KINK A ID CORALS FROM ILLINOIS 



385 



two genera suggests that Kinkaidia might 

 be the possible ancestor of Lophophyllidium. 

 Claviphyllum, on the other hand, was con- 

 temporaneous with Kinkaidia, 



Kinkaidia trigonalis Easton, n. sp. 

 Figures 1-7 



Externals. — -Medium size, almost genicu- 

 late; calyx very deep; epitheca thick, bearing 

 prominent interseptal ridges, septal grooves, 

 encircling striae and rugae; cardinal fossula 

 probably pronounced; alar pseudofossula 

 indicated. 



Transverse sections. — In early ephebic 

 stage (diameters 4.1 by 6.0 mm.) counter 

 septum very long, almost in contact with 

 relatively long cardinal septum; alar septa 

 long but not reaching axis; counter-lateral 

 septum on either side of counter septum 

 slightly longer than other metasepta; four 

 septa in each counter quadrant, three in each 

 cardinal quadrant; septa noticeably swollen 

 axially ; tabular intersections sparse. 



In middle ephebic stage (diameters 7.6 

 by 7.7 mm.) counter septum and both alar 

 septa about equal in length, meeting axially; 

 cardinal septum very short, flanked on one 

 side by three and on other by four meta- 

 septa which tend to lean toward cardinal 

 septum; counter-lateral septum on either 

 side of counter septum extend half of radius; 

 counter quadrant contains five, the other, 

 six septa; most septa axially swollen; tabular 

 intersections common; minor septa sug- 

 gested by only slight swellings of epitheca 

 between majors. 



At very slightly later stage another speci- 

 men has 25 major septa; counter septum 

 long, much swollen axially; each neighboring 

 counter-lateral septum long, one alar short; 

 neither alar septa nor cardinal septum dis- 

 tinguishable; rudimentary minor septa pres- 

 ent in most loculi. 



In very late ephebic stage (diameters 10.7 

 by 10.7 mm.), 24 major septa, alternating 

 with equal number of short minor septa; 

 counter septum very long; alar septa long, 

 not quite reaching counter septum; counter- 

 lateral septum on either side of counter sep- 

 tum extends two-thirds of radius; cardinal 

 septum short; four metasepta in one cardi- 

 nal quadrant and three in other lean to- 

 ward cardinal septum; counter quadrants 



contain six and seven septa; most majors 

 rhopaloid. 



Longitudinal section. — Tabulae both com- 

 plete and incomplete, with rather sharply 

 down-turned borders, slightly convex dis- 

 tally; tabellae broadly arched toward inter- 

 section of counter septum. 



Remarks. — This species has been listed 

 by the writer as "cup coral unidentified" 

 (Easton, 1943, p. 130) from the Pitkin for- 

 mation. 



Ontogeny. — -In earliest brophic stage (fig. 

 la) only the epitheca is present, there being 

 no septa or tabulae. The cardinal septum 

 and the counter septum are inserted first to 

 form an axial plate (fig. lb). The right alar 

 then appears (fig. lc), followed by the left 

 alar. At this stage, the top of the right alar 

 has shifted somewhat axially (fig. Id). Later 

 the four primary septa become thickened, 

 the alars move to positions nearly at right 

 angles to the cardinal-counter plane and one 

 alar septum is separated from axial contact 

 with the other septa, the cardinal and coun- 

 ter septa separate slightly, and a tabula 

 appears (fig. le). Metasepta, traceable as 

 septal grooves on the epitheca, are inserted 

 in the counter quadrants but are not al- 

 ways discernible in the thecarium (fig. If). 

 By early neanic stage (fig. lg) metasepta oc- 

 cur withinthe thecarium in thecardinal quad- 

 rants and tabulae are common; one counter- 

 lateral septum is noticeably longer than the 

 neighboring septa and is axially swollen. 



In early ephebic stage (fig. 4) there are 4 

 slightly rhopaloid septa in the counter quad- 

 rants and 3 in the cardinal quadrants; the 

 counter septum is long and the cardinal sep- 

 tum is short; the counter-lateral septa are 

 slightly longer than the neighboring septa. 

 The typical features are observed in middle 

 ephebic stage (fig. 6) where the counter 

 septum and the alar septa meet axially, the 

 cardinal septum is short, the counter-lat- 

 erals are long; 5 or 6 septa occur in the 

 counter quadrants and 3 or 4 are present in 

 the cardinal quadrants, most of them being 

 axially swollen; tabulae are common and 

 may bear traces of septal extensions as 

 spines. A section through a calyx at this 

 stage gives indications of a pronounced car- 

 dinal fossula and observable alar pseudo- 

 fossula (fig. 2a). In late ephebic stage (fig. 3) 



