New Echinoids from AvMralian Tertiary. 49 



Only one basal pore is visible, and that doubtfully. It is the 

 right posterior lateral, and is close to the inner side of a large 

 primary tubercle, as above mentioned. 



The madreporite is long and narrow and separates the posterior 

 basals and radials, as well as the right anterior radials. The 

 radial pores are as large as the ambulacral pores, and are five in 

 number. 



The fascioles are very narrow and consist of two close-set rows 

 of miliaries. The peripetalous is slightly pointed posteriorly in 

 the posterior interradius. Anteriorly it disappears before reach- 

 ing the antero-lateral ambulacrum, and it is uncei-tain whether it 

 joins the marginal. The margizial fasciole dips below the am- 

 bitus anteriorly, and runs close to it in front of the peristome. 

 As the posterior truncation is hidden by matrix its course here 

 is not visible. 



Measukemexts. 



Length, 21. Breadth, 18.5. Height, 14. 



Distance of front edge of peristome from anterior, o mm. 

 Width of posterior lateral ambulacrum near fasciole, 1.5. 

 Length of anterior lateral petal, 6. 

 Length of posteiior lateral petal, 5.5. 

 The genus is typically Eocene, but ranges into the Miocene in 

 Europe, one species, P. excentricus, Wright, occurring in the 

 Tortonian of Malta.^ The present species is very unlike it, 

 judging by Dr. Wright's figure''^ and description''. 

 The genus is new for our tertiaries. 



Locality. — Aldinga (Barwonian, ? Eocene). A single specimen 

 collected by Mr. R. H. Cummins, B.Sc. 



Bpissopsis tatei, n. sp. 



Test thin, broadl}' ovate, depressed. Vertex about a third of 

 the length from the posterior end. Apical system nearly central. 

 Ambulacra sunken. Anterior groove broadly indenting the 

 ambitus. Lateral ambulacra curved. The antero- and postero- 

 lateral of the same side forming a segment of a circle, the 



1 Gregory, J. W., Trans Roy. Soc, Edinbursh, 36 (1891), p. 630. 



2 Q. J. G. S., 20 (1864), pi. 22, fig. 3. 



3 Ann. Mag. Nat. Hist., s. ii., vol. 15 (1855), pp. 195, 196. 



