REPORT ON THE CRINOIDEA. 283 



while when the lower pinnules have keels, they are developed like those of Actinometra 

 Solaris, i.e., on two or three joints (PI. LIII. figs. 11, 12), and not on one only as is so 

 usual in Actinometra pectinata (PL LIII. figs. 17-20). 



We have already seen that there are similar variations, though of a somewhat more 

 extensive character, among the largest specimens of all which would naturally be 

 referred to Actinometra robusta ; and I do not think therefore that any other course is 

 possible than to consider Actinometra intermedia and Actinometra robusta as identical 

 with Actinometra Solaris. The variation in the extent of development of the keel — 

 from almost nothing but a mere sharpened dorsal edge to large projections on two or 

 three joints of from two to five pinnules — then becomes itself a character of specific 

 value, just as Bell pointed out for Actinometra intermedia. For so far as my experience 

 goes the basal pinnules of Actinometra pectinata are much more uniformly carinate than 

 in Actinometra Solaris. With the possible exception of the immature specimen which is 

 the type of Alecto purpurea, Muller, I have never seen any individual which would be 

 referred to Actinometra pectinata on account of its cirrus-characters, with so slightly 

 developed keels on the lower pinnules, as are shown in PI. LIII. figs. 5, 6 ; and I know of 

 none which are absolutely keelless, like the form which I described as Actinometra 

 robusta, but now refer to Actinometra Solaris. 



The habit of Actinometra brachiolata is only known vaguely as "Australia"; but 

 the geographical range of Actinometra Solaris and Actinometra pectinata is very much 

 better defined. They are limited to craite shallow water, 12 fathoms or less, in the 

 Eastern Archipelago, scarcely extending, however, beyond the limits of the tropics. 



Actinometra pectinata ranges as far west as Java and Singapore, and has also been 

 found among the Philippines and Moluccas. It likewise occurs along the north-west 

 coast of Australia, in the Arafura Sea, and on the Queensland coast from Cape York to 

 Port Curtis. I have seen examples of Actinometra Solaris from the China Sea and from 

 Hong Kong, Singapore, and Billiton ; but I know of no other localities for it between 

 Java and Torres Strait. Like Actinometra pectinata, it is abundant at Cape York and 

 down the Queensland coast to Port Curtis, in lat. 24° S. But with this exception, I 

 have never heard of either of these two species occurring to the south of the Tropic of 

 Capricorn, abundant as they are on the northern shores of the continent. They re- 

 present perhaps the most characteristic type of the Crinoid fauna of the Eastern 

 Archipelago, not extending eastwards to Fiji, nor even to Mergui on the west ; though 

 these localities have representatives respectively of the other two groups of Actinometra- 

 species which have the radials united by syzygy. A form like Actinometra paucicirra 

 occurs at Mergui, while Actinometra typica extends from Malacca to Fiji. 



But so far as my present knowledge goes not one of these three types of structure 

 is represented among the Comatulas of Southern Australia. Actinometra paucicirra 

 abounds at Cape York, was found by Jukes on the reef of Atagor, and is recorded from 



