REPORT ON THE CRINOIDEA. 193 



by the fourth to ninth brachials. This feature is well shown in Antedon anceps, Antedon 

 milberti, and Antedon variipinna (PI. XXXV. figs. 2, 4 ; PI. XXXVI. figs. 1, 4-6), and 

 also in some species described by Bell in the " Alert " Report ; while it reappears in a more 

 marked degree in some of the multibrachiate species of Antedon (PI. XLVIII. figs, 2, 3). 

 In some cases, as in Antedon milberti, the second, third and fourth pairs are all of 

 greater size than the pinnules above and below them, sometimes the second and some- 

 times the third being slightly the largest. In Antedon anceps and in Antedon variipinna 

 the pinnules of the fifth or sixth brachials (or both) are considerably longer and stouter 

 than their fellows (PL XXXV. fig. 2 ; PL XXXVI. figs. 1, 4-G) ; and in Bell's species 

 Antedon carpenteri and Antedon pumila, the large pinnule is on the fourth brachial. 

 But in Antedon carinata and Antedon parvieirra the third and the following pairs of 

 pinnules are much more ecpual in size. At the end of the group I have placed two 

 abnormal species in which the pinnule on the third brachial is absent, though in other 

 respects they conform pretty well to the general type. 



All the members of the Milberti-growp are limited to the Pacific and the Eastern 

 Archipelago, with the exception of Antedon carinata, which also extends into the Indian 

 Ocean, Red Sea, and the Western Atlantic. It was dredged off St. Lucia, in 278 fathoms, 

 by Captain Cole of the telegraph steamer "Investigator"; but all the remaining 

 members of the group are confined to the littoral zone. Most of them have been 

 obtained at depths of 20 fathoms or less ; but Antedon variipinna occurs at 36 fathoms 

 in the Arafura Sea. 



The general relations of the various members of the Milberti-growp are shown in 

 the following table : — 



-*& 



A. A pinnule on the third brachial. 



I. Second pair of pinnules the largest. 



a. Cirrus-joints short. 



1. Twenty-five cirrus-joints ; the first brachials much incised, . pinniformis, Carpenter. 



2. Barely twenty cirrus-joints ; the first brachials not incised. 



Second pinnule serrate, ..... serripinna, Carpenter. 



Second pinnule with large processes on the lower joints, . carpenteri, Bell. 



b. Twelve long cirrus-joints, ..... pumila, Bell. 

 II. Second and third, and sometimes the fourth, pairs of pinnules about 



equal. 



a. Twenty-five to forty cirrus-joints. 



Radials and lower brachials tubercular; the lower pinnules 



rounded . . . . . • • 1- milberti, Mull., sp. 



Radials and lower brachials smooth ; the lower pinnules 



carinate, ....... Ixvissima, Grube, sp. 



b. Forty-five cirrus-joints ; syzygial interval seven to ten joints, . tessellata, 1 Mull., sp. 



c. Sixty cirrus-joints; syzygial interval three to seven joints, . perspiTiosa, Carpenter. 



1 1 only know this type from the description of it which is given by Miiller ; but it is the only species recorded 

 in the list given on pp. 53-55 which I have not personally examined. 



(ZOOL. CHALL. EXP. — PART LX. 1887.) 0°° 25 



