OF NEW SOUTH WALES. 333 



phyllia, the last cycle is always more developed than the imme- 

 diately preceding, to which also the same genera are an exception ; 

 the higher orders are also reticulate or incomplete in their tissue 

 so as to be perforated or honeycombed; there is always a columella 

 (except in some species of Stereopsammia) , and it is of spongy 



texture. 



Genus Endopachys, Lonsdale, 1845. 



Corallum simple, straight, much compressed below ; no trace 



of adherance ; base keeled or with aliform appendages ; costas 



distinct, straight, formed by series of granules ; columella little 



developed ; septa exsert and granular ; only two species hitherto 



known ; one living, habitat unknown ; and an Eocene fossil from 



Alabama, N. America. 



Endopachys Australia, n. s. PI. 6, fig. 1, a, b, c. 

 Corallum elegantly cuneiform, somewhat tumid until close to 

 the base, where it becomes much compressed ; the edges of the 

 major axis slope away from the summit until about two-thirds 

 of the whole length and then suddenly bend towards a very fine 

 point, leaving two somewhat aliform obtuse angles ; the sides of 

 the minor axis are convex but slightly more on one side than 

 another ; costaa finely granular, distinct, raised, rounded, corres- 

 ponding to the septa ; a few of the higher orders uniting with 

 older at the compressed part, and the outer ones becoming curved 

 round and ceasing at the alas, the rest gradually tapering and contin- 

 uous to the basilar point ; interseptal spaces narrower than thecostas 

 and perforated ; calice broadly elliptical, the ends of the major 

 axis being a little lower than the rounded minor axis on which 

 the septa make conspicuous projections ; septa spinously granular, 

 in six systems of four cycles ; first and second conspicuously 

 exsert ; the fourth and fifth uniting with the third order about 

 half way, and these again uniting with the secondaries close to 

 the columella so that the primaries are alone free ; all uniting 

 with the columella which is reduced to a thin open almost laminar 

 tissue. There are rudiments of a fifth cycle in the four systems 

 at the end of the major axis, and here also the septa are crowded 

 and irregular. Wall very conspicuous though thin. Alt. 15, 

 maj. axis 13, min. 10 mill. Off Port Jackson, 80 fathoms. 



