TWO HKMAKKABl.E COKAI.S FFiOM THK DEVONIAN OF 

 NKW SOl'TH WALKS 



(Spoiniojihiilhiiii Ind i/nifdidex, aiul Col iiiinutrid tiniii tKihi'iixi^.) 



i;v 

 K. Ml iiKiMixiK, Juiii-., Director and Curatf)!'. 



(Plat-es vii.-ix.) 

 I. — A MoXSKTTA'lK SvO\(iul'HVM.l".M (S[ioii(jophi/JI i( in liiilyyu'tdide^.) 



A peculiar and abmn-nial S/xnuioiiliijH nm of remarkably simple 

 structure and septaless. 



Tlie specimen consists of a small corallnm two and a quai'ter inches 

 by one inch, evidently only a portion of a larger mass, and with the upper 

 surface beautifully weathered. The corallites are polygonal and vary 

 much in size, the average diameter being from four to six millimetres ; 

 they are tirmly amalgamated laterally. The walls of the respective 

 corallites, well defined and strong, are the striking feature of this coral. 



In a transverse view each corallite looks as if its polygonal outline 

 was composed of a string of minute shuttle-like figures, swelling and con- 

 ti'acting alternately. Within each calice, and continuously throughout 

 the successive visceral chambers in descending ordei", this structure is 

 actually caused by the deep and regular fluting of the walls. Looking 

 down on these walls from above, and shutting one's ej'es to the interior 

 vescicular structure, the resemblance to the meandering corallite lines in 

 Hidysifes is truly astonishing, hence the specific name I have applied to 

 this coral. 



There is the usual tripartite structure, although the demarcation is 

 ill-defined. Immediately within the fluted walls is (by comparison) a 

 broad peripheral zone of variously shaped vesicles, some large, others 

 small. This is followed by the intermediate zone, or cycle, which by 

 rights should be septate. It is extremely narrow, not always present 

 even, but when so, of a peculiar structure, to be referred to later. In 

 some corallites certainly, a few rudimentary short septa do occur, slightly 

 projecting into the central, and what in an ordinary Rugose coral would 

 be the tabulate area ; here, however, it is purely vesicular. 



In a longitudinal section all that is necessary to notice particularly 

 is the structure of what would be the septate zone and the central area ; 

 in passing, attention may be called to the very varied form of the peii- 

 pheral vesicles. From PI. viii., fig. 8, it will be seen that the intermediate 

 zone is really a tabulate area, without any muial investment, but depend- 

 ing for its demarcation on the convex surfaces of the distal peripheral 

 vesicles and the latei'al surfaces of those of the central area. It is trans- 

 versely divided by floors, mostly horizontal, but as they are parts of an 

 area at times slightlv septate, may be spoken of as dissepimental vesicles. 

 Finally, the central area of each coi'allite of one or more ranges of egg- 

 shaped vesicles, their longitudinal diameters being the greater. 



I know of no Australian Spoiujopln/Jltivi with a structure at all 

 approaching that of this coral, viz., the fluted condition of the corallite 

 walls, and practically the lack of septa. 



Loc. — Road near Beedle's Farm, Moonbi, Co. Inglis, New South Wales. 



Hor. — Middle Devonian r* 



