258 



The septa, and columella closely resemble the sajne struc- 

 tures in P. Airensis, and do not call for separate description. 



The columella figured is 7.5 mm. high and the diameters of 

 its calice are res,pectively 3.75 mm. and 2.5 mm. The calice 

 chosen as type belongs to a larger example, and its diameters 

 RTO 4.5 mm. and 3 mm. Its corallum is diminished by having 

 the pointed end broken off, but still measures 8 mm. in height. 



Locality, d^c. — In Eocene strata at Muddy Creek, Spring 

 Creek, Shelford, and on the banks of the Aire River at Fishing 

 Point. 



This species is also recent, and was dredged in Backstairs 

 Passage, at the entrance to St. Vincent's Gulf, by Dr. Verco, 

 who has handed me his examples (7) for examination. 



Platytpoehus cupvatus, spec, nor 

 PI. v., figs. 3g, b. 



With the exception of its curved outline, the corallum of this 

 species much resembles that of P. haHatu-s, but is generally 

 narrower. It has a similar spear-pointed base, and the cost?e 

 are also smooth and delicate. An epitheca is, however, much 

 commoner. In many specimens it is almost complete, and 

 fairly dense, the costse being visible only at the margin of the 

 calice. In others it is partial and in transverse, irregular 

 bands, while again some, like the type, show no trace of 

 epitheca. 



The development of the septa is less regular than in the 

 two species just described. For example, in the type one 

 of the end systems contains the same number of cycles as the 

 central pair, viz., three, while in each of the other end systems 

 there are in addition some septa of the foiu'th order; more- 

 over, in this example one of the lateral primaries bends away 

 from the line of the long axis of the calice. 



The ipapilli of the columella resemble those of the other 

 species of the genus. In the calice figured they are exception 

 ally large and few in number. 



Height of corallum, 7 mm. ; diameters of calice, 3 mm. and 

 2 mm. 



Locality, d:c. — Abundant in the Eocene of Muddy Creek, 

 Spring Creek, and Shelford; less so at Curlewds, Moorabool 

 Valley (Fyan's Ford), Wilkinson's No. 4 section, and Fishing 

 Point. 



A coral from Muddy Creek described and figured by Ten. 

 Woods under the name of Smilotrochus vacuus long puzzled 

 collectors, the alleged absence of a columella leading them off 



