150 CEYLON PEARL OYSTER REPORT. 



A. zebra should, I think, he united with A. hemprichi.* Perhaps, also, Sladen's 

 A. notograptus is another synonym, f 



(5.) The evidence in favour of the great variahility of Echinoderms is now over- 

 whelming, and new species should only be made on the most solid grounds. The 

 condition into which the genus Ophiothrix has been allowed to fall by the uncritical 

 establishment of a multitude of species is such that I had to tell Professor Herdman 

 that I could not undertake the determination of the numerous forms in his collection 

 that appear to the cabinet naturalist to be very different, but which, if we may argue 

 from what we know of the genus in our own seas, would be all brought up by one 

 haul of the dredge. A critical revision of the described species of Ophiothrix by a 

 naturalist of unlimited leisure would be a boon to the systematist ; the uncritical 

 addition to our list of forms " which appear to be distinct" is of no service whatever 

 to science. 



(6.) As in all carefully prepared collections, there are a number of small Ophiuroids, 

 many more or less broken ; I have referred all I can to their genus, and have 

 sometimes made suggestions as to their species. 



(7.) A small s]:>ecimen of Retaster, from deep water off Galle, is not unlike a young 

 example which Bedford has placed in the same bottle as an adult R. cribrosus ; this 

 species is already recorded from Ceylon. With R. cribrosus, Bedford associates 

 R. insignis of Sladen. The chorology of this species is given by its author as 

 including "Port Jackson {fide Bell)." The punctuation of the sentence is faulty, 

 but I do not delay over that, as I have to point out that I think the locality, " Port 

 Jackson," is an error. The statement is made in a paper of mine in vol. 9 of the 

 ' Proceedings of the Linnean Society of New South Wales,' the proofs of which were 

 never seen by me, and which teems with misprints ; Retaster itself is misprinted. In 

 the British Museum there is no specimen of the species from so far south as Port 

 Jackson, and in the report of the "Alert" collections, written while the collections 

 of the Australian Museum were in my hands, I record specimens from Port Molle and 

 Thursday Island (p. 134), while on p. 173 I cite the species as one limited to " inter- 

 tropical Australia." 



* I have taken the opportunity of examining the "types" of A. vehtans ; they are all immature, and 

 are, perhaps, not members of the same species. 



t Desciibers of young Star-fishes should have their memoiis placed in some scientific Index Expurga- 

 torius ; they take no trouble, and give much. 



