, Smith, and Thomas, 1940, 



Index of Paleozoic Corals, p. 124. 



Emended diagnosis. — Coralla flat, discoid 

 to elongate, possibly encrusting, with 

 wrinkled epitheca; corallites polygonal to 

 subrounded, rarely overlapping; calical 

 floors flat, convex, or concave and conical ; 

 walls more or less persistent, generally trace- 

 able externally ; septa nearly or entirely ab- 



sent except as minute structures within 

 walls; visceral cavity filled with reticulate 

 tissue which may or may not contain trans- 

 verse diaphragms, or filled with horizontal 

 tabulae which may be granular on upper 

 surfaces ; walls perforate ; epithecal scales 

 may be present. 



Genotype. — Cleistopora geometrica (Ed- 

 wards and Haime), 1851. 



Occurrence. — Genotype from Lower De- 

 vonian of Vire and Loue, Sarthe, France. 

 Other species occur in the Tournaisian at 

 Tournai, Belgium ; Z2 of Hook Head, Ire- 

 land ; Chouteau limestone (unrestricted), 

 McCraney limestone, and Prospect Hill 

 sandstone of Mississippi valley, probably in 

 Carboniferous of Utah. 



Remarks. — Leptopora Winchell, 1863, 

 has been commonly used interchangeably 

 with Cleistopora Nicholson, 1888, in Amer- 

 ica, but insofar as is known to the writer, 

 without published reasons. It is apparent, 

 however, that close similarity of external 

 form is the reason for confusion. 



Lang, Smith, and Thomas (1940, p. 137) 

 tentatively considered V aughania Garwood, 

 1913, a synonym of Leptopora Winchell, 

 although they did not state that the latter 

 'genus is a synonym of Cleistopora Nichol- 

 son. The original diagnosis of Leptopora 

 suggests the characters of Vaughania, but 

 this is because Leptopora was supposed to 

 have "interior of cells filled with a finely 

 vesicular tissue" (Winchell, 1863, p. 2), 

 whereas these structures are, more accu- 

 rately, reticulate. 



Smyth (1933a, p. 171) considered 

 Squameophyilum spumans Smyth and Strat- 

 ophyllum tenue Smyth to be closely related, 

 but transitional forms were not known and 

 the differences between reticulate and tabu- 

 late visceral structure seemed to warrant 

 placing the species in different genera. Speci- 

 mens from the Chouteau limestone studied 

 by the writer possess characters which link 

 the two species and make the combining of 

 the two genera advisable. This linkage is 

 demonstrated ontogenetically in one speci- 

 men. In its earlier stages it resembles Cleis- 

 topora in having well-defined perforate 

 walls and reticulate visceral tissue with dia- 

 phragms. In the latest stages the visceral 

 cavity is entirely filled with tabulae whose 

 upper surfaces are generally granular ; how- 

 ever, the walls remain strong throughout, 

 although they are less strong in the later 



