ECHINODEEMAIA. 165 



Arm of the larger specimen about 120, of the smaller about 

 85 millim. long ; in the former the first pinnule is about 20 and the 

 cirri 16 mUlim. long. 



Both of the specimens are white and without any dorsal median 

 line ; dark spots or marks prominently developed on the pinnules. 



Por the present, at least, I associate with A. Solaris a specimen 

 from Warrior Eeef, in which the characteristic keel to 'the pinnule 

 is developed and in which the cirri do not seem to have been more 

 than twelve in number, but in which the number of cirrus-joints 

 would appear to be less than fifteen. 



There are also specimens from Por^ Curtis and Torres Straits 

 which, though still small, hardly promise to ever have the stout arms 

 which are so characteristic of the adult ; further experience wiU, 

 I think, show them to be " dwarfs." 



Prom the Arafura Sea we have received a comparatively small 

 specimen, which is chiefly remarkable for the smaller number of its 

 cirrus-joints. 



In Dundas Strait there were dredged some small specimens which 

 approach in character A. pectinata and A. ■purpurea, but give us, 

 with our present scanty informatioh, but little aid in determining 

 the character or limits of these species. 



Prom Thursday Island we obtained a somewhat injured and large 

 specimen belonging to the " type " of A. Solaris, but which com- 

 pletely eludes my attempts to understand it. 



Under the name of A. albonotata I was inclined to separate a spe- 

 cimen from Albany Island, which is to be distinguished from the form 

 to which the name A. Solaris is ordinarily restricted by the larger 

 number (20-25) of cirri, and the less prominent keels on the basal 

 joints of the second pinnules. The general facies, however, of the 

 specimen is distinctly that of A. Solaris, with the exception of the 

 rather remarkable coloration, which has led to the proposal of a 

 distinctive name. When, however, we make a careful comparison 

 between the pattern of this coloration and that of the two speci- 

 mens first described and unhesitatingly referred to A. Solaris, we 

 see that there is really a striking resemblance between the two, and 

 we are again led to the reflection that great circumspection is to be 

 exercised whensoever we are tempted to make use of difference in 

 colour as a distinguishing mark. I have already stated that there 

 are black patches or spots on the pinnules of the first-described pair of 

 specimens ; what we find in the one now under consideration is that 

 these spots having greatly increased in number, and become more ex- 

 tensive than the white, have caused the white ground to assume the 

 appearance of spots on a dark ground. The extreme limit of the 

 species seems, however, to be reached by this form ; and as the cirri 

 are more numerous than usual, and the basal joints of the second 

 pinnule less strongly keeled, I propose to speak of it as A. Solaris, 

 var. albonotata. 



We must not be tempted by the difSculties of specific discrimina- 

 tion to make use of mere coloration : there are in the collection two 

 specimens of A. solaria from Thursday Island, one of which is uni- 



