434 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



following: It is of much smaller size and of markedly more slender build. The 

 division series are much more slender, and the arms also are markedly more slender. 

 The division series are more widely separated, and the IBr 1; which in C. multifida 

 are united, are in C. gracilis laterally free. In C. multifida the postradial series 

 divide up to seven times, while in C. gracilis they do not divide more than four times, 

 and in the type specimen there are only very few IVBr series. The centrodorsal also 

 shows noteworthy differences. In C. gracilis it is less stellate, is not separated from 

 the radials by subradial clefts, and is slightly raised above the surface of the radial 

 ring. It bears a rounded prominence in the center. 



But the general agreement between this form and C. multifida is so close that 

 Hartlaub believed himself justified in considering it merely as a variety of C. multifida. 



An examination of the notes given herewith on specimens determined as C. multi- 

 fida and as C. gracilis shows that in no single feature is there a sharp dividing line 

 between the two. Nevertheless, in most cases they are very easily distinguishable. 



It can therefore scarcely be doubted that these two forms are representatives of 

 the same specific type. What their true relation is must be left for future determi- 

 nation. 



History. This form was first described by Dr. Clemens Hartlaub in 1890, and 

 was described in greater detail and figured in the following year. 



In a paper on a collection of comatulids from the Macclesfield Bank published 

 in 1894 Bell wrote, under the heading Actinometra, sp.: 



Mention must also be made of an Actinometra to which I think it would 

 be wrong to give a specific name, so broken is it, but of which it would be more 

 wrong not to say something. It will be remembered that the late Dr. H. 

 Carpenter divided the tridistichate species of this genus into those in which 

 there is a syzygy on the second brachial, and into those that have it on the 

 third. In the specimen now before me there is no sign of any syzygy on 

 either the second or the third brachial. 



I found this specimen in the British Museum bearing the manuscript name 



Actinometra tridistichata, and ascertained that it is an example of the present form. 



While 2 of the specimens collected by Prof. Arthur Willey at New Britain and 



recorded by Bell in 1899 as Actinometra typica are referable to Comaster multifida 



(of which typica is a synonym), the third is a representative of this form. 



The Antedon indica recorded by Bell in 1902 as having been collected by Prof. 

 J. Stanley Gardiner in the Maldives proved on examination to be this species. 



In 1909 I recorded and gave notes upon 2 specimens which had been collected 

 at Singapore by the Danish consul at that port, Mr. Svend Gad. 



In 1912 I recorded a specimen from the Andamans which had been collected 

 by the naturalists of the Royal Indian Marine Survey steamer Investigator, at the 

 same time giving an annotated synonymy of this species and a summary of the 

 known records. In the list of localities Pulo Edam is said to be in the China Sea, 

 whereas in reality it is near Batavia, Java; the Philippine Islands and Cebu are in- 

 cluded among the localities inadvertently through confusion with C. multifida (C. 

 typica as there given). 



