1894- NOTES AND COMMENTS. 327 



tissue protects considerably the rock beneath from the solvent action 

 of the carbon dioxide, which likewise is split up and used by the 

 plants themselves. On the lagoon flat very little algae is present." 



We particularly wish to direct the attention of zoologists to these 

 reports, for they contain a large number of interesting observations, 

 which, from the form in which they are published, are extremely 

 likely to escape notice. The paper appears, in fact, to have been 

 issued in March of this year, though it has only just fallen into our 

 hands. It is illustrated by a chart, two outline sections, and four 

 woodcuts. 



ECHINODERMS OF THE MaCCLESFIELD BaNK. 



As another result of these important surveys, and especially in 

 consequence of the labours of Messrs. Bassett-Smith and J. J. 

 Walker, a very large number of zoological specimens have found 

 their way to the British Museum. The Echinoderms, which present 

 several features of interest to the specialist, have just been described 

 in a suggestive paper by Professor F. J. Bell. Very noticeable in 

 this collection, as also in the collection of Crustacea, is the large 

 number of young specimens. " In fact," writes Mr. Bell, " I have 

 had forced on me the conviction that Macclesfield Bank is a nursery ; 

 with a rim submerged g fathoms beneath the surface, any pelagic 

 larvae that will can enter its boundary ; being 76 miles long and 36 

 miles broad, it affords some opportunity for the larvae to settle." 

 The importance of a large number of young specimens is very great, 

 for not only does it enable us to study the changes that occur during 

 growth, and thus to determine more satisfactorily the relationships 

 existing between species, but it often leads to a happy reduction in 

 the number of species by the discovery that independent names have 

 been applied to what after all are only immature individuals. Mr. 

 Bell therefore wisely suggests that as full collections as possible 

 should always be made in areas resembling the inside of this reef. 



Although Holothurians are common on the shallower reefs not 

 far distant, yet they are almost "totally absent from the sand-flat of 

 the lagoon ; only two young specimens were dredged, here referred to 

 Colochirus tuberculosus. 



The Crinoids are represented by twenty-two species, of which 

 by far the most remarkable are the new species Antedon bassett-smithi 

 and a fragmentary Actinomeira. The late Dr. P. H. Carpenter, who 

 devoted many years to a study of the free-swimming Crinoids, 

 elaborated a scheme of classification based on the mode of union 

 of the arm-ossicles, which scheme has hitherto been found to 

 work very well. These two specimens, however, run directly counter 

 to nearly all Carpenter's generalisations on the subject. Mr. Bell, 

 who has himself an excellent right to be heard on these particular 

 points, cannot believe that the specimens are merely abnormalities, 



