b TWO SPECIES OF ASTRALIUM FKOM PORT JACKSON. 



me by Mr. C. Hedley, illustrate the fact that they present aDother 

 exami)le of, if I may be allowed the term, con\ergence of 



Fig. 0. — C. andralis. Fig. l—C. semiconvexa. 



development. Like the two species discussed above, they are, 

 w^hen adult, so alike that, devoid of their epidermis, they are 

 practically inseparable, whilst their apices are quite different. 

 They are, however, easier to identify than the two species of 

 Astralium, C. australis, having a sutural frill of epidermis, which 

 is absent in C. semiconvexa. 



To Miss M. Lodder I am indebted for the opportunity to 

 study the growth of Astralium anreum, Jonas.^ In the neanic 

 stages it is very similar to A. fimhriatnm, Lamarck [April 30th y 

 1902), 



Philippi's Abbild., 1844, Vol. ii., p. 14, t. 6, fig. 2. 



