188 



very successful, still I succeeded in obtaining a small culture of larvae, 

 which I carried along with me to Sydney. They developed fairly normally 

 unto the Bipinnaria stage, but I did not succeed in rearing them unto 

 metamorphosis. -- Later in the year, in June, Professor H. B. Kirk again 

 undertook a fertilization of this starfish and sent me the larvae he had 

 reared. None of them, however, had reached a more advanced stage of 

 development than those of my own culture. There is, accordingly, no de- 

 finite proof that also this larva has a Brachiolaria-stage, but there is, on 

 the other hand, no reason to doubt that it will prove to have a Brachio- 

 laria-stage of the same type as that of A. pectinifera. 



The young larva (Fig. 98) is of the same type as that of A. pectinifera. 

 The preserved material, including the larvae sent from Prof. Kirk, is not 

 in a very good state of preservation, the best specimen 

 being also somewhat abnormal in the anterior end; I 

 shall therefore not try to point out the specific differ- 

 ences between the two larvae, these differences being, 

 evidently, very trifling and unimportant, at least as far 

 as the young Bipinnaria-stage is concerned. 



I may here call attention to the fact, which has ap- 

 parently been overlooked, that besides Asterina gibbosa 

 one more species of Asterina, viz. A. (Patiriella) exigua 

 (Lamk.) has been recorded to have a shortened develop- 

 ment. This observation was made by Th. Whitelegge, 

 who in his "List of the Marine and Fresh-water Inverte- 

 brate Fauna of Port Jackson and Neighbourhood" 

 (1889, p. 40) states that "the ova of this species are de- 

 posited on stones in shallow rocky pools and are to be 

 found from June to December. They are particularly 

 well adapted for study, inasmuch as after the young 

 leave the egg-case they do not swim away, but remain 

 round about the empty egg-cases and never leave until 

 they assume the true starfish-form. The larvae are remarkably hardy and 

 may be kept in confinement without change of water until they have 

 passed through the larval stages." 1 ) During my stay in Sydney I had the 

 opportunity of confirming Whitelegge's observations, in the beginning 

 of March 1915, which shows that the breeding season of this species is 

 considerably longer than stated by Whitelegge; more probably it will 

 be found to breed all the year round. (In Asterina gibbosa the breeding 



Fig. 98. Larva of 

 Asterina regularis; 

 9 days old. 105 /i. 

 The larva is slight- 

 ly abnormal in the 

 anterior end; the 



fold across the 

 frontal area is prob- 

 ably due to con- 

 traction on preserv- 

 ation. 



') I have thought it proper to quote Whitelegge's short statement in full, as his paper 

 may not be so easily accessible outside Australia. 



