209 



of which correspond to the septa.. For about one-fourth from^- 

 the calice these are broad and strongly marked, when they 

 suddenly diminish to thin sinuous lines. Those of the fourth 

 order have no septa corresponding to' them, and consist of thin 

 lines throughout. They are placed in each interspace, but do^ 

 not, like the rest, rise aibove the wall, on tliei margin of which 

 they show as very slender, sharply pointed projections. 



The dimensions of the type are: — Height of corallum, 7.5 

 mm. ; diameters of calice, 8 mm. and 6.75 mm. Two other 

 specimens are slightly larger, and the rest smaller. 



Locality, d'c. — In Eocene strata at Brown's Creek (11 

 examples, most of which were collected by Mr, Kitson, the dis^■ 

 coverer of this prolific coral bed). The species is also repre- 

 sented in my collection from the Eocene of Aldinga by three 

 small flat-based individuals. 



The species name is in compliment to Mr. C M. Maplestone, 

 the well known writer on tertiary poly zoa. 



Troehoeyathus infraeompressus, spec. nov. Pi. i, tigs. 2a, 6. 



The corallum is free, longer than broad, much compressed- 

 inferiorly, and scarcely so superiorly. The lateral edges slope 

 by a gentle curve to the base, which is rounded off into a thin 

 short line. The calice is shallow and elliptical, with its major 

 and minor axes in the ratio of 10 to 9. 



The septa are in six systems, with four iconiplete cycles. 

 They are exsert, granulose on their sides, and project, con- 

 siderably beyond the wall. The primaries are stoiiter than 

 the rest, which diminish in size according to order. The ter- 

 tiaries bend towards the secondaries, and usually unite with 

 them near the columella. The quaternaries are generally 

 very short, but each system hag one longer than, the rest, which 

 bends towards and unites with the adjoining tertiary. 



The columella is lamellar, and at its margin lobatc!. There 

 are pali before the primary septa and also before the junction 

 of the tertiaries with the secondary in each system ; they 

 form two indistinctly marked icrowns. The calice figiu^ed 

 belongs to a young individual, and has only four systems suffi-- 

 ciently well preserved to sho'W the structure of their septa and 

 pali, the other two' being partly choked with sediment. The 

 extreme outer ends of a few septa are also broken off. The 

 corallum figured is exteriorly a fine exaimple, but its: calice ia- 

 very much worn. 



Tlie costise, which correspond to the septa, have distinct and 

 deeip interspaces, and are ornamented on their free surface by 

 closely packed but prominent granules. They are subequal 

 in size, and diminish gradually from the calice downwards. 

 They vary slightly in length, the higher orders usually joining 



