442 AUSTIN HOBART CLARK, 



Tha lassonietridae. 



Ptilometra macronema Dirk Hartog I. Port Phillip 



Ptilometra mulleri Port Phillip Broughton I. 



Antcdonidae. 



Antedoninae. 



Compsometra incommoda Bunbury Port Jackson 



Compsometra loveni ? Dampier Archi- 



pelago Claremont I. 



If we plot the foregoing in the form of tables showing the compara- 

 tive distribution of the crinoids on the east and west coasts certain facts 

 of considerable interest are indicated. 



The tropical East Indian species, taken as a whole, extend further 

 down both coasts that the tropical Australian species, and also their average 

 extension in somewhat greater. 



On the eastern coast the East Indian fauna extends as far as 33 50' S. 

 (4 species), and the tropical Australian to 24 00' S. (3 species); on the 

 west coast neither come quite so far, the tropical East Indian reaching 

 31 55' S. (5 species) and 32 00' S. (1 species), and the tropical Australian 

 to 31 55' S. (2 species). 



The southern fauna is not sharply separated geographically from the 

 tropical, but overlaps it both on the east and on the west. It is quite 

 possible, however, that there is in most cases a differentiation of physical 

 environment. 



The lack of correlation in the sequence of the species in the two fol- 

 lowing tables probably indicates a more or less uniform distribution for 

 the species belonging to the two tropical groups, while at the same time 

 it graphically brings out the fact that our data in regard to all the forms 

 are very deficient. 



[Note. In the following tables all the species are checked as oc- 

 curring at all points between the limit of their range and the center of 

 their distribution, in the case of the first group the East Indies, in the 

 case of the second group the northern coast of Australia, and in the 

 case of the third group the southern coast of Australia; though they 

 never have been actually recorded from certain of the localities, as 

 they occur on either side their existence there may well be taken for 

 granted.] 



