18 TORSTEN GTSLÉN, CRIKOIDS. 



to far ont of the arm», of Actinometra simplex (ibid. p. 312): »The first four pin- 

 nules on each side ha ve a small terminal comb, which is found at intervals till near 

 the ends of the arms», and finally of Actinometra quadrata (ibid. p. 331): »A term- 

 inal comb on the pinnules of the first eight brachials and then irregularly till the 

 twentieth. » 



If we wish to keep the CLARKian classification — and the scheme given by 

 this excellent crinoid student gives for us the only possible clne for keeping clear the 

 puzzling mixture of Crinoid species — all these species must then be levelled under 

 the genus Comaster. Then if all the forms given in the synonymy of Comantlius 

 parvicirra are so similar that they might have been referred to this species, further 

 if Comaster serrata is so similar to Comantlius parvicirra that A. H. Clark has been 

 able to confuse them vvith one another and finally if I show in addition that some of 

 the synonymous species of Comantlius parvicirra are to be placed in the genus Co- 

 master, it must be probable that they onght to be referred to the species serrata 

 (one cannot with certainty come to this conclusion from the descriptions of Car- 

 penter, because they are partly imperfect in the characters specific to C. serrata). 



But if these three forms of Actinometra all belong to Comaster serrata, then 

 this species has a much greater distribution, for Actinometra elongata was brought 

 home from Banda, Act. simplex from the Admiralty Islands and Act. quadrata from 

 the Tongatabu Reefs. Under these circumstances it would not be stränge if the 

 species were found on the shores of Australia. 



What makes me, in spite of this, assign the discussed specimen to Comaster 

 'multifida is partly its plainly indicated youth, partly the fact that Döderlein (op. 

 cit. Pl. 38, fig. 4) reproduces a specimen exactly similar to mine, named Actinometra 

 belli, that Clark has declared to be a juvenile form of C. multifida. 



In doing so, I leave out of consideration the question whether Comaster serrata 

 is really a species or if it may possibly be only a juvenile form of bigger Comaster- 

 species. 



I pass on, however, to discuss the syzygies and their distribution. A more or less 

 developed syzygy appearing between I Br 1 and 2 is a rather common phenomenon in 

 the Co?nasterid-iami\y (Clark says, for instance, that this is the case in Comaster 

 serrata). The occurrence of sjoiarthries and syzygies in II and III Br:s is not very 

 stränge, either, except for the condition of the III Br series, which carries the arms 

 18 and 19. This has 3 segments with a syzygy between 2 and 3, a fact that is again 

 found in the »fimbriata» group of Carpenter and the corresponding genus Capillasler 

 of Clark. (This may serve as a reminder not to attach too great systematic import- 

 ance to the number of the osssicles in the division series of the arms.) 



The distribution of the syzygies on the undivided arm is, however, more 

 interesting. 



On 15 arms there is the normal distribution of the syzygies, i. e. first syzygy 

 between Br 3 and 4, second about the 12 th segment, but at the arms 1, 4, 13 and 

 17 the state of affairs is different, for the second (or third) syzygy already appears 

 between the 5 th and 6 th or 6 th and 7 th segments. 





